[455Grandville]

Originally Posted by 77 TRASHCAN

LOL, or one of the 455 blocks you are hoarding

Originally Posted by PAUL K

Couple reasons maybe;

Original engine to the car.

Already have the block and it will work for the intended build.

I guess my issue is I never got too caught up in that original block stuff. To me it was a piece of cast iron.
I did keep the complete original 455 that came out of my GV (with less than 30,000 orig miles) but having a better 455 in there never bothered me.
I can see the original sd455 in a TA or something being an issue, but for most I don’t care.

[Jay S]

https://butlerperformance.com/i-2553...tegory:1234783

Butler’s rate there 500557 short block assembly for up to 500 hp with a 3.75” or a 4” crank......BUT

I called Jim Butler and asked him about what they recommended. He told me 350 HP mild street build with up to a 4” crank. He seemed fairly comfortable with 400 hp, after that came the qualified reluctant answer. Maybe he is a little more conservative than his kids.

I probably should have listened to him.


We have 2 500557 builds going on. (First is like Paul K number matching example)... One in my number matching 77 t/a and the other in our 68 GTO. T/A has a 4.25” crank, the other is a 4.21”. Both solid roller cams with fully ported factory heads, should be close to 600 hp N/A. The GTO is the test mule, we hope to spray it on top of that. We have been totally swamped with projects, (guys that showed interest in trying these: sorry it has taken so long to finish this) but I started going together last week and the 2nd engine just started the machine work today.

The halo is cheap insurance. If you want to get nuts, that is what the pan rail supports that tie into the halos are for. If you can afford an aftermarket block, KOOL! This is for the other guys .

It fits in stock type aftermarket oil pans. May fit in a stock pan. Not sure how it will fit in 67-69 Firebirds. Some guys have been interested in trying just the halos. It fits all 3” engines, not just 500557s. I am not sure if it will clear the pan on aftermarket caps. I have 8 extra right now. Once I get the first engine going I will look for homes for the other 8. Then if it does what it is suppose to we will offer them to the public.

[77 TRASHCAN]

Definitely two good tests there!
Looks like no machining needed to main caps? If so, that would help sales!
I sure can’t see where that device would have any negatives about it!
What other lock prep do you perform on these skinny blocks?

[Jay S]

The blocks are line honed for the long main studs, and the supports are shimmed to get the correct distance between the pan rails and the halos. May have to put a shim under the engine mounts on cars with tight cross member clearance. But it only drops the pan a quarter of an inch. Caps are totally stock.

I haven’t decided if the cap dowels should be enlarged a size, should be stock diameter dowels or should use roll pins on the weaker blocks. Earlier blocks won’t be a issue. Part of R&D is which of those options has the least cap walk without flexing the block at the dowel holes, which is where the 500557s fail. Right now one engine has roll pins, the other is using dowels.

The halo alone requires no machine work, just line hone the main caps for main studs. For the pan supports with higher hp probably drilling and tapping the pan bolts to 3/8 is a good idea. We are using stock 5/16” studs on the pan starting out though. The other option for higher hp is to use thick cross supports on the halos then machine the caps flat for cap support. The caps would be machined for that, I am hoping that is not neccessary.

[blueghoast]

I've got one that came with a garage buy out. It's been hard blocked and
I ran it for a summer until it got a slight rod knock. It ran good and went
12.70 some thing. I plan on doing a lower rebuild on it and see what it'll
handle, Maybe even throw the blower on it just to see. I'll let ya know the
results if and when I do it. I think hard-blocking would really make them
stronger and maybe last with a little more HP.

GT

[455Grandville]

That’s a nice piece, but even without going that route I’ve found most Pontiac mains should be dusted.

[Jays76bird]

A lot of good info on here, I like Jay S halo approach.
The guy hasn't gotten back to me on a time to even go look at the block. Getting frustrated with Facebook market place as a parts source. I had a guy last month jerk me around for 3 days on a 76 trans Am rear end before finally telling me he was listing for a buddy and there was a pending sale. I still have the 350 motor. I like the butler stroker kit but it is expensive probably due to the custom pistons.
I was looking at buying a 4 inch crank, the rods, and sourcing the pistons myself but you still have to figure in balancing.

[BLACKGP]

Originally Posted by Jay S

https://butlerperformance.com/i-2553...tegory:1234783

Butler’s rate there 500557 short block assembly for up to 500 hp with a 3.75” or a 4” crank......BUT

I called Jim Butler and asked him about what they recommended. He told me 350 HP mild street build with up to a 4” crank. He seemed fairly comfortable with 400 hp, after that came the qualified reluctant answer. Maybe he is a little more conservative than his kids.

I probably should have listened to him.


We have 2 500557 builds going on. (First is like Paul K number matching example)... One in my number matching 77 t/a and the other in our 68 GTO. T/A has a 4.25” crank, the other is a 4.21”. Both solid roller cams with fully ported factory heads, should be close to 600 hp N/A. The GTO is the test mule, we hope to spray it on top of that. We have been totally swamped with projects, (guys that showed interest in trying these: sorry it has taken so long to finish this) but I started going together last week and the 2nd engine just started the machine work today.

The halo is cheap insurance. If you want to get nuts, that is what the pan rail supports that tie into the halos are for. If you can afford an aftermarket block, KOOL! This is for the other guys .

It fits in stock type aftermarket oil pans. May fit in a stock pan. Not sure how it will fit in 67-69 Firebirds. Some guys have been interested in trying just the halos. It fits all 3” engines, not just 500557s. I am not sure if it will clear the pan on aftermarket caps. I have 8 extra right now. Once I get the first engine going I will look for homes for the other 8. Then if it does what it is suppose to we will offer them to the public.

Jay S... Can the full block girdle be made to fit the Pontiac 301 T block? If so, will you offer availability and pricing info in the future? Thanks.

[Jay S]

Originally Posted by BLACKGP

Jay S... Can the full block girdle be made to fit the Pontiac 301 T block? If so, will you offer availability and pricing info in the future? Thanks.

Most of the full system could be used on a 301. The pan rail supports would be the same. I believe the main bolts are a little closer together on the 301, so the holes on the halos and halo bridge support would be different, the bolt pattern would be in narrower. If someone wanted to use these on a 301 we would have to make those mods.

Honestly making a system for a 301 never occurred to me. It would not be a big deal if someone wanted one, but I do not have a 301 to play with. We do prototype work if someone wants something like that it is definitely possible. We prefer to do at least 5 of something to keep costs down.

If you are running a 301 crank the halo could be a lot thicker at the front than a bigger crank like what we are running, and have more support on the no 1 main.

Looks like the cost for the full 3” system will be in the $350-400 range w/o main studs. Halo’s are a high tensile steel, they will be around $175 w/o main studs, 301 the halo would cost a little more, but it totally depends on how many are built.

Availability depends on either waiting for our direct results, or someone’s willingness to try something new.

[LStathas]

Why do the mains need to be line honed for studs?

[Jay S]

Originally Posted by LStathas

Why do the mains need to be line honed for studs?

The studs have a higher clamping force than bolts and create a different distortion pattern on the caps. It will usually make the mains out-of-round.

455grandville alluded to it already, to get back with in spec, many engines need line honing even going back stock.

[LStathas]

Thanks, Jay. Kinda figured.

[Dragncar]

Originally Posted by LStathas

Why do the mains need to be line honed for studs?

I have a 455, built in 1990 and ran hard. About 15 years in I put a solid roller in, H beam rods(re balanced) and main studs in 4 bolt 1970 block. No line honing.
Block has not been honed or decked except by PMD.
This engine has well over 1000 1/4 mile passes and is still running.