Has anybody used a aluminum 4 bolt center main cap on a flatty? I'm just wondering of there's any cons to using aluminum. I just picked one up second hand but not line bored yet.
Um...no. I just can't see a time when that would be a better alternative than...well, anything. If you're already in for the align boring, go ahead and order a billet steel four bolt cap from somebody. I don't know, but I would suspect Pro Gram makes them. -Brad
This one originally came from Tatom and I know Wilcap makes them in aluminum as well. They claim to be stronger then the cast ones. But that is why I'm up in the air about it.
First of all, putting a 4 bolt "splayed" cap on a flathead is a waste of time. There is just not enough material around the center main to take the load.............the flathead block is weak in that area. Secondly, the aluminum 4bolt main is "stronger than a billet 2 bolt cap", the answer to that is NO WAY! If you are going to put billet mains, put them on all mains, not just the center. Doug King mains are what everyone else patterned theirs after, and his aren't that expensive. And if you want to make sure the bottom end is bullet proof, then buy one of his bottom end girdles. Sell the 4 bolt center cap or use it as "garage art"! IMHO
I have a kong jackson full girdle for a flathead and Its made outta Lunymum .It uses std caps with a crush fit .
My experience has been with several late model aluminum blocks with the billet aluminum main caps has not been good and had to be replaced with steel caps. This was 8-9 years ago so possibly there may have been improvements since then. No way would I spend the time and money on a flatty to install any aluminum main on an all out flatty power house.
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