Georgia Fiero Club Forum

All Things Fiero => Tech Tips, Tech Questions => Topic started by: Mike_21 on September 18, 2019, 05:12:12 pm

Title: V8 conversion flywheel question
Post by: Mike_21 on September 18, 2019, 05:12:12 pm
My old chevy small block motor (Archie conversion with 5 speed) has a 2 piece rear main seal. The new motor has the 1998+ one piece rear main seal and I need a new 153 tooth flywheel to match the new crank.

Has anyone done this upgrade before and can you recommend a specific flywheel?

Title: Re: V8 conversion flywheel question
Post by: Fierofool on September 18, 2019, 05:21:32 pm
I think GTXVette is a Chevy man.  He may be able to provide some info.  I think you have his contact info? 
Title: Re: V8 conversion flywheel question
Post by: Mike_21 on September 18, 2019, 06:28:45 pm
We've been playing telephone tag this afternoon but haven't spoken yet. I'll keep trying.

Title: Re: V8 conversion flywheel question
Post by: Roger on September 18, 2019, 07:21:26 pm
If you can locate one, get a lightweight flywheel. The only steel is the ring and pressure area. All else is high-strength aluminum.

You WILL notice a difference! Wallet will be a tad lighter but it's well worth it! Got one in my Firebird and it made a HUGE difference in acceleration. I don't remember the weight difference but the reduced mass is incredible.
Title: Re: V8 conversion flywheel question
Post by: Fierofool on September 18, 2019, 07:33:58 pm
Back when, we used Schaefer Lightweight Aluminum Flywheels, especially on the smallblocks.  And yes, there is a remarkable difference.  Only problem I ever remember is that sometimes the starter ring would come off. 
Title: Re: V8 conversion flywheel question
Post by: Mike_21 on September 19, 2019, 08:01:39 am
I've used lightweight flywheels in a lot of motorcycles I've built. I do like a fast revving motor!
Title: Re: V8 conversion flywheel question
Post by: GTRS Fiero on September 19, 2019, 08:12:41 pm
Hmmm.  We should try a lighter flywheel on the 2.8.
Title: Re: V8 conversion flywheel question
Post by: TopNotch on September 20, 2019, 09:20:07 am
Hmmm.  We should try a lighter flywheel on the 2.8.
Wouldn't work on a pre-88 2.8 because of the need to balance the externally balanced crank shaft with the counter-weighted flywheel.
Title: Re: V8 conversion flywheel question
Post by: Raydar on September 20, 2019, 09:24:25 am
I could be mistaken, but I think the Archie kit might have used a "kit specific" flywheel. Unless Archie sourced it someplace else.
Also, I believe the later one-piece-seal 305 was externally balanced. Make sure whether or not yours is the same.
Title: Re: V8 conversion flywheel question
Post by: GTRS Fiero on September 20, 2019, 05:31:44 pm
Hmmm.  We should try a lighter flywheel on the 2.8.
Wouldn't work on a pre-88 2.8 because of the need to balance the externally balanced crank shaft with the counter-weighted flywheel.

Maybe on a 3.4.
Title: Re: V8 conversion flywheel question
Post by: Mike_21 on September 21, 2019, 07:24:33 pm
Raydar, You are correct. The single piece rear seal is externally balanced on the rear end and the flywheel is weighted. The harmonic balancer is neutral.

I spoke with Archie for about half and hour yesterday, His flywheels were custom machined for his kits. Luckily, he still had few in stock so I grabbed one!