Radiator

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StephenH
Posts: 25
Joined: Sat Oct 31, 2015 8:28 pm

Radiator

Post by StephenH »

So what radiator do people use on their XIs? I'm guessing a lot use a standard Midget one, but do some use an aluminium one? It looks quite expensive, so I'm not doing it unless I need to. The engine will be quite high powered, I'm not sure yet just how much power, but it will be a big bore Peter May "fast road" engine using a Piper "fast road" camshaft, gasflowed head with 35mm. inlet valves and 30mm. exhaust. A 45 DCOE Weber will probably supply the fuel/air.
Westfield 129
Posts: 867
Joined: Sat Jun 04, 2011 4:20 am

Re: Radiator

Post by Westfield 129 »

The standard X flow copper/brass radiator works quite well, and there is a ready mounting for it. Properly mounted, it will work quite well, even in traffic at ambient temps of over 42C (100 F).

My engine is similar to yours, running 10.5:1 compression, scatter pattern cam, and a Longman race head with a 45DCOE.

There have been many cases of over heating with this unit, but the problem is the fan/shroud and the front ducting, rather than any problem with the radiator cooling capacity itself, which I have found adequate up to 130 HP.

Eliminating the cooling problem is easy. Just surface mount a "Puller" fan behind the radiator (pull through tie mountings work fine) and don't mount the shroud, as it blocks more than 30% of the radiator surface area. You can use fan supplied in the kit, but it is a "pusher", designed to be mounted on the front surface. It is not as efficient running in reverse as a specifically designed "puller" mounted on the back surface of the radiator. The shroud is not necessary. Throw it away. Install a floor to the frame forward of the radiator and some side pieces to form a duct. This also helps with the cooling, especially when the car is rolling. Make sure that the air has a place to go once it is exhausted through the radiator. Don't seal off the engine compartment floor unless you have a radiator outlet slot beneath the car.
Also, plumb the cylinder head heater core outlet into the plumbing. Tap the hole for a NPT fitting and run it to the radiator or to the header tank. This will further reduce the coolant temps and eliminate a hot spot at the rear cylinders.

Do not try to clean up the cooling system plumbing by reversing the inlet and outlet hoses (I know, this is obvious, but...). This will result in instant over heating. I only mention this as I have seen a couple of cars with this modification. The lower hose has to go to the lower radiator outlet and the water pump.

Alloy Radiators:

I have built a couple of custom alloy "double pass" cross flow radiators with both inlet and outlet on the left side, same side as the water inlet/outlets at the engine. It is a very light weight, lower profile double pass design that eliminates the cross over tube, increases efficiency, and greatly simplifies the plumbing. It also has the purge line for the header/fill tank, or a return for the cylinder head heater tap (plumb this into your cooling system, rather than capping it off. Engine temps are reduced by about 10C or more). I was able to use the supplied radiator piping that came with the kit and a couple of right angle bends. The weight of this unit is only 1Kg, as opposed to 7 Kg for the stock Spridget unit.

The alloy rads were built by Ron Davis Racing Radiators here in the US at a cost of around $700 USD. Way too expensive to be practical. Each was a special design. The radiator also requires a specially fabricated mounting (done on my break at home). The unit is about about 30% smaller than the stock Spridget cross flow part but is 3X more efficient. Even in very hot weather the engine runs on the thermostat at 80~90C. It is VERY efficient.

Tips: If you age going to try a custom built alloy radiator, or are looking for a racing radiator, II would definitely stick to a double pass design of a small enough size to be bulkhead mounted (or at least close to straight up and down, rather than the steep angle of the stock radiator mounting, as it is more efficient. Keep the radiator within the frame (I have seen a few cars with the rad poking out below the frame, which complicates jacking, and compromises the front ground clearance). An 8" fan that will probably fit on half the radiator, mounted to the back surface (your fabricator can integrate a mounting for your puller fan). Put both inlet and outlet on the same side, and make the core three rows or more. The lower (outlet) should face upwards at 45º, put the vent/purge on the side or the top, depending on what fitting you choose to use, and plumb it to your header tank, just as in the Westfield system drawing. You should also tap the heater outlet at the cylinder head for a fitting so that you can run a line to the header tank as well. I bought an alloy tank from Moroso, and added a second bung to the side so that I could run the radiator purge and the cylinder head heater line directly into the header tank.

