English newbie with straight 8 overheating issues

[Rustytractor]

Hi all, I'm a Brit in London and I just joined the forum. I'm pretty sure that the questions I'm posting have been covered many times before but here goes:-

About 6 months ago I found a 1952 Buick Special in a garage next to a house a few miles from my house. I'd driven by it a million times without ever considering that anything of interest would be inside but this time the door was open and I saw the front of this dusty Buick staring at me. Cut a long story short the elderly owner had just died and his brother wanted to sell the car (which hadn't moved for 25 years !!) - needless to say a deal was struck and I collected the car on my old Ford C600 Recovery truck and took it to the workshop.

Within 24 hours it was up and running and driving around pretty good for a long time slumbering old car. Exhaust blows, hard tyres etc but it ran great (short runs only as it needed fully sorting), the brakes worked and the car was totally rust free so I'm pretty happy.

Anyway, I noticed the temperature gauge was climbing so checked the obvious - sticking thermostat (there wasn't one), radiator flow (had it checked and descaled but wasn't too bad), opened the drain by the disributor and got a tiny trickle so I knew the block was clogged with years of rubbish. I then performed the following engine work:-

1. Removed the head, had it hot tanked, valve guides checked and valve seats converted for unleaded.
2. Rocker shaft stripped, hot tanked and refaced.
3. Strip and clean water pump, check bearings and seals which seemed fine.
4. Remove freeze plugs, clean out block waterways with wire picks, brushes, hot high-pressure steam cleaner (the amount of junk that came out from the back of the engine was staggering) until water flowed clean through every orifice.
5. Rebuild with new freeze plugs, gasket set and repaint as required.
6. Oil and filter change, new thermostat, new hoses and bypass hose, spark plugs, points, condenser and cap.

When trying to take the temperature sender out of the head it was seized and broke in half - part remained in the head. It worked before attempting removal but doesn't work now and I can't seem to locate a replacement.

Anyway, the car started fine after the rebuild and runs super smooth and quiet BUT there appears to be no water flow whatsoever. I removed the new thermostat to see if that was causing the problem but it made no difference. The block is clear, the head looks like new so I assume that's not blocked either.

To me it appears that the water pump isn't doing anything but I find it hard to understand why. The impeller looked ok, a bit corroded but no play in the bearing and no leak from the seal. I've read countless posts about bypass hoses, flow restrictors in the lower half of the thermostat housing, lack of flow and overheating issues wth these engines but I've gone through everything I can think of except replacing the water pump (which don't seem that easy to find, especially when you're in England!).

Is there something I'm missing here ? I have a 1952 shop manual but it sheds no light on what the problem may be but this is my first straight 8 (I'm used to V8's as i have a collection of Cadillac's ranging from 1941 to 1971, Mustangs, Thunderbirds, V8 Porsches and various V12 Ferrari's and Jaguars etc) but this lovely straight 8 engine may need something that I'm unware of. Or it could just be that the water pump is toast

I've located a water pump from Old parts Source which I can get shipped over but it's quite expensive so I thought I'd check before ordering one.

The funniest part is that I also have a 1949 Roadmaster with exactly the same "blocked up block" problem so once the '52 issue is resolved I'll be doing it all again with the '49.

So - everything perfectly clean and clear, Rad clear, pump not replaced = no water flow.

Any advice greatly appreciated.

Russ

[bob k. mando]

and I collected the car on my old Ford C600 Recovery truck


oy! i can see you've got it bad.


sorry, i've got no experience with the Straight 8s.


have you tried pulling the pump off and just jamming a water hose into the feed holes in the block?

[Rustytractor]

and I collected the car on my old Ford C600 Recovery truck


oy! i can see you've got it bad.


sorry, i've got no experience with the Straight 8s.


have you tried pulling the pump off and just jamming a water hose into the feed holes in the block?

Bob, you have no idea how bad !!! So far i'm up to 35 cars and counting. Lets call it a hobby that's become an obsession which turned into a business and leave it at that 😜
The block is totally clear. When the head was off and all the core plugs were out I spent a whole day poking, prodding, scraping and high pressure washing it until water flowed through every hole without restriction. The head was machined and hot tanked so I'm pretty sure it's clear.

But to answer your question, no - I haven't taken the water pump off again and run a hose through the engine as yet. I thought I'd ask those who know best for some advice before diving back in the deep end again when maybe the shallow end was where I needed to look.

