Need Advice badly

J

j_macy

Member
Here is the situation

1912 Touring
-engine rebuilt apprx 3 years ago by a very well respected builder (model t builder)
-Model A crank
-regular aluminum pistons(no high compression)
-new brassworks rad

This engine has never run satisfactory was far as we were concerned, we have had model t's for over 40 years so we are not new to the scene, nor is this our only T.

The car in question has started to run very hot....less than 5 miles on the road the water is boiling out the rad. What we have noticed upon our first investigation the back two spark plugs were extremely hard to remove. once removed they were very white in colour (the steel threads of the plug) while the front two looked as normal blacked by carbon. So we assumed that there might be a intake leak causing the car to run lean on the back two cylinders. So we changed the intake glands and rings. (this engine has a new exhaust and hi-flo intake). On a test drive the car ran better than ever. The way we thought it should. Upon the next attempt to try a road trip we experienced a boil over within 5 miles.

could this be a result of an intake leak? cracked block? or what? Timing is correct.
 
Car has always run hot....not until we purchased a laser thermometer did we realize just how how (280F on the head near the upper rad hose) after the glands and rings were replaced the car ran much cooler (around 200-210F in the same location which comparing to other cars seems to be normal)
 
What ignition system. What is your base timing set at. Are you advancing the timing when running. Have you richened up the mixture 1/4 to 1/2 turn?
 
Taking all you've written into consideration + your T experience I'm thinking perhaps there's a cooling system problem. You fixed a lean running condition but it doesn't appear to be the root cause of the overheating. I'm also assuming it's not the normal pukeing the T does when over filled with water. My first step would be a block cleaning or flushing of some kind. Another assumption: there's no thermostat is there? Fan operating normally? Another possibility: a leaking head gasket. It seems to happen kind of quickly and a bad head gasket would cause that.
 
I had a T that experienced that problem. Took off both radiator hoses and put an air/water power gun into the block water intake. You would not believe the mouse/varmit stuff that came out the other side. Then I did the back flush and rinsed everything for 1/2 hour both ways and never had the hot problem again. Seems a couple of the block water passages were blocked.
Something to try.
 
I had a problem like this come in to my shop, a fresh re-build also, pulled the head and found the Head Gasket did not have all the water passages punched totally out. They where 3/4 through, but not all the way. The Maker said only "sorry" when asked for the repair cost, but did send a new gasket. Good Luck.
Ken
 
if its advanced far enuff to overheat youll also have a pretty good octane knock...running the cam shaft advanced with the A crank is another story ws
 
Ken, I think the gasket supplier said sorry and no offer to cover repair was the appropriate answer in that situation. A new gasket was the only thing replaced by them because a good mechanic should always make sure the part replaced was not defective before assembly. In a case where that could not be determined then I would press for recompense.
 
Agree Bill. If he doesn't understand timing after 40 years of "T"ing he never will. But I don't believe that. Check fan operation, block/rad flush then MAYBE a compression test. It might show a bad head gasket. It's happening too fast. That's what indicates a problem to me.
 
I would tend to agree with Charlie. The extremely clean rear plugs may indicate water entering the cylinders. Some of the "boiling" may be compression leakage as well.

I would hope the rebuild of the engine included a thorough cleaning of the block but it still would not hurt to flush it.
 
J Franklin said:
Ken, I think the gasket supplier said sorry and no offer to cover repair was the appropriate answer in that situation. A new gasket was the only thing replaced by them because a good mechanic should always make sure the part replaced was not defective before assembly. In a case where that could not be determined then I would press for recompense.
Click to expand...
Not to highjack this, but to address a few things
I would agree with you on this, but for a few reasons:
Reason one, the motor was done by a well known re-builder, who would not even call me back.
Reason two: parts like this should I think, have some quality control from the factory.
Reason three: my friend was on a very limited income (S.S.I.) and GAVE UP SOME FOOD MONEY TO DO THIS as he always dreamed of making the Model "T" he owned for many years "run again".
So, in order to try and help him I made a few calls. It was a retail auto repair shop, so I would would up working the bill to the shop off. The owner was a friend, so he gave a big break on the bill.
I guess I felt that someone, should help him, just did not know at the time, it would all me.
I really feel it falls mostly on the re-builder, but the head gasket maker, has shown a big profit every year and think they could help him better then me, money wise. Just my 2¢.
 
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YUP, the comment I made was to make clear that too much advance would produce other obvious results in addition to the OH situation. I ran a direct reversing Enterprise 1000 hp tug boat for a guy a few years back. It had a bad overheat problem as well. That motor had a seawater pump and heat exchanger (lots of cooling!!!) and a 500 gallon cooling reservoir. After 1/2 hour of medium load running, the make up tank was boiling over. I pulled the four SIX INCH DIAMETER t-stats to no avail. Ultimately we pulled the 6 injectors and found moisture on the tips. Put 150 psi air in the cylinders one by one and produced lots of air in the make up rez. Hmmm... One or two bad headgaskets and one cracked head (unit cylinder config).
YES, sparkling clean cylinders, and overheating are DEFINITELY signs of leakage. A) when running,blowing cumbustion gasses out, and B) suction upon shutdown and cooling sucking water back in. ws
 
Never assume anything is right till you check it yourself and someone else also gives a second look. My guess without more info is that the two rear cylinders are getting water to them and steaming out the tailpipe might confirm it. I also agree with the combustion test where you pour into the radiator the chemical which turns color indicationg combustion gas into cooling system. Cracks, head gasket irregularities and a host of problems must be checked with the head off. Good luck and keep at it.
 
Should you be running anti freeze white smoke would indicate a head gasket leaking into the cylinders.
 
Things I would do:-
Block the left-hand side inlet hose, remove top hose and fit a pressure fitting (use a snap on stile radiator hand pump) and pressure test the system to about 15psi...leave sitting for 10 to 15 minutes the system should not drop pressure.
If pressure is lost you have a leak somewhere check to see if there is any moisture in any of the cylinders and that no hoses a leaking, as 3 & 4 are suspect I’d look them over carefully....It could be a head gasket or cylinder or head cracked.
If still unsure again pressurize the system and run the engine for a minute and see if the pressure gauge climbs if it climbs you either have a gasket leaking or a cracked head or cylinder as the pressure from combustion is leaking into the cooling system.
If the gauge doesn’t climb you have a coolant flow blockage or the head gasket is not correctly positioned remove the head and inspect.
The above assumes that the:-
Radiator is perfectly clean, the timing is correct and that you have no vacuum leaks.....to check vacuum leaks start the engine and spray some aero start around the flanges if you have any leaks the engine beat will fault.
With a model A crank the engine in now about 3.1ltr so standard jet adjustment will also see the engine run lean and hot......also check for exhaust back pressure as this will also see 3 &4 run hotter.
Hope this helps good luck.
 
Hey Doug... he's explaining how to do a cooling leakdown test on the block assembly. I agree that 15 psi would lay a (stock) T radiator to waste! ws
 
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