My son has an XY wagon with a freshly built 302W (probably original block). It runs straight gas and has electronic ignition and a slight cam. The motor is fitted with a massive radiator (custom triple bi-pass) that runs a set of EF fans off a 120 amp alternator and a 770 amp battery.
The motor runs too hot (the standard gauge hits the 3/4 line just before the RED) while on the freeway, but while I've stopped at a set of traffic lights the temp will be quickly dragged back down to somewhere between 1/4 and 1/2 depending on the temp of the day.
I feel that the fans and the radiator are doing a fine job but the cold water doesn't seem to be flowing through the block. We've tried drilling small holes around the outer edge of the thermostat and have also removed the thermostat altogether, which should have created a very cool running motor with the size of the cooling system he has (for the big block he's dreaming of putting in one day).
The bottom hose is firm (and I can feel the inner spring) so it shouldn't be sucking in.
The radiator often has foam and bubbles in it when we check the fluid level when the motor is warm.
One radiator guy suggested that he'd heard of older Windsors with "pitted" blocks due to their ages. The pits are on the water jacket side of the bores and causes microscopic amounts of water to instantly boil on the surface, then these gases collect and can gather around the water pump impellor and cause cavitation.
Any personal experience and suggestions would be much appreciated. Thanks guys.
How is your EGT?
Does the temperature drop if you run the cabin heater?
Is your valve and ignition timing correct?
Are you underfueling?
What is your vacuum doing at idle?
Are you sure your head gasket was torqued down properly and did it get retensioned after the first break in drive?
Did you skim the heads, but neglect the manifold?
Have you tried a foam supressing agent?
Are you using the right radiator cap?
Have you tried using the acid strips to see if you have combustion gases in the water?
if its 60 over it may run hot, but normally the car will always run cooler on freeway and heat up in traffic or slow driving, maybe the timing is out . u dont have a air lock in system and last , check old water temp gauge, boil the kettle and dunk the sender in the boiling water, gauge should be almost up to red or hot. remember kettle boiled water is 100 deg, and pressurised is @ 130 deg
The fans are on the inside and suck the air thru the rad and over the motor.
The water pump wasn't replaced because it was in very good condition.
What does EGT stand for ????
Heater isn't connected.
The timing is fine for gas, (about 14 degrees BTDC at idle). The motor starts easy and pulls well from low revs. The ignition curve on the electronic dissy suits LPG.
Under-fueling, I dont think so. Hard to tell without an exhaust gas analyser. Due to air temp and humidity changes - air/fuel mixtures never stay static anyway and therefore tuneups will fluctuate slightly. I tune the idle and power mixtures be ear and by driving (trial and error). I believe that because gas is dry and lacks the evaporative cooling properties of petrol, a rich mixture is worse then a lean one, so if it's out, it shouldn't be by much and could be a fraction lean if at all.
I'll recheck the idle vacuum, but from memory it was steady and in the normal range.
I torqued the heads down in stages and from the centre out to the required specs. I didn't re-torque the heads because I understood you only had to do that in the old days with old style gaskets, not the new generation ones like Felpro supply.
The heads were skimmed a little to true them up. We never skimmed the intake manifold. They appeared to align correctly and I took my time to seal all gaskets correctly with silicone. Why could this be an issue?
I haven’t tried a foam suppressing agent, (didn’t know they existed). I use an organic Nulon concentrate with distilled water.
The radiator cap was supplied by the radiator guy on the radiator, so I’m hoping he knows what he’s doing.
I’ve had a ‘sniffer’ attached to the radiator and it did detect the presence of hydrocarbons, but the radiator guy said that’s not uncommon with LPG powered vehicles, because a little gas can mix with the water in the converter, and this converter is an old one. He did say that it may pay to have a leak-down test done on all cylinders just to make sure.
I know it’s weird, because normally a motor will run cooler at highway speeds, not get hotter.
The radiator guy used his ultra sensitive laser pointing temp gauge to check the accuracy of the old XY’s temp gauge and it wasn’t far off. Not anything to worry about.
I would have thought that the timing would have to be a long way out for it to heat up the motor like this. I will check the timing again though.
As for personal experience, I did have something similar in my old lpg powered XC ute (clevo) on the highway... hot day, and it would overheat, and only when I was carrying a small load. around town, it never did it, even when overloaded... Then it went away, and the new owner has never had the problem.
i ended up putting it down to the mechanic who thought he tuned it correctly. Took it to someone who specialised in gas and that seemed to fix it.
'67 Mustang V8 4sp... what fun to drive!
Hi Rhett ,
If you have Hydrocarbons mixing with the coolant, it is most likely to be from small leaks in the Head Gasket area, I have had this problem with my 460. Not uncommon with Fords, try a large bottle of Irontite Coolant Sealer and follow the instructions , to the letter, its a quality product. 14 degrees of advance seems a bit much , try backing it off a bit in stages, you should have no more than 32 degrees Total, this is critical in an LPG engine. ( I run 10 degrees Initial and 11 degrees in the Distributor, which is 22 on the Crank ALL in by 3000 RPM.
Have your mixtures checked with an analyser, Gas works opposite to Petrol, the richer the mixture on Gas the hotter the engine will run.
Another prob. you may have is if the engine has sat for a period of time with no water in the cooling system and you fit the engine back in the car, after the first few start up's, small lumps of rust and dirt come loose from the water jackets, partially blocking the fins in the radiator, unless you have a Radiator Filter titted. This causes overheating at higher speeds, but run's normal temp. at idle.
Frank Tonitto at Silverdale in Sydney, supplies a quality Rad. Filter. ( his number is 02 4774 2022 )and is in Just Parts Magazine.
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