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440 Highway temps

Drivers head gasket looked better, bolts were more even to take out. Same white exhaust valves on the back two cylinders and darker valves on the front two. Seems that the back TBI assembly runs leaner than the front (Dual quad) so perhaps lean condition may be a contributing factor.

Will report back after work is done if highway temps get better. Thanks for the ideas, there are a few suspect items to chase here.
 
White exh valves can be from coolant entering the cyls. Was the engine using coolant?
 
Hard to tell, it has a slow leak where the pump mounts to the housing I have yet to fix. It's on the list before I add the coolant back in.

EDIT:
I will add, I don't think it was burning coolant, the back 4 cylinders on both sides had white valves (dual quad setup), there was no coolant smell, and the cylinders did not look clean like coolant consuming cylinders usually do, every cylinder had carbon build up on the piston tops.
 
i have exactly the same problem but the weather here in Qatar is just insane , 115f but yea - if the engine temps come down when off the highway and at low rpms i wouldn't worry about it ... depending on what the weather there is 220-230 isn't overheating if engine temp comes down at lower RPMS.

440 heating only on highway speeds
 
josephqatarcarguy said:
i have exactly the same problem but the weather here in Qatar is just insane , 115f but yea - if the engine temps come down when off the highway and at low rpms i wouldn't worry about it ... depending on what the weather there is 220-230 isn't overheating if engine temp comes down at lower RPMS.

440 heating only on highway speeds
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Wow.....all I can say is Qatar is a great place to be FROM......stay cool, the best you can......
BOB RENTON
 
You need to make sure your EFI system is advancing the timing properly, if it's not fully advanced by 2500rpm it will overheat quickly. Needs to be at least 35-40 degrees at cruise. I have no idea how your system controls the timing but it needs to be programmed to fully advance by about 2k and add a little extra at light load high vacuum cruising.
 
Could have discovered this much easier by reading the plugs as previously suggested, but at least you are onto the real issue. Hope you get it resolved soon.
 
#41 said:
Could have discovered this much easier by reading the plugs as previously suggested, but at least you are onto the real issue. Hope you get it resolved soon.
Click to expand...
These were the plugs. They told me I had a valve seal problem... :thumbsup:

Stealth heads are installed. I reinstalled the old plugs to get it running, i will put in a fresh set and re-read them after a bit. I will say the new heads definitely run better.

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You mentioned the engine is an RV unit. I recall some RV water pumps have “reversed” impellers? Can others confirm this? If his is reversed it would not flow well.
 
jphemi70 said:
You mentioned the engine is an RV unit. I recall some RV water pumps have “reversed” impellers? Can others confirm this? If his is reversed it would not flow well.
Click to expand...
Which engines????.....what year?.....do you have a part number of the "reversed" pump or a pix......for reference?.......
BOB RENTON
 
@zombezoo did you go for a set of the 440 source stealth heads ? Did you get the assembled heads with their valves / springs/ retainers ?
 
Canadian1968 said:
@zombezoo did you go for a set of the 440 source stealth heads ? Did you get the assembled heads with their valves / springs/ retainers ?
Click to expand...
I bought directly from 440 source. They were assembled heads. Car runs much better. The engine had what were presumably the factory steel shim type gaskets. Between leaky valve seals and presumably bad valve sealing the car did not want to idle very well with the original heads. Its much smoother now.
 
As an update to the original hightway temp topic, I finally got the chance to put a FlowKooler 180 degree high flow thermostat in to replace the parts store replacement I had installed. Unfortunately the same issue persists. It runs cool at idle and around town as long as I keep it under 50mph or so. As soon as I get on the highway and start running 70mph (727 with 2.73 gear is about 2500prm sustained) the temps creep up. It will cool back down if I slow down below 50. My next plan is to swap over to a different set of pulleys, I purchased a complete set from an AC car which appears to be a smaller diameter water pump pulley.
As im typing this I realized I never checked for lower hose collapse so I will also look for that, I'm pretty sure there is no metal wire in the lower hose I installed.
 
I just read something that the radiator hose wire was a factory piece due to the assembly process using vacuum to do the initial fill of coolant on the assembly line. It was apparently not needed to prevent collapse during operation because the radiator cap should have the system under pressure during operation. Does anyone know if these wires are actually needed?
 
Nope, but it can't hurt, and since your issue is still undiagnosed, this somewhat easy fix ought to be near the top of your list.
 
zombezoo said:
As an update to the original hightway temp topic, I finally got the chance to put a FlowKooler 180 degree high flow thermostat in to replace the parts store replacement I had installed. Unfortunately the same issue persists. It runs cool at idle and around town as long as I keep it under 50mph or so. As soon as I get on the highway and start running 70mph (727 with 2.73 gear is about 2500prm sustained) the temps creep up. It will cool back down if I slow down below 50. My next plan is to swap over to a different set of pulleys, I purchased a complete set from an AC car which appears to be a smaller diameter water pump pulley.
As im typing this I realized I never checked for lower hose collapse so I will also look for that, I'm pretty sure there is no metal wire in the lower hose I installed.
Click to expand...
I wonder if your clutch fan is pulling enough air at higher rim. My GTX doesn't use a clutch fan and it runs cool . 7 blade fan and factory shroud.
 
I many cases at 70mph+ the fan becomes an obstruction for optimum air flow and why they began adding shroud flaps to move more air at higher speeds.
 
I have heard of guys using one of these to mount their fan. It will eliminate the clutch all together letting you know if it is the problem. Might not be what you want with a/c.

Pardon Our Interruption...
 
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