Don Terrill’s Speed-Talk

I was at a friends house tonight, when i noticed a sbc in the corner. The heads on it have spread style exhaust ports like brodix -10 heads. By the rocker stud it said brodix p 3 then, on the front of the block it had the part number p405. Any idea what these are or when i need to look on them to identify them? Also it had edelbrock 2968 intake on it. Thanks for any help.

anyone?

I called brodix and they said it was a -9 head similar to a -10. Does anybody have experince with theses? Thanks

-I've had experience with one set of -9 Brodix heads.

-as far as I know they were about the first version of an aluminum GM "turbo" head in the late 1970's----might have been actually cast up for a company called Speedmaster for a year or so--and about that same era is when Brodix came onto the racing scene with aluminum heads.

-the 9 stood for a 179 CC intake port.

-I'd bet those heads are at least 30 years old---I don't remember them being available in a spread port but quite likely they had that option.

-they actually worked pretty good for that era--even on 355ci sized sprint car engines.

-JV Brotherton who was MR. Brodix at that time told me that aluminum heads self anneal with age----the older they are the softer they get----and he also said that personally he wouldn't even consider using a 10 year old set of NEW in the box heads because of the loss of metal hardness.

If thats true there are a lot of very soft oem heads out there by now.

-got pm from Mark today---apparently from Brodix--he says the story I relayed regarding the heads going soft with age just sitting in a box is incorrect.

Either way I thank you for the history on them. I plan on trying the motor, I'll post the results when I do. Thanks

Does this annealing happen when they are run?is it something to be concerned with when looking at used heads?

-there are other people who should be much more up on aluminum hardness than me--but I can say for sure that on SBC's between the two center cylinders is a major place where annealing occurs because of the concentrated heat.

-an example is: we had a really nice set of 1970's era Brownfields, guy was running'm at Bonneville and bought a late Corvette water pump that actually was for a reverse rotation multigroove belt system---so the pump was rotating the wrong direction when used with V-belts.

-all it took was just a few runs to soften the center of the heads--and the metal deformed at the gasket just like this photo of an SB2 head--between the bolt hole and the torched out area----and this SB2 has two coolant passages right there thru the torched spot.

-I fixed the engine---got the right water pump on it etc---ran the Brownfields several more times---pulled the heads of after each event----about 6 runs caused about .010" worth of deformation--the heads had been angle milled so far over the years we eventually ran out of material to mill--so the heads died a slow death.

Having built a few blown smallblock engines, I have run into this annealing problem several times and the only way to fix them properly was to groove out the portion between the cylinders and weld a portion and then hammer weld it. I stood and watched the late Quinn Epperly do it and the heads were better than new. I hope that I never have to do it again as I wouldn't have a clue who would do it for me today.

Dick Gazan

Mike Chapman has a really good hardening prosses for cooked alum heads. We don't run cast alum heads at Bonniville anymore. Cast iron works alote better for me allthough they do have a tendency to crack. I have seen alote of blown gas engines that just can't keep a head gasket in them for vary long, espesially the s/b chev at B-ville. I usually try to switch my customers over to cast iron.