15 YEARS AND NOW IT'S OVERHEATING?

[Westfield 129]

So, the 11 was parked for a while, as there was an R5Turbo blocking its exit. For nearly two years. Anyway, the R5 now moves on its own, and I took out the 11. Worked perfectly, running at its usual 80C, on the 'stat, as it should. Then, the fan switch quit, or rather kept working all the time and ran down the battery, which can be a bother. So I decided to replace it with a part from American Volt (sold direct or Amazon), that was a lovely machined cast part that held a thermo switch to turn no and off my fan. It was spliced into the top hose as it was compact and it was a quick and dirty solution to my problem.

So... the switch worked for a short time before it fried, and the engine started to run hot, at about 100C, which was unusual, even here in Sunny California. The fix was obvious, fix the fan switch, with was replaced and now switched the fan through a relay from a SPAL fan kit that I had on the shelf. Now, the fan went on and off at 70C, but the engine still was running at 100C.

A bit of history. I have replaced every piece of the drive train (including the diff, which on my car is a TranX LSD). The engine is just the original block, cylinder head, water pump, brake and clutch cylinders... Everything but one thing, which you probably guessed by now. The Radiator.

So, I looked up one from, of all places, JEG"S, one of our larger warehouse hot rod parts distributors. BIG they are. Anyway, for some "econo-dragsters", they stock an MG Midget alloy radiator for about $200. I was going to order one, but then decided to do a quick internet search on MG Midget alloy radiator, and found that the same Chinese made rad is all over the internet for about $140. Being just a little cheap, in that I don't always accept "retail", I ordered one from "Winning" something... I believe that I ordered a coolant recovery tank from them a few years ago that is lovely, but I am not using it at the moment (though I should). Anyway, the thing came, weighed next to nothing and seemed to be properly packaged and well made. It arrived in just a few days.

I jacked up the 11 and finally got around to doing the change. The rad fit perfectly, but used 8X1.25 metric bolts rather than the 10-28 or whatever was used for the original British part. It took an hour or so to get it in. I made a small change to the cooling system, adding a hose barb to the heater port on top of the head so that I could run a hose to the 5/16 inlet on the rad next to the inlet. This does reduce the temp of the rear cylinder. Easy to do, as all that is needed is to tap the hole 3/8 NPT and screw in a right angle 3/8 NPT fitting to stick a hose onto. I used a 3/8~1/4 NPT reducer bushing, and a right angle 1/4 NPT fitting. Stuff I had on the shelf. 'Surprised that I had not done this sooner.

I raised the nose a bit more (to make sure that coolant got into the back of the cylinder head, and hooked up my "AirLift" vacuum cooling system tester and filler. The cooling system held a depression of 27" HG, collapsing all the hoses. I then put the fill hose into the gallon of pre mix coolant and opened the valve. The system was fulled in about a minute, free of voids (I hoped. The AirLift usually works perfectly).

Tired of rolling around on my back and being bent over a two foot high car, took a couple of days off. Well, what actually happened was Hurricane Hillary, a once in two lifetimes event here in California. It hit us as a tropical storm and then HURRIQUAKE! Biblical, don't you think? Anyway, the heavy rain subsided this afternoon, and I finally got the car out of the garage.

I tried to get it to run hot. I have to admit, it was only about 23C here, but I lugged it up the hill several times and found that the engine now ran at 70C, on the thermostat. The fan switched on at 70C as well. Prior, it would run at 80C as I had an 80C thermostat installed. Now, it runs cooler, and when parked and the temp allowed to rise, will immediately cool to 70C. So, Ok, it's fixed, and I didn't have to do anything silly, and it only cost about $140 USD.

Pointing my contactless IR pyrometer around the engine showed that the temps ere being thermostat controlled, and that the back of the cylinder head is now the same temp as the front. The new rad is shedding more than 38C, which is a lot better than the old, rotten copper/brass item.

I am quite happy with the results, the engine now running cooler than ever. I am going to have to put the 80C thermostat back in, but I am going to wait, you know, Climate Change...

I wanted to do a new radiator installation with the radiator leaned back, for a better flow into the front of the bonnet, then through the rad and exiting down under the chassis, into the low pressure area, sort of like the original 11. That will have to wait for a while as I design the brackets and work out the hoses. I have done this setup before, using a very expensive dual pass custom made race rad that was unbelievably efficient. Using a stock form Midget rad is a little more complex, as the hose at the bottom can't extend below the frame, and the top one has to angle back up. I have seen this done before, but not very neatly.

With the rad angled forward as it is, the air gets trapped in the frame and can't really make the corner to exit under the car. I had fixed this problem on my RHD build, but have not done a thing with my own car. I shall get around to it.

The engine is now around 15 years old, and has around 20,000 miles. It still uses about a pint every 3000 miles, which is really nothing for a 10.7:1 compression engine with a very hot cam. While redlined at 7200 RPM, I have set the limiter at 6400, as it is making about 125 HP at that point. It has been completely reliable and has not required anything other than a single valve adjustment (roller rockers) in all that time, and with its Pertronix ignitor, never had a timing adjustment. When it began to overheat, I was not really worried much. Only recently, it ran fine, and there was nothing that had happened to it. I do compression tests from time to time, and they are always the same. In the end, there was only one part left to change that was left over from the original build, done years prior to my acquisition of the car. So now, it is back to its old self; a proper road rocket that, believe it or not, is actually quicker than my Morgan +8 (but not for long... The +8 is getting its engine blueprinted, ported and cammed. Should have another 100+ when done).

