In my case, the pistons, coupled with detonation were the cause of the engine failure. Here is the breakdown of the motor build:
1mm over dished 280z pistons
stock turbo cam
this comes out to 2967cc motor.same as a 300ZX
Now the reason the pistons failed is because when i built the stroker, i knew nothing about what piston/rod combination to use. Nor could i find the info. At the time, I had a friend who had a motor built by Rebello and they had used 240 rods w/280 dished pistons in an L28 block. The motor was not turboed. in order to compensate for deck height, they machined the tops of the pistons. I don't recall how much they removed for his setup, but the dish was nearly gone. At the time, I had no intention of turboing my car and I decided if it worked for Rebello, It'l work for me. So I cut 2mm off the tops of the 280 dished pistons and the deck height came out to 0. At the time, I had a ported e88 head and Isky race cam and tripple Webers. It ran great and I never had a problem w/it. Then I found a turbo 280ZX and decided it would be fun to turbo my 3.0. It lasted 1 year and let me tell you. This is my daily driver and I am very hard on it. I also drag race it on the weekends. Now, the motor is still running, it just has tons of blowby, and I have not taken it apart yet. I am sure that I will find that the rings are shot. But, this is because they are 2mm closer the the combustion chamber and subjected to some detonation.
As for you inquiry as to my ign. system:
I am using an MSD 6-BTM.
The reason the engine detonated was because I had trouble with getting enough fuel to the injectors. I finally installed a NOS high flow fuel pump, 1/2 feed line from the pump to the Paxton adjustable fuel pressure regulator that I installed on a custom built fuel rail sporting 30lb/hr Ford Motorsport injectors. That alleviated the pinging. However it cost me about a grand! Oh well. If you want to play, you got to pay!
BTW, It is possible to turbo the n/a motor without any internal mods. I don't see anything wrong with that. However, fuel and ign. are a very critical part of how any turbo motor runs and stays together. As long as the motor doesn't detonate, it will be fine. As we all know, the L-series motors are very tough. I also do not see a reason for installing a metal head gasket on the motor in this discussion. The 81 is 8.8:1 and that is fine for turboing. In fact, I am turboing a stock L24 that is 9.0:1. We are using a blow-through setup w/the stock carbs and manifold. So far the whole setup has cost $200.00 (junkyard exhaust manifold and turbo). We'll see if it runs good.
> the pistons are not neccesarily the reason
> for that. Remember, compression ratio is
> related to a series of factors. increasing 1
> mm of head gasket can lower you compression
> quite a bit an reduce the chances of blowing
> your engine.
> did you take any precautions against
> ignition advance?
> when in boost (after 6 psi) youp should have
> maybe that is another reason for it to blew.
> I am not blaming you for blowing your engine
> just wanna say that it is possible to turbo
> the n/a w.o having to install the complete
> turbo engine./