454 with interanlly balanced flexplate ?
Thread Starter
Le Mans Master
Joined: Jul 2006
Posts: 8,117
Likes: 104
From: charlotte north carolina
454 with interanlly balanced flexplate ?
i've got a "5445" casting motor mated to a th400 with an after market crank pulley and balancer. the motor is a replacement engine in a 69. the trans is original to the car.
i finally separated the two and found an internally (un-weighted) flexplate. i'm thinking that whoever replaced the original 427 motor just got lazy and used the old flexplate.
my question is this-the 5445 casting should be a 454 and need an externally balanced damper and flywheel (the th400 is going in one car and the engine into a 4 speed car), but how can i be sure which flywheel it needs without opening the engine? it's got good compression and ran well before i pulled it. i'm just trying to save a little work.
i finally separated the two and found an internally (un-weighted) flexplate. i'm thinking that whoever replaced the original 427 motor just got lazy and used the old flexplate.
my question is this-the 5445 casting should be a 454 and need an externally balanced damper and flywheel (the th400 is going in one car and the engine into a 4 speed car), but how can i be sure which flywheel it needs without opening the engine? it's got good compression and ran well before i pulled it. i'm just trying to save a little work.
Melting Slicks
Joined: May 2002
Posts: 2,717
Likes: 121
From: Sulphur LA
St. Jude Donor '05-'06,'11,'13-'14,'16,'18,'19,'24, '25
that's a hard one, if your not sure of the life of the engine.
Is it possible that someone had some machine work performed on the engine and it could have been internally balanced?
If no one has had the engine internally balanced than it should have the weighted flex-plate.
I can't think of any way to tell without pulling the oil pan.
I've herd all 454 engines were externally balanced.
Neal
Is it possible that someone had some machine work performed on the engine and it could have been internally balanced?
If no one has had the engine internally balanced than it should have the weighted flex-plate.
I can't think of any way to tell without pulling the oil pan.
I've herd all 454 engines were externally balanced.
Neal
Drifting
Joined: Mar 2011
Posts: 1,347
Likes: 121
From: Kernersville NC
[QUOTE=L88Plus;1582151856]I'd think it would shake like a puppy dog passing a pine cone if it were that far out of balance.
Is the balancer external or internal balance?[/QUOTE
Check the balancer for a weight and check the part number of the flexplate and see what it is for.
Is the balancer external or internal balance?[/QUOTE
Check the balancer for a weight and check the part number of the flexplate and see what it is for.
Le Mans Master
Joined: Dec 2006
Posts: 5,557
Likes: 9
From: Oquirrh Mountains
St. Jude Donor '09
I'm betting you have a replacement block with your original 427 internals inside. But your problem is an easy one if you don't want to look. Just reuse/replace your flexplate with a like/kind unit. No point in making this complicated.
It, however, is easy enough to check by just dropping the oil pan and getting the casting number off the crank if your curious.
It, however, is easy enough to check by just dropping the oil pan and getting the casting number off the crank if your curious.
Thread Starter
Le Mans Master
Joined: Jul 2006
Posts: 8,117
Likes: 104
From: charlotte north carolina
ben, you were right. it's a 3904816 crankshaft stuck into a 454 block, and the counterweights are drilled.
my new question. with a shorter stroke, the original pistons would reduce the compression considerably. how can i determine what pistons are in the engine. i can't see any identifing marks on them.
my new question. with a shorter stroke, the original pistons would reduce the compression considerably. how can i determine what pistons are in the engine. i can't see any identifing marks on them.
Last edited by jnb5101; Oct 29, 2012 at 04:00 PM.
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