MG MGB and MGB GT Tech Talk
Need some advice. I'm building a hot street motor for my customer. He lives in Ariz. so needs the best cooling. His old radiator needs replaced due to age and collision repair. Any one have any comments regarding installing the late, '77-'80 taller(?) radiator in a '73? I would plan on ducting air from the windowed lower valance.
I know that I'll need a surge tank.
Anyone have a nice one for sale?
I have an old one sitting here if you need any measurements. I've never had a heating issue with my stock CB one and twin electric fans.. even on 95 deg days. Guess it gets hotter than that in AZ but you wouldn't catch me driving a B when it is.:hot:
Dave,
it will not fit the mounts, as the steering rack limits space at the bottom on cars up to 1977 for fitting late type radiators or the works V8 ones.
Have you talked to your customer whether he would agree to a Ford Mustang unit as used on the early ones?
An other approach might be a new std. radiator with an earlier opening t'stat and a vent that kicks in earlier.
On my B, I changed the old one for a cheap Moss replica from the FE, checked the clearance of the water pump impeller and adjusted it to BMC specs, run a heavy gauge wire throng the water ways of the head (don't imagine the rusty swarf from poor carsing, that came out of it that way) and fitted a vent switch to the top hose, that kicks in at 84° C. Newer had any problems anymore since.
BTW, I run flat tops, 12.5 GCR, lightened crank, lightened con rods, rally/race head, 292° cam, custom dizzy, HIF6 carbs with red springs and BDR needles. Rolling road results on 100+ (ROZ) octane fuel was 123 at the wheels, but no issues with overheating at all.
Ralph
I run in 100+ weather here with stock cooling system on a warmed over engine with no overheating issues.
Dave,
I make duel electric puller fan set-ups for all B's but the late ones. Have no heating problems in the hot weather even when pulling long hills. They pull 1678cfm between them. I also mounted my oil cooler down below the deck and have the special tuning air dam. The hole in the middle is directly in front of the cooler so it still gets lots of air flow and doesn't get in the way of the radiator. The radiator is moved forward 1 1/8" so a baffle was made to seal off the hole. It is very important to prevent air from escaping around the radiator. The fans are also sealed to the radiator on the backside and so all the air going through them also goes through the radiator. The fans free wheel when going down the road and don't cause any back pressure to speak of. A Haydon 3651 adjustable thermostatic controller runs the fans and the A/C wire runs the manual switch. Another thing I did to help out in the hot weather is to also put a Saab 900 fan delay relay in line with the controller to keep it hot and operable for more than 5 minutes after the engine is shut off. It helps with preventing hot soaking problems. My son is coming over sometime this week to do a video that I will post on YouTube. My avatar has the fans on my demonstrator.
I live in Southern Arizona and have had two Bs with stock cooling systems and never had a cooling issue. Just be sure the stock radiator is in good shape. I also have any A/C and have a switchh-controlled electric fan which I have not had to use. The stock cooling system seems just fine for these cars.
Dave.
I have a thicker than stock core in my 1965 MGB race car and it sticks right at 160 degrees (thermostat temp) even when racing in Bakersfield at 110 degrees plus.
No modifications were required to the apron to install it.
I'd suggest this would be a better way to go than having to jump through the hoops installing the later radiator.
Kelvin
Dan's kit is a thing of beauty that really pushes some air (or pulls it).
I'm bumping this to the top for additional comments. Great info posted so far! Thanx:spinning:
My stock ('67) radiator has been runing at close to atmospheric due to a crack in the head-tank with 80/20 h2o to coolant and redline water wetter. The stock fan was removed and it has a cheap-o pusher electric fan.
The dual gauge is kaka (replacement gauge that is whacko) so I can't tell you the temp it runs but I do not overheat. Yes, hot water comes out the crack and "steams" but I am NOT boiling over (and this is at 5000' elevation).
The engine has been getting the kind of abuse you rarely see on the street... back to back auto-x laps in 90+ degree weather.
9.3:1 compression.
Decent working order stock radiator should be fine.
