454 flywheel balance question
03-12-2016, 07:31 AM
#1
Cruising
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454 flywheel balance question
I have a 454 that we rebuilt to use in a '67 corvette restoration project. During the engine rebuild, we used the original crank, pistons, rods and front damper, but i needed a new flywheel because the old one was from a truck and was gigantic.
Where i screwed up was by buying a 427 flywheel that i ordered from Paragon Corvette. I was not aware that the 427 is internally balanced.
The engine is installed and during initial startup, we noticed the vibration.
Now, i have to pull the trans, clutch, etc and install a new 454 externally balanced flywheel that i just purchased from Summit. My question: do I bolt it right up while the engine is in the car or does it have to be matched to the engine somehow?
Thanks
Where i screwed up was by buying a 427 flywheel that i ordered from Paragon Corvette. I was not aware that the 427 is internally balanced.
The engine is installed and during initial startup, we noticed the vibration.
Now, i have to pull the trans, clutch, etc and install a new 454 externally balanced flywheel that i just purchased from Summit. My question: do I bolt it right up while the engine is in the car or does it have to be matched to the engine somehow?
Thanks
03-12-2016, 08:29 AM
#2
Le Mans Master
I have a 454 that we rebuilt to use in a '67 corvette restoration project. During the engine rebuild, we used the original crank, pistons, rods and front damper, but i needed a new flywheel because the old one was from a truck and was gigantic.
Where i screwed up was by buying a 427 flywheel that i ordered from Paragon Corvette. I was not aware that the 427 is internally balanced.
The engine is installed and during initial startup, we noticed the vibration.
Now, i have to pull the trans, clutch, etc and install a new 454 externally balanced flywheel that i just purchased from Summit. My question: do I bolt it right up while the engine is in the car or does it have to be matched to the engine somehow?
Thanks
Where i screwed up was by buying a 427 flywheel that i ordered from Paragon Corvette. I was not aware that the 427 is internally balanced.
The engine is installed and during initial startup, we noticed the vibration.
Now, i have to pull the trans, clutch, etc and install a new 454 externally balanced flywheel that i just purchased from Summit. My question: do I bolt it right up while the engine is in the car or does it have to be matched to the engine somehow?
Thanks
Good luck... GUSTO
03-12-2016, 09:26 AM
#3
Team Owner
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I have a 454 that we rebuilt to use in a '67 corvette restoration project. During the engine rebuild, we used the original crank, pistons, rods and front damper, but i needed a new flywheel because the old one was from a truck and was gigantic.
Where i screwed up was by buying a 427 flywheel that i ordered from Paragon Corvette. I was not aware that the 427 is internally balanced.
The engine is installed and during initial startup, we noticed the vibration.
Now, i have to pull the trans, clutch, etc and install a new 454 externally balanced flywheel that i just purchased from Summit. My question: do I bolt it right up while the engine is in the car or does it have to be matched to the engine somehow?
Thanks
Where i screwed up was by buying a 427 flywheel that i ordered from Paragon Corvette. I was not aware that the 427 is internally balanced.
The engine is installed and during initial startup, we noticed the vibration.
Now, i have to pull the trans, clutch, etc and install a new 454 externally balanced flywheel that i just purchased from Summit. My question: do I bolt it right up while the engine is in the car or does it have to be matched to the engine somehow?
Thanks
http://www.vettemod.com/forum/showthread.php?t=8031
03-12-2016, 03:03 PM
#4
Race Director
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2023 C1 of the Year Finalist - Modified
2015 C1 of the Year Finalist
Beginning in 1963, there were two different size flywheels used for the Chevy V8 engines: 12 3/4in-153 teeth and 14in-168 teeth. PERIOD!
Up through 1985, ALLLLLLLLLLLLLLLLLLLL Chevy V8 flywheels have EXACTLY the same bolt pattern for the crankshaft. Thus, PHYSICALLY, they are all 100% interchangeable.
As already mentioned, ONLY, ONLY, ONLY the SB400 and 454BB engines were externally balanced by using a unique harmonic balancer and flywheel.
