Hey guess what, guys: designing a cooling system is not that fun.

"Ramblin Rover - The Vivisector of Solihull" (RamblinRover)
07/15/2014 at 22:36 • Filed to: None

So, I'm trying to figure out cooling for the Ranchero. Not using the original rad, because 3x the HP and using the tired and bent brass old one didn't sound clever. What makes this suck? The fact that *theoretical* load means most engines *could* be frying on the half-shell at full tilt, so it's inherently worrying. So... finally decided on two MGB radiators if I can fit them, a universal Griffin from Summit if I can't.

Why am I looking at two radiators? Well, because otherwise airflow control under the hood will be very tricky. Non-original engine in different place with stacks means that I have a recipe to force-feed my engine toastiness unless I punch through the hood and seal it - no thanks. If I have a chance to dump my hot air, I'll take it. Thus, a bit of cleverness later, I plan to dump in the fenders Mini style and louver it out. I thought perhaps OG Mini rads would work - maybe, but the numbers scared me. Sprite? Nope. MGB? Big enough compared to what's run in modded MGBs and the MGB GTV8 that I'm not too worried. *If*, *if* they'll go.

DISCUSSION (11)

Satoshi "Zipang" Katsura > Ramblin Rover - The Vivisector of Solihull
07/15/2014 at 22:43

Just make sure you know what you're doing. I know it's not exactly the same type of part, but Volvo thought it was a good idea to mount two intercoolers with a radiator between them for the first-gen S60R/V70R. It didn't work out on semi-hot days unless you had access to 100+ octane.

Ramblin Rover - The Vivisector of Solihull > Satoshi "Zipang" Katsura
07/15/2014 at 22:50

It wouldn't be two radiators in proximity to one another. One radiator per side, each dumping in a fender - the easiest way to route them due to my induction/manifold plan will actually be to have one "top hose" per bank, and two thermostats. This means I really should have two temp gauges. At the end of the day, it's like 30lb+ either gone or moved toward the back of the car, too, which is no bad thing.

The original radiator location is not only complicated by the engine being farther away, but also by some of the bodywork I'm going to be doing to go for a more trim look. Since I don't want a whole series of chin holes, a radiator nowhere near the engine, and hot air down my stacks, shenanigans it is.

 V8 Rustler > Ramblin Rover - The Vivisector of Solihull
07/15/2014 at 23:54

What is the entropy of your system?

V8Demon - Prefers Autos for drag racing. Fite me! > Ramblin Rover - The Vivisector of Solihull
07/16/2014 at 00:05

The upgraded radiator in my Cougar just sprung a leak on the seam by the core the other day. It was marginal for my combo. The car makes about 385-390 flywheel HP. I just ordered an even larger radiator than what I had. More power=more heat=more radiator needed. I feel your pain and am thankful I'm dealing with a motor that is in the stock location and do not have to go through what you are. Best of luck! Pictures when done for us, please!

McMike > Ramblin Rover - The Vivisector of Solihull
07/16/2014 at 05:50

I still think VW had fun with this one. "More hoses," they said.

Old-Busted-Hotness > Ramblin Rover - The Vivisector of Solihull
07/16/2014 at 07:39

MGB's aren't known for running cool, and only had about 80 HP. I think you're looking at a lot of trouble for something that ultimately doesn't work, even if you mounted them in the air stream.

BiTurbo228 - Dr Frankenstein of Spitfires > Ramblin Rover - The Vivisector of Solihull
07/16/2014 at 07:58

What a kickass little solution. I'd love to see the setup when it's being done :)

RamblinRover Luxury-Yacht > Old-Busted-Hotness
07/16/2014 at 09:01

I've based my sizing off the heat capacity of air vs. kW of the engine (some standard formulas), flow rates of available fans, a more free-flowing core, and what's worked for upgrading MGB GTV8s to e.g. the Ford 302. I'm not flying blind. Worst case, I do a fan upgrade.

It's also more radiator total than the Range Rover Classic had, FWIW, and that is the preferred level of cooling compared to the RR P38.

RamblinRover Luxury-Yacht > V8 Rustler
07/16/2014 at 09:09

Don't remember all the figures off the top of my head - working with 260hp and the standard rules of thumb (hp figure = heat energy needing to be dumped, multiply x70%, rule assumes a proportion of bhp:exhaust entropy:coolant entropy) left me with a max dump requirement of 3000CFM per radiator needed/100 degrees F air temp increase. If I can squeeze 4000CFM, air temp is only 75 degrees F, etc.

I don't expect it to be oversized for doing laps in 120 degree weather, certainly, but any occasion I see close to max HP should be with enough of a pressure kick to make that 3000/100 a worst case. I can get 3000cfm fans that'll fit the MGB rads, if nothing else.

RamblinRover Luxury-Yacht > V8Demon - Prefers Autos for drag racing. Fite me!
07/16/2014 at 09:10

I'm headed for probably ~260hp at the flywheel, so it's possible I'm over-engineering a bit - but better that than the alternative.

V8Demon - Prefers Autos for drag racing. Fite me! > RamblinRover Luxury-Yacht
07/17/2014 at 14:32

Indeed. Every time I modify a car now, I think about how it will affect the car as far as areas that I HAVEN'T modified. Sometimes one must factor upgrading other parts into the cost. Yours is a perfect example.

About 4 years ago I swapped the camshaft in my car to better compliment my combo. I went with a custom grind. I needed bigger springs, different pushrods, retainers, stem seals, as well as the gaskets to put it all back. Almost $900 in total for a cam that was $325.

Car got better power AND gas mileage so it worked out in the long run.....

I'll never go with an off the shelf camshaft EVER again.