What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Odd 307 build help needed

3789817....283...62-64...2
3789817....327...62-67...2
3790721....283...62-64...2...Chevy II recessed oil filter boss
3790721....327...65-66...2...Chevy II recessed oil filter boss

Per Mortec, I have the 817 block. The early 327 sm journals shared some of the same castings as the 283.
 
77crewcab said:
3789817....283...62-64...2
3789817....327...62-67...2
3790721....283...62-64...2...Chevy II recessed oil filter boss
3790721....327...65-66...2...Chevy II recessed oil filter boss

Per Mortec, I have the 817 block. The early 327 sm journals shared some of the same castings as the 283.
Click to expand...

Interesting info...

Ok, concerning 307's... I've always heard something about the nickel content, and that you should steer clear of some of them. Does the 817 casting use a different alloy?
 
That I don't really know. I have heard rumors about the 307 being a weak casting and also that this is totally bogus. Honestly from what I can tell when working with an actual 307 block the biggest thing is not to bore too big or the walls become very thin. Similar to the 400 block. I wouldn't set out to search for a 307 to build, but if you have one already, or in my case the makings of one, then they can make for a good street cruiser that is still economical with a little grunt. I think with a mild cam, the 305 heads, and TPI injection, combined with overdrive tranny, it will be very enjoyable for what I am wanting. And the biggest thing is making a good usable engine/tranny combo out of what I have laying around. Then only added cost other than a regular rebuild is the purchase of the 307 pistons and rings. To me that is a good deal.
 
Be careful if you are going to use 307 pistons. IIRC they are flat tops. With the 58cc 305 heads and flat top pistons you are going to have a pretty high compression ratio.
Be sure to take that into consideration with your build. I am guessing you will be over 10 to 1
 
77crewcab said:
That I don't really know. I have heard rumors about the 307 being a weak casting and also that this is totally bogus. Honestly from what I can tell when working with an actual 307 block the biggest thing is not to bore too big or the walls become very thin. Similar to the 400 block. I wouldn't set out to search for a 307 to build, but if you have one already, or in my case the makings of one, then they can make for a good street cruiser that is still economical with a little grunt. I think with a mild cam, the 305 heads, and TPI injection, combined with overdrive tranny, it will be very enjoyable for what I am wanting. And the biggest thing is making a good usable engine/tranny combo out of what I have laying around. Then only added cost other than a regular rebuild is the purchase of the 307 pistons and rings. To me that is a good deal.
Click to expand...

Not trying to hijack your thread or steer it off course, but I'm actually wanting to do a stroker motor with a 400/383 crank with the 307 bore. It'll end up being only slightly above 350cid. The idea is to get more bottom end torque than you'd normally get with a "regular" 350 by using less bore and a longer stroke.

I came up with the idea and then thought it was stupid until a guy competed in the 2002 Engine Masters Challenge using the same setup. He didn't win it (3rd place), but still managed to pull 518 lb/ft of torque out of that combo. He'd bored it some as well and got it up to 365cid.

307's are cheap when you can find them, so are 283's. I see them locally on Craigslist often. I wouldn't shoot for 500+ lb/ft, but I think the combo would make a really good truck motor.
 
When I worked in the machine shop, I was building a stroked 307 for a circle track guy. They had a 360cid limit and the engine came out to be 359ci. We used a reground 400 crank,350 rods and custom pistons. That little engine was a mover. I would do it again in a heartbeat. I would have to find out what pistons he used cause I dont remember(it was 10yrs ago).
-Lance
 
SoCal'75 said:
When I worked in the machine shop, I was building a stroked 307 for a circle track guy. They had a 360cid limit and the engine came out to be 359ci. We used a reground 400 crank,350 rods and custom pistons. That little engine was a mover. I would do it again in a heartbeat. I would have to find out what pistons he used cause I dont remember(it was 10yrs ago).
-Lance
Click to expand...

Good to know... :D

Did you have to clearance the block at all for the rods?
 
I have a 307 in my Nova got no issues with it. Had a friend that had a built one did alot better then most 350 around at the time
 
You must log in or register to reply here.

Latest Posts

Top Bottom