WHEN AN ENGINE IS BUILT FROM SCRATCH (or rebuilt using new parts such as pistons, rings, bearings, etc), THE ENGINE'S BALANCE WILL BE CHANGED!!!!!!!!!!!!! EXCEPT FOR THE SB400 AND 454 FLYWHEELS, ALLLLLLLLLLLLLLLL harmonic balancers and flywheels are NEUTRAL balanced (theoretically). Thus (again, theoretically) you should be able to swap a 1955 flywheel onto a 1969 427 and all would be good. NOT SO ON A SB400 OR 454!!!!! The reason is because the SB400 and 454 are externally balanced and EVEN THOUGH ALL EXTERNAL BALANCE 454 FLYWHEELS ARE SUPPOSED TO HAVE THE SAME AMOUNT OF ADDED WEIGHT ON ONE SIDE, THEY DO NOT ALWAYS MATCH!!!!! Depending on how your 454 was rebuilt (and balanced by the machine shop), simply installing an UNbalanced 454 flywheel may or may not eliminate any vibration. If you do the flywheel swap (or install one of the balance plates behind the flywheel), and the vibration is gone, GREAT! Otherwise, if there is still a vibration, then MAYBE the only option is to disassemble the engine and have the machinist balance the rotating assembly with the balancer and flywheel that is to be used.
Now, with that said, if a 454 flywheel cannot be located, a neutral balance flywheel can be used simply by UNbalancing it. That would be done by drilling or milling metal from one side of the flywheel until sufficient metal has been removed to end up with a correctly balanced engine assembly.
Below is a flywheel which has had metal removed for use with a SB400 engine.
ALLLLLLLLLLLLLLLLL Chevy flywheels and crankshafts have 7 holes. Six of those holes are for the attaching bolts and the 7th hole is for an indexing pin. THE INDEXING PIN IS NOT NEEDED for internal balance engines. BUUUUUUUUUUUUUUT, on SB400 and 454 engines, the indexing pin is mandatory because when those engines are balanced, the flywheel MUST be installed at only one position.
Here is a comparison of 168 teeth neutral balance and EXternal balance flywheels.
Up through 1985, ALLLLLLLLLLLLLLLLLLLL Chevy V8 flywheels have EXACTLY the same bolt pattern for the crankshaft. Thus, PHYSICALLY, they are all 100% interchangeable.
As already mentioned, ONLY, ONLY, ONLY the SB400 and 454BB engines were externally balanced by using a unique harmonic balancer and flywheel.
WHEN AN ENGINE IS BUILT FROM SCRATCH (or rebuilt using new parts such as pistons, rings, bearings, etc), THE ENGINE'S BALANCE WILL BE CHANGED!!!!!!!!!!!!! EXCEPT FOR THE SB400 AND 454 FLYWHEELS, ALLLLLLLLLLLLLLLL harmonic balancers and flywheels are NEUTRAL balanced (theoretically). Thus (again, theoretically) you should be able to swap a 1955 flywheel onto a 1969 427 and all would be good. NOT SO ON A SB400 OR 454!!!!! The reason is because the SB400 and 454 are externally balanced and EVEN THOUGH ALL EXTERNAL BALANCE 454 FLYWHEELS ARE SUPPOSED TO HAVE THE SAME AMOUNT OF ADDED WEIGHT ON ONE SIDE, THEY DO NOT ALWAYS MATCH!!!!! Depending on how your 454 was rebuilt (and balanced by the machine shop), simply installing an UNbalanced 454 flywheel may or may not eliminate any vibration. If you do the flywheel swap (or install one of the balance plates behind the flywheel), and the vibration is gone, GREAT! Otherwise, if there is still a vibration, then MAYBE the only option is to disassemble the engine and have the machinist balance the rotating assembly with the balancer and flywheel that is to be used.
Now, with that said, if a 454 flywheel cannot be located, a neutral balance flywheel can be used simply by UNbalancing it. That would be done by drilling or milling metal from one side of the flywheel until sufficient metal has been removed to end up with a correctly balanced engine assembly.
Below is a flywheel which has had metal removed for use with a SB400 engine.
ALLLLLLLLLLLLLLLLL Chevy flywheels and crankshafts have 7 holes. Six of those holes are for the attaching bolts and the 7th hole is for an indexing pin. THE INDEXING PIN IS NOT NEEDED for internal balance engines. BUUUUUUUUUUUUUUT, on SB400 and 454 engines, the indexing pin is mandatory because when those engines are balanced, the flywheel MUST be installed at only one position.
