Gene Berg enterprises

Online Parts Catalog

The Proverbial Questions About Cases!!!

Practically every day we get asked, "Which is better, the single or dual oil pressure (OP) case?" They are both the best! They are designed for different applications. The single OP case is to replace non-smog applications with the regular factory fan and cooler and the dual OP is for replacement of engines with the dog house cooling systems.

The dual OP case has larger galleries to flood more oil (larger pump) into the head to soak up the head temperature caused by the smog devices or improper tuning and to take it back to the also larger cooler and larger fan that pumps more CFM of air. Now all of the cooling parts can be retro-fitted either way with the GB 111E cooler adapter gasket kit, however, the pump and gallery size will have some affect on the results if mismatched. I, personally, would not have a dual OP case without the proper matching cooling system and oil pump.

The big problem today is getting stuck with a second or a reject. All of the engine cases we sell go through an extensive inspection before we accept them from our supplier. We reject almost 30 percent of the cases we inspect. We hear people saying they need a case with the back filled in behind #3. Yes, Germany did make the 1975-on dual oil pressure FI engines with the back filled and CB Performance (formerly Claudes Buggies) had a Brazilian single oil pressure case with the back filled which is no longer available. Do you need this on a high performance engine? We have never used one of these cases and have not had any such failures that people trying to sell you a filled case claim you will have if you do not have one.

First, the case will never break behind #3 unless you over heat the engine or have pre-ignition (detonation). I have ran 14.1:1 compression ratios for over 15 years on our race engine and over 180,000 miles on my 1968 (1900cc 138 HP) engine and have never had a case crack.

At this time only Brazilian AS41 cases are available.

Factory Stock Cases — FYI

We have never had any problem using the factory stock case for high performance engines. We have many (with 86mm stroke) running daily after 150,000 miles or more with well over 3 times the original HP and race engines producing 275 real dyno HP for over 10 years of racing. Before you think you need an aftermarket case for your high performance street engine maybe you should be sure you have quality parts that do not damage the case rather than try to find a case that resists damage caused by poor quality parts or combinations. Poor quality crankshafts are by far the largest cause of case failure. See crank section.

Case Torque Change

Developed by Gary Berg 1/87

We have tested cases with increased torque on the 6 center main bearing nuts on all high performance engines. This has provided great improvement to case life. First, "never" use the red sealing nuts with the seal down. I use the flat washer and the 19mm wrench size nuts, which we can supply. When you use the red seal nuts, install them with the red side up away from the washer. The o'ring in the case at the stud will seal the case properly against leakage. With this combination we increase the torque on street applications or engines running up into the 6000 to 7500 RPM range to 29-30 lbs. and on all out race applications or over 7500 RPM to 33-34 lbs.

We have been running tests on all of our race and most street engines and found another area of great benefit to case life has been to spot face all the 8mm stud or bolt locations so we can use the 8mm head nut with the 15mm wrench size, and the larger diameter and thicker head nut washer. With this combination we move the torque from 14 lbs. up to 19-20 lbs. In some instances the studs will need to be backed out of the case slightly. Only back out as needed to achieve full nut coverage. These nuts and washers are available individually or in kits from us.

Case Conversion Kits

GB KIT-110 Case conversion kit. Consists of: Both GB KIT-115 and GB KIT-120. SW 2#

GB KIT-115 8mm x 15mm Conversion kit. Consists of: (15) GB 409NUT, 8mm x 15mm wrench nuts; (18) HDW8MMHW, 8mm head nut washers; (3) HDW8X55Z 8mm x 55mm bolts. SW 2#

Note: The one center top through bolt 15mm nut will hit the (dog house) fan housing on the 8mm by 15mm nut conversions. Either use the normal configuration nut and washer or dimple the housing. Also, see LA CASE025 spot face case.

GB KIT-120 12mm x 19mm Conversion kit. Consists of: (6) VWA043-101-129, 12mm washers; (6) VWA113-101-131A, 12mm (19mm wrench size) main bearing seal nuts.

Note: The one center top through bolt's 15mm nut will hit the (dog house) fan housing on the 8mm x 15mm nut conversions. Either use the normal configuration nut and washer or dimple the housing. See LA CASE025 spot face case.

Genuine VW Cases

All have 8mm head stud inserts and should use genuine VW head studs. These cases do not have a groove for the cam plug and require VWB040-101-1572 neoprene cam plug. SW 31#

VWB043-101-025 Type I, II Brazilian dual oil pressure relief valve case. We have installed the full size 3/4" pickup tube with Loctite, swedged it into place, installed lock stud and case plug. Cases that previously used 10mm studs will also need an 8mm head stud kit, VW 043-198-035P for dual port or VW 043-198-035S for single port. New AS41 material.

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CASBCL Same as VWB043-101-025, however, clearanced for stroker crankshafts.

