The 5.94"rods work, that's what's in my 302 with std compression height 350 pistons.

Large, actually medium journal 327 cranks are still around. Regardless you'll need bearing spacers for a GM 302 or 327 crank or thick bearings from King to fit the 400 block.

 

5.94 rods will work then, I just need to get stock compression height 4.125 bore pistons? That's good to know, I'm trying to keep this build as cheap as possible for now.

So maybe you can clear this up, the 68-69 3.00 cranks that were in the Z28's, are they large or medium journal? They are commonly call large but I don't know if that is just large compared to the previous journal size or large as in 400 mains as opposed to 350.

Thanks for the info,

Jeremy

 

You want pistons for a 5.7 rod 377.

Yes there is confusion when technically referring to main journal size. The 68- small blocks are referred to as large journal by everybody with the 400 referred to as just that, 400. Technically though as you know there are 3 sizes, small, medium and large.

All 265 and 283 cranks are small journal as well as early 327 and 302 cranks.

All 307, 350 305, 262 and 267 cranks are medium journal along with the late 302 and 327 cranks.

400 is all by itself.

While not on topic all small journal blocks are 2 bolt main.

King and Federal-Mogul offer various bearing solutions for swapping there are also inexpensive bearing spacers available so you can stack medium journal main bearings into a 400 block. They work just fine.

 

Thanks for the clarification, I learn something new everyday

Do you know if there are any HP or RPM limits to those bearing spacers or thick bearings?

Thanks,

Jeremy

 

I don't really think so. They're pretty common in short track engines which regularly run up to 8000 or so with more stroke lap after lap. I'd run 'em. Our nitroused 377 goes 8600 with spacers. Never had to put bearings in it.

 

That's good to know, and with a set running $60 it won't break me either

Thanks Mark, now if Denny get's me the hook up on a cup block I'll be set.

Jeremy

 

Call or email these guys : http://www.davejensensouth.com/

They moved from my neck of the woods to Mooresville because of the used parts market. They are very good people and can help you out.

 

Thanks again mark, I'll call them tommorow.

Jeremy

 

I have a couple factory forged large journal 327 cranks in std size

 

Well if think you want to let go of one of those let me know. See anything you like in my forsale thread?

I'm not so stuck on 3.00 stroke that i'll pass up a good deal

Jeremy

 

You're welcome Jeremy.

Good luck!

 

They have been hanging in the rack for years...I will wet-mag them tomorrow and let you know.

 

Thanks

 

Jeremy

Here's how I calculate those numbers

Standard Chevy block deck 9.020

Add together 1/2 the stroke - The piston compression HT - the rod length - the amount you have to cut the deck to square it up. Then subtract that from 9.020

My 348 combo

Stroke 1.625
Rod 6.250
Piston 1.100
Tot = 8.975

9.020 - 8.975 = .045 cut the deck for zero deck use the head gasket to create the deck clearance of .039 for steel rods or .050 for alum rods

Of course you can get them to make you any crank you want.
Ok so get a 400 main with Honda rod journels. (1.850 dia - .655 width)
Honda rods = .866 pin dia
Pins @ 2.500 length .150 wall = 98 gr
*4.030 2 eyebrow piston weighs 350 gr add a bit for the 4.125 or 4.155 bore and you have a really light rotating assm.

What do you think of that???

Now the only problem is getting C/R - It takes a 40 cc head to get to 14 to 1
My first choice would be Brodix -12 SP-P Stage 3 Porting 2.150 by 1.625
Brodix makes a manifold for these heads - get it ported of course (either std Holley or dominator)
Cam:
Int= 308-274-.481 W/1.65 .794
Exh= 312-280-.508 W/1.5 .752
Sep@ 108
Int C/L = 104

I gaurentee this puppy will make 675 to 710 no problem.


Denny

 

Well that's definately off the shelf stuff.

I hear ya with the custom crank and 12 degree heads, but i'm really trying to keep this to something anyone can build, with a "normal" budget.

I'll have to try that combo sometime later, maybe after I rob a bank

You ought to see the chambers on these heads, they look like they are in the 40-45cc range Gonna make for some good compression.