Oh oh that's no good Keep us posted...

 

We just ordered the cams for the new engine.

We already have the GT3 Cup heads, lifters, GT3R valve springs, Carrillo rods and GT1 oil pump.

The case will be boat tailed and shuffle pinned. The crank will be knifed edged. The heads will be fully ported and polished.

Currently looking for some GT3 Cup sized valves that are sodium filled. The stock Cup valves are stainless steel.

 

Do you think that the oil plug blew out due to case flex? Are you using the GT3 valve train or the turbo variable lift set up?

 

At this point we do not know what caused the plug to blow. The plug was not the original issue. We had previously changed both vario cam solenoid valves and the tensioner in an attempt to eliminate the tick. The tick was definitely coming from the valve train. When the plug blew the engine was warming up. With the metal shavings we found in the oil filter, I believe something got plugged. We should know next week.

The ticking sound was first noticed when we were putting the car through it's paces just prior to the dyno run. We did an acceleration run where the G tech recorded a 0-60 of 1.9 seconds. My belief is the Tilton clutch, 3.16-1 first gear and the 275's/335's increased the power delivered to the ground to a point that something broke in the motor. The motor was internally stock, however with the just installed turbo's and nitrous, we estimate the motor was putting out about 750 rwhp.

In a way I wasn't surprised. I have been told by people in the know from Motorsports that if you push these motors with stock internals 140-150% past their maximum rated power, be prepared for this. If that is so 610-630 rwhp on stock internals is the point where you are looking for trouble unless you change both the upper and lower ends of the motor.

The GT3 Cup heads use the vario cams and hydralic lifters. The GT3R heads use solid lifters. If you hope to pass the smog test you can't use the solid cams. The GT3 Cup uses stainless steel valves. People in the know say these valves will work, however due to the uncreased heat of a turbo motor, their life is drastically shortened. This is why we are currently looking for someone who can make custom sodium filled valves to the GT3 Cup valve size. Anyone know who might do this kind of valve work?

 

Hi Chad,

Sorry to hear about your engine failure.

Just looking at the plug that popped out it does not appear that it is related to high power.

A guess is that the pressure relief in the oil pump may have stuck causing high oil pressure. This can cause bent valves and poor idle when cold due to the hydraulic lifters overpumping.

It will be really interesting to see what you come up with as far as the damage.

Good luck with your project.

Jeff

 

The only sodium filled valves I've seen had a much larger stem diameter than usual. However these were in older engines. Are the stock turbo exhaust valves made of a higher temp stainless material than the GT3 valves? What did the long distance factory turbocharged race cars use in the past?
Did your engine loose oil guage pressure when the oil plug came out?
The camshart part numbers you gave appear to be stock 04 GT3 cams.

 

No bent valves ......... leak down was perfect.

 

Larger valve stems are not a problem. Actually, not sure the sodium filled would hold up to the 8000 RPM'S. The stock GT2 Re stainless steel while the turbo's are sodium filled. I may increase radiator and oil cooler size and just go with the GT3 Cup stainless steel valves. I do not know as of yet what older factory turbo's used. Yes, the oil pressue dropped slightly.The motor was warming up at an idle.

The cams are from the stock GT3. I don't want too much lift or duration. Good eye.

 

GT3 cams should have plenty of duration for a turbo motor. I'd assume that cams for an 8200 rpm NA motor have much more duration than stock turbo cams. I wonder if the hot shot German tuners use the GT3 cams in their high end turbo motors that use GT3 heads?
For some reason I thought you were running ported stock turbo heads. Did you go with GT3 heads instead?
Hopefully the oil leak didn't damage the rod bearings.

 

I believe Ruf, Manthey and 9ff uses the cams on certain of their motors. I don't believe they use the GT3 Cup heads. My 3.6 motor was stock internally. My 4.0 motor is not.

It really doesn't matter about the rod bearings on this motor. I have an extra GT3 crank and Carrillo rods that are going to be installed. I'll be posting pics of the damage ...... whatever it is.

 

Should have pics of the bottom end being disassembled on Monday or Tuesday. The cams arrived from Carnewal today. We now have all the parts.

The motor will have 104 mm Wossner pistons and is being built to handle 1.8 bar and a 250 shot of nitrous. Turbo's will be 40/45's. Redline will be 8100 rpm's.

 

This should be fun!!! Does it ever end?

 

cjv,

Why have you gone for 40/45s out of interest, they seem very large? (I am assuming you refer to garrett sizes)

The top Skyline GTRs (a world I am much more familiar with in terms of seriously high bhp) tend to only need 3037s to get to the 1100bhp at crank level (with 2.7litres at circa 9000rpm, but using 2.0 to 2.3bar boost).

Guy

 

Guy,

The pic of the above turbo's are 30/35's. That was with 100 mm pistons and turbo heads. We are using 104 mm pistons and heads that have larger ports and valves and different cams for both intake and exhaust. In addition we are boosting significantly less along with running less rpm's than the Skyline GTR's.

We have the experience of one 4.0 motor and this one is being build to vastly reduce any lag. Don' forget, the NOS system isn't being utilized for outright off the line power. It is a two stage pill controlled, programable system. That is to say the system when armed doesn't activate or shut off until a certain rpm. In addition the NOS starts at let's say a 10 shot and then adds an additional 10 shot every tenth of a second for the next two and a half seconds. You can set the shot quantity and timing at any value you want. The NOS is really only an assist to eliminating any turbo lag.

If if doesn't work as we planned then we can always step down on the A/R ratio.

 

What we intend to do to this motor:

The GT3R crank will be knife edged.
The GT3R crank will have the oil passages reworked.
The GT3R crank will be balanced.
The case will be boat tailed.
The case will be shuffle pinned.
The GT3 Cup heads will be ported and polished.
The GT3 heads will have grooves machined in for metal o-rings for head gaskets.
The heads will have new valve guides made of different materials installed.
The heads will be given a three angle valve job.
Certain coating will be applied for heat dispersant, ceramic coatings etc.
The case and the GT1 oil pump will be machined to mate.

Pics will be provided as this work is completed.