If replacing a pre 1970 single oil pressure relief case, or building from scratch, purchase VW 113-198-033 conversion kit for the relief valves and all the extra parts you will need.

Note: All VW cases are "pickled" when new. Pickling is a preservative that leaves the case colored. This color varies from gold to green. It is not to be removed as it is meant to protect the magnesium from corrosion. Locations that we have machined have LPS metal preservative that is to be washed off.

Super Case? — Special Note

You will notice that I do not sell what is often called a super case. Any one telling you that you need to weld up or fill behind #3, shuffle pin or makes any type claims of what makes it better just wants your money for nothing. I, personally, have never found any of these items to be beneficial in any way. In fact, they usually cause faster failures. Welding on #3 destroys the material and warps the case so much that they often need to be line bored when still new. What few people realize is that no case fails behind #3 unless it has been subjected to overheating or detonation. This is not the case's fault, it is the owner's fault.

Shuffle pins are another unneeded item. Why not fix the problem rather than put a bandage on your elbow for a sore on your knee. If a quality crankshaft is used that does not bend or flex (shuffle) then the case will not move. In fact, we get many complaints from people having the case break at the center main web after they have installed shuffle pins.

I have never ever had any of these problems with any of our properly manufactured products and combinations, so do not get ripped off by a sales pitch that is designed to have it fail so they can sell you more sooner.

Technical Information

The Stock VW Case

I would like to share some information about the stock case. The first thing practically every shop will tell you is to line bore your case if it is worn. Have you ever asked, "Is this rebuilding the case?" Not so, according to a document on the applications and effects of magnesium when used for engine and transaxle housings that are heated and cooled many times. The document was written by the Quality Control Department of a major German car builder. It disclosed that the engine cases made with the AS41 material (no longer used for VW parts, now all cases are AS21) are designed as non-rebuildable items. In other words, when it needs to be reconditioned, replace it with a brand-new case. Naturally, this will depend on how bad and how much more use you think you can get for the money you will spend patching it up. Remember, you are only patching it up to run a little longer, not reconditioning it. Why does the case pound out and get bad in the first place? Why does it have over-heating and low oil pressure after it is rebuilt? What are the facts about all this?

AS41 magnesium is a very lightweight material. When used in ideal circumstances, it will give 100,000, maybe even 150,000 miles of trouble-free service in the VW engine when never overheated or ran over 4400 RPM. When I read available documentation about the AS41 and AS21 material used in the VW cases, I was shocked when I saw how weak the AS41 is when subjected to conditions beyond the normal VW temperatures and stress. This, however, substantiated many evaluations I made from my own years of research and development and answered some questions previously unanswered regarding the memory, rigidity, resistance to elongation and strength which was reduced drastically. The higher the temperature, the faster the case is reduced to junk! A new material called AS21 was available, however, it required slower, expensive production procedures and was not introduced until the FI engines in 1975. The Volkswagen factory of Brazil has informed us that the AS21 case containing 2% aluminum and 1% of silicon have not been available since 10/25/95. They have been replaced with the new AS41 case. The new AS41 case has been upgraded with a new alloy composition consisting of 4% aluminum and 1% of silicon, giving the new AS41 case 2% more aluminum and the same amount of silicon than the AS21 cases had. This gives the new AS41 case better flexibility and durability than the previously desired AS21. AS21 is stronger and resists problems of the old AS41. The AS21 markings can be found at the side of the case and often in large letters in the bell-housing area. Most engine builders have noticed these cases show a considerable decrease in pounding or distortion as compared with the old AS41. When any of the cases are overheated (AS41 old material being the worst) they are stretched, pushed out of shape and the center main bearing area starts to wear. The materials are subject to stress beyond their design limits. This overheating is more apt to happen to the smog controlled engines (1968-on) that are run very lean, which causes overheated heads that come loose or head studs to pull out. The more times this happens the worse it gets. This is irreversible damage. It soon pounds out the center main saddle enough so oil leaks between the case and the main bearing. This loss robs the engine bearings of needed oil. More heat is produced due to less lubrication and more damage occurs. Soon the number one bearing starts to do the same thing. By now the case has lost most of its resistance to elongation and the center main saddle is pounded so badly that the cam tunnel has moved over and is wearing the center cam bearing. A non-counterweighted crank only aggravates this condition especially when the engine is often turned to its upper limits. Even if a properly counterweighted crank is used under the conditions I spoke of, some of this damage may still occur. Some of this stress can be dealt with by stress-relieving the case 3 or 4 times, removing the case studs, machining both halves flat, re-install the studs, torque everything, and remachining every surface to the proper size. This is still not a guarantee of being 100% like new and at today's labor prices it is out of the question. A new case is far cheaper and will assure 100% life ahead. That's one of the reasons Volkswagen cast new cases for their factory rebuilt engines from the mid 60's and on.

