towner99

400's are externally balanced the dowel is there for keeping the counterwieght in proper position. just make sure you line up the hole properly and you should be fine. If your harmonic is counterweighted I'd make sure the flywheel is also counterweighted flywheels just don't loosen up.

Throttle Fever

iTrader: (9)

Yes but those engines are also "internally balanced". Like I said do it right or you will be revisiting the same issue. Or take some of the advise of the other posts, but you better use alot of loctite and good grade eight bolts.

cubicinches

From the factory, the dowel pin is only present on externally balanced engines for one reason... to correctly orient the weight. It serves no other purpose such as keeping the bolts tight, or keeping the flywheel in place.

olysan

I think that the flywheel was never properly torqued and there was definitely no loctite used. it was doomed from the start. I've got some good ARP bolts, and a tube of heavy loctite, and I'm going to use the pin to make sure it's correctly oriented and then leave the dowel out.

stevesxm

well... suit yourself. but those bolts you will be using were never designed to support a shear load of any significance. while the dowel will certainly insure that the orientation is correct , its primary job is to keep the repetetive shock and shear loads from the clutch or ( in this case, the coupler) from putting those loads into a threaded section of the fastener.

flywheels that don't have dowels use shouldered bolts where the shoulder is a tight fit in the flywheel and the crank is counterbored for it so that the shoulder is lower than the shear plane of the crank/fw interface.

but by all means leave it out and head down to napa for some fine grade cheese bolts and sling it back together with some locktite.

then we can all read about it again next year.

Throttle Fever

iTrader: (9)

Steve Agreed, but others think otherwise. What do I know, have only been doing this for the last 19 years. Have about a dozen or so running on tracks out here, with the dowel....

cubicinches

How did millions of 350 small blocks make it all these years without a dowel pin, and not shear the bolts off?

Edit: Oh.. I just saw it. It's the special bolts that a 350 uses, because it has no dowel.

Every V8 Chevrolet uses shouldered flywheel bolts... dowel pin or not. Same goes for flexplates.

Throttle Fever

iTrader: (9)

Dude read the posts over. INTERNAL (350) VIRSES EXTERNAL (400 454) SHOULDERED BOLTS, That kind of stuff nothing important..... wow. Get it back together and enjoy your summer.

cubicinches

What does it matter if it's internal or external, relative to shearing the bolts off? They all use the same bolts.

Throttle Fever

iTrader: (9)

Cubic give it a rest, its not helping with the guy's issue. Oh and to answer your they all use the same bolts comment. They do not! There are differant part #'s for 350 virses a 400. If I am wrong I guess ARP packages all the the same bolts in differant packaging with differant part #'s for the fun of it. Just because the size and thread pitch is the same they are not all the same. Oylsan Sorry for the pi$$ing match on your post. Hope you get it fixed and have a great summer. Pete