BritishV8 Forum

Cooling issues seem to be a common topic on these conversions. As a refresher, I'm running a 400 HP Ford 302 in my MGB. For the cooling system I'm running a 22" crossflow aluminum rad., Maradyne 16" puller fan and a 180° thermostat. Pics. are in the HIWD - http://www.britishv8.org/MG/JimDurham.htm
    In the Pacific Northwest, we typically don't have extremely hot weather. In 80° temps., the car stays at 180° and the fan never turns on unless sitting idle for an extended period of time. Then the temp. will climb to 190°. the fan will run for a minute or so then shut off. Well, yesterday I took it for a long drive that included freeway (70 MPH) and residential (30 MPH) speeds with the outside temp. of 100°.  There was no difference in cooling performance. The fan only came on a couple times and the temp. never went above 190° which is the "ON" temp. for the fan.
   All said and done, the car did just fine in those temps. Me, not so much. That's too hot to be in a convertible with black interior. 100° wind cools the car fine but NOT the driver.

A beautiful car.

Thanks for a 'real world report' of what works.

From looking at the HIWD, your car has;
- ceramic coated headers
- holes in the inner fender for the headers,

and does not have an oil cooler.

Has the radiator support panel been work to eliminate extra holes?

Thanks Paul.
No oil cooler. I've never seen a need for one.  I removed the factory "wings" that are welded to the fenderwell, mounted my rad. as far forward as possible and then welded in new wings that seal the side of the rad. I spent many hours welding up all the factory holes in the engine compartment but that was for looks, not function. Pretty much all the air that enters the front valance or the grill openings has to go through the rad. I was prepared to seal the top of the rad. to the underside of the hood if need be but it wasn't necessary. I spent a lot of time talking to radiator and fan manufacturers at SEMA one year and came up with this combination and it works very well. My only concern was what others said about getting the air out of the engine compartment and having to add louvers to the hood or some other openings. Thankfully, that isn't needed.
I'm still recovering from that 100 mile drive in 100°. I was longing for some A/C on that drive.

Jim,

Who's rad did you use? At 22" wide I assume you had to cut into the 'front rails' to fit it? Any photos of that area by chance?

Thanks,
Mike

Yes Mike, I had to cut and box in the front rails. No big deal and once re-inforced, as strong, if not stronger than original. I was limited to a 19" tall rad. as I didn't want it to hang down and worry about clearance issues. I also wanted as thin of a core as possible because of well, more clearance issues. All the rad. manufactures I talked to at SEMA agreed that a 19 X 22 crossflow aluminum rad. with 2 rows of 1" tubes would be the way to go and recommended the puller fan to use. The manufacturer of the rad. doesn't really matter. I got mine from Speedway Motors for $150.
I'm sure there are many different ways to achieve proper cooling. This is the way I chose and it worked incredibly well.

I hear ya about the hot weather Jim!
A couple of years ago when we drove the car to the Colorado Springs British V8 meet, we passed though some areas where it was 108F outside. The thermometer inside the car was reading 114F.
We found the best way to drive in extreme heat, was to drive with the top up, the back window un-zipped, side windows down, dash vents open and drink LOTS of cold water!

Bill

Ya Bill, yesterday was one  for the record books. A smarter person would have stayed home or at least driven a car with A/C. I had a commitment with the MG at the Shelton car show that I couldn't break.

A spritzer bottle full of water is a great idea on those hot drives out west. It's like squirting coolness on your skin. We did that going through Death Valley, Bakersfield, places like that.

Jim

I have a Ford v8, not at the 400 HP level but 328 at the wheels, so it is still reasonably powerful. I am using stock rubber bumper radiator supports (the forward versions), stock rubber bumper cooling fans, and an aluminum version of a stock MGB radiator (supplied by D&D). I installed through the fender headers and had them ceramic coated. There is no oil cooler and the remote oil filter is mounted in the engine compartment behind the left radiator support. The thermostat is a 180 degree item. In 95 degree weather the engine temperature stays at 200 or less and the cooling fans only come on at idle. The temperature is stable both on the highway and in traffic. In cooler weather the engine temperature stays at the thermostat temperature (180 degrees). So, it is possible to have adequate cooling even with mostly stock MGB components.

It's also relatively easy to use thinwall square tube and run the forward frame rails out at an angle that matches the inner wing. This means the bumper support has to be relocated to match but that is a fairly simple mod, and it allows the use of up to about a 32" wide radiator and can retain the stock appearance. See the Roadmaster or 340 thread for details. Bear in mind these are extreme examples and pretty much exemplify the limits of what can be reasonably done. The same effect can be had with simpler methods.

Jim

JWD,

Thanks for the photos. Now if only I was a welder to seal it all back up. Now on my 3rd rad and its leaking from the core. One problem with aluminum rads, can't fix them easily when it's where the core meets the end plates. Epoxy seems to be the only way and so far not successful. This was a very expensive rad and it only has a few thousand miles. Perfect fit with only cutting the lower panel to pull the rad forward. If these rads only last a short time would rather make room for the 22x19 off the shelf stuff. Anyone else having issues with alloy rads?

