Crank hangs up after trans overhaul
#3228090
04/19/24 01:33 PM
04/19/24 01:33 PM
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Joined: Mar 2006
Posts: 9,835 MI, usa
dvw
OP
master
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OP
master
Joined: Mar 2006
Posts: 9,835
MI, usa
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First off let me state God was watching over me. Pulled the trans in my racecar for freshening. Started reinstalling the trans. Rotating the crank to install the 3rd converter bolt, crank stops, dead. Won't move either way more than 2-3 degrees. Don't want to force it backward with the Jessel belt. Pull the dist and oil drive, pump spins, losen the alternator (brand new) and vacuum pump belts, nope. Pull all the rockers and pushrods. All look great. Lifters can be pulled up with a piece of tig rod. Now the crank will rotate counter clockwise about 300 degrees and then, stops dead. Pull the trans back out to make sure something didn't hang up in the flexplate. I mean it was fine when the crank was rotated to pull the trans, right? Found nothing. Tried a bore camera saw nothing. Rreinstall the trans and pull the pan. Everything looks good. Pistons # 4 &# 7 won't clear TDC about 30 degrees either side. Take a guess at #4 1st. Pull the header. Pull the exh valve spring and replace with a checking spring. Try the camera and see nothing. I'm lost. Decide to pull the passenger head. Pull the intake. One last gasp. Pull the intake valve spring and swap with checking spring. Push the valve open. What do I see. A undamaged 5/16" nylock nut setting on the piston below the exhaust valve. Where did that come from? Only thing I can think of is when the accumulator was relocated during the alternator upgrade. It's the only item thats been removed that uses that nut. Engine had been started several times to check the alternator. Then moved into the hoist bay. Then started again after the oil change. I really hadn't cracked the throttle far until then. No marks on th episton. Cylinder leaks 5% cold. Not all a total loss of time. The screen windage tray was cracked again. So thats not going back. I'll fab a baffle above the pick up. The intake gaskets are climbing the head, again. So I'll replace them as well. First race is in 2 weeks. Doug
Last edited by dvw; 04/19/24 01:36 PM.
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Re: Crank hangs up after trans overhaul
[Re: dvw]
#3228094
04/19/24 01:38 PM
04/19/24 01:38 PM
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Joined: Mar 2005
Posts: 1,550 Michigan
Kiddart
pro stock
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pro stock
Joined: Mar 2005
Posts: 1,550
Michigan
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Geeez!!! Good luck and glad you found the problem!!
Thank you Kiddart
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Re: Crank hangs up after trans overhaul
[Re: fast68plymouth]
#3228108
04/19/24 03:15 PM
04/19/24 03:15 PM
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Joined: Jan 2003
Posts: 9,996 Frostbitefalls MN (Rocky&Bullw...
gregsdart
master
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master
Joined: Jan 2003
Posts: 9,996
Frostbitefalls MN (Rocky&Bullw...
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Great catch Doug! On the gaskets, i had the same problem , but mechanical fuel injection allowed me to use silacone sealer, no gasket. Any minor air leak i could compensate for by adjusting the injection system . There must be a better way to seal that intake when running carbs. My guess is it will require some form of metal gasket with a sealant imprinted on it, or a MLS type gasket, pinbed to the head or intake?
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Crank hangs up after trans overhaul
[Re: slantzilla]
#3228211
04/20/24 06:51 AM
04/20/24 06:51 AM
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Joined: Jul 2018
Posts: 169 Sticky South
Rodenteliminator
member
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member
Joined: Jul 2018
Posts: 169
Sticky South
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Good find, starting it multiple times and moving it around and not doing any damage you would almost have to believe it worked its way in there on the last start. Doug
Sorry honey I spent the rent
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Re: Crank hangs up after trans overhaul
[Re: Rodenteliminator]
#3228232
04/20/24 10:08 AM
04/20/24 10:08 AM
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Joined: Jan 2003
Posts: 8,165 Plymouth, MI
Blusmbl
master
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master
Joined: Jan 2003
Posts: 8,165
Plymouth, MI
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That's a fantastic find and it's great you caught it before it hurt the cylinder head, a valve or a piston!
'18 Ford Raptor, random motorcycles, 1968 Plymouth Fury III - 11.37 @ 118
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Re: Crank hangs up after trans overhaul
[Re: B1MAXX]
#3228461
04/21/24 07:15 PM
04/21/24 07:15 PM
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Joined: Jan 2003
Posts: 9,996 Frostbitefalls MN (Rocky&Bullw...
gregsdart
master
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master
Joined: Jan 2003
Posts: 9,996
Frostbitefalls MN (Rocky&Bullw...
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About 48 years ago a friend and i stopped to say hi to a guy working on his 1970 Chevelle 454 drag car. He was missing a carb stud nut, thought it rolled under the car . He fired the motor, heard BANG! BANG! BANG, TINKLE, as the missing nut came out rhe collecter! Pulled the head, three dings, no other damage. The big rollercam he had in it allowed that nut to enter and exit without damage to the valves or seats!
Last edited by gregsdart; 04/21/24 07:16 PM.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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