Had my new engine running great for a while, maybe too good one night when it reved faster than my TH350 could shift.

I heard the valve float and new I had screwed up but luckily the engine seemed fine. No unusual noises or anything and I thought I had gotten away with it.

Fast forward two weeks later, getting off the interstate after criusing at 3500 RPM for about 20 minutes, I heard the loud tapping. I have no idea how long I ran the engine like this because I couldn't here it on the interstate. I limped the car another two miles home and shut it down.

When I removed the valve cover I found a small peice of my valve seal retainer laying in the top of my cylinder head. It looks like this little piece, broken when I overevved, eventually managed to bounce up between the valve spring coils and bind them up, killing the cam.

I already plan to remove and redo both cylinder heads but am unsure If I should strip and rebuild the shortblock.

Is it recomended that I rebuild or will a cam swap suffice? I'm already planning to redo both cylider heads with new springs and seals.

Thanks for any input...

 

I'd try to get by with just the heads and cam. A leakdown and compression test will tell you if the shortblock is toasted. But I think you'll be ok.

 

That metal went SOMEWHERE... the last motor I disassembled that had a wiped cam was UGLY. Every single bearing was wasted, some worse than others. I hate to say it, but you may be looking at having to redo all the bearings in the bottom end.

 

PUt it back together with a lowbuck cam and see if it otherwise performs ok. Take it to one of those shops that can flush the oiling system. Like 40bucks. You can probably do that for not much over 100bucks (even with lifters it should be less than 150ish). If it fails after that you only dumped a minimal amount.

 

im afraid i have to agree with hawk. if your valves locked up then you probably have some nasty crap floatring around in your oil. id say as long as you have your motor torn apart go ahead and change all your bearings. you probably wont have to get your crank turned or block bored but that depends on how bad your bearings are torn up. save yourself the future aggrivation and do it now.

i feel your pain, i just got done swapping my 305-350 and with 200 miles on it it started smoking pretty bad. now i get to pull my motor and replace the cooked rings

 

Yeah, I know you guys are rite, I'm pulling the motor now and will definatley pull the main caps off and take a look.

Damn, what waste of $3500.00... This thing was balanced and bluprinted and put down 426rwt and 285 rwhp. The hp would have been higher but a restrictive exhaust cut the top off the hp curve.

I'm leaning towards just scrapping this whole engine and starting over with a new roller cam block. Maybe just get a goodwrench shortblock and transfer my parts over with a new comp roller...

Thanks for the input everyone.

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