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I would not be afraid of the SCAT cast crank at 600-625 Hp as long as it wasn't in either circle track/road race constant RPM use or Marine offshore boat use.

Street and street/strip or even bracket race regularly at 600 Hp wouldn't even make me blink.

Speedway Motors claims to have built several hundred 550HP+ circle track and street rod engines using SCAT cast cranks with no failures attributed to the crank itself breaking. The big 400 main journal overlap adds a bunch of strength to the crank.
 

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a cast GM crank will last longer in a oval racing engines than either a Scat or Eagle.
the GM crank would last 900 to 1000 laps on a 1/4 mile track, and it not broke would be cracked when mag checked.
get a forged crank and forget it unless oval racing.
 

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Well. For one.. I operated a machine as I said. I was a machinist. I never said I was a builder.

I did what was on the order. I ground every crank you can imagine from caterpillar to 8" oil rig cranks.. yes I also Stroked many cranks. A 383 crank is nothing more than grinding 400 mains to 350. Or a 351 Windsor offset ground to fir to Chevy rods. I never said I was a engine builder.

I understand what stroke and indexing. I have assembled many motors. I don't see why you feel the need to insult me.

Anyway... I know their are pistons and 5.7 rod and crank 4" stroke combos for 400s that with my bore will make a 434 ... that is probably a bit more than I want to push a 817 block. And I don't have the money for a dart shp.


What I am asking is that do you know of a COMBO where if I had a grinder offset the rods to 3.8 stroke that would give me a deck clearance of around .010 down or so that is cheap. Most internally balanced kits i have seen are either stock, 3.75(406 ) or 4.0 (434) if I went with the 4.0 stroke kit with 6" rods I would need about 15cc dish pistons And the notching for the added stroke. I'm ok with that option. But I want to know if anyone stroked a OEM 400 crank. LLike off set to give me 3.8 to fit the cheaper small journal 5.7 rods and what pistons would work well with those? would stock 350 pistons now sit out of the hole? I don't know I'm not a builder.

Go ahead and insult if you want . I am trying to explain it best I can.

Basically in a nutshell.. I want a bigger displacement cheap without buying a new crank and custom rod and pistons.

If it doesn't work fine. I don't know. Maybe a combo does exist. I'm asking if you know of a combo?
TRW offers an inexpensive flat top forged piston for a.030 over(4.155”) 400 block with 5.700” rods and a 3.75” stroke. You work in a Machine shop, so you have access to an engine lathe. Put the piston in a 4 jaw chuck using brass shim stock to protect the skirts and Face off .025”. That should work for a 3.800” struck.
 

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TRW offers an inexpensive flat top forged piston for a.030 over(4.155”) 400 block with 5.700” rods and a 3.75” stroke. You work in a Machine shop, so you have access to an engine lathe. Put the piston in a 4 jaw chuck using brass shim stock to protect the skirts and Face off .025”. That should work for a 3.800” struck.
I mean stroke
 

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I'm so confused as to how you can grind crankshafts for a living and not understand stroke and indexing.
You cannot stroke a 3.750 crank to 3.800. Stick to the 406 for your budget is very tight to begin with.
Sure you can! Actually you could easily get 3.875”. You got to remember that half the stroke length is the center line of the crank to rod journal Centerline distance. So you’re only offset grinding the crank .025 to get 3.800“ stroke.
 

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I stand corrected. 3.850” stroke is the maximum
Actually, if you grind to small journal rod and the smallest available undersize you can find a bearing for(SJ @ .050" undersize) 3.900" is possible with accurate machining a an intact standard diameter large rod journal to start with.
The heavy metal balance job is going to cost you $$$$ though.
 
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