333pg333

As an addendum to this thread, we continue to have h/g issues on the track car. We even turned the boost back down to 18psi and thought that might sneak through. Worked for a little while (read, half a day) but then we saw the signs of coolant on parts of the car underneath. Still managed to record some very good times with the car but this failure rate is distracting and becomes expensive over a season.

So now the motor is out and the head and block are being sent off to be O ring'd and we'll get a custom copper gasket made up. Our intention is to be able to run about 1.8bar on the straights either via lateral grip or even a push to pass button. Maybe rising with rpms. Not 100% on the method yet.

rlm328

When tried them we used copper coat to seal the water passages side of the gasket.

Eric_Oz_S2

No retorque. As that is "optional" (ie not specified by the FWSM), and involves a whole bunch of disassembly (belts, pulley, cams), I did not.

Patrick - what thickness Cometic do you use?

Do you have a knock light installed in your car? Knocking is a funny thing - it never showed up on the dyno in my car, yet I still get quite a few counts on track. Running E85 probably helps you a lot though, I run 98RON + Octane booster on track for about 101RON resultant.

David Floyd

Cometic .040" is the thickness I have been using

333pg333

What do you use now Bob? What boost and fuel do you run?

I think you can just re-torque them overnight to allow for any bolt stretch Eric. Again, without qualitative data this might be an old wive's tale but I know some do this.
I don't actually know which thickness my h/g is. Sean will know. I can't remember being offered anything but what we use. I think Corleone used to pull his apart and put hylomar inbetween all the layers too. Could be overkill but his build is stuff of legend.

No knock light but we can run one if wanted. We run Motec knock control. Have had some minor counts but now running Martini E85 said to be 116oct. I am a bit dubious over those oct claims but "all the fast guys are using it" and it works for us. Not cheap though. Do you have any United or Caltex servo's near you that vend their pump E85? Might be worth making the change.

David, who specified that particular thickness ? Do you know what your c/r is?

David Floyd

8:1 cr
When I switched to Cometic I chose .040 as closest to stock without lowering cr anymore.

rlm328

[QUOTE=333pg333;11473274]What do you use now Bob? What boost and fuel do you run?

I have only run about 17 psi at it using 98 octane. I have a .051 Cometic now had it at the track a couple of weeks ago, track temp was around 130 F no problems. I have been using it about 6 months now. I thought I had an issue around March but it was the radiator cap.

My engine was rebuilt with MID sleeves, very different thermal expansion than the alusil block which is the main reason I switched to the Cometic as it flexes a little where the copper does not. If you go with the copper you may want to consider stock head studs for the extra stretch.

My ECU is a Motec. So I can control most parameters.

ehall

I got a buck. Will that do? thanks for the tip!

Paulyy

WOT trigger + RPM would be the best one.

KSira

I retorqued my head studs after driving for a while of boost/very low boost. This was a major PITA as it is a 16V head, but several of the nuts where not holding specified toque and did move enough to make me concerned for what had happened if this had not been done. This was with Raceware studs and a cometic gasket.

chrenan

Chris, is this a direct swap for the stock coolant bleeder or do you need to drill and tap a new hole?

FYI I'm another buyer for your book, hurry up and get writing!

ehall

Good question. I presume it is yes.

As for the book, you should see his photography book. Seriously, it was amazing!