6 sp flywheel questions
6 sp flywheel questions Hey everybody, I'm in the process of getting the 383 shortblock I recently bought swapped in my car, just have a couple questions. The motor was built for an auto car...mines 6sp, so the flexplate is balanced for an automatic transmission flywheel. So I need to get my flywheel balanced to match it by a machine shop. Should I just re-use the stock style one I have (get it resurfaced) or upgrade to a chromoly or aluminum lightweight flywheel? Any ideas on how much it costs to balance a flywheel? Anybody have experience with swapping to a much lighter flywheel? 
FYI...car will have 420 RWHP with RAM HD clutch mostly street driven.
FYI...car will have 420 RWHP with RAM HD clutch mostly street driven. Here is a link with a detailed description of the motor I bought:
https://ls1tech.com/forums/parts-cla...lock-sale.html
Seller mentions: "You need the balancer and flexplate, it's balanced with the rotating assembly."....that means externally balanced correct?
https://ls1tech.com/forums/parts-cla...lock-sale.html
Seller mentions: "You need the balancer and flexplate, it's balanced with the rotating assembly."....that means externally balanced correct?
TECH Veteran
Joined: Apr 2008
Posts: 4,985
Likes: 112
most 383 motors are "internally" balanced meaning you use a "neutral" balanced flexplate or flywheel. Stock motors are "externally" balanced meaning the flexplate or flywheel has a weight on it.
look at the flexplate and see if it has a weight on it. I assume the TCI one you have has a part # on it. Call TCI for the 411 on it.
I spend $40-$50 to have a stock FW neutral balanced and resurfaced for my 383. They grind off the cast on weight and then add pins in the outer holes of the FW to final balance it to "zero" aka "neutral".
If for some reason your motor was balanced using a weighted flexplate you would need to take that flexplate and FW to a machine shop and have them match balance your FW to it.
LT1 stock motor is neutral balance on front damper and external balanced on flexplate/FW
look at the flexplate and see if it has a weight on it. I assume the TCI one you have has a part # on it. Call TCI for the 411 on it.
I spend $40-$50 to have a stock FW neutral balanced and resurfaced for my 383. They grind off the cast on weight and then add pins in the outer holes of the FW to final balance it to "zero" aka "neutral".
If for some reason your motor was balanced using a weighted flexplate you would need to take that flexplate and FW to a machine shop and have them match balance your FW to it.
LT1 stock motor is neutral balance on front damper and external balanced on flexplate/FW
You need clarification from the seller as to whether or not the "balancer" is actually used as a balancer for the rotating assy. It does indeed read like it is used, however many get a damper and balancer confused.
The machine shop I use to balance (neutrally) and resurface a flywheel is ~$90.00
The machine shop I use to balance (neutrally) and resurface a flywheel is ~$90.00
The rotating assembly was balanced as one unit. The shop that balanced it needed to add mallory at the front counterweight of the crank, and offset it at the balancer (it was drilled to remove weight). The flexplate had to be weighted because where the shop needed to add weight at the rear of the crank, it would have been too far forward at the rear counterweight, so it was added to the flexplate. The original flexplate setup iirc (I don't have the invoice for it in front of me) is an internally balanced (399174) unit (the part number should be on the flexplate next to or on the SFI certification sticker). It's $75 for me to have a flywheel or flexplate matched for the balance. Just bring the shop the one that's on the motor right now and the new flywheel.
Last edited by 93Z2871805; Aug 30, 2011 at 05:43 PM.
Trending Topics
The original intent was to keep all the weight towards the center, but due to where the shop needed to add/remove weight they needed to add/remove from the balancer/flexplate. The front and rear counterweights would've been too far out, so it had to get put on the balancer/flexplate.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Well if your 383 is fully internally balanced I have an internally balanced SLP LW billet steel flywheel for $330 shipped, here are some pics, lmk if you're interested. Email me at z24.turbo@gmail.com or pm me here for fastest response.
http://s1110.photobucket.com/albums/h460/z24turbo1/
http://i1110.photobucket.com/albums/...T1parts002.jpg
http://i1110.photobucket.com/albums/...T1parts003.jpg
http://i1110.photobucket.com/albums/...T1parts001.jpg
http://s1110.photobucket.com/albums/h460/z24turbo1/
http://i1110.photobucket.com/albums/...T1parts002.jpg
http://i1110.photobucket.com/albums/...T1parts003.jpg
http://i1110.photobucket.com/albums/...T1parts001.jpg
OK, now I'm really confused....so I've been calling around machine shops around Charlotte trying to find ANYBODY to balance my damn flywheel to match the balance on the flexplate I have that came with the motor. Nobody has the equipment for balancing except for this one shop "Carolinas auto machine"....I've called them explaining how the motor was balanced and that I just need to flywheel to match the balance of the flexplate; but they INSIST the whole rotating assembly must be re-balanced at a cost of over $200...WTF?! Somebody that knows about engine balancing please clarify if they know what they are talking about or are just blowing smoke up my ***...I have no idea. I've called them explaining how the motor was balanced and that I just need to flywheel to match the balance of the flexplate; but they INSIST the whole rotating assembly must be re-balanced at a cost of over $200...WTF?! Somebody that knows about engine balancing please clarify if they know what they are talking about or are just blowing smoke up my ***...I have no idea.
holy bunch of confusing............look take the flexplate that came off the 383 and your new/or used flywheel to a machine shop.......tell them to make the flywheel balance the same as the flexplate and your done...........if the engine builder had any kind of sense upon the build the balancer and the flexplate/flywheel should be at 0 balance........
....therein lies the problem ....they added weight to the flexplate...
SS RRR gave me a machine shop to contact to see if they can match balance..I'll see what they say....I also PM'ed Kenny who sold me the short-block to see if his local machine shop can do it for me....(he mentioned they do it for $75) it seems the only local shop around here will not do it because of the liability of ******* up the match balance and giving me an unbalanced motor because of it.
The shop SS RRR gave me will match balance (thanks) It's $125 + shipping to and from MD. You would think with all the Nascar teams here and racing hub that Charlotte is there would be one decent machine shop.....apparently not
Maybe Kenny's shop on the other side of the state can do it for less. Sucks I got to ship to them though.
It's $125 + shipping to and from MD. You would think with all the Nascar teams here and racing hub that Charlotte is there would be one decent machine shop.....apparently not Maybe Kenny's shop on the other side of the state can do it for less. Sucks I got to ship to them though. Good lord...after spending half the afternoon talking to to every damn machine shop in the tri-county area (and even a shop in MD) I finally talked to some dude who recommended some other dude who owns his own machine shop in Gastonia (Nicols' Engineering 30 mins away)...said he can do it for $50 Thanks for your help everyone.
Thanks for your help everyone. The shop SS RRR gave me will match balance (thanks) It's $125 + shipping to and from MD. You would think with all the Nascar teams here and racing hub that Charlotte is there would be one decent machine shop.....apparently not Maybe Kenny's shop on the other side of the state can do it for less. Sucks I got to ship to them though.
It's $125 + shipping to and from MD. You would think with all the Nascar teams here and racing hub that Charlotte is there would be one decent machine shop.....apparently not Maybe Kenny's shop on the other side of the state can do it for less. Sucks I got to ship to them though.Make sure to keep that flexplate as your "master."
Not unless the builder would have changed it to completely internally balanced.
Here is where people get confused, a STOCK LT1
Internally balanced in the front.
Externally balanced in the back.
True story
Last edited by gregrob; Sep 19, 2011 at 09:47 PM.
they have hub balancers on the front? that means its balanced on the front then, right??
