454 popping through carb help
09-20-2017, 10:22 PM
#12
Registered
iTrader: (3)
had a 454 boat motor doing the exact same thing,it had blown the head gasket between 4 and 6 and the more gas you gave it the worse it got.i discovered upon teardown that #6 had broken rings and a lot of oil was entering the cylinder causing it to detonate,ended up doing a complete rebuild including boring&new pistons.runs like a champ now.
09-20-2017, 10:39 PM
#14
Charter Member # 55
Charter Member
My first guess was intake valve is stuck open or exhaust valve is stuck closed. I don't hear any valve train ticking noise though so Mike could have it right.
I'd do a compression test.
I'd do a compression test.
09-21-2017, 06:00 AM
#16
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09-21-2017, 08:06 AM
#18
Platinum Member
Platinum Member
iTrader: (6)
sounds like a valve not going up and down, or a muffler bearing going south....
09-21-2017, 03:39 PM
#20
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Thread Starter
iTrader: (7)
Tks for the help everyone. Mike I hope your not right for my friends sake but get what your saying. I'm gonna start with valve covers tomorrow and hopefully we'll find a broken exhaust stud or rocker. if nothing visual we'll role engine over and check intake and exhaust valves for full lift. Hope it's not a wiped out exh lobe. Next will move onto comp test. Just pressed for time but wanna help out a friend.
Keep all posted in what we find.
Tks
jr
Keep all posted in what we find.
Tks
jr
