r33_racer

I can say with adapter plates and the greddy plenum on the 26 throttle bodies on a 25/30 will hit the clutch master cylinder and hit the lines exiting the brake master as well. So far 12mm packers under the sub frame has fixed the issue. However with a factory rb26 plenum it is fine with good clearance everywhere. In a r33 gtst engine bay. Possibly pointless info there, but in case any one wants to know. The adapter plates are 12mm thick each, so 24mm packed out from head.

I would think everyones different camshafts would mess with your comp readings from engine to engine.

Unfortunate about the old engine! But it will certainly be interesting to see how this new setup performs in relation to the old setup. Especially with the addition of the new head. What sort of port job was done to the old head? My mates car runs low 9's with a near std head, ports are just cleaned up. Makes about 880rwhp. What bigmikespec has said holds true, port finish 101 regardless of head type or setup usually doesn't go any finer finish then 80grit. Polishing the surface slows air speed and ruins mixture motion through the port. But maybe this particular guy has a formula that works for him and it goes against the theory that everybody else in the world works around. It will be interesting to see if it makes a difference or not. Gotta keep an open mind about everything!

Measure your piston protrusion, cc your chambers, then do all the maths....dont bother guessing when its not that hard to do it properly.

Rock auto is an american website that sells remanufactured oem car parts for cheap. The vg30 engine seems to use the same hydraulic lifters.

Alot of those parts you can get on Ebay for a good price. You can also get brand new replacement hydraulic lifters from Rock Auto for like $13/each. The ones that suit the 300zx are the same as the RB25 lifters.

That is pure porn man. Insane. I want my car finished NOW!

The ones in that ad looks very similiar to the ones we made for our race car lol.

Definitely need a stainless or plastic tank if running methanol. It eats raw alloy easily and quickly. If you must use alloy then get it anodised so it can handle the methanol abuse. I have the cooling mist kit with the digital gauge controller for my twincharge setup. I got 1 injector in the compressor outlet (before supercharger inlet) and 1 injector before the throttle body. I fabbed up a stainless tank for the boot that holds about 20L from memory. However it isnt running yet so I cant report on how good or bad it is.

From memory its only on the exhaust side.

Very nice! What kind of power are you chasing with those two turbos?

That is a great result! Always good to see the difference of before and after when doing basic changes.

There was a really good thread on the hydridz forums about a 'lehmann' style dual plenum inlet manifold being designed and made for an L28 I think it was. It was a long thread but had alot of drawings and CFD testing done with the guys design, think he got it all CNC machined out of two big chunks of billet in the end. Looked amazing! Damn you Michael! I want to make one now!

Nice work mate! Always great to see people having a go. Love it! They look the shiz.

Looking good man! I don't know how you manage to do that much wiring....its so fiddly and frustrating!

The guy who did it on PF is who I got the idea from. I was lucky enough to have been taken for a spin in his twin charged vl and it was it crazy! There is enough room to fit it all, it just takes time and a lot of customization to make it work.

CHEAT!

A leak down test will tell you if air is bypassing rings or valves and help you pinpoint where. Compression test cant really do that properly. A leak down tester isnt really that expensive to buy either. You can find them for $100 or less these days and they are straight forward to use, you just need compressed air.

The problem with the CP ring package and the package that comes with most aftermarket pistons is they are too thin, made of too harder material(top usually) and oil control ring doesnt have enough tension. They state the use of better materials, but even so, the rings still cant handle the heat; not enough material or meat in them to dissipate it into the block adequately without losing tension over short periods of time. Also the ring being too thin just doesnt offer enough sealing area to properly contain combustion pressures when the power starts climbing in these performance engines. Hence why people start having blowby issues after a rebuild. Then the builder is told to focus on getting the bore finish, cross hatch, bore size, trueness and distortion (torque plate) as close to perfect as possible just to try and give the thin rings a chance at working properly and lasting. Not that they shouldnt be doing those things anyway, but piston manufacturers will typically blame issues(poor ring sealing) on the machining processes rather then their piston/ring package just being inadequate. We noticed this issue a few years ago and we now use the 1/16, 1/16, 3/16 ring set with a second gapless which means custom pistons for the right groove size which is no big deal, the benefit results in a near perfect 1-2% leakdown or less constantly. Ive never seen signs of 'ring flutter' and our ring guy reckons he has never seen it before either in the last 20-30 years of ring manufacturing....another supposed myth he claims lol.

So people dont get confused about the thread form incase they dont use the speedflow fitting. I used some generic steel fitting from the hydraulic shop down the road. 1/2"bspt/AN-10 male-male fitting.

Ill post it again in this thread cause I love putting my ms paint diagram to use! WOOOT! I dont have the side or rear head drains drawn in as they arent really needed if everything is setup properly and engine is built well. Lol even though on my road car I have put in the side drain also as it is the lowest point in the head.

You should do a leak down test and see just how well the rings are sealing. I reckon your issue is blow by in which case the pressure build up in the crankcase and whole engine is whats forcing oil/air out into your catch can. You need a decent size catch can with some baffling in it and a crankcase vent from inlet side straight to your catch can and have ample sized breathers on it, say 2 x 32mm filters. Dont feed the catch can back into your intake and as said above make sure you have 1 hose for each cam cover. Have the valve stem seals & guides been replaced at any stage? If they are heavily worn & still 20+ years old its possible some intake/exhaust gas is leaking there and helping to pressurise the engine also. Thats a bit of a stretch in terms of likliness but you never know.

What exactly does the bare head come with? Does it have cam caps? Or is it proper bare with nothing?

You could look at just deshrouding the valves by scalloping into the quench pads each side rather then removing them completely. Then see what that gets you in chamber volume and use headgasket thickness to achieve the rest. WIth fuels and tuning as good as they are these days, you can run in the mid to high 9's without any worry. It's only going to help off-boost drivability and reduce lag.