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Really we should be looking at how Chads block is done I assume its a production Olds block, for a car to run the MPH it does you have to turn over 7300-7500 RPM in the lights, which he's done consistently.
I'm pretty sure that's a production Olds big block with one piece Jeff Smith girdle on the 2-3-4 caps tied to pan rail, but I could be remembering that wrong.
Really we should be looking at how Chads block is done I assume its a production Olds block, for a car to run the MPH it does you have to turn over 7300-7500 RPM in the lights, which he's done consistently.
Yes it's a '65 425 block that's filled. Billet main caps and a Jeff Smith girdle that ties into the pan rails. Don't waste your time with a halo. Either do this or just run studs and straps and cross your fingers.
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Originally Posted by chadman
Yes it's a '65 425 block that's filled. Billet main caps and a Jeff Smith girdle that ties into the pan rails. Don't waste your time with a halo. Either do this or just run studs and straps and cross your fingers.
Thanks for showing us. I also notice your freeze plugs are square as well, I guess that comes with good machine work.
Couple of questions, straps do the caps get milled just enough to be flat? What studs are used? And in regards to the halo isn稚 the halo just a tied to gather strap system in a sense?
Couple of questions, straps do the caps get milled just enough to be flat? Not absolutely necessary but recommended. I actually just dust them on a surface grinder. What studs are used? And in regards to the halo isn’t the halo just a tied to gather strap system in a sense? In my opinion yes, that is all that it is. No better, no worse. Just more expensive and complex to install correctly.
Yes it's a '65 425 block that's filled. Billet main caps and a Jeff Smith girdle that ties into the pan rails. Don't waste your time with a halo. Either do this or just run studs and straps and cross your fingers.
Nice!!
This build is in another league. Max HP & TQ build that required a well thought out bottom end support.
When I think of the halo, or straps its in the 500 HP max entry level HP build.
Last edited by Bernhard; December 15th, 2020 at 06:42 AM.
I am working on my 403 build. If I have a mild cam, 9.0 compression with 7a heads, and cast pistons, I think I am looking at 325hp ish at 5200. Do I need to do any bottom end mods at this power or RPM on a 403? When do you need a girdle? 6000? 7000? I know these are heavy pistons. Would there be any benefit from balancing the reciprocating assembly? I previously had it done on a 350, and the engine builder said it wouldn't hurt anything but not necessary unless I was going 6500+.
Depends on who you ask- some say it does absolutely nothing and some say it helps keep the caps from walking around.
I have one, and the caps showed signs of walking, so maybe it does nothing.
What it should do by connecting all the mains together is it make a more stable assembly. Kind of like boxing a frame.
Except you are not boxing the frame! You are boxing the main caps. The weak spots are the webs. It can help somewhat but what difference does it make when the webs are not being reinforced. The only good solution is to be tied to the block like chadmans girdle.
What it should do by connecting all the mains together is it make a more stable assembly. Kind of like boxing a frame.
That is exactly what I was trying to do. I installed my hallo without milling caps 1 thru 4. I can't see that it doesn't help. This is not a 600 ho + build. So I think it will help and certainly won't hurt. If I was to build a motor such as chadman's, I would certainly use a girdle. A girdle is the only option for high HP/TQ. The HP/ TQ in my build does not warrant a girdle and the cost of one.
That is exactly what I was trying to do. I installed my hallo without milling caps 1 thru 4. I can't see that it doesn't help. This is not a 600 ho + build. So I think it will help and certainly won't hurt. If I was to build a motor such as chadman's, I would certainly use a girdle. A girdle is the only option for high HP/TQ. The HP/ TQ in my build does not warrant a girdle and the cost of one.
I have been think about a girdle like Chadmans. Unless you are making more than 500 hp at the flywheel I see no need. Reason my 468 is around 480 and no cap walk. I have no halo . When I refreshed it I could have re -used the bearings but I bought new. Jmo
Last edited by wr1970; February 20th, 2022 at 05:45 PM.
I did this to a customers engine only because he had already bought the parts. It痴 a stock type build so I just cut the caps enough to install the halo under the straps. Didn稚 have to clearance the pan either.
in the end it would have been less to get four billet caps ..either way it痴 getting line honed and labour
Chadman, where did you source the girdle and parts? Can't find Jeff on the internet
Originally Posted by chadman
Yes it's a '65 425 block that's filled. Billet main caps and a Jeff Smith girdle that ties into the pan rails. Don't waste your time with a halo. Either do this or just run studs and straps and cross your fingers.
Last edited by Jj77firebird; May 10th, 2024 at 02:30 PM.
Reason: Mistake
Jeff Smith is no longer around. He passed away a few years back. BTR stopped making his girdle as well due to the new RR block being available. If you are looking to make serious power the RR block is by far the best option. By the time you have a full girdle made and pay to have it installed correctly you are a good ways toward the purchase price of a RR block.