The 11 is quite shop worn, as it was when I acquired it, but with primer blotches on its nose, from when someone backed ito it. It should look better than it does, and hopefully, I will be able to make it pretty again. But, scars be damned. It is mechanically excellent, with plenty of power, a Datsun 5 speed and LSD to rocket off corners without the annoying inside wheel spin. It does stick a bit too well on the 185/70/13 tires. More 7 than 11, but I do have 15" s on my wish list, along with the proper Dunlops, which nobody cares about here. We are short a daily driver here for a while, so the 11 will be an occasional grocery getter (very small groceries, of course) and will be taking me to the dentist tomorrow. Now in my 70s, it is a bit of an exercise to get in and out of, but where can I get such exercise that is actually fun?

This weekend, going to carve a couple of canyons.

[bobwhittaker]

See my comments Friday August 18 2017 Re heater tap mod , nice and simple no problems in six years .
However I don't have big power and ambient conditions in the Yorkshire Dales don't match those of " The Canyons " .
The kit made 58 years old this year ( Chassis No 123 ) and I have made 80years , " Thank the Lord for the NHS " ! ! ! !

[bobwhittaker]

Correction to my previous post .
Kit is 38 years old chassis no. 123 ( 1985 )
Donor is 56 years old ( 1967 )
I have made 80 years ( 1943 )
Cheers everyone Bob Whittaker .

[jonclancy]

Morning All,

Thanks for the write up, Jan. I’ll have to have a look at this radiator of yours. Sounds like a bargain! Seeing as the weather is nice, why don’t I drop over for a look-see?

That’ll be the thread mentioned by Bob.

https://www.westfield-eleven.org/forum/ ... 9&start=20

Time certainly flies - my chassis (as built by Tony Lincoln) is 2007, with a 1970 donor. I’m fast approaching 60, but hope to be enjoying the car for at least another 25 years!! My eldest son already has staked his claim. Still in the collection growing phase, so No 2 won’t miss out.

The kit thermostatic switch is a Ford item, and is reasonably robust. Mine did die at Le Mans last year, but a cheeky shorting link in the plug did the job perfectly as a get-you-home. I replaced the whole switch on returning, but beware that there are a few different ratings - that standard Fiesta etc ones run much hotter than we need. That was sorted, and it’s been golden since. A relay is a good idea, of course.

I recently had to shell out for a new dual Temp/Oil P gauge. The only one reasonably priced and available was a Deg F unit. Plumbed in fine, and the car runs pretty well (especially given the lack of love recently). My XI was garaged last October to late July. Unearthed to renew the MoT Test. All passed, and we then took a nice jaunt with Splat and KB around the Cotswolds. Downside to the day was a van rear ending the bright red Healey in traffic, but, thankfully, no injuries and only minor damage done. If it had been one of the XI in the way, I doubt he would have seen us. Lucky escape. I was thinking about installing a small LED high level brake light after that episode. And painting my car fluorescent orange!

Cheers

Jon

[Westfield 129]

A quick word about the Ford sourced thermostatic fan switch... The switch failed on my customer build as well. My guess is that it was burned out, and the fix would be a fan relay for the little thermostat switch to trigger. I bet that would solve the problem. It certainly did for mine, which uses a thermostat switch of unknown origin, that burned out almost immediately on installation. The fix was a relay. So far, so good. The switch works perfectly, the car runs cooler than ever. Fans pull a lot of power, and that burns out the thermostat switches. A relay is the fix. It was relatively easy to add one in with my Painless fuse block with all of the labeled power sources/circuits.

Now I have to fix this strange noise that comes and goes... And it is a really bad noise...

More on this when I get into the car later this week.

[jonclancy]

I’m keen to hear what you find, Jan. A very strange noise indeed!

[Splat]

My thermostatic switch repeatedly failed. Once on the very first run after installing a new one. This was my solution for adding a hidden but accessible relay into the fan circuit:

http://www.westfield-eleven.org/forum/v ... .php?t=702

[Westfield 129]

Ah yes, The noise...

Looking at everything led me to check the fan belt. The noise was intermittent, and it didn't sound mechanical. One of the adjusters had some black stuff on it, and the belt itself was a little loose. Since I have a turnbuckle fan belt adjuster, it took about a minute to tighten the belt. After that, no more noise. Note that I had not adjusted the belt in about a decade. Sometimes, the problem is simple to solve.

[Westfield 129]

An interesting note about my new radiator.
It holds a temp of 75C, even in ambient temps of 39C+. This gave me another interesting benefit.
My Weber is jetted pretty well, with excellent throttle response most of the time. There is a little flat spot off idle when the engine gets up to around 80~85C. I have become used to this, and have not really considered fixing the problem. It is something that only I notice.

So, now the engine doesn't run that hot, and the throttle response is excellent, all the time. No more flat spot. The carb seems to run right in that sweet spot between 75~80C. So, after 15 years, it just keeps getting better.