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Author Topic:   307 stroker?
AC156
Dirt Freak

Total posts: 295
posted June 29, 2002 09:55 PM
Have any of you guys ever stroked a 307 with a 350 or 400 crank? How did this combintaion work? What machine work would have to be done to the block? What type of pistons did you use? any information on this would be appreciated.

birdcage
Dirt Full Roller

Total posts: 57
posted June 30, 2002 01:23 AM
Yes, when I ran a few high dollar limited late model shows the were on a 7 1/2 lb per cubic inch weight rule. A 331 cid engine worked out to be the minimun weight. A 3.25 stroke 327 cid engine didn't produce the torque needed. I used a 307 block with a 3.905 bore and a 3.48 stroke with 6.0 rods. The problem with a 307 block is I had broken a few main caps (only avail as a 2 bolt) so we strapped the main caps, problem fixed or install aftermarket caps. I always have custom pistons made for all my engines so pistons weren't a problem. I had mine made with a maximum dome and comp worked out to 14.2 to one with a 62 cc head. It have a pair of small -8 brodix heads and a flat tappet cam. I would have to pull the dyno sheet but I think it was mid-500 hp and 460-ish on torque. Hp was at 6900 or 7000 and torque was around 5200 rpm. Nothing real special to build one except pistons. I acually only ran the motor three times turned it around 8600 rpm. It only has about 120 laps on it and I still have it If you would be interested in It. It's a real nice piece It was all new parts except the head castings they were used 1 season on another engine. It would cost about 8,000 to dublicate this part for part.
If interested I can give you dyno sheet and list of parts and a Phone # of a person that drove my spare car with this engine If you wanted another opinion on how it ran. The engine has been sealed up and setting for a little over a year and a half now.

race8k
Dirt Forum Racer

Total posts: 98
posted July 01, 2002 12:16 PM
If you bore it to 4.00 and use 350 crank and pistons you have a standard 350.Have run them at 4.030 and had no problems in a ss or mod.

Eljojo
Dirt Freak

Total posts: 273
posted July 01, 2002 09:07 PM
Have some fun with it! Take the crank and slip it into a 400 block.I THINK you'll have to use pistons for a 6.125 rod and run them on a 6" rod....Should build a boltload of hp @ upper rpm ranges--but not a lot of torque due to the short stroke. I had gotten some input off this forum last winter and it sounds to me like it would be the ticket in a stock crank 355 class---with a light car

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