Heat savings of Biral versus cast iron?

[dtw]

So the Jekyll project car has been ripped apart for final rust destruction, paint, upholstery, trim, etc. While the engine's out, I'm going to tear a bunch of stuff apart, beautify, fix leaks, etc. One of the problems I'm gonna address is heat - the car has been running at 210 on good days, and has seen 230 on hot days. All those new horses are cramping the oil system's style! Oh well, that Mocal fender cooler and pile of Aeroquip on my shelf is finally going to go to use.

I might be able to come up with a set of Biral cylinders to replace my iron T cylinders. I sent some to the machine shop ages ago, and they finished them, then sorta lost 'em. Not that I've been chasing them about it. But now I'm thinking, maybe I'll chase after them to cough them up, and swap them out while everything is stripped.

Money question: How many degrees might I expect to save with this switch??

[Wayne 962]

Interesting question. I'm not sure you'll benefit from a temp drop with the switch in cylinders...

-Wayne

[dtw]

Any body else with experiences/opinions on this?

[cnavarro]

We manufactured biral cylinders at one point, but they were more like a sleeved aluminum cylinder, rather than a twice cast one, like mahle's birals. There are certainly advantages to using the biral, but there are also disadvantages, including washboarding, heat soak, and general thermal overload that occurs when heatsoak separates the liner from the fins. From our observations, we really didn't see a huge drop in temps, maybe 25 degrees or so, but we did see a slight increase in horsepower. Also, we observed that in race conditions, the liners and rings actually weared less than typical cast iron cylinder. But this last observation isn't directly comparable to a mahle liner, since our birals could not have the aluminum separate, since there was a significant interference fit, requiring the cylinders to exceed 600F before "wandering" of the fins would occur.

Charles Navarro
LN Engineering
http://www.LNengineering.com
Aircooled Precision Performance