307 Pistons in 250 L6

[old28]

Has anyone out there installed a Chevy 307 FT piston in a Chevy 250 L6 motor? I know it is an easy change to up the CR.

I am looking for someone that may have done one and I would like to find out if they think it was a good move.

Also does anyone know if you can get forged 307 pistons & were without having them custom made? All I can find are cast.

 

[lfgt]

Has anyone out there installed a Chevy 307 FT piston in a Chevy 250 L6 motor? I know it is an easy change to up the CR.

I am looking for someone that may have done one and I would like to find out if they think it was a good move.

Also does anyone know if you can get forged 307 pistons & were without having them custom made? All I can find are cast.

Im looking for the same answers to your post. Did you find out anything?

Jim

 

[Kurtm333]

Would be good to know. [P[P[P

Kurt

 

[Willowbilly3]

307 is a 283 bore and a 327 stroke. 250 has a 283 bore but the stroke is 3.53 (according to Wiki), not the 3.25 of a 327 (307)
I think what you need to research is the piston compression height on both pistons to see if they would be compatible

 

[Willowbilly3]

Also there is a book by the guru, Leo Santucci, that would be a good resource to have if you are building a cheby six.

 

[zpi28]

http://www.amazon.com/Chevrolet-Inline-Six-Cylinder-Manual-Edition/dp/1931128278/ref=sr_1_1?ie=UTF8&qid=1357007872&sr=8-1&keywords=Leo+Santucci

Thanks for the name willowbilly3 here is the book. This is good to know, I may get one for a future reference.

 

[old28]

Sorry I have not been on RRR for a while. I have been making some modifications to my SDRA Vintage 6 cylinder dragster to get it ready for the 2013 season.

Maybe I can add a little more information to this thread for all to read and comment on. First off I have Leo's Second addition and have read it front to back a few times, real good and all 6 cylinder guys should have a copy.

The 307 FT pistons in a 250 motor with a normal 3.53 stroke with it's 1.655 CH will put the piston .020 down in the hole and leave .015 to mill off the block for a -0- deck. Normal 250 pistons are .035-.042 in the hole. Installing these pistons by their self will increase CR to about 9.5/1, if you mill the block for -0- deck you will get around 10.0/1 and with 72-74 CC heads milled .060 you get about 10.5/1CR. It is a cheap way to raise CR without buying custom pistons for 500-600 dollars.

My main reason for asking about them is I can only find them as cast pistons and would like to run forged FT pistons if I can. The 256" motor I am going to build for this season will make around 280-295 HP and turn 6800-7000 RPM on the 1/4 mile top end.

Hope we get more feedback on the pistons.

 

[Torch]

Hope we get more feedback on the pistons.

How come you never hear a cook ask for feed back

 

[old28]

It's Called "EGO!!!!!"

I've built a lot of SBC & BBC in my 45 year drag racing game, but this is my first inline 6 and I still have a lot to learn about old school combinations.

 

[old28]

Come on guys, someone out there has got to have tryed this piston swap in a Chevy 250 L6 engine.[S

Let me know the in & out of this combination.

 

[hoggyrubber]

yes i have read about it several times, but haven't done it myself. i think several times on inliners board several years ago, also on the stovebolt site. i have yet to get Leo's second book but i have 3 copies of his first. i thought it was suposed to be a pretty straight foward swap. 250 con rods/ 307 pistons.

 

[old28]

Hoggyrubber -- Ya it is more or less a straight forward deal as fare as I can tell, just was looking for someone that had done it. May check on inliner board to see if someone over there has done one.

Leo's Second edition is great reading and has tons of good information, read it more than once. Lot of high dollar stuff, but not much home brew hot rod information.

 

[hoggyrubber]

i do remember several post on it thru the years. i haven't been on the inliners board in prob 6 years or so. my password stopped working so i never tried to post anymore and haven't even looked in in a while. i know i saw several post on the stovebolt forum too. i want to get that second book sometime.

 

[old28]

Thats the best reading a 6 cylinder guy can do, pick one up, tons of excellent information.

I signed up on Inliners so I will post something tonight and see what they have to say.

 

[gonegonzo]

If anyone has made any progress here , please post a reply .

I want to build the same engine for my 50 Chevy truck . Some details would be nice to know .

Thx ,
Gonzo

 

[BlueNorther]

not sure if this will help in your search, but the 307 forged piston used to be available from TRW under part number L2402F, a flat top with 4 valve reliefs.

found these come with rings:

http://12bolt.com/250292_products/250_pistons_57_rod_stock_length