Will the tooth fairy come?
Discussion
Martin Keene said:
That's external... It wouldn't find it's way into the sump.
The way P revs that engine, anything's possible! 
You have to admit though, even with a lot of teeth missing (from wherever), these chevy engines still keep going!!
Edited by gtr-gaz on Saturday 15th December 13:19
Martin Keene said:
That's external... It wouldn't find it's way into the sump.
They aren't sprocket teeth, they are gear teeth. I'd be looking at distributor drives, oil pump drives, camshaft it not chain driven, as a starter for 10.
Martin's right Steve, these were all stuck to the mag sump plug.They aren't sprocket teeth, they are gear teeth. I'd be looking at distributor drives, oil pump drives, camshaft it not chain driven, as a starter for 10.
All will be revealed when Charles Dunn opens her up.
Any SBC builders out there care to guess?
Martin Keene said:
That's external... It wouldn't find it's way into the sump.
They aren't sprocket teeth, they are gear teeth. I'd be looking at distributor drives, oil pump drives, camshaft it not chain driven, as a starter for 10.
Oh yes they are sprocket teeth! They are the upper part of the teeth from the duplex timing sprocket.They aren't sprocket teeth, they are gear teeth. I'd be looking at distributor drives, oil pump drives, camshaft it not chain driven, as a starter for 10.
Regards Dave
Visit to Charles Dunn's today, and here's what we found:
Four teeth? Four gaps on the cam sprocket:
A bit of piston and ring missing?
and what sort of damage would those bits of piston do??:
And just for good measure, throw in a broken main cap:
Your guesses as to the cause on a postcard please.........
Four teeth? Four gaps on the cam sprocket:
A bit of piston and ring missing?
and what sort of damage would those bits of piston do??:
And just for good measure, throw in a broken main cap:
Your guesses as to the cause on a postcard please.........
Edited by LuckyP on Saturday 26th January 12:19
Detonation caused the broken ringland but the piston/head could also be from a foreign body rattling around which may have traveled across the intake manifold and damaged other cylinders? Got any broken valve guides? The first pic you posted was a piece of ringland if it's aluminium. Your ccam chain may have jumped thus altering timing events.
CanAm Dave said:
That's some serious detonation damage Pete! Looks like the tooth fairy has been chewing on your pistons. I hope you get it all sorted for the new season ahead.
Regards Dave
Detonation was the reason given by Charles. I did run out of fuel in one tank at Snetterton last year, 120mph under full load. Could that have done it?Regards Dave
What causes the edge of the piston to break up like that though?
LuckyP said:
CanAm Dave said:
That's some serious detonation damage Pete! Looks like the tooth fairy has been chewing on your pistons. I hope you get it all sorted for the new season ahead.
Regards Dave
Detonation was the reason given by Charles. I did run out of fuel in one tank at Snetterton last year, 120mph under full load. Could that have done it?Regards Dave
What causes the edge of the piston to break up like that though?
What did surprise me is that the mixture look rich and I didn't see any signs of overheating. Do you know the compression ratio and that the timing was correct. Did the plugs look ok?
Edited by Boosted LS1 on Saturday 26th January 13:31
Boosted LS1 said:
...What did surprise me is that the mixture look rich and I didn't see any signs of overheating. Do you know the compression ratio and that the timing was correct. Did the plugs look ok?
Dunno about CR and timing, plugs looked OK some dry, some oily (and one without a tip!!)I'll see what I can find out fron Charles.
Pete
ringram said:
Very tasty looking pics. Though no signs of busted pistons on some of the other pistons, yet they show signs of damage!?
Yes, I thought some more about this earlier. I'd wager it's detonation caused by an ignition fault (not fuel) so would suspect the dizzy, dizzy drive gear or a camshaft woodruff key fault. Most of the damage is in the quench pad areas whilst very little is in the chambers. Also, heat has had a nibble around some of the inlet valve seats. Plus, top rings have been broken which is again caused by pressure/shock waves. If the car's been fine for a long time and then just did this out of the blue then it could be componant failure elsewhere which caused the detonation.Davrianman said:
Why is your name Lucky?
I do ask myself this sometimes 
But actually this sort of stuff is all rather interesting really. Quite reasuring that after building a car the only thing that fails big time, is something that I've not had a hand in. Perhaps I should have build the engine too??
Boosted LS1 said:
ringram said:
Very tasty looking pics. Though no signs of busted pistons on some of the other pistons, yet they show signs of damage!?
Yes, I thought some more about this earlier. I'd wager it's detonation caused by an ignition fault (not fuel) so would suspect the dizzy, dizzy drive gear or a camshaft woodruff key fault. Most of the damage is in the quench pad areas whilst very little is in the chambers. Also, heat has had a nibble around some of the inlet valve seats. Plus, top rings have been broken which is again caused by pressure/shock waves. If the car's been fine for a long time and then just did this out of the blue then it could be componant failure elsewhere which caused the detonation.Strange thing is that I've not noticed anything recently with it. Right up to taking it off the road, it idled OK and performed alright on track. Odd.
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