I tested 100 line bored cases in stock 1600cc engines. Over 80% had low oil pressure when normal temperature was reached. This often occurred in less than 5,000 miles. Most of them never performed well and got poor mileage. FAT Performance line bored the case on one of their 1600cc off-road race engines. The dyno revealed that it was down 17 HP from previous tests. Another engine that made the correct HP was disassembled and every part, piece by piece (except the case) was swapped, still down 17 HP. I was called in as a consultant. My only comment, "Replace the case." This advice was not taken at first. In fact, a newly designed head was tried first. Better, but still not up to normal. Finally, Ron went for the new case. "Voila!" a magical 19 HP appeared. Ron said, he has heard me saying this for years and never paid much attention, but now had the actual experience of what I have been seeing for years.

If nothing else, use your common sense. When you use up 75, 80, 90% of the life of the part why put it back into service and ask it to take more stress and strain than it did when it was new? Don't spend a bundle for machine work on an old worn out case and expect it to give the service of a new one? It is your gamble. What is it worth to you to know it is good for 100% of its life rather than 10% or 20%?

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Checking Out The Case

How do you know if the case is bad? It is usually obvious. Before you disassemble the engine you are suppose to check the torque on the main bearing nuts (also the heads). Torque the main bearing studs to 30 ft. lbs. and see if the crank still turns. If not, the case is warped for sure. If the crank still turns but the nuts were loose, you will usually find fret marks on the case halves. (Often when you install a new main bearing and torque the nuts it will then seize up). The bearing will be shiny on the OD & may have printed into the case. Often you can feel the wear in the saddle and at the #2 main stud areas. If you do not see the original machine marks on both halves of the center main flat where it meets, then it has been moving enough to wear them off. I would never reuse that case even for a stock engine.

Case Reconditioning

We are often asked about line boring a case, be clear that line boring does not recondition the case, it only patches it up to go a few more miles. Every line bored case we tested suffered from low oil pressure when hot (with the stock pump), often within as little as 1000 miles. That is the reason people sell huge oversize oil pumps, booster springs and longer relief valves. If the case was properly reconditioned it could use the stock VW pump, relief valves, springs and have normal oil pressure at idle when hot just like it did when new.

When VW reconditioned cases (up until 1968) they did far more than just line bore. To properly recondition a case today consists of; cleaning the case, bolting it together with an alignment bar in the crank and cam tunnel, torquing to stress relief specifications. Have the case stress relieved for 3-1/2 hours and let cool in the oven. When cool, take it out of the oven and re-torque to stress relief specifications and again stress relief for 3-1/2 hours. When cool remove from the oven and disassemble, remove all of the studs and alignment pins, machine both halves of the case flat and reinstall all of the studs and pins and torque to running torque specifications. Now, line bore the crank, and cam tunnel, often back to standard, bore the oil pump, pulley, flywheel seal holes and the cam seal groove. Lastly, the brass drive gear must be cut smaller on the OD the same amount that the 3 and 4 side of the case was machined.

After all this work and expense (far more than a new case costs) you have a case that will only provide 70% to 80% of the life that a new one will (and that's when used for stock applications). The life would be far less with a performance engine. Obviously, VW stopped reconditioning cases in 1968 due to the cost in relationship to the cost of a new case, plus now being assured of 100% of the engine's life, especially if used for higher performance applications. VW could melt the old case, cast a new case and machine it in the new automatic machinery far cheaper.

What About Line Boring

Sometimes you are forced to use a line bored case, this could be from financial reasons to time. Whatever the requirement, it is your choice to be responsible for and it is critical you know that it is unlikely to provide 100% life and will never stand up to any hard use. Treat it tenderly and it will give back the most it can.

When the case is only slightly worn and you want to line bore and reuse it, the #1 question will be, "Who is qualified to do it the correct way? Do they have the correct tools? How can I tell if they did it right if I don't have any precision tools?" Those are the $64,000.00 questions. Most shops use a simple electric drill (some use a lathe to feed the same tool) driven tool that centers on the pulley and seal holes. This is a poor way to be assured of a precision center. The pulley end will rarely be round and straight. The tool, which is inserted in both ends of the case, is bushed to allow the bar to turn. These bushings are fairly good when brand new. As they wear they get sloppy and allow the alignment to change and have no adjustment to them. These will determine whether your line bore is maintained in the same place or moved as well as what size it is. When it is perfectly straight to the pulley, cam tunnel, and flywheel, all is great. However, most of the time it ends up out of alignment, then the gear size is way off, pulley and/or flywheel seal leakage’s show up after a few thousand miles. The one failure seldom connected to a line bore problem is wrist pin keeper failure. Because the crank is no longer lined up, the rod runs at an angle and pushes against the pin loading the keeper beyond it’s capabilities. All of these are undetectable with normal measuring equipment so it is really a gamble. When the case is mounted on its original (tooling) fixture pads to be line bored the chances of a proper line bore are much better, there are only a couple of these machines in the USA Now it gets down to the capability of the machinist. How close can he dial into the original center line and how close can his machinist perform the operation? How close can he set his tools? The message in all of this is buyer beware. Do not just listen to their story. Check out what they can do. Look over the equipment. What I do is have them tell me what they use for equipment and how they measure it for alignment to the cam, pulley, flywheel seal hole, and cylinder seating surfaces. If the answers do not support what has just been covered, just say "Thank you" and find someone else. Whatever you do, please do not use this information to make them wrong or you will get to hear their story on how they have done 250,000 cases this year and never had a failure, low oil pressure or overheating problems.

