The V8 Owners Forum -

i've been looking for months now on a well known auction site at a very pricey stainless rad. you have all probably seen it and i'm wondering does it just look pretty or is it a good idea.

the reason i'm asking is since i put a 5.0 litre tuned TVR lump in my SD1 about 4 years ago, it always runs hot in traffic and i don't necessarily mean stopped traffic

cheers

would probably be better if i got my head in gear before engaging my mouth the rad is of course alloy

Hi
Stainless steel is a pretty poor conductor of heat, especially when compared to ally, if it is an ally core with stainless top and bottom then it will funtion well as a rad, however if the ally is in electrical contact with stainless then you will have issues with the ally corroding. I think I would avoid if you are looking to solve a cooling problem, especially if it is Stainless cored.
Best regards
Mike

I have a stage III 4.6, 285 BHP lump in my Cob replica. It only has a poxy Sierra 2.3 diesel rad but never gets hotter than 83 degrees. I run a 74 degree stat and a decent Pacet 14" puller fan. The fan cuts in at 83 and goes off around 80 degrees.

The lump runs around 77 degrees when driving.

I guess my point is that you don't always need to replace the rad if you have temperature issues.

i have a similar engine to above and use an Audi 100 alloy rad,
and this is more than ample for cooling my 4.6.

Stainless rad

Forgive my ignorance but that seems like a really bad idea, heavy AND a crap conductor!!!!!

topcatproduction wrote:Stainless rad

Forgive my ignorance but that seems like a really bad idea, heavy AND a crap conductor!!!!!

The chaps second post in this thread, states that he meant an ali rad!

thanks for that TC

yeah it is ali but kinda looks like a stainless centre (although not sure)

i've got the cooler thermostat as well but hasn't really solved the problem and as i've now decided to put the car back on the road i just want to make the right choices before spending the hard earned stuff

If it always runs hot is your mixture correct?

Lean will make it hot

Ian

ah thats interesting, thanks

i've had the car a long while 21 years but i'm only a novice when it comes to looking after her and i will check that out

Black Dog wrote:i've been looking for months now on a well known auction site at a very pricey stainless rad. you have all probably seen it and i'm wondering does it just look pretty or is it a good idea.

the reason i'm asking is since i put a 5.0 litre tuned TVR lump in my SD1 about 4 years ago, it always runs hot in traffic and i don't necessarily mean stopped traffic

cheers

Yes, I've seen that (the ally one). But isn't copper a better conductor of heat?
The ally is probably to save weight.

My SD1 EFI runs hot too - in traffic on a hot day the aux fans come on and the gauge goes over 100C. But never actually boils over. And it has the larger AC rad. Some others don't. It does drop back on the move, though.
If you can find a rad specialist that actually repairs them these days it might be possible to fit a larger core to your existing one. For a lot less than the asking price of that ally one.

yeah thats it !

we share the exact same problem.

i ended up fitting twin fans to cool her down but of course that hasn't solved the problem it just kinda of eerrr well cools her down with a loud humming noise and i would add a smiley face here but they dont seem to work for me !!

Black Dog wrote:yeah thats it !

we share the exact same problem.

i ended up fitting twin fans to cool her down but of course that hasn't solved the problem it just kinda of eerrr well cools her down with a loud humming noise and i would add a smiley face here but they dont seem to work for me !!

According to the BL manual, export AC cars to hot countries had a single (larger) aux fan. So it would appear one large one is better than two small ones?

DaveEFI wrote: Yes, I've seen that (the ally one). But isn't copper a better conductor of heat?
The ally is probably to save weight.

Copper is a good conductor of heat but ali is used in high performance rads because it is stronger, the weight of the rad is mainly due to the coolant in it rather than what the rad is made from. The strength means that the tubes that carry the coolant can be thin walled and be oval in cross section. The large flat sides of the oval tubes have more contact area with the fins than round tubes so the heat is pulled out of the coolant more efficiently.

In fact many so called 3 row ali rads do not actually have 3 vertical rows of tubes they have one "very ovalized" set of tubes!

BTW, I'm not a "brain box"....I read all of the above in my 4 stroke tuning book!

Pete

DaveEFI wrote:

Black Dog wrote:yeah thats it !

we share the exact same problem.

i ended up fitting twin fans to cool her down but of course that hasn't solved the problem it just kinda of eerrr well cools her down with a loud humming noise and i would add a smiley face here but they dont seem to work for me !!

According to the BL manual, export AC cars to hot countries had a single (larger) aux fan. So it would appear one large one is better than two small ones?

One fan / 2 fans
Always debatable

But have a look at replacement fans and look at say 2 by 11 inch and you'll get a total of about 1600 cubic feet of air per minute going through

A single 16 inch and you'll probably get over 2000 cubic feet per minute

Do the maths! More air - more potential to remove excess heat

But with even more modern technology in fans you can get really small fans thet move an extreme amount of air (4 inch can do 250cfm) the downside is they tend to spin faster and make more noise

It's worth looking into it in the kit car builder tyope sites - loads of info


Last think when the fan is running get out the car and check it is drawing the air from the front and pushing it backwards - connected incorrectly they end up almost making a dam of stagnant air in front of the rad when driving slowly!

IAn

Ian