Thread: Trying to break the heating cycle

Blocked radiator internally.

Originally Posted by BigJon

Blocked radiator internally.

Possibly, first eliminate all possibility of a faulty cooling system. Next, your car is said to be supercharged. What boost is showing when the under load overheating occurs? Do you have an inlet air temperature gauge. What heat is your blower pumping into the engine? Are you getting detonation? Do you need an intercooler?

Originally Posted by Brian Hjelm

Possibly, first eliminate all possibility of a faulty cooling system. Next, your car is said to be supercharged. What boost is showing when the under load overheating occurs? Do you have an inlet air temperature gauge. What heat is your blower pumping into the engine? Are you getting detonation? Do you need an intercooler?

I would also suggest lean fuel, The only good thing about a holley is it's tunability. Try some , say, 68 or 72 main jets and drive it again. It'll use a bit more fuel but atleast you may be able to run some more spark advance with richer mixtures.

I mention this because I had a 110 that was running a 3.9 motor with the original SU's. The people that fitted the mtr didn't re jet for the bigger capacity engine. I went up 3 needle profiles and hey, no more overheating when towing and heaps more go. Not much of a fuel increase either.

This is the big plus with EFI when supercharging/ turbocharging, being able to increase fuel when under boost and not at cruise. Difficult to do with a Holley.

JC

I agree with Justinc, but add that while off road, in low range you are only using short bursts of boost but at 100kmh you are on constant boost which also increases intake temps which with a lean mixture will promote detonation and there for engine temp and if left unchecked will burn the tops out of your pistons or valves.

Rejet you Holley and try it, I think you will be happy with the results as you will get a wider power band to play with and if you dont drive it hard you wont notice a huge change in economy.

Carbi's are a pain in comparison to EFI so if funds allow get an EFI set up with motec or wolf control and then you will have tonnes of get up and go.

I’m running about 4-5 psi, cruising on the freeway I may just push 1 psi @ 110km/hr otherwise I have vacuum. As for intake pressures on my last outing the carbie froze up as did the accelerator mechanism and the intake manifold was only just warm. The Holley has been jetted to match the now conditions and is running a little rich to account for any leaning out but I will investigate this further sounds very plausible. This was all learnt over many moths as back firing was a major problem due to lean out. Fuel consumption is poor @ around 250km per tank running premium. Timing is a little advanced on standard but not enough to cause pinging even when almost @ boiling point.
I have a winch and spot lights covering the front grill could there be an air flow restriction at high speed. The radiator is new aluminium from a Ford, mind you I had this problem with the original RR rad and I thought the alloy may help. I thought it maybe the temp gauge or sender but when it’s on the red it boils alright.
The engine bay it’self doesn’t appear to be overly hot though, it’s not like you get heat struck when you open her up.

On the weekend I had an over due replacement exhaust system fitted. Nothing extravagant apart from a set of extractors from a donor vehicle with a 2.25 inch system with straight through muffler and resonator. Took her for a burl and he presto, thermo’s don’t even turn on and running cooler than even. It appears the old muffler was that shagged there just wasn’t any flow through the system. You learn something every day.

Been there done that another one for blocked radiator internally.

Needs pulling out the tank taking off and the radator man rods the inernals out. Core is grown over.

Took mine in they stripped it did it reassembled for $80.00
Cheers

i had this years ago also... i couldnt work out what it was... faster you went the hotter it got... turns out the fins were missing in the radiator.. slower you went the slower the air went over the radiator hence taking the heat away... faster you went it just shot through the rad... not taking much heat away! replaced the rad.. all wsa good (this was not on a landie however!)

if it was blocked.. surely it would over heat at the low speeds / climbs also?

Thanks

Steve