Technical Information

8mm Head Studs

To insert or not to install inserts or case savers? All VW cases imported into the USA after 1972 come from the factory already equipped with factory inserts to use the 8mm stud kit. One word of caution; many suppliers sell or furnish the "cheapo" aftermarket head stud kits made out of a substance as bad as Limburger cheese (because they stink) and in doing so have given the 8mm stud kit an unwarranted bad knock of stretching or coming loose. I have used the "genuine VW" head stud kits absolutely trouble free since their inception in 1972 on engines up to 150 HP for daily driving. They are made of a special composition of alloy material and heat treat for the correct expansion and contraction rates of the air cooled engine. They have the perfect torque at all operating temperatures the engine is made to run within. I, personally, would not use for street use, special chrome moly or cheapo studs, as they do not have the proper expansion rates. The cheapo ones will stretch and the chrome moly have "0" stretch, so after being hot several times they often let the torque relax when cold and the heads start to leak until they get up to operating temperature. Soon they simply leak all of the time. Some all out turbo charged race engines, or other applications of causing too high of piston pressures, may require the special chrome moly stud kits. However, this is a short term run engine and will likely require retorquing or rebuilding at regular intervals. Also, in a short period of time requiring resurfacing the heads and case where the cylinders will crush into them. No, I do not sell them.

Special heat treated chrome moly head studs will be mandatory for some race applications with large bores. They may also be needed for long stroke, low compression street motors with very thick cylinder spacers that require a longer than stock stud. In some cases 8mm can be used and in other applications 10mm. We can furnish any of the chrome moly studs you require, please inquire.

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Note: When the proper parts and procedures are used, and torqued to the correct torque on installation, no need to retorque the heads again after break in is ever needed.

Genuine VW Head Stud Kits

Complete with all of the studs, nuts, and washers for one engine. Note: The 9th long stud goes into the #3 top front hole. This is often called the deep stud. Berg copyrighted torque and installation instructions. SW 5# set.

VW 043-198-035P Dual port 8mm head stud kits black oxided to prevent rusting. Genuine VW. Don't ever use aftermarket studs for street cars.

VW 043-198-035S The same as above for single port engines.

GB KIT-200 This head stud kit is utilized when a large stroke/low CR motor with extremely thick barrel spacers are needed to achieve proper deck height. These studs must be cut to length.

Oil Relief Kit

Conversion kit from single oil pressure case to dual oil pressure case, or has all of the parts for a new case. The kit includes all of the proper oil pressure plungers, springs, screws, gasket, Type III filler plate and gasket, studs for the lower engine mount, fuel pump studs, 6 to 8mm cooler studs and much more. Individual relief valves, springs and screws cost more than the kit alone. Has some extra parts for other conversions that you will not even use.

VW 113-198-033 For new case or single port to dual oil pressure conversion kit.

Case Clearancing

Special Note

Did you know that our 86mm Porsche rod crank fits in the same case clearancing space as a 78mm VW rod crank. This means that there is no strength difference in the case with the standard case clearancing that we have done for years. You can install OUR 86mm crank with no concern as to strength loss or engine life.

Note 1: Longer than 86mm stroke cranks (such as 88mm and 90mm) can be installed in the stock VW case.

The extra clearance to case or camshaft is not the issue; it is the cylinder length and tinware fit. The cylinders are not long enough to keep the piston straight at the bottom of the stroke. Strokes longer than 86 pull the piston too far out the bottom of the cylinder, it rocks, unloading the rings and puts extreme side load on the bottom of the cylinder causing blow-by and often piston and cylinder breakage. Some people use an aftermarket cylinder that is longer. I, personally, have not had any of the aftermarket cylinders work correctly for longevity or cooling. All my engines require all of the proper cooling fins and the material quality. What I did was to have the bottom of the Cima/Mahle cylinder extended. Unfortunately, this is very expensive to do. The set we had extended cost over $375, obviously only for the serious builder.

