Man, Frank. I guess it is possible for pressure to get into the oil passage. I had pressure going into the water jacket. You could see exactly where it was happening. I had no signs of water in my oil. You can do the head gaskets in a day or a weekend.

This thing is going to be a super G raider. Going to be awesome when complete and running great.

You need a SR rear axle now.

Or the whole truck! lol

Frank, SDS makes a piggyback fuel computer that will drive 2-4 extra injectors, programmable. It leaves the stock ecu alone. Your FPR won't work with it, I think. It wants just a MAP referenced constant fuel pressure. All it needs is rpm, tps, and your programming, plus 2-4 injectors and a fuel feed/return for them, and two weld on injector bungs. SDS also has nifty injector bungs with injector retainers so you don't need to fab a fuel rail, but the fuel line needs to be attached to the injectors with clamps.

You've hit the demon I was afraid you'd run up on - detonation due to lean out plus 8.9:1 compression.

I dunno, Eddy - I was just about to put it on a chassis dyno and read the exhaust for mixture, but wanted to build another exhaust system first.... shoulda/woulda. I'm not sure yet if it was lean or if the ignition curve is wrong... or both. Next time I'll install the MSD ignition delay and set it for 2psi threshold and 2 degrees ignition retard/lb of boost - that'll give 8 degrees retard at 6psi.... don't know what'll happen off the line at full boost, though. <img src="/forums/images/graemlins/lol.gif" alt="" />

The AFR gauge has shown rich under boost and the transition is good - I just don't know how rich.... maybe not enough, but I'm more suspicious of the combination of ignition timing and CR than fuel mixture.

I looked hard at the SDS unit and I looked at the MS unit for a long time last week - MS doesn't have any provision for A/C and P/S idle control... don't know if that would be an issue or not..... Haltech doesn't either, though.

I don't like the idea of extra injectors. I suppose they could go before the blower and help cool the charge - but any backfire would sure make a bomb outta the blower.

I do agree 8.9:1 is really on the edge without better data feedback and control. When I tear it down I expect to find the need for new pistons, so that'll be the time to put some 8.0:1s in it - along with better head gaskets and/or maybe even a head shim.

It sure was fun while it lasted, though. <img src="/forums/images/graemlins/wink.gif" alt="" />

Frank

Awww, man.

I'd be <img src="/forums/images/graemlins/ignore.gif" alt="" /> <img src="/forums/images/graemlins/mrt.gif" alt="" /> &^$**&^ <img src="/forums/images/graemlins/angry.gif" alt="" /> <img src="/forums/images/graemlins/ignore.gif" alt="" />

[The agony of (temporary) defeat.]

The wife would be cringing and the kids would be scarce. <img src="/forums/images/graemlins/smile.gif" alt="" />

You're obviously lighter of spirit than I.

Lemme know if I can help.

Ed

When it breaks it just means more fun! It's like having your own project but on Franks bank account <img src="/forums/images/graemlins/smile.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" />

Frank, I know what you feel, I can imagine the frustration..., but like you said, this is the price we have to pay sometimes and the final result would definitely be worth it.

If this makes your feel better, I went offroading last weekend and broke rear axle again - it's a third time I broke it.

Developing and building something is never ending process, sometimes everything is going good and sometimes not so good, but all this is keeping us alive...

Risto

Sounds like you need a SR , or a Sport Locking axle Mr escalade drivetrain.

Hi, Risto... home again and well, I presume.

Actually, I'm not so frustrated... a little disappointed that I pushed it beyond the limit, but then I didn't know where the limit was until I crossed it. <img src="/forums/images/graemlins/wink.gif" alt="" /> I'm more curious than anything - curious to know exactly what happened and why.... and what I can do to correct it.

I think the combination of a high static CR, stock ignition curve, no intercooler (heat), stock exhaust (restrictive), the original catalytic converter (restrictive) and 6psi on stock pistons probably did the dirty deed by keeping CHT high.... causing detonation. Until I tear it down, I won't know... if I get lucky, it'll only be a head gasket, but I'm expecting much worse.

Cryin' about it won't help.... learning what went wrong and trying to correct it MIGHT. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Frank <img src="/forums/images/graemlins/cheers.gif" alt="" />

3000TT pistons, and you keep the quench areas - quite important to do so esp. if boosted. I've seen gasket spacers make detonation worse because you lose the quench and resulting turbulence and dead spots where it can't detonate.

Look at the plugs for bright specks of what looks like aluminum spatters - usually quite small. Those are the sure sign of detonation. The unburnt air layer next to the metal gets blasted away from the suface by the shock wave of the det, and lets the combustion heat actually touch the surface of the piston and combustion chamber instead of being isolated by that molecules thick layer that won't light because of the nearby heat conduction that keeps it below the ignition point (surface quenching), and little flecks of molten aluminum go flying around.