Constantly running too HOT

[582r10]

I've got a friend (and customer) that has a '57 Chevy truck we built for him. He supplied a lot of the stuff he had aquired for the build including the engine (350) and (cheap aluminum 2 core) radiator. After it was done and painted it kept running hot. He had a friend put on a set of electric fans that looked like they came from a Ford escort or something like that. It still ran hot. Since that time I have completely rebuilt the cooling system to no avail. New flex-a-Lite fans, new 3 core copper brass radiator, flow cooler water pump, high flow thermostat, 15w50 synthetic oil, timing reset, vac adv hooked up to manifold vacuum. It does run cooler now, instead of going to 250 while driving with the a/c on it will only go to 210. That's 210 with a 160 thermostat in it. My experience tells me it should be running right at 160 or so and never a significant amount over that.

I am at this point positive that the problem is something wrong with the engine. Have any of you seen something like this before. Problem? Cure? The cooling system that's on this truck right now should keep any 350 cool, easily. Every part in the cooling system has been replaced except the heat pump (engine). HELP PLEASE!



Thanks, Roger

[af2]

Put a real radiator in it. Everyone thinks going to aluminum you can go 1/2 big! It doesnt work that way.

[Dodge Freak]

Since that time I have completely rebuilt the cooling system to no avail. New flex-a-Lite fans, new 3 core copper brass radiator, flow cooler water pump, high flow thermostat, 15w50 synthetic oil, timing reset, vac adv hooked up to manifold vacuum. r

That new 3 core copper brass radiator, seems like a real radiator to me.

[Kevin Johnson]

Is it possible the block has been filled? You might want to stick an oil cooler on there (at least check that temp too).

[582r10]

Since that time I have completely rebuilt the cooling system to no avail. New flex-a-Lite fans, new 3 core copper brass radiator, flow cooler water pump, high flow thermostat, 15w50 synthetic oil, timing reset, vac adv hooked up to manifold vacuum. r

That new 3 core copper brass radiator, seems like a real radiator to me.

That's my thought too. The radiator is an original equipment replacement for a 1975 Nova with a 350 and a/c. I don't have the exact dimensions in front of me but something like 26" wide by 18" tall. With a pair of 12 inch fans sealed all the way around to the radiator. The fans are a replacement kit for a Jeep Cherokee with a 360 engine. It was dimensionally an exact fit for this truck. I built this damn thing from the ground up as I've done many and it can hardly be driven unless it's a cool day. I'm stumped and just a little upset over it. It does run cooler with the cooper brass than it did with the aluminum radiator. Just not cool enough.



Roger
582r10
puttin' it in tommorow!

[582r10]

Is it possible the block has been filled? You might want to stick an oil cooler on there (at least check that temp too).

The block filling seems unlikely on a near stock 350. The oil temp is no doubt elevated because the water temp is so out of control. It shouldn't need an oil cooler though, to me it's no different than any other mild 350. Well except it constantly runs hotter then it should. I've put this kind of stuff together my whole life and this stupid truck is the first, ever, to do this, that's what makes me think that the guy that sold my bud this motor knew it was messed up. I was just trying to see if someone had run into this kind of thing before and what it was.


Roger
582R10
gonna put the
582 in the r10
TOMORROW

[Dave Koehler]

May I ask about the water pump with the fancy name. What do they promise it to do better than oem?

[Dodge Freak]

May I ask about the water pump with the fancy name. What do they promise it to do better than oem?

I believe flow higher at idle speeds yet have no more drag at higher rpms.

Isn't boring a block too far out can cause the cylinder walls to be too thin and the motor will run hot?

[582r10]

May I ask about the water pump with the fancy name. What do they promise it to do better than oem?

The one I put on my truck (505r10 at the time) had a machined impeller with the back end not being open like the OE's are. It's supposed to pump a lot more coolant at lower rpms. I put one on the '57 because at least there is no question about coolant flow now.




Roger
582r10
soon

[af2]

Since that time I have completely rebuilt the cooling system to no avail. New flex-a-Lite fans, new 3 core copper brass radiator, flow cooler water pump, high flow thermostat, 15w50 synthetic oil, timing reset, vac adv hooked up to manifold vacuum. r

That new 3 core copper brass radiator, seems like a real radiator to me.

Woops!
Missed that.

[Kevin Johnson]

Is it possible the block has been filled? You might want to stick an oil cooler on there (at least check that temp too).

The block filling seems unlikely on a near stock 350. The oil temp is no doubt elevated because the water temp is so out of control. It shouldn't need an oil cooler though, to me it's no different than any other mild 350. Well except it constantly runs hotter then it should. I've put this kind of stuff together my whole life and this stupid truck is the first, ever, to do this, that's what makes me think that the guy that sold my bud this motor knew it was messed up. I was just trying to see if someone had run into this kind of thing before and what it was.


Roger
582R10
gonna put the
582 in the r10
TOMORROW

I just mentioned it because I did a search on the question and that scenario has come up before and matches your symptoms -- a person trying to create a stock or near stock engine using a collection of parts, one of which was a rescued former racing block that had been filled. It sure sounds like you've addressed the more common causes.

[Dave Koehler]

The water pump sounds an awful lot like the same principal as most of the flex a lite fans. Might be fine for a drag car but worse for a street machine. Anything that takes less Hp as the rpm goes up has to mean it's not moving as much water as it should.

Something else not mentioned. Does this truck by chance have some trick looking race pulleys that actually slow the pump speed?

[582r10]

The water pump sounds an awful lot like the same principal as most of the flex a lite fans. Might be fine for a drag car but worse for a street machine. Anything that takes less Hp as the rpm goes up has to mean it's not moving as much water as it should.

Something else not mentioned. Does this truck by chance have some trick looking race pulleys that actually slow the pump speed?

The water pump information says that it pumps more coolant up to 3500 rpms where it levels off to the same as a stock pump. It may just be a gimmick but I had one on my hot rod truck (505 r10) and it stayed at the thermostat regulated temp no matter how I was abusing it. As for the pulleys the '57 truck has a set of stock pulleys for a mid sixties chevy with power steering and a/c. They don't look under or over driven to me. The crank pulley looks about the same size as the water pump pulley.


Roger
582r10

[RW TECH]

Where is the radiator cap located?

[Kevin Johnson]

How about he actually obtained a 400 block with 350 heads and the steam holes for the siamesed bores were not drilled in the head gaskets (and heads) -- also fits the symptoms. Or possibly a complete 400 with undrilled 350 head gasket? Or possibly a 400 with clogged steam holes?

Some really easy way to check the stroke?

I am trying to imagine what might go wrong if you have a bunch of sbc parts sitting around and you try to make a complete motor out of them but you don't know the differences between a 400 and 350.