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Author Topic:   3 9/16" Stroke
ff0021
Member
posted December 27, 2001 07:32 AM
ffoo21, finding a true 3.562 stoke crank is hard.......at least one that is priced right.
Most manufactures stock a 3.550 stroke crank. Both these cranks use the same piston, they just have a different deck heigth (.006)difference........
also, piston manufacturers have different compression hieght for the same bore x stroke combinations......equaling different deck hieght.........9.000 to 9.008

I would find a cheaper 3.550 stroke crank, if you run a flat top piston deck the block for a ZERO deck......or out of the hole a few thousands.......

good combination

[This message has been edited by awkwardjeff (edited December 27, 2001).]

ff0021
Member
posted December 27, 2001 02:19 PM
If you already own a 3.480" crank , you can have it turned down to a small journal 3.562" , and re-heat treated . Used small journal 6" rods are very easy and inexpensive to come by these days , due to the Cup boy's running all Honda journal cranks now . I ran the 3.550" combo that Jeff spoke about , ten years ago . I liked it very much , and it was much more driver friendly than the longer stroke engines .

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


ff0021
Member
posted December 28, 2001 08:11 AM
The best combo would be with a 6.200 rod . But if you own 5.7's and 6" rods already , then I'd go with the 6" rod . You can use a piston that is for a 3.500" stroke , with a 9.025" deck (stock deck height) , and your piston will end up .006" out of the hole . We run our flat top motor's anywhere between .005"-.010" above the deck , depending on what combo we are putting together for a guy . This is not a problem if you use a JE piston that runs tight in the bore , and retain a minimum of .030" piston to head clearance . A looser running piston , will have to be more like .035" piston to head clearance .

The advantage will simply be more torque . The horse power number's should not be too different from a stock stroke engine . If you can use the 6.200" rod , this would be better yet ! Your torque band would be much longer up through the RPM range ,and horse power would increase . This would all be due to a better Rod/Stroke ratio , and improved cylinder fill . If you are limited to the 5.7" or the 6" rod though , I would go with the longer 6" rod for sure !

Steve Hendren

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


awkwardjeff
Member
posted December 28, 2001 04:05 PM
ffoo21, Bill knows his stuff, I haven't read this thread for a few days, so sorry for not replying......But Bill is giving you all the same thoughts on this combination that I have had in the past.

Our little motor is a 3.562 stroke crank, 4.030 bore, JE pistons.....13.5 to 1 compression........we have a set of Crower sportsman 6 inch rods...........

If I were to build a new motor today, I would build the same motor but with a 6.125 rod length..........if I was wealthy enough, I would get the Honda rod size and super light crank then maybe a 6.200 long rod...

The only reason to stay with the 6.125 is the money of it all.........pistons are harder to get for the 6.200 and crank, and everything is hardr to get and a little more expensive with the 6.200 rod.......at least around here........

You could buy used rods from a cup car, and save a few dollars, but they seem a little heavy for me..........again the expense keeps me in the 6 inch or 6.125 rod......and replacement parts come faster if needed.



ff0021
Member
posted December 29, 2001 07:51 AM
No problem !! Let us know how you end up !!

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


ff0021
Member
posted December 29, 2001 08:35 PM
no

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780


ff0021
Member
posted December 30, 2001 11:12 AM
thanks again. If you know of anywhere to buy some of these pieces used please let me know.

Thanks!

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