Visit The Dirt Forum for More Information

Author Topic:   3 9/16" Stroke
ff0021
Dirt Roller

Total posts: 11
posted December 27, 2001 07:32 AM
Our rules allow are as follows:
Chevy 350 .070 over plus 4 cubic inches for wear. Which if my math is correct is a total max cu.in. of 366.2 Must use production iron head(no vortec but bowtie okay) 4bbl low rise intake and holley 4412 carb. The carss weigh 3000# and run stock camaro front clips, 10" hard tires on dirt. Should I consider building a 350 .030 over and a 3.5625 stroke crank for a cubic in of 364? Or should I just do what everyone else does and run a 350 .060 over and a stock stroke. Just trying to come up with a different combination than everyone else uses to gain a little advantage if possible. Thanks!

awkwardjeff
Dirt Freak

Total posts: 458
posted December 27, 2001 11:10 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
Dirt Roller

Total posts: 11
posted December 27, 2001 02:19 PM
awkwardjeff Thanks for the reply. Do you think the 3.550 stroke crank will give me better torque than 3.48? Or what is the advantage? Should I use 6" rods or 5.7" rods ? Any other information would be greatly appreciated. Thanks again.

ff0021
Dirt Roller

Total posts: 11
posted December 27, 2001 09:10 PM
awkwardjeff, Thank you!!! What do you think the advantage of a 3.550 stroke would be over a 3.48? More torque? Also if I did go with the 3.550 stroke what length rod 5.7 or 6.0? Any other suggestions or ideas would be appreciated.
Thanks!

sdhnc29
Dirt Freak

Total posts: 467
posted December 27, 2001 09:17 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 .

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

ff0021
Dirt Roller

Total posts: 11
posted December 28, 2001 08:11 AM
Bill, Thanks for the reply. I don't own any of the pieces so I need to start from scratch. I think I can find a reasonably priced crank (approx $400) for a 4130 Forged Steel 3.562 Stroke Crank. should I start with that? 6" or 5.7" rods? have to use flat tops. What do you think the advantage of this combination would be over a stoke stroke 358"? Thanks again.

sdhnc29
Dirt Freak

Total posts: 467
posted December 28, 2001 12:28 PM
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

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

awkwardjeff
Dirt Freak

Total posts: 458
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
Dirt Roller

Total posts: 11
posted December 29, 2001 07:51 AM
Steve and awkwardjeff, Thank You very much for the advice!! It looks like it time for me to do some shopping to see what I can find for parts to put this together. I have been following most of the postings on this board for quite a while and you both seem to give common sense reliable suggestions and I was glad you responded to mine. Thanks again and I'll let you know how I make out with it.

sdhnc29
Dirt Freak

Total posts: 467
posted December 29, 2001 05:12 PM
No problem !! Let us know how you end up !!

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

ff0021
Dirt Roller

Total posts: 11
posted December 29, 2001 08:35 PM
Ooops, next question. If I go to a 6.2" rod then does the block need to be clearanced?
thanks again.

sdhnc29
Dirt Freak

Total posts: 467
posted December 29, 2001 10:54 PM
no

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

ff0021
Dirt Roller

Total posts: 11
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!

Back to the Archives