Mike, Do you have a ground wire running from the radiator to the frame? Your aluminum radiator will be eaten from the inside out by stray current in the coolant if it isn't grounded and depending on the current, it can happen quickly. Years ago I read an article in a body shop trade magazine on this problem. Some were neglecting to re-install the factory ground wire when doing front end repairs and the radiator was being consumed and started leaking. There's lots of info. out there on the subject - http://www.aaen.com.au/wp-content/uploads/2015/02/adradSTRAY.pdf

JDW,

Interesting. Had not thought of that but the Rad is grounded by its mounts in the side panels etc. I will try my DVM in the tank to make sure though. I must state though the first rad was not anyone's fault but my own (jack slipped), second was a stop gap fix due to the first issue. But this last rad is just a dribble from the RHS. Will try some Epoxy again when I get the chance. If no luck its cutting time then on the rails, I am not paying $520 USD again for another Rad!

Mike, good point about repairing aluminum radiators. I had been starting to come around to the idea of using an aluminum radiator in a project but now I'll content myself to using traditional copper/brass parts.

I remember reading that copper/brass transmits heat better because IR frequencies are transferred better by copper than other materials.

Paul

I prefer aluminum over brass/copper radiators any day of the week. That's all I've used in everything I've built in the last 30+ years, which is approx. 15 different cars. Never had a single issue with cooling or a leak in any of them.

Paul,

As Jim mentioned earlier lots of different ways to solve the cooling issues. Who knows, maybe my present issue is electrolytic corrosion. Seeing as I have a sacrificial drain plug in the Rad, plus the Rad is in direct metal to metal contact with the Rad support panels, I doubt it but until I tests it I cannot claim its not the cause. Now if you use the 19x22" generic rads and only pay $150 we would not be having this chat. The setup I used was from a specialist in MGB V8 conversions and was very costly. The alloy is not easily repaired and too expensive to redo in the same manner. Hence looking at alternatives. I am not a fan of Down flow 65 Mustang rads for whatever reason. So JWD setup looks appealing. There use to be a Howe 19 x 19" (HRE-342I) rad that almost fits. Would need some trimming of the side chassis rails, not a full cut like Jim shows here though. Anyone with experience with Howe Racing rads?

Hey Mike,

I've used aluminium rads by Northern for years. Never had a corrosion or stress failure.
They are fully aluminium with tig welded tanks and furnace brazed tubing. Tig welded billet fittings and no epoxy anywhere!
Lordco carries them and the last one I purchased was a 19 X 31" crossflow for under $200.00 cad. ( that's free in usd.)
Make sure that you mount them so that they float in rubber bushings. This avoids the vibration transfer that cracks the core.

Cheers
Fred

While a copper/brass rad. may have a SLIGHTLY better BTU rejection factor over aluminum, on equal sized rads., the copper one will be over twice the weight due to requiring thicker materials. That may be important to some of us conversion guys that don't want the added weight way out front. There's a reason that car manufacturers have used  aluminum rads. for decades.

QuoteThere's a reason that car manufacturers have used aluminum rads. for decades.

Yep!...because they are lighter and cheaper to produce. It's all about the almighty buck, not performance.

Never mind

Graham has the long and short of it. Money, money money.

However, brass is a good bit heavier so if weight is any concern at all it can make a significant difference. Also I think the brass radiators actually use the thinner walls because the material is stronger. There are in fact countless analysis of why one or the other is better but with current refinements to each type their real life performance seems to be extremely similar. Meaning that you might as well choose on the basis of weight and, yes, money.

Now there is a very good reason for using a cross-flow radiator instead of downflow in these cars particularly, and that is because the radiator typically sits so low in relation to the engine. The issue is air in the system, and a crossflow tends to make plumbing designed to remove air simpler. Other than that I'm not sure there is an advantage. But if you look at well engineered conversions such as Graham's SBF based one you'll see that the size of the radiator does not necessarily mean the frame rails have to be cut. I, OTOH tend towards overkill and use the largest radiator I can get cheap from Summit, and move the bumper mounts outward so that any collision damage does not automatically kill the radiator. Since I've been known to bump things that is a valid concern, as is a reinforcement below the radiator to prevent curb damage.

YMMV.

Jim

"Also I think the brass radiators actually use the thinner walls because the material is stronger."

The opposite is true. Aluminum is much stronger. Copper/brass radiators have tubes 1/2 the size because of their weakness. That's why they have 4 - 5 rows compared to aluminum rads. 2 row cores.
I could have probably gotten by with a narrower rad. than 22" but horsepower creates heat and like you, I prefer to go overkill and do it only once.

During my working years, part of my job entailed dealings with radiator suppliers.
Generally speaking, an aluminum rad supplier is going to rave about the performance of his product and the copper/brass rad supplier is going to do likewise. ie a supplier, like Griffin, is not going to extol the performance of Cu/brass rads. Here's some typical examples
Article from Hot Rod magazine with input from Griffin Aluminum rads
http://www.hotrod.com/articles/ccrp-0211-aluminum-or-copper-radiator-for-your-car/

Article from Copper Development
https://www.copper.org/applications/automotive/radiators/design_innovations.html

And some general discussion on both.
http://www.customlineclub.org.au/Alum_v_Copper_Brass_Radiators_June_2011.pdf

So there you have it – depending on who you listen to either rad is superior. One comment that I remember from one of our rad suppliers (who manufactured both products) was that: "rad for rad, the Cu/brass will cool better", but by their very construction they can't be identical.
Unless copper comes down in value and weight, aluminum rads are here to stay!

Here we have it "MONEY"  Don't expect any Brass beverage cans any time soon, aluminum is here to stay. :-)

Sorry for opening a can of worms. All I wanted to do was offer my real world experience on cooling a high HP engine in a confined space.There are plenty of ways to do it and this was the way I did mine and it worked extremely well. Nothing more, nothing less. See ya.