Thread: Stroke
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Old 09-27-2006, 02:11 PM
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Location: Gore. New Zealand., SI
Cobra Make, Engine: DIY Coupe, F/T ,MkIV.
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Quote:
Originally Posted by quickjack
A friend of mine wants to build a monster small block with a 4.250" stroke.
My gut tells me this will not be a very happy motor and will also likely be much more sluggish than he imagines.
That said, I do not personally have any first hand experience with that big of a crank in a windsor. Have any of you?

Jack
Only Block It would fit into would be 351w with 351c crank/cam centre distance[ Fontana?] unless you use very small rod journals for rod cam clearance. Rod ratio would be around 1.5 to 1. Thats with 6.375" rod, 1.00" comp height on piston , which will require profile work on counterweights. I think your friend will be very dissapointed with the result.

I fitted a 400m crank & rods to a 351w block using a one of piston set 0.900" comp height. This gave rod ratio of 1.65/1. This combo was real strong but eventually pulled the webs out of the 351w block. Your friends combo with another 0.125" shorter pin height will have to have the 2nd ring & oil ring in the pin area along with small rod journals to clear the cam which will require a small base circle. 6.6" rod will give him 1.55/1 rod ratio.

Having done it I dont recommend it!!!
Jac Mac
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