danger in overboosting!
 

Oh what fun it is to take a perfectly good Porsche 3.3 engine, install an in-cab boost knob, turn it way too far and have detonation… rule of thumb; less is more.

munchovie.

http://930turbos.com/images/930wayboosted.jpg

http://930turbos.com/images/930wayboosted-2.jpg

Yikes!

here is a closeup - it's a shame because the engine looked so nice on the outside ;)

http://930turbos.com/images/930wayboosted-3.jpg

That's why I stay at 0,8... that picture scares the hell out of me. I think the 930 is a pretty fast car at stock boost.
I am sorry that happened toyou.. I am sure you'll build it faster, stronger and lighter than it was before the grenade went off.

Really sorry for you wmunchovie.....it's a pity...so much damage.....how much pressure did you have...?.....I heard about racing engine runing with 1.85 Bar and no damage...?...so...?...what's going on...?

What boost level caused the damage? What are the specs on that engine?

It appears there are/were higher compression pistons in the engine. 7.5 or 8.0 : 1?

bummer

looks like your broke the ringland (hole in the piston) on the what could have been the leanest cylinder . the temperatures in that cylinder must have been staggering.

but you threw the rod as well , a forged rod for that matter, you must have overrevved or something else . that is alot of damage for just overboosting . the head studs should have snapped way before that would have happened.

it looks like the whole engine is scrap now ...

btw. newb to this forum here ...

I feel your pain - don't ask how, or I'll send you my pics.....

Last known statment prior to destruction:

"Hey doods, look my boost is ad-just-able........let's crank it up!"

;)

Well, I’m happy to let you guys know that I bought the car after the damage was done; I just never got around to taking the engine apart. After further inspection it seems as though the 930 was a 3.4 - Ross pistons 8.0:1 101.5mm and had nitrous rings – so I suspect now that not only over-boosted but the big nitrous switch was stuck on… This could account for destroyed rod, it seems.

Anyway, the crank on no. two is pretty bunged up; boat anchor or have the crank repaired? It seems that three of the six cylinders are ok, but I’m just a little shy about using anything from the bottom-end.

The heads looks pretty good; I’m going to disassemble them this weekend, clean them up and check the valves, etc. They are twin plug heads with 38mm intakes.

Munchovie.

The nitrous is where the rod blew up (Nos backfire?) and way too much timing. Unless the boost went way to high. Ive run my car for short sprints at 25 Psi and no problems.

I was told by an engine expert where I work that the magic number to a failure of the rod-snapping sort is 10,000 psi in the cylinder.