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Copyright © 1998 GENE BERG ENTERPRISES all rights reserved

Gene Berg enterprises

Online Parts Catalog

The Proverbial Questions About Cases!!!

Practically every day we get asked, "Which is better, the single or dual oil pressure (OP) case?" They are both the best! They are designed for different applications. The single OP case is to replace non-smog applications with the regular factory fan and cooler and the dual OP is for replacement of engines with the dog house cooling systems.

The dual OP case has larger galleries to flood more oil (larger pump) into the head to soak up the head temperature caused by the smog devices or improper tuning and to take it back to the also larger cooler and larger fan that pumps more CFM of air. Now all of the cooling parts can be retro-fitted either way with the GB 111E cooler adapter gasket kit, however, the pump and gallery size will have some affect on the results if mismatched. I, personally, would not have a dual OP case without the proper matching cooling system and oil pump.

The big problem today is getting stuck with a second or a reject. All of the engine cases we sell go through an extensive inspection before we accept them from our supplier. We reject almost 30 percent of the cases we inspect. We hear people saying they need a case with the back filled in behind #3. Yes, Germany did make the 1975-on dual oil pressure FI engines with the back filled and CB Performance (formerly Claudes Buggies) had a Brazilian single oil pressure case with the back filled which is no longer available. Do you need this on a high performance engine? We have never used one of these cases and have not had any such failures that people trying to sell you a filled case claim you will have if you do not have one.

First, the case will never break behind #3 unless you over heat the engine or have pre-ignition (detonation). I have ran 14.1:1 compression ratios for over 15 years on our race engine and over 180,000 miles on my 1968 (1900cc 138 HP) engine and have never had a case crack.

At this time only Brazilian AS41 cases are available.

Factory Stock Cases — FYI

We have never had any problem using the factory stock case for high performance engines. We have many (with 86mm stroke) running daily after 150,000 miles or more with well over 3 times the original HP and race engines producing 275 real dyno HP for over 10 years of racing. Before you think you need an aftermarket case for your high performance street engine maybe you should be sure you have quality parts that do not damage the case rather than try to find a case that resists damage caused by poor quality parts or combinations. Poor quality crankshafts are by far the largest cause of case failure. See crank section.

Case Torque Change

Developed by Gary Berg 1/87

We have tested cases with increased torque on the 6 center main bearing nuts on all high performance engines. This has provided great improvement to case life. First, "never" use the red sealing nuts with the seal down. I use the flat washer and the 19mm wrench size nuts, which we can supply. When you use the red seal nuts, install them with the red side up away from the washer. The o'ring in the case at the stud will seal the case properly against leakage. With this combination we increase the torque on street applications or engines running up into the 6000 to 7500 RPM range to 29-30 lbs. and on all out race applications or over 7500 RPM to 33-34 lbs.

We have been running tests on all of our race and most street engines and found another area of great benefit to case life has been to spot face all the 8mm stud or bolt locations so we can use the 8mm head nut with the 15mm wrench size, and the larger diameter and thicker head nut washer. With this combination we move the torque from 14 lbs. up to 19-20 lbs. In some instances the studs will need to be backed out of the case slightly. Only back out as needed to achieve full nut coverage. These nuts and washers are available individually or in kits from us.

Case Conversion Kits

GB KIT-110 Case conversion kit. Consists of: Both GB KIT-115 and GB KIT-120. SW 2#

GB KIT-115 8mm x 15mm Conversion kit. Consists of: (15) GB 409NUT, 8mm x 15mm wrench nuts; (18) HDW8MMHW, 8mm head nut washers; (3) HDW8X55Z 8mm x 55mm bolts. SW 2#

Note: The one center top through bolt 15mm nut will hit the (dog house) fan housing on the 8mm by 15mm nut conversions. Either use the normal configuration nut and washer or dimple the housing. Also, see LA CASE025 spot face case.

GB KIT-120 12mm x 19mm Conversion kit. Consists of: (6) VWA043-101-129, 12mm washers; (6) VWA113-101-131A, 12mm (19mm wrench size) main bearing seal nuts.

Note: The one center top through bolt's 15mm nut will hit the (dog house) fan housing on the 8mm x 15mm nut conversions. Either use the normal configuration nut and washer or dimple the housing. See LA CASE025 spot face case.

Genuine VW Cases

All have 8mm head stud inserts and should use genuine VW head studs. These cases do not have a groove for the cam plug and require VWB040-101-1572 neoprene cam plug. SW 31#

VWB043-101-025 Type I, II Brazilian dual oil pressure relief valve case. We have installed the full size 3/4" pickup tube with Loctite, swedged it into place, installed lock stud and case plug. Cases that previously used 10mm studs will also need an 8mm head stud kit, VW 043-198-035P for dual port or VW 043-198-035S for single port. New AS41 material.