Here is a comparison of 168 teeth neutral balance and EXternal balance flywheels.
03-14-2016, 06:55 AM
#5
Cruising
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thanks for the responses. I just got the new billet steel flywheel with the holes drilled on one side for the external balance. I'll make sure it is aligned properly during install and hope for the best.
I had a guy question the compression ratio on the engine as i have assembled it. I have Pro Comp oval port heads with 118 CC chambers. Flat top pistons that are flush with the deck at top of stroke, .040 head gasket. My compression ratio calculations are:
4.25 bore, 4.0 stroke, .040 head gasket, 118CC (46.4567 Cubic inch) chambers
flat top pistons, flush to deck at top of stroke
comp ratio = V1 + V2 / V2
V1 = cyl vol + gasket thickness + chamber volume
453.9612 (bore x stroke) + 4.1224 (gasket) + 46.4567 (chamber volume) = 504.5403 total cubic inches at bottom
V2 = gasket thickness + chamber volume + deck height (zero in my case)
4.1224 (gasket) + 46.4567 (chamber volume) = 50.5791 compressed volume
504.5403 / 50.5791 = 9.975 compression ratio
am I correct, or did I miss something?
thanks,
I had a guy question the compression ratio on the engine as i have assembled it. I have Pro Comp oval port heads with 118 CC chambers. Flat top pistons that are flush with the deck at top of stroke, .040 head gasket. My compression ratio calculations are:
4.25 bore, 4.0 stroke, .040 head gasket, 118CC (46.4567 Cubic inch) chambers
flat top pistons, flush to deck at top of stroke
comp ratio = V1 + V2 / V2
V1 = cyl vol + gasket thickness + chamber volume
453.9612 (bore x stroke) + 4.1224 (gasket) + 46.4567 (chamber volume) = 504.5403 total cubic inches at bottom
V2 = gasket thickness + chamber volume + deck height (zero in my case)
4.1224 (gasket) + 46.4567 (chamber volume) = 50.5791 compressed volume
504.5403 / 50.5791 = 9.975 compression ratio
am I correct, or did I miss something?
thanks,
03-14-2016, 08:14 AM
#6
Race Director
I get 57.606 cubic inches for chamber volume using .0610237 cu in to 1 cc
118 cc = 7.2008 cu in
8 cyl = 57.606 cc
That would drop the calculated compression considerably so you might double check it. Also is the piston truly flush with the deck or just visually so? A few thousands one way or the other can make some difference.
Hope the above is right - I haven't had my morning coffee.
118 cc = 7.2008 cu in
8 cyl = 57.606 cc
That would drop the calculated compression considerably so you might double check it. Also is the piston truly flush with the deck or just visually so? A few thousands one way or the other can make some difference.
Hope the above is right - I haven't had my morning coffee.
03-14-2016, 09:03 AM
#8
Race Director
That's what I came up with also.
03-14-2016, 10:09 AM
#9
I have a 454 that we rebuilt to use in a '67 corvette restoration project. During the engine rebuild, we used the original crank, pistons, rods and front damper, but i needed a new flywheel because the old one was from a truck and was gigantic.
Where i screwed up was by buying a 427 flywheel that i ordered from Paragon Corvette. I was not aware that the 427 is internally balanced.
The engine is installed and during initial startup, we noticed the vibration.
Now, i have to pull the trans, clutch, etc and install a new 454 externally balanced flywheel that i just purchased from Summit. My question: do I bolt it right up while the engine is in the car or does it have to be matched to the engine somehow?
Thanks
Where i screwed up was by buying a 427 flywheel that i ordered from Paragon Corvette. I was not aware that the 427 is internally balanced.
The engine is installed and during initial startup, we noticed the vibration.
Now, i have to pull the trans, clutch, etc and install a new 454 externally balanced flywheel that i just purchased from Summit. My question: do I bolt it right up while the engine is in the car or does it have to be matched to the engine somehow?
Thanks
Take the McLeod 460130 30# flywheel remove the bellhousing inspection cover, bolt on the proper weight and presto, you now have an externally balanced flywheel for a 454.
03-14-2016, 11:54 AM
#10
Cruising
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Nope, i got the Summit billet steel flywheel for the 454. It has holes drilled in one area for the proper balance for the engine. Going to install it today and hope all is smooth going after.