[455TA]

Originally Posted by 69FIREBIRD76MM

I just went in that group and noticed they were asking the same question about highest Hp factory block , Bruce Fulpet is in that group already talking chit about Jim butler. What a douch.

He's not on there anymore

[455TA]

Originally Posted by ta man

Its a good group!Plus all Pontiac engines!

Thanks man! I figured we needed a good Pontiac only group on there. Pontiac Drag racers is another good group.

[ta man]

Originally Posted by 455TA

Thanks man! I figured we needed a good Pontiac only group on there. Pontiac Drag racers is another good group.

Its awesome when you kick out the Chevy guys!

[RUDOLFSSON]

I'm doing a 10 year fresh up on mine... bearings/rings etc... Plan on beating on it some more, no cracks in cast block/crank... I'd say I'm close to 1k wheel hp

[Jim Robertson]

830 hp. First dyno runs were in 1999. approximately 50 dyno pulls since then and 250 passes in my car in the signature. No issues... Good luck.

[455TA]

Originally Posted by ta man

Its awesome when you kick out the Chevy guys!

I give them every opportunity to not sit there and boast about their Chevy or whatever, and they continue to do it and continue to argue with me about how "it's all GM", so I just boot em!

[J.C.you]

Originally Posted by Jack Gifford

J.C.- How were the split spacers held in location in the main bores? What wall thickness? Material?

Very small set screws at approx. 10/2 and 4/8 o'clock if I remember right. 3" main block bushed to a 302 ford main diameter which is around 2.48" if I recall correctly. Not sure of the actual thickness now...been along time. Program engineering made them for me. I believe it is the same material their caps are made of. They installed the saddles in the caps so fitting had to be done on the upper halves only.

[Tom Vaught]

It would take a bunch of engineering and machining capability but if you reduced the main size to say 2.76", put a 1/2 shell spacer in the block side that was tied to pan rail dowel pins, basically making a Steve Barchek style girdle close to the block, not below the block, maybe you would get a bit more strength by not allowing the block to spread (which cracks the main web at the camshaft hole). A splayed cap block is trying to use the beefy splayed main cap to pull the block together.

Heck of a lot of work vs just spending the $$$ for a proper aftermarket block.
Maybe a bit less crank main bearing surface speed for lower oil temps.

Tom V.

[J.C.you]

Originally Posted by taff2

How would mains spacers strengthen the block in any way? Unless they were cast iron spacers welded in place and then line bored I can't see how they would add strength.

No expert, but the thinking was harmonics of the forces traveling through the spacers would be less as it traveled through the block under load.

[J.C.you]

Originally Posted by Tom Vaught

Maybe a bit less crank main bearing surface speed for lower oil temps.

Tom V.

That was another thing I was trying to do with the deal for the circle app.

I was limited to....no aftermarket blocks in that class, oem only, thus the mods.

[blueghoast]

Originally Posted by J.C.you

That was another thing I was trying to do with the deal for the circle app.

I was limited to....no aftermarket blocks in that class, oem only, thus the mods.

Are you using an older crank like from a 347-370 ?
Or something different altogether. I had thought of using an older crank
like that in a newer block like a 400 just to do something different.

GT.

[Tom Vaught]

Kaase used Mopar 340 bearings (2.5" mains and 2.0" rod journals) in the All Pontiac Block with special main bearing spacers. He used a fully counter-weighted crank from Bryant. (A well known Ford Crank Builder). With a Chinese crank it probably would not have lived.

See article from many years ago. http://www.hotrod.com/articles/0606e...racing-engine/

Many say the Ford 2.76" main might be a better choice for the average crank out there.

The 370 crank might be in the ball park, and a lot less $$$$

Tom V.

[Dragncar]

Pretty sure the old HO "326" was a 316 block with a 370 crank. shift point, 8500, red line 9300. Factory parts.

[Jack Gifford]

Originally Posted by Dragncar

... the old HO "326" was a 316 block with a 370 crank...

If so, they would have needed to turn the 370's 2.625" mains down to 2.500", which I don't remember them doing. I thought they used one of the '56 forged cranks, but I could be wrong.

[Jack Gifford]

Originally Posted by Tom Vaught

... The 370 crank might be in the ball park, and a lot less $$$$...

The 370 forged cranks were good, although I don't know the SAE designation of the steel used.

[Half-Inch Stud]

Well, a decade ago on PY i bashed the pursuit of a 1-piece Girdle for the reason of the factory block stresses from the bell-flange counter-torque not being taken-out. Because the Front-plate (better with mid-plate) as far more direct, effective, and less complex, and easier to implement.

Very much in favor of a Front & Mid plate, and stiff tail cross member wherea the 3 mounts can also be stiff for stiff chassis.

And you can imagine that a twist-flex chassis and soft mounts mounts should cause front&mid plated block to get the splits. So the remedy for Factory block splits really seems to be a stiff tube chassis.

Well, now time has gone by whereas factory blocks have survived with & without the various Girdles. And Factory blocks got he case of the splits without and..... with various Girdles?
Can the folks that have 1-piece girdle experience proclaim success with mention of the chassis stiffness (all tube).

Have there been "do-nothing" Girdles in factory flexible frames?

Aside: the front damper effectiveness remains paramount to the #2 Main integrity.

Hope this drool reveals a way forward.

[Tom Vaught]

Originally Posted by Jack Gifford

J.C.- How were the split spacers held in location in the main bores? What wall thickness? Material?

1) All Pontiac Block is 3" main.

2) Kaase had a special 2.5" main crank made by Bryant so 1/2" difference in the main.

3) So .500" difference divided by 2 = .250" spacer thickness.

4) Main cap is custom on most deals like this especially with the 1/2 shell spacer so the
main cap is made by Program Engineering with the proper dimensions for a 2.5" main bearing shell.

5) So now you have a upper shell spacer that is positively locked by the lower main cap and cannot possibly move, you have a 2.5" upper bearing shell, and you have a main cap holding the lower 2.5" main shell. All torqued to proper spec.

6) If the 1/2 steel shell spacer is made properly and the mains are aligned for the 2.5" main shell proper dimension the crank centerline is true, the bearing speed is reduced, and the steel 1/2 shell can have the oiling mod done to the back side of the shell (Tony B oiling Mod) for improved oiling that everyone knows works well.

Tom V.

You could basically do the same mod to the factory 4 bolt 3.25" main blocks but it would not be as strong as the IA-2 deal and would take excellent machining to do. You would also need a Ford 2.76" main bearing system.

[b-man]

Originally Posted by Dragncar

Pretty sure the old HO "326" was a 316 block with a 370 crank. shift point, 8500, red line 9300. Factory parts.

The HO-Racing 326 was simply a +.060 bored 1956 316, sporting a pair of 1970 RAIV heads.

Originally Posted by Jack Gifford

If so, they would have needed to turn the 370's 2.625" mains down to 2.500", which I don't remember them doing. I thought they used one of the '56 forged cranks, but I could be wrong.

You are correct Sir.

[GTOGEORGE]

I have a 350 HO short block sitting on an engine stands.........if someone is interested.


GTO George

[charlie66]

What is the difference between a HO 350 block and a regular one?