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CASBCL Same as VWB043-101-025, however, clearanced for stroker crankshafts.

If replacing a pre 1970 single oil pressure relief case, or building from scratch, purchase VW 113-198-033 conversion kit for the relief valves and all the extra parts you will need.

Note: All VW cases are "pickled" when new. Pickling is a preservative that leaves the case colored. This color varies from gold to green. It is not to be removed as it is meant to protect the magnesium from corrosion. Locations that we have machined have LPS metal preservative that is to be washed off.

Super Case? — Special Note

You will notice that I do not sell what is often called a super case. Any one telling you that you need to weld up or fill behind #3, shuffle pin or makes any type claims of what makes it better just wants your money for nothing. I, personally, have never found any of these items to be beneficial in any way. In fact, they usually cause faster failures. Welding on #3 destroys the material and warps the case so much that they often need to be line bored when still new. What few people realize is that no case fails behind #3 unless it has been subjected to overheating or detonation. This is not the case's fault, it is the owner's fault.

Shuffle pins are another unneeded item. Why not fix the problem rather than put a bandage on your elbow for a sore on your knee. If a quality crankshaft is used that does not bend or flex (shuffle) then the case will not move. In fact, we get many complaints from people having the case break at the center main web after they have installed shuffle pins.

I have never ever had any of these problems with any of our properly manufactured products and combinations, so do not get ripped off by a sales pitch that is designed to have it fail so they can sell you more sooner.

Technical Information

The Stock VW Case

I would like to share some information about the stock case. The first thing practically every shop will tell you is to line bore your case if it is worn. Have you ever asked, "Is this rebuilding the case?" Not so, according to a document on the applications and effects of magnesium when used for engine and transaxle housings that are heated and cooled many times. The document was written by the Quality Control Department of a major German car builder. It disclosed that the engine cases made with the AS41 material (no longer used for VW parts, now all cases are AS21) are designed as non-rebuildable items. In other words, when it needs to be reconditioned, replace it with a brand-new case. Naturally, this will depend on how bad and how much more use you think you can get for the money you will spend patching it up. Remember, you are only patching it up to run a little longer, not reconditioning it. Why does the case pound out and get bad in the first place? Why does it have over-heating and low oil pressure after it is rebuilt? What are the facts about all this?

AS41 magnesium is a very lightweight material. When used in ideal circumstances, it will give 100,000, maybe even 150,000 miles of trouble-free service in the VW engine when never overheated or ran over 4400 RPM. When I read available documentation about the AS41 and AS21 material used in the VW cases, I was shocked when I saw how weak the AS41 is when subjected to conditions beyond the normal VW temperatures and stress. This, however, substantiated many evaluations I made from my own years of research and development and answered some questions previously unanswered regarding the memory, rigidity, resistance to elongation and strength which was reduced drastically. The higher the temperature, the faster the case is reduced to junk! A new material called AS21 was available, however, it required slower, expensive production procedures and was not introduced until the FI engines in 1975. The Volkswagen factory of Brazil has informed us that the AS21 case containing 2% aluminum and 1% of silicon have not been available since 10/25/95. They have been replaced with the new AS41 case. The new AS41 case has been upgraded with a new alloy composition consisting of 4% aluminum and 1% of silicon, giving the new AS41 case 2% more aluminum and the same amount of silicon than the AS21 cases had. This gives the new AS41 case better flexibility and durability than the previously desired AS21. AS21 is stronger and resists problems of the old AS41. The AS21 markings can be found at the side of the case and often in large letters in the bell-housing area. Most engine builders have noticed these cases show a considerable decrease in pounding or distortion as compared with the old AS41. When any of the cases are overheated (AS41 old material being the worst) they are stretched, pushed out of shape and the center main bearing area starts to wear. The materials are subject to stress beyond their design limits. This overheating is more apt to happen to the smog controlled engines (1968-on) that are run very lean, which causes overheated heads that come loose or head studs to pull out. The more times this happens the worse it gets. This is irreversible damage. It soon pounds out the center main saddle enough so oil leaks between the case and the main bearing. This loss robs the engine bearings of needed oil. More heat is produced due to less lubrication and more damage occurs. Soon the number one bearing starts to do the same thing. By now the case has lost most of its resistance to elongation and the center main saddle is pounded so badly that the cam tunnel has moved over and is wearing the center cam bearing. A non-counterweighted crank only aggravates this condition especially when the engine is often turned to its upper limits. Even if a properly counterweighted crank is used under the conditions I spoke of, some of this damage may still occur. Some of this stress can be dealt with by stress-relieving the case 3 or 4 times, removing the case studs, machining both halves flat, re-install the studs, torque everything, and remachining every surface to the proper size. This is still not a guarantee of being 100% like new and at today's labor prices it is out of the question. A new case is far cheaper and will assure 100% life ahead. That's one of the reasons Volkswagen cast new cases for their factory rebuilt engines from the mid 60's and on.

