Engine Temps

[Author nameAuthor names are only available to PAS members.]

I had my 37 Seagrave out today for a parade it is powered by a V-12. Temps outside were 80.

I have a temp gauge in each head and run regular anti freeze. I can’t for the world of me understand why the left side of the engine , the side with the water pump runs at least 15 degrees hotter than the right side. The engine and radiator have been flushed and the water pump has been rebuilt with modern day seals. Any ideas? Thanks

[Author nameAuthor names are only available to PAS members.]

Clogged or restricted water flow will make huge differences in heat conduction from the engine to the coolant.

There are lots of variables within a cooling system and engine..

If one bank of cylinders is running lean, it would be hotter, for example.

Greg Long

[Author nameAuthor names are only available to PAS members.]

Greg is correct. Also timing could be off on a set of points causing it to be slightly restarted. I vote for plugged head passages or even ten Guage irregularities.

[Author nameAuthor names are only available to PAS members.]

Hi Tim, with Ed’s comment in mind, have you swapped the temperature sensors to see if the 15* difference swaps with the sensors?

The water distribution manifolds on each side of the engine have a box, with several 1/2″ diameter tubes coming out of the box. The water pump pushes water through the external elbow, into the box, then the cooler water leaves the box via the tubes. The tubes go between cylinders and are aimed at the exhaust valve seats and port passageways. With the coolest water hitting the exhaust seats and ports and the castings around the valve guides, these very hot running items get the most cooling, then the rest of the inside of the water jacket has the water circulate up through the coolant passageways in the block, through the matching holes in the head gasket, and matching passageways in the cylinder head.

It would not take a very large piece or flake of rust to wedge in a coolant passageway to restrict the flow. Any differences in flow patterns would result in different temperature readings.

One thing to think about; the side with the hotter coolant discharging from the head.. This could mean that the coolant is picking up more heat from that bank of cylinders than the coolant leaving the other bank of cylinders..

So the real concern might be to check and see if the ‘cooler’ bank of cylinders actually has HOTTER cylinder head and exhaust port or manifold temperatures ? s

What temperature does the water in the top tank of the radiator average out to be ?? 160-180* ?

Hope these ideas help.

Greg Long

[Author nameAuthor names are only available to PAS members.]

Greg and Ed

Thanks for your replies. I will check those items out and report back.

Tim

[Author nameAuthor names are only available to PAS members.]

Check both temperature gauges to assure that they are reading correctly.

[Author nameAuthor names are only available to PAS members.]

I have a lazer digital hand held temp guage that is really helpful in checking temp at multiple places around the

engine.I just point the lazer beam at an engine part and it instantly gives me a temp reading. I like to let the engine run till warm then go all over it and check the temps side to side to compare.

Its also really helpful when checking the temp at the top and bottom of the radiator to see how effectively it is cooling……its a very valuable tool for your tool box.

[Author nameAuthor names are only available to PAS members.]

Under normal circumstances the hottest place on a Pierce V-12 is at the back of the passenger side. I use an inline 170 degree thermostat on the drivers side return line to induce more flow to the warmer passenger side. Seagrave enlarged the water jacket size, but the flow pattern should still be the same.

My experience with our 1247 over the last 16 years showed that timing is extremely critical. Even a slight retardation will cause temps to increase noticeably. If in doubt, advance is better.

The laser temp gauges are cheap and very helpful to find both hot and cold spots, the latter indicating a clog issue.

If you don’t solve the problem, I’d gladly swap our never hot 1959 Chevy/Howe front pumper for your Seagrave. Fire trucks are the best vintage vehicles for parades!

[Author nameAuthor names are only available to PAS members.]

I would like to thank everyone for your comments and suggestions. Unfortunately the fiber disks broke again and I lost the part from the water pump that connects to the disk on the dog bone. Thank goodness for John C he had the part. Now I can get it all back together and use everyone’s suggestions to diagnose the problem.

[Author]

Posts