Broken rod

[gingerale]

I think I broke a rod in the 86, a few weeks ago. The car is pretty well modded and has never been dyno'ed or to the track, but it was well over 400 HP for sure. (ported everything, big valves, boport 1.9 cam, BW S200 turbo, 85 pph injectors, Megasquirt, intercooler, etc.) That morning it was nice crisp and cool fall air and it was running especially strong. I got on it about 3/4 throttle and just as boost came on and it started pulling hard (4000-ish RPMs), there was a loud POP and it instantly lost power. I immediately pushed in the clutch, revved a little and it was still running, but rough, so I shut it down. Coasted to a stop and steam was coming out from the hood. Opened the hood and there was oil and antifreeze everywhere on the passenger side, and pouring out on the ground. I parked it and haven't looked at it since. What is most likely....rod bolt failure, or rod itself? Either way...looks like I'll be building a new short block in the spring.

[dagenham]

What is done to the bottom end?? Did you change out the rod bolts at least?? If you didn't, then that would be my first guess.
Either way, it sounds like you broke the block.

[MikeFleming]

Disassemble. Disassemble.

Take pics.

[blueboss]

You definitely ventilated something that isn't designed to be. I'd like to see pics of this one.

[SVORob]

if you didn't hear the knock of the rod you might have blown a head gaskit. Had one blow on a dyno while i was standing next to it ... what a mess

[gingerale]

Nope, not the head gasket....there's a hole the size of my fist in the block, next to #2 cylinder. Will take pics whenever I get it out and torn down.

[MikeFleming]

...there's a hole the size of my fist in the block, next to #2 cylinder.

Uh, yeah. That's bad.

[Under Pressure]

That will be interesting, Very interesting. I'd be Interested what caused a hole in the block. Pictures

[TheSVOTrust]

Let us know ASAP what you will be doing. May have a block option for you. (if you are willing to drive 15 Mins north)

Have a strapped lower end block that needs to be bored (did one cylinder years ago at .040 to clean up). IF YOU ARE DOING CUSTOM PISTONS - this may be a great start. Again let know ASAP - may surprise you.

Mark

[gingerale]

Thanks for the offer Mark. I'm on a very tight budget right now and have two cars to fix before starting on this one. Met a guy a few months back at Wal Mart who says has a complete carb'd turbo motor sitting in the corner of his shop. The bottom end on those is the same, right? Will try to get ahold of him in a few weeks. For the moment I'll just have to stick with the stock bottom end, and keep the boost turned down some. It was overboosting due to too much preload on the wastegate I think, so that's why I never went over 3/4 throttle....

[gingerale]

Under Pressure: I met a young guy some years back (10 years ago?) from Newnan who wanted to build a 2.3. Pretty sure I sold him a motor that came out of an 85 TC, but as I recall he never did do anything with it. Was that you, or someone you know?

[MikeFleming]

Met a guy a few months back at Wal Mart who says has a complete carb'd turbo motor sitting in the corner of his shop. The bottom end on those is the same, right?

Pistons, pins, rings are different. The carb'd turbo engines used a 9:1 static CR. I suspect they also have forged pistons, but I've slept since then.

Rods & crank are all same though.

[TheSVOTrust]

Let us know ASAP what you will be doing. May have a block option for you. (if you are willing to drive 15 Mins north)

Have a strapped lower end block that needs to be bored (did one cylinder years ago at .040 to clean up). IF YOU ARE DOING CUSTOM PISTONS - this may be a great start. Again let know ASAP - may surprise you.

Mark

I guess this didn't excite you. (nor did the fact that I could get it from Detroit to 15 min's from you)

Mark

[Under Pressure]

No I don't know who that is.

[gingerale]

9:1 compression would actually be pretty nice. I do believe those pistons are forged. Will post up pics in a month or two.