[firstofeight]

Seems something is plugged. The suction hose CAN collapse. Before pulling the pump as Bob suggested, Perhaps remove the elbow from pump to block and see if pump pushes water out there. I have never seen a pump that would not pump! The water floes from pump through the elbow into block , through block to back and then up into the head and back to front of head to thermostat housing. I do not think possible, but perhaps it is, to get head gasket installed such that return from block to head is blocked. The bypass mentioned is the small port on the bottom of the thermostat housing that connects to a small port on the pump. Uses about a 1 inch length of heater hose. If the pump portion is plugged and a thermostat is installed, very little water circulates until the thermostat opens. I had this on a pump "professionally" rebuilt.

Good luck.
Ben

[Rustytractor]

Seems something is plugged. The suction hose CAN collapse. Before pulling the pump as Bob suggested, Perhaps remove the elbow from pump to block and see if pump pushes water out there. I have never seen a pump that would not pump! The water floes from pump through the elbow into block , through block to back and then up into the head and back to front of head to thermostat housing. I do not think possible, but perhaps it is, to get head gasket installed such that return from block to head is blocked. The bypass mentioned is the small port on the bottom of the thermostat housing that connects to a small port on the pump. Uses about a 1 inch length of heater hose. If the pump portion is plugged and a thermostat is installed, very little water circulates until the thermostat opens. I had this on a pump "professionally" rebuilt.

Good luck.
Ben

Ben, the whole thing has me stumped. All components that make up the entire cooling system (thermostat housings, elbow etc) have been removed, sandblasted, refaced, checked and reassembled. The small bypass hose was replaced as were the top and bottom hoses and thermostat. I also took the back plate off of the water pump, cleaned it out, checked the impeller, seal and bearings were ok and reassembled with a new gasket. As as mentioned in my original post the rad was flushed and pressure tested and was ok.

If im correct water passes from the block to the head through the head gasket by cylinder #8 so I suppose if the head gasket was fitted the wrong way round flow would be stopped but the gasket is clearly marked "Front" so I don't thing it was fitted the wrong way round (is this mistake even possible ??). My partner refitted the gasket and head while I was working on another car and I've already asked him about this - he said he definitely fitted the gasket the right way round.

I can't see anything other than the pump being the cause but for the life of me I don't see why because I checked it.

Very puzzled !!

[firstofeight]

Anything new on this problem. Please don't leave us hanging.

Ben

[bob k. mando]

i dunno, man.

fluids are pretty straight forward. you either have pressure or you don't. if you have pressure, the water is going to flow UNLESS something solid is blocking it.

if all the individual components flow, then there has to either be a problem in assembly or no pressure from the water pump, somehow.

[LONG]

welcome. and I believe you'll find a thread that states you need the tstat in place. verify coolant is getting to your rear cylinders. there is a petcock on the right side of block. I would remove it and make sure there is no muck in there. also take a womens pantyhose and put around your upper rad pipe....this will keep the crap out of your rad.

[LONG]

like this fun debris found completely blocking 7-8.

[Rustytractor]

like this fun debris found completely blocking 7-8.

No progress I'm afraid - life, holidays and a new grandson have meant the Buick problem is on the back burner

Re debris - that's exactly like what came out when I cleaned the block, except I got WAY more out than that !

Re petcock comment - this is what originally alerted me to the problem. As previously mentioned in this thread the top half of the engine has now been disassembled, totally overhauled and thoroughly cleaned plus the block fully flushed out - and a new petcock fitted ! Clear water now drains from the block petcock without a problem.

Ive been in contact with a guy in Holland who rebuilds old American water pumps who says if the clearance between the impeller and the pump housing is too big due to impeller wear the vanes won't be effective and will basically just thrash around without driving water around the system. He also said that the impeller can also come loose from the shaft when warm so is ineffectual.

Everything points to the waterpump so at some point soon I'll remove and re-inspect it and either get a new one or get the guy in Holland to rebuild mine. Its a real shame as the engine now runs great and starts on the button.

In the meantime I could still do with some advice about removing/fixing/replacing the broken water temp
sender - while removing the head the original one (which worked fine) came apart leaving half in the head. Anyone else found a replacement source or know how to remove the broken part ? I've never seen a temp sender like this before as most cars use electric senders.