TheSamba.com :: View topic - Help me build a BOMB PROOF H Case 1500/1600 single port.

Sun Apr 29, 2012 10:06 am

I'm looking for any tips / advice on building the best stock engine I can. So here's what I'll be working with

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Engine Number H0462492 September 1965

It recently seized due to water in the cylinders and I stripped it down to the case so far, I will be splitting the case soon.

I want to try to build a BOMB PROOF engine as it might get shipped to the bottom of South America and need to get it's self up to Canada.

Here's what I think I've worked out do far.

Once I've done a total strip down I will check everything I can for tolerances. Should I keep and re-use OG parts where I can or just replace all bearings etc with best quality new? I believe it's a 1500 but the mixture of different brand cylinders that are in there are 1600. Do I go 1500 or 1600? I've heard 1500 engines were the most reliable air cooled engine, but I also heard that FORGED Mahle pistons are higher quality and so far I can only find them in 1600.

I'm think I will get a 3 angle valve job done and get new valves (again should I reuse OG if their still good?) Perhaps just seating the valves using the grinding paste thing will do?

I will balance everything where I can myself (rods / pistons) - or get a machine shop to do the bigger balancing jobs IF I can afford it.

And when I split the case I'll replace the plugs so I can clean out the oil ways.

Thats all I can think of for now.

I've got "how to rebuild your Volkswagen air cooled engine" and I've swapped out 1641 heads and pistons / cylinders.

Thanks in advance for any expertise offered.

I will try and keep a photo build up here and post what I've been doing.

Sun Apr 29, 2012 10:48 am

To bomb proof an H case, replace it. Ask me how I know....

Sun Apr 29, 2012 11:09 am

If you want to drive cross country like that the best thing to do is burn that old H case.
Replace with a single relief as-21 if you want bomb proof, nobody wants the single reliefs........so you should be able to get one for 500 or less

The crank flywheel and rods can be re-conditioned, if it's a single drilled crank make sure to use the KS bearings with the grooved center main

If the heads are cracked real bad find some good used ones to re-build

Use a Web camshaft with CB or empi or engle lifters

Lapping valves and replacing bearings is not a re-build, that would be a patch-up job, like for selling a used car with no warranty :wink:

Sun Apr 29, 2012 4:11 pm

I understand what you want to do. you can go the inexpensive route and run for a while or take the high road and run for a long time. In a bus consider dual releif case balanced crank shaft with some more stroke to it to move the heavy bus. Others will chime in as well.

Sun Apr 29, 2012 4:26 pm

If you are going to use the H case, spend the money and put in case savers, a line bore and have someone that knows what they are doing go over the block. They will look for fretting, cracks and overall condition.
If the engine has many miles on it, replace all the valves, springs and retainers. I don't use a tripple angle on a stock engine. The valves will stay cooler with a stock valve job. There is more contact surface to transfer heat. Any cracks in the head or bad threads for the plugs, replace it.
You can replace the rotating parts with a rebuild kit, if yours need to be reground. They come with most of what you need.

Sun Apr 29, 2012 4:35 pm

I donno bout that, if the H-case is low mileage than maybe, but chances are slim
A "U" case would be far more deserving of case savers than an H, and it is rare to find a good one of those also

Sun Apr 29, 2012 4:36 pm

First step, GET RID OF THE "H" CASE..
Abolutely the worst cast VW ever made IMO...

Sun Apr 29, 2012 6:51 pm

sorry to tell yo but you cnat bomb proof any case, unless you build a glass box around it and then use it for a coffie table. even then there is still a chance of a bomb hitting it.

Sun Apr 29, 2012 6:54 pm

It is an odd choice of words, since they ARE essentially war surplus incendiary bombs........

Sun Apr 29, 2012 7:10 pm

LOL @ "Bomb Proof H Case"

Sun Apr 29, 2012 7:19 pm

DOn't stand too close after you throw it into the campfire. could get sunburned

Sun Apr 29, 2012 8:31 pm

Here is one of the weak spots on an "H" case engine.

It will happen sooner or later....Notice the crack on the right side of the crank and how close it is to the oil gallery plug.

Once it gets there the plug will blow out and instant dead engine.

Go ahead and put a grand or more into it for a rebuild and see what happens.

