Thanks for the clear explanation. I have a 1985 GM 4.3L V6 (2 piece rear main seal) in my garage that I want to mate up to a manual trans. The flex plate that came with the 4.3 has no weight on it. Now I know I can source a flywheel from a 1985 or older small block with a manual trans and go with it.
Neutral balance balancer is a harmonic damper then and not a balancer at all. Calling it a balancer when it's a non counterweight damper I believe causes more confusion than anything.
So if I need to swap flywheel from 1 piece to 2 piece crank, my 10.5 clutch will still bolt up ok? And starter should fine as well? Just the mounting to crank changed?
Long story short, rebuilt 700r4 all new sonnax parts, replaced factory flexplate as two welds were cracked, have since put 3 flexplates and still have a vibration and have also replaced TQ convertor twice. Old flexplate "weight" best i can measure weighs 2.19lb, new flexplate weight weighs 2.32lb nearly a full 2oz or more over factory. Can this be causing my vibration? Vibration occurs during all RPM and in Park, Neutral and all others, ranges from 600-6000rpm, very bad at 1200 and 4000. How i measured was laying flexplate flat on a scale and a box that was simular hight and a 50/50 weight distribution on the scale and the box the best i could.
I know someone who ran a 427 flywheel on a 454 and was going through main bearings all the time until he found out what was causing the problem. (Flywheel)
I have a 1 piece seal 350/5.7 chevy that I am rebuilding. Would it benefit me to internally balance this motor, then balance it again with the flexplate and harmonic balance?
Technically, there are no internally balanced 350's from the factory. the 2 piece crank 350's had an external "wing" that was part of the crankshaft. The 1 piece crank 350's could not use the external "wing" because of the 1 piece seal design. Chevrolet had no choice but to add the required weight to the flywheel or flexplate.
@@MariusSalvetti The real issue is that the block was never meant to house that much stroke. It was originally designed for a 3" stroke 265 that had a round flywheel flange. Just going to slightly larger pistons in the 283 required notching the flywheel flange for balance.
All 400's used a 2 piece rear main seal and factory external balancing. There are conversions to fit small block 2 piece seal cranks into 1 piece seal blocks, originally developed to fit cut down 400 cranks into newer blocks when building a 383, but none the other way around. If you've got a 2 piece seal block, you need a 2 piece seal crank.
Hi. Good information. I have a question. I bought a 350 vortec one piece. The motor was on truck with std transmission,. Can i use flex plate for automatic transmission??? Thanks.
I have a 1973 400 sbc that’s in my 74 c10 I bought this from a friend but he dnt knw anything about the previous work on it. So I’m asking if you know or can point me in a directions if that year was internally or externally? It is a two piece rear main came with a 400 externally 168 flexplate but had a balancing plate? Is this needed or is it wrong and just needs a internally balanced flex plate?
This question pertains to the SBF as they went from a 28 oz. to 50 oz. and why can't the assembly just be zero balanced? I realize you were explaining SBC for your customers, but all of this pertains to all 3 manufactures that have a similar design.
I’ve got a 350 one piece rear main marine engine , it’s got a flywheel on it I did notice it was drilled out when rebuilt, I did question engine builder when replacing balancer they said neutral or internal balancer will be fine ? I just don’t know whether to believe them Help please
I'm having truble. Spent grip of money on her Balancer given me a hard time. Take it to the builder. Let him fk it up. At least then I can tell at someone. Lol
I have a 383 that was “blueprinted” and balanced by a shop before he sold the car 67 Camaro. I have a noticeable difference in the feel of the engine between 25-2800 rpm. It’s worst if I cruise in that range but hardly noticeable if I’m powering through that range Does that sound like an engine balance thing or could it be something more simple. Like a plug not functioning fully,? gap being off slightly ? A valve adjustment thing? It runs really good otherwise. It’s got the Holley sniper EFI and Hyperspark ignition. We have new poly mounts I feel it more in the shifter (Muncie M21). Never driven older cars before buying this so I have no reference on how it’s supposed to feel.
@@LemonmilkMusic that does sound like a slightly out of balance thing. It should be smooth all the way through the rpm range. Probably why they sold it because its not gonna be that easy to fix.
To note - this is incorrect for the LT1 in a 95 Camaro, regarding the 383. For example, when making it a 383 using an eagle crank that is internally balanced, you need a zero balance flywheel.
It's a video from a Chevy dealer. He's talking about when guys would cut O.E.M. 400 cranks down to 350 mains and the cranks used in current GM's 383 crate motors. There are other 1 & 2 piece seal stroker cranks from the aftermarket that are internally balanced as well. With enough Mallory metal($$$) any crank can be internally balanced but for assembly line motors external is easier for the longer stroke.
I came over from "Low buck Garage" to figure out what he is talking about and not to present myself as a Little idiot in the comment section over there...😂Thanks for the Video. Much appreciated Low Buck Garage ua-cam.com/video/zsd8_CDx_No/v-deo.html
2👍's up SD thanks again for having us all along with you for the rest of the story
Thanks for the clear explanation. I have a 1985 GM 4.3L V6 (2 piece rear main seal) in my garage that I want to mate up to a manual trans. The flex plate that came with the 4.3 has no weight on it. Now I know I can source a flywheel from a 1985 or older small block with a manual trans and go with it.
Neutral balance balancer is a harmonic damper then and not a balancer at all.
Calling it a balancer when it's a non counterweight damper I believe causes more confusion than anything.
Your very good at getting to the point thanks
Thank you so much not confused anymore
Would putting the pressure plate on in a different position cause a vibration ?? 4 speed AMC T-10 externally balanced. Thanks for your help
So if I need to swap flywheel from 1 piece to 2 piece crank, my 10.5 clutch will still bolt up ok? And starter should fine as well? Just the mounting to crank changed?
