rage2

Well, it was bound to happen. My first broken motor =).

Some history...

2.8L block, sleeved, stock rods, stock crank, JE pistons, removed balance shafts. Turbo had some problems (T04/KKK hybrid), and smoked a lot, rebuilt fixed that and back on the road 2 weeks ago. It's winter, so I've been running low boost (10psi) on 91 octane, and rev limit of 6000 due to some interference with the new plug wires causing misfires at 6000rpm. SDS runs fuel and timing, and everything was fine. The rods I believe are original to the car, one of the few original pieces left.

Drove like I usually do to work yesterday (partial jackass). Got into downtown, 2nd gear 2000rpm, about 5psi of boost, wham. Smoke. Parts. Oil. Shut down within seconds of it happening. Parked to the side of road, and saw what looked like a piece of the rod. Towed the car to Marcs and this morning confirmed that rod #4 shot out the block.

I did notice that there was something weird during decel yesterday morning, when I let off. It felt like the car was decelerating more than usual. I guess that's a sign of something going horribly wrong... I just thought it was my e-brake not releasing properly, so pulled on it and let it go, and it went away.

Engine is being removed to see what can be salvaged, so pics will be coming soon. Will also try to figure out what exactly failed, rod, rod bearings, etc. And of course, will show what 15,000miles of hard driving how the sleeves held up.

I would've thought with the 2.8L experiment, it would've been the sleeves that killed me. But looks like it's being cheap, and not getting a fresh set of aftermarket rods.

daniel951

that sucks rage. Hope u can salvage alot and start another project motor

rage2

Oh ya, where would one go to buy a bare sleeved 2.8L big bore block? There's a nice hole in mine, so it's gonna be wasted .

Duke

Oh no! Sorry to hear that

This adds on to my already somewhat worried thoughts about not changing the rods in my new high hp 2.5 engine...

Porsche-O-Phile

R.I.P. That TOTALLY sucks. . . I've been considering going the 2.8L direction with the Callaway engine and know what a pain (and how expensive) that is! My sincerest sympathies!

Now get a 3.0L. Natural solution.

TonyG

Sorry to hear about the rod.

Been there... done that....


TonyG

Porsche-O-Phile

Any ideas on a potential failure cause at this point? What kind of conn. rods did you use? Connecting rod nut came loose?

gcb951

Rage,
Thats too bad man. I'm sure you'll get it back up and running though. I have a question for you though. Did you have to sleeve your block in order to use JE pistons? Or is that only a concern for the rings you use. I was thinking of buying a new set of pistons for my 2.5 but it is not sleeved. What do you think?

BC

Please do suply us with pics no matter what happens. If the "forged" 951 rods can't handle 400rwhp.... Many of us are in Trouble across the front engine water pumper world.

rage2

Yea I dunno what really caused it to fail yet. I mean, I've run over 450whp on the stock rods and they were fine, but I guess that was in short bursts on the roadcourse and drag strip with my 2.5L motor. But I guess I do run around 400whp daily so maybe it's taking more stress? But it broke at maybe 350whp on low boost for winter tires and I wasn't even driving that hard. Or it could be from the vibrations after removing the balance shafts too. I do a lot of day to day driving, and the vibrations are the worst at part throttle between 2000-3500rpm.

I'll get as many pics as I can though. Maybe it'll be blatantly obvious to someone hehe.

daniel951

i am going to have to check this thread out frequently to see why it failed since i was going to start a 2.8L motor on mine

Porsche-O-Phile

So they were S2 or 968 conn rods? I thought only the 968 ones were forged but I could be wrong on that. . .

Zero10

They were 951 rods (as mentioned above).

Interesting. I wonder if it was a sleeve failure?...
Those were Rolls-Royce sleeves, correct?
I'm also interested in seeing some pictures of this.
Do you still feel that the smoking was a result of turbo problems, or in retrospect, does it seem more like a warning sign of your engine's condition?

Anyways, this is terrible news. I had always wanted to run with you at an auto-x or something, just to see how much faster your car is than a stock 951, and now we won't get that chance for a while. Are you planning to build another 2.8L? Or are you going to stoke the next one?...

hosrom_951

Rage,
Why do you have a problem with the balance shafts? (the vibrations)

rage2

Not sure what caused it yet. Not going to rule anything out, nor jump to conclusions. But, a sleeve failure wouldn't be so sudden. Honestly, yesterday was the first time in a LONG time where my car had zero oil leaks, zero smoke out of the exhaust. I mean it ran nearly perfect (other than a slipping power steering belt).

The bad smoking I had was definately the turbo. It completely went away after the rebuild.

I think I'm the first 2.8L big bore to fail with the rod so lets hope it's an isolated incident. Good news is I guess we'll all see how the sleeves and the pistons held up. I guess after seeing that I'll decide on 2.8 or 2.5 as a replacement.