You can see all the water plumbing in the album images of the engine and cooling system installation. The secondary lines are all push on hose, eliminating the hose clamps, with a pressure limit of 150 PSI.

You can also find an alloy radiator of the same dimensions, or lower in profile, as the standard Spridget cross flow that fits the mountings that are supplied with the kit. This means that there are mounting pads on the top edge, while the bottom fits into the supplied mounting plate. This will give you a more efficient, and lighter system, and allow the use of the original mountings that came with your kit.

The mounting of the current custom built, alloy double pass radiator is covered in my build album at Westfield_Eleven or at Westyxiownersbuildersdrivers.
bobwhittaker
Posts: 194
Joined: Sat Sep 08, 2012 5:42 pm

Re: Radiator

Post by bobwhittaker »

I have used one of the older pattern brass upright radiators ( Bought new about £120.00)
There are advantages as follows :-

a) Price.
b) Large self contained header tank.( No additional plumbing )
c) Far less fragile than aluminium ,even to something as minor
as snagging during installation.
d) Fitted vertical so no shrouding due gills being angled to airflow
e) Plumbing far simpler,top hose is nothing more than a simple
90 degree bend from Tstat housing to radiator.See further
comment below.
f) Easy access to fit a pusher fan. ( Seldom runs)

In addition I have paneled the underside of the chassis from the bottom leading edge of the bonnet / hood
rearwards to just clear of the lower tank of the radiator,fitted panels to the chassis sides, panels from the
radiator sides to the chassis side panels and paneled the gap from the top of the header tank to the underside
of the bonnet. This work ensures all the air scooped up through front grill passes through the radiator. I have
not paneled to the rear of the radiator so the air has free passage to exit.
I have a pusher electric fan on a manual switch, seldom if ever used in UK summers provided I keep rolling,
even in traffic.
The top hose ( 90 Bend ) is a Mini item with a 1/2" bore " T " ready bonded to it and I have run a short pipe
from the heater connection at the rear of the cylinder head into this, much in line with previous suggestions
to help prevent a hot spot.
In addition I run a thirteen row oil cooler which obviously assists the overall cooling.

The car will run at 4000 rpm ( 5 speed gearbox, 3.9 Diff, 165 x 14 tyres, 22.3 mph / 1000 ) at steady coolant
temperature and oil pressure without the electric fan.

Over and above all the foregoing ensure the water spaces in the cylinder block and head have been thoroughly
cleaned before the engine build. Knock the core plugs out and either chemicaly clean or power wash. If it is a
rebuilt engine I would even suggest the initial runs be done with the thermostat removed and a stainless steel
domestic " Pan scrubber " stuffed in its place to act as a filter. Nothing worse than plugging the tubes on a new
radiator with scale and crud, the scvrubber can be discarded and the Tstat refitted.

I hope it has all made sense and wait till you get the car on the road ! ! People can't believe they are a copy
of a 60 year old car and you will have to add time to you journey if only to talk to the many admirers.

Cheers Bob Whittaker
Westfield 129
Posts: 867
Joined: Sat Jun 04, 2011 4:20 am

Re: Radiator

Post by Westfield 129 »

Our experience here in Sunny California, is that the early upright rads don't cool during the summer with a stock, 65 hp engine in an ordinary Bugeye. Adding a pusher fan only makes things worse, but if it is a puller, that helps, a little. Double the HP, and, well, you really need the crossflow radiator. The couple of W11s I had here with the upright radiator overheated even on short drives in the canyons.

The W11 kit comes with everything necessary to use the cross flow Spridget unit so mounting is easy. Nothing to fabricate. The only mod that I recommend is to put a puller fan on the backside of the radiator, and discard the shroud/fan mount as it blocks most of the rad. The kit comes with a proper header tank and plumbing, as well as over the counter radiator hoses that are not expensive.

The floor panel in the frame from the nose to the front frame bulkhead is definitely a necessary mod, regardless of which rad you use. A couple of side pieces make a lot of difference as well. All the air has to go from opening through the radiator or the thing wont cool, regardless of which rad you use. This was an early problem with the Distributor's demo car (one of the first of the late chassis W11s) that I had to prepare for testing. It overheated. No air through the radiator...

