Just finished upgrading my water pump to a higher output model from D&D and smaller pulley. Also added an insulator under the carb to prevent vapor lock during the hot Florida summers. Now to fix the small oil leak around the oil filter/pump, fuel gauge and speedometer.

I'm speculating that you're having cooling issues - higher coolant flow is not your problem...it's lack of airflow.
I'd be ditching the pusher fan in favour of a puller and close fitting shroud that pulls air from ALL corners of the rad.
Also noted is your lack of recirc sealing around your rad - you need to prevent hot air recirculating back through the front of the core.

It's a very impressive looking water pump and pulley. But moving water around faster is seldom the solution to engines running hot, in fact it can make matters worse by moving the coolant through the rad too fast for it to cool properly. Faster rotating water pump pulleys can also induce cavitation at the impeller, reducing water flow.
I wouldn't worry about the fan position, my 2 x 9" "pushers work well, but of course I'm not in Florida where the problem is the ambient temperature of the incoming air, you can't change that. The problem is worse in traffic conditions, when some of the incoming air is spill from the cars in front, and moving air through the rad faster often comes up against an under hood pressure build up which reduces air flow, irrespective of fan size and speed, and pushes hot air forwards when stationary, for your fan to re-use!
It looks like your rad is man enough, but check timing and mixture, both of which have a profound effect on running temperature.

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soonerv8

Thanks for all the great advice. The water pump is actually from D&D (AluminumV8.com). He said the water pump that was on there before had a pulley that was too large and the impeller was a flat blade. New blade is curved and pulley is proper size. It also open up some space to put a puller type fan if I can find a thin enough one. I agree that the shroud would help to push more air though the radiator so may try and fabricate something that looks and works well. I will also check timing and mixture. The carb is oversized 650 CFM for a 3.9L Rover engine and has been running a bit rich. I also had a space on the back of the hood to create a gap to let hot air out but have restored it to seal like it did originally. I also installed an insulator under the carb to prevent vapor lock that was happening while sitting in traffic in 95F heat. I may actually be moving it to Colorado so may not need to do anything else. Would the thin air at 9000 ft make it even run richer? Any sources for thin pusher fans?

Running a slightly rich mixture helps to cool things a touch in the combustion chamber, so not a bad thing and better than a weak mixture.
What diameter is the pulley David?

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soonerv8

Absolutely - you'll end up changing jets to lean out the fuel.
Those that have switched to an electric puller have indicated that OEM type fans (Ford Taurus, Dodge Caravan, Volvo,,....) are an excellent choice.
Maybe a visit to your local wrecker is in order......

Looks like a Buick 300 water pump, which is what I use.

I had hot running issues when I moved from the UK to Texas with my factory V8 whilst driving here in the summer. Having spoken to Glen Towery, (v8Glen) I made the following changes which have helped no end, but it is STILL a work in progress, even after 13 years here.

His suggestions were to change out the 160 deg thermostat and install a 195 deg..

Obtain a TR7 13 bland fan and attach to the waterpunp as a puller which I did, making an adaptor to do so, and retaining the electric pusher fans as backup.

Make a shroud as per pics, to fit around the bottom of the radiator to stop air from going around the rad instead of through it, which I did, attaching it by the bumper iron bolts. BTW! The bucket is not fitted!!

Hopefully you can see that the shroud fits between the rad and the rear of the hole in the center of the special tuning air dam, and can only be seen from under the car. It helps, but I have another idea up my sleeve to get it even better that involves a couple of 4" electric fans at the rear of the engine bay to suck out heat.

It is true, that owning an MG, is an uphill battle, but one well worth fighting.



Edited 2 time(s). Last edit at 2019-02-02 10:14 AM by Cornfgl.

We might be from a parallel universe. Same last name, similar cars and same water pump!

My experience has always been that airflow was the key along with the biggest radiator that could be made to fit. My original MGB conversion many years ago with a 283 Chevy V8 with a Mustang V8 radiator with a small flex fan mounted on the crank pulley. I don't remember there being any shrouding other than the original MGB stuff and there was never an issue with overheating in Florida. All of my current MGB V8's use the biggest radiator I can find and I cut the frame to accomodate them. Even with a 454 Chevy there was never an issue with overheating. My Jensen GT with Olds 215 (Rover style) had a severe overheating issue when i got it. Cured it with a larger mechanical fan mounted as close to the radiator as possible along with a shroud along the top that kept the air from spilling out and kept the air flow through the radiator as the fan extended above the top of the radiator. Those modifications dropped the cooling temp about 80 degrees F! When I had the 454 in the MGB the only slight issue with higher temps was at highway speed the temp would increase as I went from 70 to 80 MPH. This indicated to me that the cheap chinese electric water pump wasn't flowing enough at higher RPM's to maintain the heat transfer. It wasn't that big of an increase and if memory serves me it was only around 200 degrees. The engine slung a rod before I had a chance to investigate further. The cooling is so good on the two 350 powered MGB's is a toggle switch for turning on the fans at a stoplight. Even in summer the temperature never goes higher than about 160 on the open road. Normally, I will gut the thermostat and rely on the radiator for regulation. I know the possible negatives of this but it works for me.

Before and after pix of fan in Jensen GT.

Cheers,
Bill

Here's a link to the pages where we were mounting the aluminum 32" x 17" radiator in the Roadmaster:
http://forum.britishv8.org/read.php?2,166,page=51

And then when it came back from paint here:
http://forum.britishv8.org/read.php?2,166,page=61

Here's the first photo showing the old radiator:
http://forum.britishv8.org/read.php?2,166,page=37

Along with a video when we first started it, featuring me, Dan, Steve, Carl, and Max:


Should be construction details on the frame mods, lower guard and bumper supports in the 340 thread as it was a copy, but basically the frame was splayed out along the inner fender for a wider opening.

Jim