Broken piston(s) SBC - Page 3 - Motorgen - Automotive Events, Meets, Cruises and Forums

enkeivette · 06-05-2009, 03:49 PM

Bearings are pretty and wear free, I will reuse them.

Pistons all look okay to me, except for the obvious one and the still questionable one. Here's it is, no cracks from what I can see. I think a tiny piece of the other piston found its way into this cylinder and did a little dance with this piston.

I plan to file down the little blemishes and run it, unless you guys think it's a big mistake.

BRUTAL64 · 06-05-2009, 03:56 PM

Not to be a "doom" sayer. You might not see any wear on the bearings. "Crush" is what is effected. Crush is what keeps the bearings from spinning in the rod.

I've seen it before. Broken rings or broke piston- changed- and 2 or 3 months later they spin a bearing. Just want you to know. Your call.

enkeivette · 06-05-2009, 03:58 PM

How about the piston? Cool to run it?

BRUTAL64 · 06-05-2009, 04:06 PM

Yes, just smooth it out. NO sharp edges. You may want to take the time to go over all your pistons and smooth all the sharp (even semi-sharp) edges. Anything that the flame front will see.

BRUTAL64 · 06-05-2009, 04:20 PM

Quench--remember our discussion on this?? I think you said it was not a problem with a forced induction engine. Well, a by product of too much quench is detonation.

I know I can be a pain, but I just want you to be aware. I know how much time and money you have in this engine. Really, I'm just watching your back. Honest.

enkeivette · 06-05-2009, 04:36 PM

Maybe you were right about the quench. And I never said quench was not a big deal with blown apps, I said that others have told me this. Others being tech from AFR over the phone. I don't claim to know anything about engine theory.

Just placed a summit order, I ordered two new bearings to meet you half way.

BRUTAL64 · 06-05-2009, 05:05 PM

Yes, I remember you stating that you were told by other people that with forced induction you need not worry about quench. I didn't agree, I've always built S/C motors with no more that .045 quench. But, that's just me.

As far as the bearings, seems like a fair call.

I'll be here at work for 5 hours tomorrow if you have any questions.

enkeivette · 06-05-2009, 06:27 PM

Thanks Glenn

SeanPlunk · 06-05-2009, 06:40 PM

I'm glad to see the damage isn't too bad. How long until you have her back up and running?

enkeivette · 06-06-2009, 10:03 AM

Quote:

Originally Posted by SeanPlunk

I'm glad to see the damage isn't too bad. How long until you have her back up and running?

Took only about 12 hours to pull it all apart, (including 2 hours making a special socket to get to my rear oil pan bolts) should go back together in about another 3 half days. Piston is special order, but I'm sure it'll be waiting for me when I get back from NY next week.

Let's hope these rings make up for that low cylinder pressure and low hp that I've always had a problem with. For those of you who forget my motor pumps out about 135psi while similar setups are in the 180 psi range. Leaky HGs, intake manifold gaskets, and piston rings... need another dyno day.