Long story short, rebuilt 700r4 all new sonnax parts, replaced factory flexplate as two welds were cracked, have since put 3 flexplates and still have a vibration and have also replaced TQ convertor twice. Old flexplate "weight" best i can measure weighs 2.19lb, new flexplate weight weighs 2.32lb nearly a full 2oz or more over factory.
Can this be causing my vibration? Vibration occurs during all RPM and in Park, Neutral and all others, ranges from 600-6000rpm, very bad at 1200 and 4000.
How i measured was laying flexplate flat on a scale and a box that was simular hight and a 50/50 weight distribution on the scale and the box the best i could.
I know someone who ran a 427 flywheel on a 454 and was going through main bearings all the time until he found out what was causing the problem. (Flywheel)
I have a 1 piece seal 350/5.7 chevy that I am rebuilding. Would it benefit me to internally balance this motor, then balance it again with the flexplate and harmonic balance?
Question are marine 383 vortec external engines. Internal or external? Please help
Can I use a normal four-speed standard flywheel for a internal balance 400 small block
Technically, there are no internally balanced 350's from the factory. the 2 piece crank 350's had an external "wing" that was part of the crankshaft. The 1 piece crank 350's could not use the external "wing" because of the 1 piece seal design. Chevrolet had no choice but to add the required weight to the flywheel or flexplate.
Integrally balanced might be a more accurate description for the 2 piece seal crank.
Yes, that is much more accurate. If gm would have used a little lighter piston they could have internally balanced them.
@@MariusSalvetti
The real issue is that the block was never meant to house that much stroke. It was originally designed for a 3" stroke 265 that had a round flywheel flange. Just going to slightly larger pistons in the 283 required notching the flywheel flange for balance.
Does the engine block set the internal versus external, one-piece versus two-piece application? I'm looking at a used 400 SBC block
All 400's used a 2 piece rear main seal and factory external balancing. There are conversions to fit small block 2 piece seal cranks into 1 piece seal blocks, originally developed to fit cut down 400 cranks into newer blocks when building a 383, but none the other way around. If you've got a 2 piece seal block, you need a 2 piece seal crank.
Hi. Good information. I have a question. I bought a 350 vortec one piece. The motor was on truck with std transmission,. Can i use flex plate for automatic transmission??? Thanks.
Yes, you can bolt a flexplate in place of the flywheel. No issue there.
I have a 1973 400 sbc that’s in my 74 c10 I bought this from a friend but he dnt knw anything about the previous work on it. So I’m asking if you know or can point me in a directions if that year was internally or externally? It is a two piece rear main came with a 400 externally 168 flexplate but had a balancing plate? Is this needed or is it wrong and just needs a internally balanced flex plate?
And also has a bad vibration at low rpm’s 🤷🏽♂️🤦🏽♂️
External balance
This question pertains to the SBF as they went from a 28 oz. to 50 oz. and why can't the assembly just be zero balanced? I realize you were explaining SBC for your customers, but all of this pertains to all 3 manufactures that have a similar design.
I’ve got a 350 one piece rear main marine engine , it’s got a flywheel on it I did notice it was drilled out when rebuilt, I did question engine builder when replacing balancer they said neutral or internal balancer will be fine ? I just don’t know whether to believe them
Help please
One piece real main seal small block came from the factory with an external balance flywheel or flexplate and a neutral/internal balancer.
@@Sdpartscenter apologies it’s two piece rear main
Does a 383 crank. Use the stock dampener bolt. On holding in balancer
Yes, it does.
Mine is like 1/2 bolt.
Is a big block balancer bolt. It be bigger then 350 chevy
I'm having truble.
Spent grip of money on her
Balancer given me a hard time. Take it to the builder. Let him fk it up. At least then I can tell at someone. Lol
I have a 383 that was “blueprinted” and balanced by a shop before he sold the car 67 Camaro. I have a noticeable difference in the feel of the engine between 25-2800 rpm. It’s worst if I cruise in that range but hardly noticeable if I’m powering through that range Does that sound like an engine balance thing or could it be something more simple. Like a plug not functioning fully,? gap being off slightly ? A valve adjustment thing? It runs really good otherwise. It’s got the Holley sniper EFI and Hyperspark ignition. We have new poly mounts I feel it more in the shifter (Muncie M21). Never driven older cars before buying this so I have no reference on how it’s supposed to feel.
@@LemonmilkMusic that does sound like a slightly out of balance thing. It should be smooth all the way through the rpm range. Probably why they sold it because its not gonna be that easy to fix.
Can I take a early sbc flywheel /clutch and install it on a mark4 bbc
Yes, the flywheel and clutch off a 2pc rear main seal SBC will fit an internally balanced BBC.
To note - this is incorrect for the LT1 in a 95 Camaro, regarding the 383. For example, when making it a 383 using an eagle crank that is internally balanced, you need a zero balance flywheel.
It's a video from a Chevy dealer. He's talking about when guys would cut O.E.M. 400 cranks down to 350 mains and the cranks used in current GM's 383 crate motors. There are other 1 & 2 piece seal stroker cranks from the aftermarket that are internally balanced as well. With enough Mallory metal($$$) any crank can be internally balanced but for assembly line motors external is easier for the longer stroke.
There is no external Ballance 350
What did he say?
I want to.build a perfect balance 302.
But I think that it would.weaken the crank
If it doesn't have weights, it's not a "balancer". It's a damper.
It's basic if your dad taught you. Boarding school teaches nothing
I came over from "Low buck Garage" to figure out what he is talking about and not to present myself as a Little idiot in the comment section over there...😂Thanks for the Video. Much appreciated
Low Buck Garage
ua-cam.com/video/zsd8_CDx_No/v-deo.html