[Arnout]

Dear Mc Gregory,

First of all I must make a compliment regarding your will and courage to have this engine built in Poland in three days. Obviously anyone in the whole world have told you a racing engine cannot be made in three days, nor can you really ‘wait for it’ but hey… you tried! Now anyone can learn from you.

I read you have problems with the very fundamentals of reducing the weights of the moving parts in the valve train. First of all let’s get the correct names for everything. The piece you refer to as ‘eine kleine stuckchen’ is called a ‘lash-cap’. This is a cap you place under the ‘bucket’ (that big round thingy).
A lash cap is an adjusting shim you place ‘under the bucket’ hence the name ‘shim under bucket’.
If you put the bucket on the scale together with the lash cap, you will see this combination is like 10 grams lighter than a bucket with a shim (shim-on-bucket). Reducing the weight of the moving parts in the valve train allows the engine to rev higher, as the valves can be opened and closed faster (the pressure on the springs is less).
I don’t know if the claim of 10k RPM is correct, it can be if you have stiffer springs (double springs for example). Anyways, reducing the weight in the valve train is ALWAYS good.
Shim under bucket is one of the most fundamental ways of reducing weight. It is used in various engines like the 4A-GE 20 valve and the newer generations 3S-GTE (the ones to be found in the ST205 Celica and the newer SW20 models).
Besides the loss of weight in the valve train, a shim under bucket conversion gives you another advantage namely this: The bucket diameter is always bigger than the adjusting shim to be placed on top of the bucket. The bigger the diameter the cam is pushing on, the more aggressive cams you can use. Aggressive cams means: higher lift and stronger (faster) lift. We make these racing camshafts with a very respected company in England, who have made more racing cams than you can ever break in your entire life.
As I’ve already told you by phone I can not understand why the engine shop does not know a thing about a shim under bucket conversion while they are building a ‘800 HP engine’ (your words, 800 HP). But that’s not my problem.
Adjusting the valve clearances is pretty straightforward. First of all, this is a process you need to do AFTER fully assembling the engine. You cannot adjust the valves on the head with the head off the engine, as there is always some torque distribution in the head, rendering your measured valves useless, or next to useless.
Put the head on the engine and torque the bolts. Re-torque later again, just to make sure. Put the lash caps on the valve stems and put the buckets on top. Check how much to grind of the lash caps. Yes, you have to adjust the lash caps (the caps under the buckets). Grind them down until you have the correct valve clearance. Obviously the valve clearance on a 800HP car is completely different from that of a 400 HP car. I strongly suggest you to read some good books on how to build a racecar in three days. Very important is to raise the valve clearance on the exhaust side.
I’m not very good at German, but from your story I understand your engine shop guy thinks the lash caps cannot stand the pressure from the cams? Note the lash cap is bigger than the valve stem. Does he think the valve will brake in two when it is pressed in?
One side note I have regarding the work seen on the pictures. Removing an engine from a car is much easier with everything attached to the engine. Next time, take the wiring harness out of the car together with the engine. Also, working on the ground like in the picture is very bad for your back and your health in common. You can buy an engine stand at any hardware store and work easily and clean. Clean is very important. We assemble engines in a clean room. With bearing clearances of 5/100 of a mill even a tiny grain of sand can be the difference between a happy face and a near to suicide experience.
Next you are suggesting you will have Christian (Suprasport) install the racing cams with the lash caps. Christian has no ‘engine shop’. Christian does installations, and he is doing a very well job if you ask me. But he cannot adjust the lash-caps, as this needs some grinding which is to be done in an engine shop, a shop you are currently visiting. I don’t have my car washed at the rim shop either, although they both work at cars, you get my point?
You called me with a few questions, of which I could answer the lash caps problem. Next I asked you ‘what is your goal’. This is always a question you have to ask yourself if you are starting a project. What is my goal? What do I want? What do I want to reach? You told me you want a street drivable car of 300 hp and if you take it to the track you have 800 hp. Well, I can help you out of that dream: this is only possible by having TWO cars. It’s either having a very shitty ‘300 hp drivable car’ or having a very dangerous (detonation and such) 800 hp car. Obviously you can raise the boost slightly and put some high-octane gas in (like the C12 racing gas we are selling, 117 octane) but this will more put you in the ‘one hundred’ horsepower difference (say 550 hp or 650 hp with racegas). During our phone conversation, I found out you don’t know what you want, nor do you know how to reach that. This can be an explanation why you choose to have your engine build by a shop that doesn’t know what they are doing (we call that research, but we don’t have customers pay for it).
I asked you what compression ratio are you going to run. This is really the MOST FUNDEMENTAL question you have to ask. What compression ratio are you going to run? Do I want high compression ratio and low boost applications or do I want to relieve the static compression slightly and allow more boost. Well, you could not answer my question so again: Do you actually KNOW what you are doing?
Your next question was what to set the piston to wall clearance to. Again this is something SO fundamental and this is just from the books (it’s also on the paper that comes with the pistons and with the rings). Everyone who install JE pistons must know this, otherwise I would run away as FAST as I could! Also, please allow more piston clearance when running nitrous (1/5 more). Note your engine might consume oil, in return of the bigger clearance.
The piston rings should not need any adjustments. This is only in the movies like ‘twins turbos’. Forget about this. Just check them by putting them in the bores and see for yourself they will fit perfectly. Also make sure you measure the piston ring gap while having the torqueplate (I shipped that one to Christian by UPS) securely mounted on the block as a replacement of the head. If you don’t use the torqueplate for honing the block or for measuring the piston ring clearance, you are converting the engine to old iron!

So far my tips. I hope everything is clear. If you don’t take my advice to hire a van and trailer and bring everything to me, good luck with the adventure and please keep us posted!

Peace!
Arnout