383 crank balance question
Thread Starter
Instructor
Joined: Nov 2004
Posts: 110
Likes: 2
From: Portland Oregon
383 crank balance question
I recently picked up a used 383 SBC which I was told had a weight welded onto the crank which would allow me to re-use the flywheel off of my 327. Please see the attached pictures of the weight welded on the rear end of the crank.
Knowing that my 327 is internally balanced and uses neutral balanced flywheel, and the 383 is an externally balanced engine which normally uses a weighted flywheel I'm hoping for some re-assurance on this before swapping motors.
The research I've done hasn't mentioned this as a method for balancing an externally balanced engine.
I'm hoping someone recognizes this method of balancing an externally balanced crank so that it can use a neutrally balanced flywheel from a 327 or 350 SBC instead of what is typically used (a weighted flywheel for a 400 crank).
Let me know if this looks familiar.
Knowing that my 327 is internally balanced and uses neutral balanced flywheel, and the 383 is an externally balanced engine which normally uses a weighted flywheel I'm hoping for some re-assurance on this before swapping motors.
The research I've done hasn't mentioned this as a method for balancing an externally balanced engine.
I'm hoping someone recognizes this method of balancing an externally balanced crank so that it can use a neutrally balanced flywheel from a 327 or 350 SBC instead of what is typically used (a weighted flywheel for a 400 crank).
Let me know if this looks familiar.
Thread Starter
Instructor
Joined: Nov 2004
Posts: 110
Likes: 2
From: Portland Oregon
Yeah I hear ya, but I'm not seeing any evidence of the internally installed weights (which I believe are usually drilled and recessed into the crank counterweights) so I'm thinking its externally balanced.
It does have the 400 style dampener on the front.
It does have the 400 style dampener on the front.
Drifting
Joined: Jun 2010
Posts: 1,781
Likes: 15
From: Oxford Ohio
It looks like a fair amount of weight. It is added to the external portion of the crank. It's in the same location as a weight plate that lets you use an internal balance flywheel or flex plate on an external balanced engine.
Never seen that way of balancing.
Looks like someone put some effort into it though.
Never seen that way of balancing.
Looks like someone put some effort into it though.
Thread Starter
Instructor
Joined: Nov 2004
Posts: 110
Likes: 2
From: Portland Oregon
Yes, with the weight it looks like it is what I was told it should be (ready to use a neutrally balanced flywheel) but I'm hoping that I can get some feedback to assure me that this method of balancing a 383 will do that.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
only a balance shop can confirm that crank is IB, If you ask me........... It is a bubba cast 400 crank that somebody ground the journals to 350 main size and welded some weight to for what ever reason
Thread Starter
Instructor
Joined: Nov 2004
Posts: 110
Likes: 2
From: Portland Oregon
I was hoping somebody would recognize this as an acceptable method of balancing a 383 but I'm starting to think it might be best to take the engine to a balancing shop to have it confirmed.
Drifting
Joined: Jun 2010
Posts: 1,781
Likes: 15
From: Oxford Ohio
[QUOTE=gkull;1581198370]only a balance shop can confirm that crank is IB, If you ask me........... cast 400 crank that somebody ground the journals to 350 main size and welded some weight to
It's like the weight plate, and the guy had some welding skills, however I would be skeptical of higher rpms.
To answer your question, I've never seen it done that way before. Would it be my idea of the way to do it? No, not really. Will it work? It may, probably be hard to find someone to guarantee it.
It's like the weight plate, and the guy had some welding skills, however I would be skeptical of higher rpms.
To answer your question, I've never seen it done that way before. Would it be my idea of the way to do it? No, not really. Will it work? It may, probably be hard to find someone to guarantee it.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Normally balancing of cast crank shafts is accomplished by adding heavy mallory metal to the crank throws. Bubba in this case cut up another crank shaft and welded the throw to the end of this stroker crank. Is it truly balanced................. Or did it also require a damper of equal weight as a matched set.
Would I use it ................ NO! When new internally balanced cranks are so cheap.
Would I use it ................ NO! When new internally balanced cranks are so cheap.
Drifting
Joined: Jun 2010
Posts: 1,781
Likes: 15
From: Oxford Ohio
Would I use it ................ NO! When new internally balanced cranks are so cheap.[/QUOTE]
I personally wouldn't even try it. Like Was said you can get then for not that much without the odd engineering.
I personally wouldn't even try it. Like Was said you can get then for not that much without the odd engineering.