Main cap options for a 426 HEMI

[Meep-Meep]

I have a factory 426 HEMI block and the #1 and 5 main caps are very loose so I'm thinking about going with an aftermarket cap as a solution, but from who? Anyone have any experience in this area? Or does anyone have a junk HEMI block with good caps?

 

[Hemirunner]

1 and 5 on a hemi are the same as a 440 block. You could even use some off a 400. It'd make it easier to align bore as you'd have overhang on each side. If you just want to align hone, find some off a 440 that line up well which can be difficult. I probably have a couple of aftermarket steel ones lying around. I'll look tonight.

 

[Cranky]

Is it the caps that are the problem or the block? I took some 440 caps for a 413 block and they fit really nicely! Align bore/hone is always recommended no matter tho but I mic'ed them and they were good to go. It surprised the heck out of me!

 

[Meep-Meep]

Is it the caps that are the problem or the block? I took some 440 caps for a 413 block and they fit really nicely! Align bore/hone is always recommended no matter tho but I mic'ed them and they were good to go. It surprised the heck out of me!

Right after I posted this it did occur to me that the block may be out of whack but I didn't have a good way to measure it. That section that grabs the sides of the cap are not very tall so my inside mic won't work. A good set of dividers maybe.

 

[Meep-Meep]

1 and 5 on a hemi are the same as a 440 block. You could even use some off a 400. It'd make it easier to align bore as you'd have overhang on each side. If you just want to align hone, find some off a 440 that line up well which can be difficult. I probably have a couple of aftermarket steel ones lying around. I'll look tonight.

Technically they are not the same. The hemi caps have more material in the arch area, but the 440 caps would fit and probably not make a hill of beans worth of difference. I just thought there must be plenty of aftermarket stuff for these and wanted to get some feedback from someone who has actually gone through it. DC used to sell the ductile iron caps as a stronger replacement for wedge engines and I think these were just hemi caps.

 

[Cranky]

I've seen people peen the block about a 1/8" or so away from the edge of the fit with good results. A 1" wide dubbed chisel is the tool of choice.....yeah, it's shade tree but a lot of shade tree stuff works but imo, it depends on how much power you are wanting to make too. Don't think I'd care to peen it if I was going to make a ton of power with it.

 

[rrowdy]

Mancini racing has them and also BCR has them http://www.bcrproducts.com/ Ebay usually has them also.

Good Luck!

 

[68 HEMI GTS]

aftermarket caps are one option (they'll be wider than the factory ones leaving a little room to have the width cut down). its usually the registers on the block that get beat up from the caps walking. having the original caps spray welded (or tig), then the width re-cut, along with an align hone will get you back in business with your original parts. have the same shop do all the work. this is a common problem but easy fix.