lifter bore bracees
 

who made this brace? i bought it off here 15 years ago...lol for the same 455 block im test fitting it on now. i have since bought a sd mega brace which is nice but i kinda like this one...seams pretty well made

https://www.krepower.com/Pontiac%20M...ck%20Parts.htm
Scroll down to find their lifter bore brace..

Looks like the KRE one to me….

looks to be the one....i need to start looking at the kre site more often

Its a KRE brace, I own one and 2 Mega Brace's. The KRE brace is still in my tool box and both SD brace's are in service. There are very good reasons for it.
The SD brace is better in every single way. The KRE brace, you have to drill AND tap 5/16" coarse threads in your freaking block, right on top of your cam bearing bosses....... Nope, nope.
It is simply held down by small 5/16 bolts, what could go wrong ?
The SD brace has steel plates that sandwich your lifter bores, clamp around them. You can take a pry bar and rip that KRE brace out. Not happening with a SD brace. Its held down by eight 3/8" grade 8 bolts into steel. Not self tapped into cast iron right on top of your lifter bores. Carefully fit your aluminum blocks to your lifter bores. Put in place, mark contact points with sharpie and grind away aluminum, repeat until you get as much full contact as possible. And when you put the JB Weld on have a old hyd lifter on hand to check for lifter bore distortion. The brace can pull hard enough to make that happen.
About the only thing the KRE brace is good for is if someone wanted to take a chance and slowly nickel weld the brace on a block. And that a big chance too.
The KRE brace is a POS in my opinion.. Little contact area and held down by self drilled small bolts, all bad.
I am no KRE hater either, I like their stuff. Just not this one.

the mega brace i bought did come with jb weld, but ive been actually meaning to ask around on the subject of filling the gaps.


a few years back we did a pipeline gas job at work that the mating flanges had to be filled with a product called splash zone. its a Carboline product. comes in 2 one gallon cans. both parts are like puddy that you hand nead together adding some water to your glove to keep it loose.

stuff is almost as strong as steel ince dried, and from what i read on google, its the same stuff moroso sells to epoxy heads when you break through while porting.

anyone ever used this stuff in place of jb weld on something like this ...it was amazing on the pipe joint and i got almost a full kit of it

Splashzone is a marine epoxy.It will setup underwater.It is also avail in smaller cans.Many head porters use it in intake ports to reshape the port.GREAT stuff.Tom

glad i held onto it now. we were gonna throw it out because it expired but it looked the same as it did new so i took it home

And there is this one
https://forums.maxperformanceinc.com...ighlight=brace

There are better epoxy's than JB Weld. Belzona is better but also really expensive. But JB Weld has been used many, many times with the SD Brace and has been proven to be good enough. Its not holding anything together, just filling gaps and giving more contact area. You should also take a file and knock down casting flash on the bottom of your lifter bores for the steel plate to mate against.
You need to be careful grinding away the aluminum though. You can grind off too much to where you can tighten the bolts and get 'no clamp". I almost did with my last one but IMO they need to be fit for more surface area on the lifter bores.
I did not go all the way to 40ft pounds of torque like the instructions say either. Stopped at 35 lbs with Red Locktight. They would distort a tiny bit when I went past 35 lbs and if I heard a "crack" when getting to full torque the whole block was junk. It was a little nerve wracking but it all worked out.
Just remember that even with a lifter bore brace you need to pick out a safe roller. I used both methods. The "cam intensity" method where you subtract the advertised duration from the @.050 duration and you want 32 or larger split to be safe. This is from Tim G at Bullet. I had him re grind a brand new camshaft I bought on the advice from a guy who told me it was safe but it had a number of 29, not safe. New cam is 34 . And it runs great, very happy with it.
While the SD Brace might not make it bulletproof I have heard of more snapped with the KRE brace then the SD. I think the more surface area and better clamping has everything to do with it.

That is a poorly designed brace. The lifter bores at risk of failure are on the right bank. The force that breaks the lifter bore comes from the lifter levering against the bottom of the bore, starting a crack...& history is made. The brace needs to be butted against the bottom of the bore, not halfway up the bore. I make my own LB braces that address this. I doubt epoxy would do anything because there would be enough compressibility in it to allow a crack to start....

Wrong answer. Those aluminum blocks are fit down close to the bottom of the lifter bores. And brace's that use only what, four 5/16 bolts that some are drilled and tapped right into your cam bearing boss's. you know, the area where blocks can split up the middle are in no way as held down as good as the SD brace. Have you ever took a good look at one ? Where those steel plates that spread the load among the bottom of 4 lifter bores are far stronger than even your brace. Which does have some good aspects to it but you would be better off if you incorporated steel plates that go under the lifter bores to hold it all down.
I am happy that people are making parts for our old engines we need. But that brace has been the standard for a long time now and I do not see that changing anytime soon.
Can your brace distort a lifter bore enough to make a lifter hang up if you over tighten it ?
Have you taken a good look at a SD brace and fit one ?

I think many of the SS racers using stock blocks are using the SD braces form pictures I have seen.

On a related does, anyone have first hand experience with a broken lifter bore?.... With or without a brace? ..... Any details you can provide?

One done with splash zone and a modified kre brace.

Blew one out with the mega brace. I bought a used race stock block, could have already had a crack that I missed.

What cam was in it ? Cam card still around ?

Only heard a story from my dad. Broke a lifter bore in his comp cam solid lifter flat tappet 400 in the 90s. He doesn’t know what caused it to break. There were no braces.

I may have mentioned that I have never personally experienced a broken lifter bore on a Pontiac engine (thank God). I also have never actually installed an aftermarket brace. I have just preferred to deal with this unfortunate design deficiency by choosing a used block with sufficient meat around the lifter bores, making sure the lifter to bore fit is not too loose and choosing a cam that is not ultra aggressive accelerating the lifter at the critical point where side loads would tend to push the bore out. Since my personal racing has never been in NHRA classes where every HP is critical, I have been willing to give away a little HP to keep the lifter bores in the block.

I have certainly seen a number of blocks break out lifter bores, but I don't have any data on if those breaks were due to particular bores that were thin castings or excessively worn to start with. I have also seen some blocks with lifter bore braces that have had failures. It seems to me, without any real proof that drilling holes and adding glue and stuff to the lifter bore area may be more of a feel good exercise than an actual structural bridge to strengthen the block. I am sure this post will be controversial.

I can say we have made well over 750 HP NA on 1971-1974 stock 455 blocks and over 1200 HP with nitrous oxide injection and never broken a lifter bore. Typically crossing the finish line around 7200-7500 RPMs. Ran hard enough to break 3 blocks through the #2 main oil feed holes to the cam tunnel but never lost a lifter bore without a brace. This is all anecdotal evidence of course. Your experience may be completely different.

I have worked on several Beswick old blocks that had little steel struts welded to the bottom of the lifter bores in a similar pattern to what would later become the "funny car blocks", SD-455 blocks and Ram Air V blocks. So I have to assume they did this because of prior lifter bore failures. FWIW

Yes