Mon Apr 30, 2012 1:42 am

[email protected] wrote: LOL @ "Bomb Proof H Case"

:oops: after reading the first days comments can i get the award for the most stupid title in the performance - engine/transmission forum ever? :oops:

I'm going to try and see if I can get my hands on an as-21 case.

What numbers / years does the as-21 case run between?

I have another engine but I'm pretty sure the numbers been ground off I'm going to splitt it anyway to see what I can use. How can I tell if it's an as-21?

Also with regards to moving away from stock components - increasing stroke etc... I thought a good rule of thumb was to stay completely stock?

Thanks for all the advice - I gotta make a samba donation when my bus get it's wheels turning.

Mon Apr 30, 2012 1:50 am

modok wrote:

Lapping valves and replacing bearings is not a re-build, that would be a patch-up job, like for selling a used car with no warranty :wink:

Ok so if I wanted to build an engine worthy of a 7 year unlimited milage type warranty what would I do? This way if it blows up I can return it to myself, and punch myself in the face until I give money back :D

Mon Apr 30, 2012 6:47 am

superman73 wrote: Glenn wrote: superman73 wrote: how do you tell if you have an as-21 case? would it be marked?
It says AS21 or AS41 on the left side of the case down ad the bottom.

thanks.

Got it

Mon Apr 30, 2012 7:47 am

now be nice john lol come on john remmber how well we used to like the old H cases . i built many a good running H case and i bet you did to john . if your going to build a bomb proof motor (this guy must be from world war two lol ) i would use a alum. case CB cheater cam fomoco heads 35mm by 33mm valves 74mm CW crank . thick wall 92 mm A&A cyls . or better yet buy a Hot vws mag may 2012 there a story about building a better bus engine story by the great the man him self dean kirsten i think you will find it just what your looking for .for your bus motor . spencerfvee [email protected] wrote: LOL @ "Bomb Proof H Case"

Mon Apr 30, 2012 8:43 am

burwin wrote: :oops: after reading the first days comments can i get the award for the most stupid title in the performance - engine/transmission forum ever? :oops:

What numbers / years does the as-21 case run between?

The only stupid question is the one that never is asked.

Just try to find the latest model case you can, the newer the better. Try to find something from 1972 or newer. Have a good VW machine shop check it out from top to bottom. Alternative, call Brother's VW Machine shop or Rimco or ACE and see if they have any good used cases there waiting to be sold, you never know.

As for engine parts in general, a stroker crank is always a good idea. P/C sets, there are certain sizes that are tougher and will take more abuse like the 88mm turned down machine in, 90.5mm and thick wall 92mm.

Depending on your money situation and how much you want to do to the case these are a couple of options. The machine in 88mm P/C set has thick wall cylinders but the barrel base is turned down to fit the stock case 85.5 opening, so they will fit without machining the case. A 74mm crank, combined with stroker rods, will sometimes fit right in or only require minimal hand clearancing. The 88 x 74mm gives 1800cc.

If you can machine the case then open it for the 90.5's or the thick wall 92's. You can clearance the case for a 78.4 or 82mm crank. This will give you from 2017cc to 2180cc. If this sounds like more than you're willing to get into that's OK, bigger isn't always better. Just something to consider though. Remember, engine size has very little to do with reliability. Reliability and longevity depend on quality of parts, care in assembly and having a good tune on the engine.

One more suggestion, if you are going to build this engine then it's worthwhile to check with the machine shops like I mentioned above, tell them what you want to do and ask them to price an engine kit for you. This way you'll have all the machine work done for you, you'll get good parts that the shop uses to build their own motors and they'll be there for tech help or any questions you might have.. They can often sell you a carb setup that will be jetted very close to what you'll need too.

Mon Apr 30, 2012 11:30 am

My idea was to use a particular kind of engine case, a single relief as-21 brazil case, the idea would be it would work fine with your old style cooling system, so you could get a new or several year old case for fairly cheap. They are still availible new

Mon May 07, 2012 2:16 am

Thanks for the further advice I'm taking it all in (looking at my wallet) and thinking what direction to take.

I Did find a number on my other engine. It was under the fan shroud so I guessed it was a type 3 engine. TO 4xxxxxx ( cant remember the rest) but it places it as a 1967 Type 3 engine.

In the case that I have to use one of the two engines that I already have which should be the better base?

I'm guessing the one in better condition right? :roll:

Mon May 07, 2012 2:21 am