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Longest stroke?


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Howdy all,

 

I was just going through Grumpy's latest self help list and it made me wonder how far you can stroke a 350 chevy. There was a 3.8 crank listed and this made 388. Standard 400 crank was 3.75. My thinking was that you can get a 6 inch rod and piston combo for this stroke, so why not run the 5.7 rod and 6.0 piston and increase the stroke to 3.9? You could even use the standard 400 rods and stroke it even further if, and this is the crunch point, it will fit. I think i have seen the 350 out to just over 390 cube in a mag artical i read a while back. Can it be done?

 

Cheers

 

Douglas

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with the correct rods you can put a 4" stroke crank but the block mods are extensive and the power you get for your effort is not worth the trouble in my opinion, the longgest stroke crank that is a reasonable fit is the 3.875" and that requires a special profile rod and a small base circle cam just like the 4" stroke crank but the block grinding envolved is much less, now if your interested there are special blocks available with wide pan rails, extra tall deck heights, and higher cam placement centerlines that will (with tons of money)allow you to build 454-462 cid engines that appear to be small block engine!

look here,

 

24502495 - Aluminum V8 Block for Big Displacement Engines

This tall deck (9.525") aluminum block can be bored to (4.160") and stroke to (4.125" with minor modification and 4.250" stroke with major modifications). The deck height is 9.525" with a 1.125" deck surface that can be machined as low as 9.000". The bores start at 4.119" and can be bored to 4.160" with a 2.65" (400-type) main bearing size and the camshaft is raised 0.391" from production location. Pan rails are spread 0.400" per side for clearance of connecting rods. The main caps are four-bolt design of 8620 steel with the three inner middle caps having ball-end outer studs that are angled outward at 20º to anchor the caps to the strongest part of the block. The four-bolt front and rear caps have straight outer bolts for oil pan clearance. The main cap hardware includes premium bolts, centerless ground studs and 12-point nuts. The rear main uses a 400-type two-piece rear seal (Fel-Pro P/N 2909). This block uses a priority main oiling system and is a dry sump design with no provisions for an internal oil pump. The oil filter pad is eliminated so the starter can be mounted on either side and the fuel pump boss is also removed.

Technical Notes: Special oil pan, camshaft, and timing chain are required for this block. Use cam bearing kit P/N 12370843.

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Thanks G.V.

 

I can see myself doing the race block any time soon. cry2.gif

 

I was more interested in pushing the boundarys of the 350 i already have. With the 3.875 crank and a .30 over piston this would be around 393 cube, Whouldnt it? That should be enough to get my lardy arse down the road. icon_biggrin.gif

 

Cheers

 

Douglas

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Dart manufactures or markets both aluminum and cast iron blocks for this also.

 

Worl products has blocks also, but cast iron only.

 

Cast iron has a 125 lbs weight penalty.

 

Both manufacturers (I believe) can give you main bearings in either 350 or 400 size.

 

Chekc 'em both out...

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Guest Anonymous

Yeah you did that right, its about 392.25 inches.. icon_biggrin.gificon_biggrin.gif

 

Thats a neat combo, wonder how it'd horsepower since I don't recall a combo of that size mentioned before. What would the rod angle ratio be on a setup like that? icon_confused.gif

 

Regards,

 

Lone

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