I tested 100 line bored cases in stock 1600cc engines. Over 80% had low oil pressure when normal temperature was reached. This often occurred in less than 5,000 miles. Most of them never performed well and got poor mileage. FAT Performance line bored the case on one of their 1600cc off-road race engines. The dyno revealed that it was down 17 HP from previous tests. Another engine that made the correct HP was disassembled and every part, piece by piece (except the case) was swapped, still down 17 HP. I was called in as a consultant. My only comment, "Replace the case." This advice was not taken at first. In fact, a newly designed head was tried first. Better, but still not up to normal. Finally, Ron went for the new case. "Voila!" a magical 19 HP appeared. Ron said, he has heard me saying this for years and never paid much attention, but now had the actual experience of what I have been seeing for years.

If nothing else, use your common sense. When you use up 75, 80, 90% of the life of the part why put it back into service and ask it to take more stress and strain than it did when it was new? Don't spend a bundle for machine work on an old worn out case and expect it to give the service of a new one? It is your gamble. What is it worth to you to know it is good for 100% of its life rather than 10% or 20%?

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Checking Out The Case

How do you know if the case is bad? It is usually obvious. Before you disassemble the engine you are suppose to check the torque on the main bearing nuts (also the heads). Torque the main bearing studs to 30 ft. lbs. and see if the crank still turns. If not, the case is warped for sure. If the crank still turns but the nuts were loose, you will usually find fret marks on the case halves. (Often when you install a new main bearing and torque the nuts it will then seize up). The bearing will be shiny on the OD & may have printed into the case. Often you can feel the wear in the saddle and at the #2 main stud areas. If you do not see the original machine marks on both halves of the center main flat where it meets, then it has been moving enough to wear them off. I would never reuse that case even for a stock engine.

Case Reconditioning

We are often asked about line boring a case, be clear that line boring does not recondition the case, it only patches it up to go a few more miles. Every line bored case we tested suffered from low oil pressure when hot (with the stock pump), often within as little as 1000 miles. That is the reason people sell huge oversize oil pumps, booster springs and longer relief valves. If the case was properly reconditioned it could use the stock VW pump, relief valves, springs and have normal oil pressure at idle when hot just like it did when new.

When VW reconditioned cases (up until 1968) they did far more than just line bore. To properly recondition a case today consists of; cleaning the case, bolting it together with an alignment bar in the crank and cam tunnel, torquing to stress relief specifications. Have the case stress relieved for 3-1/2 hours and let cool in the oven. When cool, take it out of the oven and re-torque to stress relief specifications and again stress relief for 3-1/2 hours. When cool remove from the oven and disassemble, remove all of the studs and alignment pins, machine both halves of the case flat and reinstall all of the studs and pins and torque to running torque specifications. Now, line bore the crank, and cam tunnel, often back to standard, bore the oil pump, pulley, flywheel seal holes and the cam seal groove. Lastly, the brass drive gear must be cut smaller on the OD the same amount that the 3 and 4 side of the case was machined.

After all this work and expense (far more than a new case costs) you have a case that will only provide 70% to 80% of the life that a new one will (and that's when used for stock applications). The life would be far less with a performance engine. Obviously, VW stopped reconditioning cases in 1968 due to the cost in relationship to the cost of a new case, plus now being assured of 100% of the engine's life, especially if used for higher performance applications. VW could melt the old case, cast a new case and machine it in the new automatic machinery far cheaper.

What About Line Boring

Sometimes you are forced to use a line bored case, this could be from financial reasons to time. Whatever the requirement, it is your choice to be responsible for and it is critical you know that it is unlikely to provide 100% life and will never stand up to any hard use. Treat it tenderly and it will give back the most it can.

When the case is only slightly worn and you want to line bore and reuse it, the #1 question will be, "Who is qualified to do it the correct way? Do they have the correct tools? How can I tell if they did it right if I don't have any precision tools?" Those are the $64,000.00 questions. Most shops use a simple electric drill (some use a lathe to feed the same tool) driven tool that centers on the pulley and seal holes. This is a poor way to be assured of a precision center. The pulley end will rarely be round and straight. The tool, which is inserted in both ends of the case, is bushed to allow the bar to turn. These bushings are fairly good when brand new. As they wear they get sloppy and allow the alignment to change and have no adjustment to them. These will determine whether your line bore is maintained in the same place or moved as well as what size it is. When it is perfectly straight to the pulley, cam tunnel, and flywheel, all is great. However, most of the time it ends up out of alignment, then the gear size is way off, pulley and/or flywheel seal leakage’s show up after a few thousand miles. The one failure seldom connected to a line bore problem is wrist pin keeper failure. Because the crank is no longer lined up, the rod runs at an angle and pushes against the pin loading the keeper beyond it’s capabilities. All of these are undetectable with normal measuring equipment so it is really a gamble. When the case is mounted on its original (tooling) fixture pads to be line bored the chances of a proper line bore are much better, there are only a couple of these machines in the USA Now it gets down to the capability of the machinist. How close can he dial into the original center line and how close can his machinist perform the operation? How close can he set his tools? The message in all of this is buyer beware. Do not just listen to their story. Check out what they can do. Look over the equipment. What I do is have them tell me what they use for equipment and how they measure it for alignment to the cam, pulley, flywheel seal hole, and cylinder seating surfaces. If the answers do not support what has just been covered, just say "Thank you" and find someone else. Whatever you do, please do not use this information to make them wrong or you will get to hear their story on how they have done 250,000 cases this year and never had a failure, low oil pressure or overheating problems.

