which flywheel inbalance?

dlb1982 · 10-15-2002, 10:05 AM

This may be a dumb question but with my 331 stroker im building i need to know which inbalance (0, 28.8, or 50oz.) to use for a flywheel so i can buy the right one to have when i get the rotaing assembly balanced.

I know for my year of car that it's a 50oz inbalance on the stock flywheel... Will that change with a different crank? Or will the people balancing it add the weight to the flywheel. Im not real familiar with externally balanced engines.

LX XLR8R · 10-15-2002, 10:48 AM

i am prety sure it is still a 50..but the 347 is a 28..***** my minds gone blank..dont quote me on that

WADS56 · 10-15-2002, 11:54 AM

You can get it ballenced to what ever you want. 0 would be the best for a race engine and 50 is fine for a street/strip motor. If you want to ballance it to 0 it will cost allot more because they will have to use allot of "heavy metal" on your crank. My 347 is a 50oz and it was a mistake I made when doing my engine. I spin it to 6800 causing increased ware on my mains from the 50oz counter ballence. I wish i did 0.
Wade

dlb1982 · 10-15-2002, 01:25 PM

Well ive been looking around and pretty much all the 331 rotating assemblies say to use a 28oz offset flywheel. So i guess i will go for 28, its going to cost me a lot more to go 0 ballance and get a ballancer for an internally ballanced ford engine.

Just a street car project anyway.

THanks for the help.

302 LX Eric · 10-15-2002, 01:37 PM

28oz is the way to go. You can balance it to 50oz, but will require a lot of drilling on the crank - makes it look like swiss cheese!

Stick with 28oz for your application. This comes directly from Tom Naegle at DSS.

I took my entire stroker package (rods, wrist pins, pistons, crank, alumimum flywheel, Fluidampr, etc) to Fowler's Engines here in Columbus for the balancing. They also said 28oz was best for my 331.

Hope this helps.
E

BTW - if you get an aftermarket fly, it should come with weights in 50, 28, and 0 increments for balancing purposes.

andy669 · 10-15-2002, 07:25 PM

I think the 50oz imbalance works great if you run a lightweight piston and rod combo. The further away from the crank centerline the weight is placed, the less overall weight you can run. Zero balancing often requires adding mallory to the crank, as Wade mentioned. This makes the whole rotating assembly heavier. In effect, if you were to take a 1 pound weight off of your flywheel, it may take 1 1/2 or 2 pounds on the crank to make up the difference.

IMO, having less weight is more important than where the weight is placed.

Andy

10-15-2002, 10:05 AM	#1
dlb1982 Registered Member Join Date: Sep 2002 Location: Macomb IL Posts: 42	which flywheel inbalance? This may be a dumb question but with my 331 stroker im building i need to know which inbalance (0, 28.8, or 50oz.) to use for a flywheel so i can buy the right one to have when i get the rotaing assembly balanced. I know for my year of car that it's a 50oz inbalance on the stock flywheel... Will that change with a different crank? Or will the people balancing it add the weight to the flywheel. Im not real familiar with externally balanced engines. __________________ 94 GT (Full length headers, Off Road H Pipe and Flowmasters) MSD Ignition, 75 shot nitrous, cold air induction. 65mm t.b. pulleys and 3:73 gears. everything else STOCK!! 60' = 2.04; 1/4 = 13.9 on street tires dynoed with 87 octane at 240hp 310 lb torch w/out nitrous. Its a pooch but im working on it.

10-15-2002, 10:48 AM	#2
LX XLR8R Dirk Diggler Join Date: Feb 1999 Location: SLOATSBURG, NY Posts: 1,931	i am prety sure it is still a 50..but the 347 is a 28..***** my minds gone blank..dont quote me on that __________________ 95 undecided cubes, AFR 185s,undecided cam, undecided intake, and a 150 hit 89 "turbonotch" 2.3T You might want to hold on..i saw this on a cartoon once

10-15-2002, 11:54 AM	#3
WADS56 gear banger Join Date: Aug 2000 Location: CHICAGO Posts: 1,144	You can get it ballenced to what ever you want. 0 would be the best for a race engine and 50 is fine for a street/strip motor. If you want to ballance it to 0 it will cost allot more because they will have to use allot of "heavy metal" on your crank. My 347 is a 50oz and it was a mistake I made when doing my engine. I spin it to 6800 causing increased ware on my mains from the 50oz counter ballence. I wish i did 0. Wade __________________ 79 Hatch: NA 347, Stage 2 Canfield Heads, Victor JR. Intake, Blueprinted Holley 750 HP, Solid Roller Cam, Shooting for 10's on motor 93 LX: Tremec, dual friction clutch, fms flywheel, Hedman shorties, O/R H-pipe Ricer hater's club member #49

10-15-2002, 01:25 PM	#4
dlb1982 Registered Member Join Date: Sep 2002 Location: Macomb IL Posts: 42	Well ive been looking around and pretty much all the 331 rotating assemblies say to use a 28oz offset flywheel. So i guess i will go for 28, its going to cost me a lot more to go 0 ballance and get a ballancer for an internally ballanced ford engine. Just a street car project anyway. THanks for the help. __________________ 94 GT (Full length headers, Off Road H Pipe and Flowmasters) MSD Ignition, 75 shot nitrous, cold air induction. 65mm t.b. pulleys and 3:73 gears. everything else STOCK!! 60' = 2.04; 1/4 = 13.9 on street tires dynoed with 87 octane at 240hp 310 lb torch w/out nitrous. Its a pooch but im working on it.

10-15-2002, 01:37 PM	#5
302 LX Eric or '331 LX Eric' Join Date: Jan 1999 Location: Columbus, Ohio Posts: 2,142	Go with 28oz. 28oz is the way to go. You can balance it to 50oz, but will require a lot of drilling on the crank - makes it look like swiss cheese! Stick with 28oz for your application. This comes directly from Tom Naegle at DSS. I took my entire stroker package (rods, wrist pins, pistons, crank, alumimum flywheel, Fluidampr, etc) to Fowler's Engines here in Columbus for the balancing. They also said 28oz was best for my 331. Hope this helps. E BTW - if you get an aftermarket fly, it should come with weights in 50, 28, and 0 increments for balancing purposes. __________________ 1991 5.0 LX Coupe - 40,750 miles 331 cu. in. / Tremec 3550 / BFG Drag Radials 12.22 @ 114.31 mph - w/1.89 60'

10-15-2002, 07:25 PM	#6
andy669 Registered Member Join Date: Jan 2001 Location: Moline Il Posts: 901	I think the 50oz imbalance works great if you run a lightweight piston and rod combo. The further away from the crank centerline the weight is placed, the less overall weight you can run. Zero balancing often requires adding mallory to the crank, as Wade mentioned. This makes the whole rotating assembly heavier. In effect, if you were to take a 1 pound weight off of your flywheel, it may take 1 1/2 or 2 pounds on the crank to make up the difference. IMO, having less weight is more important than where the weight is placed. Andy __________________ 88 coupe 91 LX NMRA Pure Street 5120

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