Use the automatic thermostat switch that comes with the kit, because there is nothing more embarrassing than to forget your fan switch and overheat your engine in traffic. The thermostatic fan switches are very reliable, and used in every new car made. You can even use the electric fan that is supplied, wired in reverse. But it is not as efficient as a proper "puller" design. I have yet to see a thermostat switch fail, but I have fixed a lot of head gaskets when an owner forgot to throw the switch.

The advantage of sticking with the cross flow is a simple one. It fits with the parts that come in the kit, and makes a proper modern cooling system.
bobwhittaker
Posts: 194
Joined: Sat Sep 08, 2012 5:42 pm

Re: Radiator

Post by bobwhittaker »

To coin a phrase " There is more than one way to skin a cat." and as we all know there are no two W11s alike. We would
have nothing to talk about if they were all the same.

Mine is an early kit, Chassis No. 123 , probably manufactured about 1985-86, which I purchased unbuilt in 2010. There were
no obvious mounts for any radiator, upright or cross flow and I used items I had to hand as well as fabricating items I needed.
This has resulted in a reliable straight forward car which I modify / improve as I go along. So far the best upgrade has been
the Ford five speed gearbox with the use of a proper clutch release bearing instead of the carbon faced MG component.

The car went on the road December 2012 and has now covered some 15,000 miles since build with no problems at all, except
the early clutch release bearingfailures. It has never given cooling problems and I can only quote from my own experience that
the system installed works well and is more than equal to " A proper modern cooling system ", albeit I am not claiming any big
numbers as regards engine output. It might also be nothing more than ambient conditions here in the UK are not as onerous as
those in other parts.
Cheers, Bob Whittaker
Westfield 129
Posts: 867
Joined: Sat Jun 04, 2011 4:20 am

Re: Radiator

Post by Westfield 129 »

The cross flow from the Midget works fine (with a puller fan setup, eliminating the fan shroud that comes with the kit), and the kit has everything to mount it, as well as a production car thermostatic fan switch and mounting bung in the coolant pipe. I imagine that most of the kits are built this way (as it is an easy assembly, and the parts are provided). I am using this setup in my personal car that now has over 65,000 (maybe more) miles, using a 125+ HP engine, in California, driving in the summer' in the mountains, deserts (track time), and in Los Angeles traffic. 'Works fine.

Just plan on a floor panel in front of the radiator, and maybe a couple of small triangular pieces to guide all the air through the radiator. About another 15 minutes of very easy fabrication for maximum cooling efficiency. If you need a picture, I can supply. PM me for any specific instructions or images of a complete installation of either an alloy custom radiator, or the normal X flow installation.

Just plan on not using the radiator blocking shroud. You lose about 40% of your cooling with that part, including the fan center, all blocking the air flow...

My car is also an early one. Chassis 129 was built in '84 and has been driven more than 60K miles over the 10 years that I have had it. It came with a spridget cross flow radiator, and a floor panel in front of it, and some pieces of plastic held together with tie wraps, which I replaced with some alloy panes that were easy to shear and install. It has worked fine, even when I increased the power by more than 2X. The radiator mounting was not badly done, and I have not changed much over the years other than to move the fan, fixing the overheating problem that had plagued the car since its construction. The floor and the pieces of plastic indicated an attempt to fix the problem. They were going in the right direction but the fan was not...

I have built three of the late chassis cars using the Spridget radiator, and found that the installation was straight forward. No surprises. Everything fits.

The only problem using the Spridget cross flow is that it's heavy. But it works just fine.
erictharg
Posts: 680
Joined: Thu Jan 29, 2009 7:50 pm

Re: Radiator

Post by erictharg »

Best radiator I've found that meets all the above criteria is for an early A Series Metro. It will mount in front of the chassis at about 70deg to horizontal (so it is just shy of touching the bonnet) and gives an efficient two pass copper brass unit at low cost. As Jan says the stock Midget unit is OK if you ditch the frankly shit Westfield fan mount that masks maybe 50% of it's area, and ensure the incoming air is ducted through it. When racing I'd have 75 to 80 deg coolant temp at 20 ambient. Rig up the fan behind it so as to mask as little of the core as possible. Genuine new old stock rads can be had to less than £40.
Westfield 129
Posts: 867
Joined: Sat Jun 04, 2011 4:20 am

Re: Radiator

Post by Westfield 129 »

The late production W11 kits have a modern cooliong system, with a fan switch, and a header/purge tank.

