RV8 cooling

[chesterak]

Does anyone know of, or have, a generic method/formula for calculating any given engine cooling requirements and hence deciding radiator size? The problem I am having is that the recommended radiator for my kit (CR Viper) is an SD1 and its too tall. Eric and the others guys with CR Vipers have, I think, got around the problem but all seem to use sloping rads but,by sloping the rad to fit, I'm reducing its efficiency and causing other problems in relation to body fitting, bonnet hinge mounting etc so I want to try and ensure the rad fitting does not dictate/restrict my options.
I can easily decide the height and width of a rad fitted vertical, but how many rows?, core type? etc. The engine is 4.6L mildly tuned, probably no more than 250BHP. Any help appreciated
Stan

[kdavies3]

Hi Stan,
I reckon if sloping the rad by a few degrees, has enough effect to compromise the rads cooling abilities to the point of over heating,then the the rad must to small capacity anyway I would think.

I would think a few degrees of slope isn't going to make a lot of difference but if you're talking 45 degrees that'a different matter.

If you get your available space dimensions and go along to Serck or another rad supplier they may be able to advise you.

Kev Davies

[STEVE G]

Stan I have a 3.5(163bhp) that gets hot in traffic.I have discovered my rad is from an auto and has part of its capacity taken up by the trans cooler. I have a theory that all RV8s with heating problems have the same rad.I will be changing my engine this winter for a 4.6 and intend to get an ally rad made.I have been told for the same size you get 50% more cooling so going for a 3 or 4 core unit (depending on cost)I may have to put a gas burner under the sump to heat it up.I have heard Pace in Suffolk are reasonable for price but havent got a quote yet.
Regards Steve G.

[Kevin W]

You could try using a sierra diesel radiator. Its the standard fitment on all Sumos with V8s. Most people seem happy with the solution, and I think its slightly smaller than the SD1 item.

Kevin

[chesterak]

Steve,
Since posting this message I have talked to a few radiator suppliers....it seems the original SD1 rads were of dubious quality. I went to a manufacturer yesterday and he showed me the difference between a "quality" high efficiency core and an OEM SD1 rad-the "gilling" or fins per inch were significantly more for the quality rad. He also advised against going for too many rows as by the time the air reaches the back row it is very hot and can have a detrimental effect on the overall rad performance. I have ended up with a design as follows...27" wide, 14/15" high (depending on exactly which tanks he can get) and 3 rows deep, the cost is £120 + vat. With these dimensions I can fit the rad vertical between the front chassis rails. Time will tell if it performs ok.
stan

[chesterak]

Kevin,
Thanks for the info...see my reply to Steve for the solution I've decided on.
stan