MG Sports Cars

3.4L V6 in my 'B' pegs the "H" (or 240 degrees) idling in around town driving t-stat opening around 175 degrees. Currently using single large pusher electric fan and have even put the stock plastic fan back on the pulley to help pull the air flow. Cools down rapidly on the road, but would dearly love to survive stop and go situations. My radiator is a modified stock MGB with larger core and larger expansion tank. Running a Fiero water pump as I understand the Chevy pump turns opposite direction...? Thoughts please. TIA Jim

For two radiators with the same dimensions, aluminum doesn't usually provide a significant cooling advantage over copper/brass - but as long as you're buying a new radiator, now might be the time to make other more substantive improvements to your cooling system.

Pusher fans are generally less effective than pullers for a given size.

It's easier to design a good shroud for a puller.

A good shroud can be hugely helpful.

Is your filler cap high enough, and are you able to get the system properly bled of air?

Are you able to pressurize the system properly?

This old article might provide another useful idea or two: [www.britishv8.org]

Posting a photo might be helpful.

Jim:

Have you checked how the recored radiator is working? Use an infrared thermometer and check the temperature of the rows, top to bottom. (Should get at least a 30 degree drop, top to bottom. You're looking for "hot spots", cold spots, etc.)

We swapped to an alloy radiator in the racecar. (It was a nice 10 lbs lighter!). It has otherwise only ONE advantage-- sitting, it dissipates heat faster. AT speed, however, it cooled exactly the same as the copper OE it replaced. (The copper was a staggered core. The alloy are straight cores, but larger.)

I doubt the alloy would be the fix, unless it turns out your existing radiator is having problems anyway.

$.02

Max

Many people think that since Copper has better heat dissipation that copper is better then aluminum. The difference is really more in what they can do with aluminum and how it is contructed. With aluminum they can actually construct it with more surface area for heat dissapation then copper. Having said that, the difference is less importnant then total surface area as was mentioned before.

While there are differing core design and manufacturing techniques employed for C/B and AL rads, there are really only two advantages to an aluminum rad - weight and cost!

I have an aluminum cross-flow radiator that I love. For me, the construction material was never an issue as much as finding one that would cool the V8 and fit within the space I had to mount it without dragging on the ground. Traffic bumps are surely a thing of the past and I will have to plan my route through parking lots. Such is life when you drive a cool car.

BTW, the stance of the car in my avatar to the left is pre-V8; it sets somewhat lower these days.

Paul



Edited 1 time(s). Last edit at 06/05/2013 11:00AM by pspeaks.

Like I said, Aluminum does cool better not because of the material but because of how they can custruct it.

Hello Tom Ahlstrom I have not been on here for a while. I think I can help you find some answers to your cooling problem. The first thing you must determine is whether your problem is water flow or airflow if the car cools just fine on the highway your problem is probably airflow. Two things that I pick up on from what you said is this you said you have a big pusher fan I have never seen a pusher fan that works worth a crap. +2 fans running on each side creates turbulence and disrupts airflow. My TR six is 500 hp it runs very lean with very high exhaust gas temps EGT's I do not have a large radiator no room for it it is an aluminum Fiero radiator but my fan works incredible I tried a lot of fans none of them worked one of them was a very expensive aftermarket puller from be cool it cost me $240 and it was junk it did not work. So I did what I do best went to my local junkyard where the guys there call me the mad scientist I told them I wanted to test radiator fans they laughed I spent six hours in a back room wiring up radiator fans and shrouds to find the best pulling fan I tested over 200 of them. I do not have a Dino for fans but what I do have is brains I took with me a 36" x 36" piece of 16gauge aluminum and a piece of 14gauge steel the object was to see what fan and shroud pick the metal sheets up off the ground and from how far away my version hillbilly version at that of a fan Dino what I found was amazing there was only one fan that would pick up the steel and it did it from 6 inches away that fan and shroud our 1993 through 1995 Dodge Caravan that fan and shroud cost me 40 bucks I have since used them on many customer hot rods just last week a guy brought me a 65 Shelby cobra 427 side oiler to four barrels 750+ horsepower and he told me please fix my car I just want to drive it it had many problems the worst of which he said that it overheated from the day it was new he thought that's just the way the car is. He was wrong I modified a junkyard Dodge Caravan fan and shroud for his cobra he called me back to days later and said the car runs between 160 and 165 no matter how you drive it he was so excited with all the things I fixed on his cobra that he wrote me a check for an extra thousand dollars and said the car did not run that well the day it was new thank you the Dodge Caravan fan is a three speed motor if you are interested in how to wire one up just let me know and I will post something on here about that in the Caravan they are a three speed fan I run them as a two speed you cannot run one without three relays it is very simple to do if you want more information just give me a shout signed sincerely been there and done that

Hi Tom,
I think I will look for a Dodge caravan fan here at the local junk yard and try that one out. Thanks for the info.
Werner

Hello it's me Tom I will try to post some more information in the next day or so on caravan fan shrouds I will try to post pictures dimensions and wiring instructions it really takes three relays and 10gauge wire to run one of these things I found one in the shop that is stock uncut I can get dimensions off from signed British automotive design

Werner - if you're going to a salvage yard & can, comprare the caravan fan to 3.8L Ford Taurus & to S70, S90, 940, 970 etc. Volvos. Googling around indicates the Lincoln Mark VIII fan is the best one out there but it's too big for our cars. Next seems to be the Taurus & many swear by it. The Volvo is, I believe, the same fan motor & blades as the Taurus, but it's packaged in a way that makes it easier to remove & mount to a simple shroud you can make to fit your radiator. Interesting thing to me is I don't think either the ford or the volvo would pick up a 36x36 piece of 14 gauge from any distance, let alone 6" away. If the Caravan fan really does compare favorably, it'd be useful info for a lot of us on this site. While you're getting the fan, do get a fan relay from one of those volvos. It is a nice, self contained relay pack that will handle the amps the fan draws as well as shutting off low speed when the it switches to high speed.

Interesting discussion guys. Some useful info here. Keep it coming with thanks, Jim

Hello it's me again that Ford Taurus fan is a very good fan all my friends with Corvettes seem to like the Taurus fan if it's in a Corvette like it was made for it but it doesn't seem to have the torque of the caravan fan

Hello here's basic wiring for Dodge van the black wire going in is full-time ground the dark green wire is switched positive for low speed the light green wire is switched positive for high speed the green and yellow wire is switched ground for high speed the low in the high-speed circuits run together on this motor to test the fan tie black wire together with green yellow wire hook them to ground tied dark green and light green together hook them to positive and that is high-speed. I will tried to post a relay diagram tomorrow some pigtail colors are different on some the yellow wire has a green stripe and some it's just yellow





here are some photos the one photo with help from my wife shows smoke sucked in the front of the car most of which goes out the cowl of the hood will have to be careful this topic could turn into arrow dynamics. The other photos show the fan and shroud are approximately 4 1/2 inches tall. Notice the curved blades on the shroud I mounted one of these fans and motors without the curved blades in the shroud it did not work near as well the curved blades held get the air rotating rather than straight flow off the fan blades from my experience they work best keeping the shroud and just cutting the ends to size if you take the fan blade off be very careful nutt is very tight usually rusty and left-hand thread I have broken more than one my best luck soaked in liquid wrench and then use small electric impact good luck



Edited 1 time(s). Last edit at 06/07/2013 05:37PM by tomsbad6.