My early car has just a amall alloy swirl pot/filler with a pressure cap. No header tank, and the fan switch is a thermostatic one with a sensor that slips beneath the radiator hose. Very crude, but it all works. The early cars required a bit of fabrication where the new kits don't.

My cars all have oil coolers, but not everyone shares my interest in cool oil. There is one additional virtue to adding a cooler, in that plumbing it in can get rid of the main oil pipe on the side of the engine that gets in the way of the distributor hold down plate and the timing adjustment. Pluming directly into the main oil gallery outlet and return cleans up the side of the engine, and makes oil filter changes a snap.
jonjh1964
Posts: 64
Joined: Sat Feb 18, 2017 10:10 pm

Re: Radiator

Post by jonjh1964 »

After the Stoneleigh weekend with 2 x 150+ miles journeys in increasingly hot weather I found that the water temperature increased with 'spirited' driving and went down whilst static in traffic when the fan cut it; oil pressure dropped with temperature too much for my liking in traffic at idle. My setup is largely the standard Westfield design with the only modification being connecting the heater outlet to the top water pump hose.

The car is currently off the road awaiting a replacement aeroscreen which suffered cracking/crazing around the top bends in the heat. I've fabricated some ducting closing out the bottom and sides of the space from the bonnet intake to the radiator. I'm now looking to fit an oil cooler, my current plan is to mount it on the lower radiator ali mount, cut a slot the size of the oil cooler and fabricate a ducting that goes under the main radiator duct.


I'd welcome photos of oil cooler mounting and any ducting to help me finalise the design.
Westfield 129
Posts: 867
Joined: Sat Jun 04, 2011 4:20 am

Re: Radiator

Post by Westfield 129 »

If you still have a cooling fan mounted to the shroud in front of the radiator, get rid of that setup immediately. That causes lots of cooling problems. We don't even bother with that setup here in Sunny California where a normal spring day is likely hotter than a "hot day" in the UK.
Attach the fan to the backside of the radiator without a shroud. Use through the core mounting, and make sure that you have a proper "puller" fan for the best efficiency. Use an automatic thermostatic fan switch so that you don't forget to turn the thing on.
Hooking up the heater outlet on the head to the top hose is an excellent idea.
Filling in the frame space in front of the radiator will form the bottom of a duct to keep all the air going into the radiator rather than under the car.
You can fill the spaces between the forward leaning radiator with alloy to give your duct some side panels. You can also make side panels that fit within the body when it is closed. Every little bit helps.
Make sure that you have a good quality cross flow radiator, or you can try an alloy radiator. I had a double pass alloy rad built for me at great expense. It worked extraordinarily well. But it was also extraordinarily expensive. And... My early Westfield still has a Spridget rad that does the job with a 125 HP engine. No overheating here in CA in the summer. Max test temperature was 110F ambient. 43C.
Make sure that you have the right timing setting for your engine.
Make sure that you have the proper voltage from your alternator (this can be problematic if you are running points. Too much voltage can burn the points and make the engine run more advanced, and increase temperatures, especially if you are running at high speeds. If you have points, get rid of them and install a Pertronix Ignitor or similar magnetic trigger or magnetically triggered distributor.

The oil cooler can be mounted on a plate between the frame tubes behind the radiator. This is the easiest mounting, requires no ducting and has plenty of air flow. You can easily pop rivet an alloy plate to mount the oil cooler. Use -10 hose if you have it. You can also use -8 hose. Push on hose is excellent for this installation, and will save you money. Very easy fabrication. You don't need to get carried away with duct work, and you don't need to install the cooler in front of the radiator. Use the airflow behind the radiator, rather than blocking the air flow to the radiator.

I use a hook up that replaces the external oil line with a line from the block, and a line back to the oil filter.

Your oil pressure can be adjusted with shims in the relief spring, or you can get one of the adjustable relief valves.

As I recall, oil pressure should be 40 psi, no more, no less, at cruise~max RPM. You may want to check this in Vizard's book.
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