Chasing the heat

E-Type
1

Hi all
I’m getting to the short end of my to-do list to solve my “almost overheating” problem. No boil over, but into the bottom of the red zone, and dieseling at shut down.

So far I’ve:
Used a infrared tester to confirm temp of radiator at top is >200° Outlet is about 185° ( “calibrated” IR tester on boiling water)
Checked the functionality of the otter switch
Replaced all coolant hoses and continue use of metal center portion of bottom hose.

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Replaced the OEM fan blades with Flex-a-lite blades( using factory round motors). Someone on the list said that combination had better flow than even the CoolCat fans.
Confirmed fan rotation rotation is correct, and pulling air through radiator.
Fresh premixed 50/50 coolant
Added Red Line Water Wetter
Checked plugs and no sign of running lean
Using a piston stop, dual stop method, confirmed timing marks on damper and set timing to 10° BTDC

The only things I can think of are radiator and water pump. No signs of failure of the wp and according to the PO the radiator was redone about 2010 and it looks fresh:…and it hadn’t seen many miles.

I’m tempted to pull the radiator and bring it to a shop, as that’s all I can think of for a next step.

Possibly my distributor isn’t 41060 distributor isn’t advancing??

I’m at a loss… one thing is my fans never shut down. Once they reach temp and engage, they never get the coolant temp down to stop running. So I’m thinking that it’s a problem with the cooling, vs a problem with creating too much heat. (Running lean, timing off)

Thoughts on next step? Pull the radiator or??

2

Easy to verify by watching the timing marks with a timing light as you rev the engine.

Failure to advance would cause running issues but I don’t think it would cause hot running.

Are you quite confident that you have all the air out of the cooling system?

3

Here’s a photo of the radiator and shroud. You can see both look like they’ve been refreshed not too long ago.

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4

Hmmm. Not sure how I would do that. I did have the impression that the S2 system had the small hose from thermostat housing to top of radiator and I thought that was there to remove any air. But tell me more.

5

I use aftermarket fan blades with the stock motors and they move more air than the factory blades, but I don’t think they equal the amount of air the Coolcat fans move. Your aftermarket blades look different than mine.

Check timing and advance, mixture. Do you have the correct thermostat and is it operating properly?

6

I think that was the intent, but on mine that small hose and the bobble-thingy in thermostat housing did not let air thru easily enough to eliminate air from the system. To improve the situation I drilled a hole in the thermostat and positioned it at 12:00:

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I made it larger than I really needed to but in Tucson (and pehaps Florida) I rarely need immediate cockpit heat so I made it bog enough to be very sure the head would easily fill with no air pocket.

2 Likes
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The blades are Flex-a-lite, 10”. They seem to generate more flow than the OEM, as I stand by the side of the car and get hit by the blow. But that’s not an objective evaluation I know.

John did you do the evaluations of fan options?

I have my timing at 9 to 10° btdc.
The thermostat is the type with the foot, that should block off the round bypass outlet. There was a bit of corrosion to the mating surface of the housing, where the thermostat “ foot” seats, but I cleaned it up as best I could.

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I had the bobbly thing at 12:00 and checked the housing to be sure the small fitting was open enough so it would work, or so I thought. I am running the 4.2 Triple su manifold, and that has the sender on the top of the intake manifold. I pulled it and the coolant was right up to the top. Would that be an indication that there is no air trapped?? ( My thinking is that it sits at about the same height as the bleed hole in the thermostat.)

9

Bob, yes 200 + seems hot for light loading or idle, but I would try to fix the dieseling. Try more advance?

10

Robert here are Coolcat fans in my car. From this view both rotate counter-clockwise. Are they different orientation than yours ? If so do you think it makes a difference ? Link below is thermostat I am pretty sure is in my car. Has been years since I installed but my memory is this was the style I got with the lowest temperature opening I could find back then.

David
68 E-type FHC

https://xks.com/i-6918766-jaguar-180-degree-thermostat-ja-ebc3576.html?ref=search:https%3A%2F%2Fxks.com%2Fsearch.html%3Fq%3Dthermostat

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Bob, I agree with those who say check your timing.
I do not know the history of your heating problem, but how much difference have the changes you made effected the overheating? How much have the fans, additives, hoses, etc. helped reduce the temperatures?
How much variation in temperature do you have from idle to speed? In other words, do you see your temperature being pretty well regulated at 200F, or is it 205 at idle, dropping to 185 at light cruise?
I would consider pulling and check the thermostat.
Tom

12

I’m a rookie when it comes to cooling fans. I know enough to know you can’t believe some of the claims made by manufacturers and sellers. I’ve seen the same fan listed in one place with an output of say, 900 CFM and the same fan on another site claiming a much higher number. As in all things, do research and buy from someone you trust.

I bought the Flex-a-lite blades years ago and had them on the 2+2. I did so just to see if they worked better, turns out they do. They move more air than the stock blades with the stock motors. About 20% more by my rough calculations involving a home made wind tunnel and an anemometer. All that is at zero static pressure; no radiator sitting in front of the fans to impede airflow. I’ve no idea how much static pressure the radiator, and in my case AC condenser, creates.

13

I’ve only got the dieseling when it was into the red, once or twice. So I’m thinking if I can cool it down that will go away.

14

Hi David.

Thanks for the photo. Mine rotate clockwise from this perspective. So the blades angle, while different on mine, I believe would be correct for that direction of rotation. When I mounted the new blades I was careful to match the angle of the new blade to the old.
As a quick test, to confirm, I held a piece of cardboard in front of the radiator and it was pulled in towards the car.

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David

I’m fairly certain that I bought that exact same thermostat from XKs. I was specifically looking for a 180° one, and that had the appropriate “foot” to seal the bypass.

16

Bob
I have searched the Flex a Lite website but could not find 10" fan blades, do you by any chance still have the part #4sale

17

Hey Len

Here’s the fan blade I got from Summit Racing

18

Interesting.

The fans I bought are somewhat different, narrower blades.

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Hey Tom

This had become my primary concern, because when I bought the car it had no timing marker, so I had to attach one, and opted for the timing cover version, which has me set timing to cylinder #3.

That was awhile ago, and the timing marker has oval holes for adjustment. At the time, I just centered the marker.

A few days ago I got ahold of a piston stop, and used the double stop technique, to find TDC. I have a Snap-On timing light and set it to 9-10° bdtc.

I then went for a drive and between the Water Wetter, New fan blades and timing adjustment I’m a bit running cooler. I was getting into the edge of the red zone consistently. Now while running at 35-40 mph I stay just past the L. But once into stop and go traffic, it starts to climb, getting just short of red zone.

Thoughts??

20

Thanks Bob, placed my order for two