Technical Information

8mm Head Studs

To insert or not to install inserts or case savers? All VW cases imported into the USA after 1972 come from the factory already equipped with factory inserts to use the 8mm stud kit. One word of caution; many suppliers sell or furnish the "cheapo" aftermarket head stud kits made out of a substance as bad as Limburger cheese (because they stink) and in doing so have given the 8mm stud kit an unwarranted bad knock of stretching or coming loose. I have used the "genuine VW" head stud kits absolutely trouble free since their inception in 1972 on engines up to 150 HP for daily driving. They are made of a special composition of alloy material and heat treat for the correct expansion and contraction rates of the air cooled engine. They have the perfect torque at all operating temperatures the engine is made to run within. I, personally, would not use for street use, special chrome moly or cheapo studs, as they do not have the proper expansion rates. The cheapo ones will stretch and the chrome moly have "0" stretch, so after being hot several times they often let the torque relax when cold and the heads start to leak until they get up to operating temperature. Soon they simply leak all of the time. Some all out turbo charged race engines, or other applications of causing too high of piston pressures, may require the special chrome moly stud kits. However, this is a short term run engine and will likely require retorquing or rebuilding at regular intervals. Also, in a short period of time requiring resurfacing the heads and case where the cylinders will crush into them. No, I do not sell them.

Special heat treated chrome moly head studs will be mandatory for some race applications with large bores. They may also be needed for long stroke, low compression street motors with very thick cylinder spacers that require a longer than stock stud. In some cases 8mm can be used and in other applications 10mm. We can furnish any of the chrome moly studs you require, please inquire.

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Note: When the proper parts and procedures are used, and torqued to the correct torque on installation, no need to retorque the heads again after break in is ever needed.

Genuine VW Head Stud Kits

Complete with all of the studs, nuts, and washers for one engine. Note: The 9th long stud goes into the #3 top front hole. This is often called the deep stud. Berg copyrighted torque and installation instructions. SW 5# set.

VW 043-198-035P Dual port 8mm head stud kits black oxided to prevent rusting. Genuine VW. Don't ever use aftermarket studs for street cars.

VW 043-198-035S The same as above for single port engines.

GB KIT-200 This head stud kit is utilized when a large stroke/low CR motor with extremely thick barrel spacers are needed to achieve proper deck height. These studs must be cut to length.

Oil Relief Kit

Conversion kit from single oil pressure case to dual oil pressure case, or has all of the parts for a new case. The kit includes all of the proper oil pressure plungers, springs, screws, gasket, Type III filler plate and gasket, studs for the lower engine mount, fuel pump studs, 6 to 8mm cooler studs and much more. Individual relief valves, springs and screws cost more than the kit alone. Has some extra parts for other conversions that you will not even use.

VW 113-198-033 For new case or single port to dual oil pressure conversion kit.

Case Clearancing

Special Note

Did you know that our 86mm Porsche rod crank fits in the same case clearancing space as a 78mm VW rod crank. This means that there is no strength difference in the case with the standard case clearancing that we have done for years. You can install OUR 86mm crank with no concern as to strength loss or engine life.

Note 1: Longer than 86mm stroke cranks (such as 88mm and 90mm) can be installed in the stock VW case.

The extra clearance to case or camshaft is not the issue; it is the cylinder length and tinware fit. The cylinders are not long enough to keep the piston straight at the bottom of the stroke. Strokes longer than 86 pull the piston too far out the bottom of the cylinder, it rocks, unloading the rings and puts extreme side load on the bottom of the cylinder causing blow-by and often piston and cylinder breakage. Some people use an aftermarket cylinder that is longer. I, personally, have not had any of the aftermarket cylinders work correctly for longevity or cooling. All my engines require all of the proper cooling fins and the material quality. What I did was to have the bottom of the Cima/Mahle cylinder extended. Unfortunately, this is very expensive to do. The set we had extended cost over $375, obviously only for the serious builder.

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