Fastguy

When I swapped in my 454 I bought a new flywheel. My short block is from a 74 Suburban. It has an Edelbrock cam and Torker II with Hooker SuperComps and Comp Engineering poly lock motor mounts. The engine seems to be unbalanced and vibrates. I'm not sure if its the stiff mounts and lumpy cam or if I have an unblanced assembly. Any ideas?

zwede

There are internally and externally balanced flywheels. The internally balanced ones were used on 396 and 427's. External on 454 and 502's.

The balancer also needs to be correct. There are internal and external balanced ones, same applications as for the flywheels.

GDaina

That depends....there are internal and external blanced cranks, ranging from 3.76"-4.50" strokes. You have to match the flywheel & harmonic balancer to the crank....internal to internal, external to external....

the 454 crank has a 4.00" stroke, and more than likely is an externaly balanced, but then again, if the builder put an internaly balanced crank..... You can verify that by looking at the harmonic balancer....

norvalwilhelm

. My short block is from a 74 Suburban

You need a flywheel from a 454. If you have a flywheel it will have alot of holes on one side to make it lite in this area. If you are talking about a flex plate and automatic transmission it will have a weight on one side.
There is little chance that it has an internal balanced crank. That requires expensive slugs that most will not bother with.
Make sure your flywheel if for a 454 and do not use one for a 427/396.

GDaina

not quite true. Norval, you can buy an internally balanced crank in 4.00-4.50 inch strokes. Been on the market for the past 3-4 years. Eagle brand, think Scat brand, sold by Summit, Jegs, etc.

Depends if that motor is bone stock, then yes, dude has to match external components, but suppose builder used an internal balanced crank like I did when I bought the 502 bare block, now, all bets are off the table, and what one may think is an externally balanced motor, in fact, is internally balanced.

Suppose I sell the 533 cube motor, without the wheel and harmonic balancer, and forget to tell the buyer the crank is internally balanced.....the assumption on the buyer will be an externally balanced motor.......

Fevre

You would think a nice big 'I' or 'E' would be cast into the damn things to make it a little easier to distingish, drop the pan and look at the front or rear for it. I know you can actually do what Norval said and use heavy metal to turn it from ext to int but it could be remarked.

GDaina

Yep, that was the case decades ago, but why bother when now, one can buy a crank that's internally balanced.

Fastguy

I remember the guy I bought it from specifically stating it was a 454 flywheel,not a 396 or 427. Its just odd I have such a harsh idle. I'm guessing it may be the solid mtoor mounts.