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Discussion Starter · #1 ·
Hi - i know there are a billion articles out there i just want to know about the 350 sbc 1pc rear (880 block)..

If I drop in a neutral/internal balanced crank do I need a neutral damper and flywheel?

If i drop in a ext balanced stroker crank - do I need a weighted flywheel or neutral and keep the stock damper with the weight?
 

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Race it, Don't rice it!
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Yes to both
Everything rotates together should work together.
In general you would use a Ext damper and a external flywheel/flexplate and the whole assemble would get balanced at the machine shop together. IF a part needed changing later, you have to them match up the balance to the old part.
Internal tends to be easier to balance and makes parts changing later easier.
Keep in mind that engine balancing a V8 is a imperfect science with lots of theory's that hard hard to quantify so opinions vary widely and theres lots of gray area. In general, if you have to buy a crank, get a internal one for the ease and balancing and parts changing later. Most will say internal is also easier on the bearings.
 

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While it can be done other ways ,a stroked aftermarket internally balanced crank uses 6" rods for easier balancing . There are also combinations that use a neutral damper & an external flywheel . I " think" that anything using other than 6" rods requires heavy metal $$$$ balancing . The only trade off with 6" rods is that they require a shorter piston that puts the wrist pin up in the oil ring . I called competition products when I built mine , internal( neutral balance) crank (Scat )damper & flywheel ,6" rods (clearanced) & pistons , balanced ,ready to assemble . I clearanced the block , checked the clearances , pretty straight forward .
 

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Discussion Starter · #4 ·
ok tx - trying to avoid balancing costs, this isnt going to see more than 4000 rpms so im not too worried about balancing, hence the option for an internally balanced crank with neutral damper/fw- that way most of the balancing is in the rod/piston pairs .. this is for a marine application - stock valve train so will do the HT ramjet cam on a stroked bottom end.. custom build but mild budget for a customer.. I have a few flywheels weighted and non at the shop too so I can kinda pick and choose..
 

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There is one option for flywheels , a " balance plate " allows an internal bal flywheel to be used on an external balanced engine , its sandwiched between crank flange & flywheel . One down side to the 6" rod / piston I forgot to mention , finding a low enough compression ratio , flat tops , I had to use 70cc heads to get down to 10.2:1 .There may be other options now .
 

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Discussion Starter · #6 ·
Oh cool - i thought that was only 2pc rear! thats an option - but I guess id have to check stud length as well as possible interference with the coupler / etc

There is one option for flywheels , a " balance plate " allows an internal bal flywheel to be used on an external balanced engine , its sandwiched between crank flange & balancer .
 

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More for Less Racer
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Seems that several posters missed the fact this question is about the 1-piece seal cranks only.

They all take the standard 1-piece seal flexplate, which always has a weight on it but is still considered a "nuetral" balance.
383 strokers for this crank/block style, external balance means weighted harmonic damper, internal balance means un-weighted, neutral damper.....but both take the same standard for 1-piece seal weighted flexplate.

This is because the big round flange for the 1-piece seal changed the shape of the back of the crank, they could no longer have a odd shaped flange having some of the necessary weight offset in the tail end of the crank......so all flexplates/flywheels for 1-piece seal crank are weighted.....stock or stroker.
 

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Discussion Starter · #8 ·
Eric thanks for clearing that up - so any 1pc sbc balance is purely between the crank and damper? Good to know- always wondered about the non weighted flywheels and the weighted dampers on the 1pc (typing that for the ones who missed it again)
 

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Marine applications are extreme duty so things like balancing is more important! Remember marine the engine is usually at 60% output on a continuous duty. A good marine engine needs full blue printing and quality parts unless power output is very low.
 

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Discussion Starter · #15 ·
moose yep understood- I dont blueprint any marine engines at my shop, power is just stock. Ive "built" (assembled) more than 100 so far, just check all specs / clearances - all good. I hone the bores 1-1.5 thou extra for the colder blocks and usually just reuse/replace hyper pistons - no need for forged pistons on NA stuff.. crank/rods another story on the heavy boats though- the GM stuff can take a beating and then some- on most of the smaller boats 25 and under stock cast steel cranks n rods works perfectly for years and years.

Most folks out here fish on the ocean and dont really care about top speed bragging rights - they just wanna get back home without a tow! no lake rooster tale types with open headers wrecking the sliver of peace most ppl go to up to the lakes for anyway :) I would not feel very humane taking an open header ice cream stick to a dead quiet lake with quiet folks and cabins, just not cool imo. ok rant over!
 

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Funny I used to live on the private side of a small lake a long time ago. The opposite shore was a public park with a small ramp. There was this guy that showed up now and then with a race boat that they tried to test there. Not much space for his tests all he could do is start at one end then about the time he hit full throttle in a straight line he’d have to shut it down as there was no space to turn a boat like that. This certainly didn’t fit the culture of a fishing and paddling with kids wading in the shallows and people picnicking on the lawn by what was really a big pond. Now I like loud engines and fast speeds but really this was pretty unkind to everyone else especially when there are very large lakes like Washington with miles of space or the salt water of Puget Sound any of these a short additional drive from our little pond, lake. Just one of those things I don’t get.

Bogie
 
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