View Full Version : TR2/3/3A TR3 Oil Cooler

07-18-2006, 11:02 PM
I plan on adding a 13 row oil cooler to my '56 small mouth. Is there any practical way to mount the cooler without cutting openings in the lower apron under the mouth?

07-19-2006, 11:37 AM

I assume it's a street car, so won't suggest removing one of the headlight buckets to serve as an air intake. /ubbthreads/images/graemlins/wink.gif

Yes, just mount the cooler directly in front of the radiator. Keep it quite close, say within a quarter inch of the rad, near the bottom. Look at Mocal's website and you'll see that this is recommended: kept very close to the radiator doesn't distrub the airflow through to the radiator, too much space between the rad and the oil cooler and it can cause problems. Positioning the oil cooler right in front of the rad isn't likely to "rob" cooling effect from the radiator, assuming the cooling system is in reasonably good condition.

Just fab some brackets that fasten under the radiator mounting brackets. You can see photos of this mounting method on my TR4 chassis, at the link below (which are not presently close enough to the radiator... I'll be moving it closer, or will be opening vents in the lower valance/apron and moving it further away).

BTW, do you plan to use a thermostat to prevent overcooling? Overcooled oil is in some ways worse than overheated. A 10 row cooler is the more common size installed on 2 liter TRs, 13 row will give more cooling, might be too much unless it's kept in check, but I'd personally use a t'stat on any size, just to be safe.

If you are using a spin-off filter conversion, Mocal has a really neat oil cooler take-off that can stack on top of it (between the spin-off adapter and the filter), is only slightly thicker than a plain takeoff, but has got an intergrated 185F thermostat. Again, there's a photo at the link below.

Hope this helps.


07-19-2006, 12:30 PM
Regarding oil cooler thermostats, Revington TR specifically recommends against them. They question the benefit and reliability. Revington TR know these cars well.

On the other hand, Mr. R.Williams in his "How to Restore TR4 & 4A" book mentions them. I appreciate his book, but I think he is a lesser authority. His book on TR4A in particular is just plain wrong in many places...

07-19-2006, 01:22 PM
After building my TR3 engine with milled head, Elgin cam w/280 duration, roller rockers giving .427 lift @ valve, Webers, header, Mallory dual pt. etc., the engine frequently ran too hot. I added an oil cooler vertically on the side of the radiator and made an aluminum shroud to fit it, added an electric fan and punched louvers in the bonnet. I did not have a t-stat for the cooler. The engine generally ran too cool unless really pushed. Oil pressure was also quite high. I removed the cooler and concluded my street TR3 really didn't need an oil cooler. I've been running this engine for about 15 yrs. since.

07-19-2006, 03:50 PM
The engine generally ran too cool unless really pushed. Oil pressure was also quite high.

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Thus, the need for a thermostat.

Regarding oil cooler thermostats, Revington TR specifically recommends against them. They question the benefit and reliability. Revington TR know these cars well.

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Yes, Neil makes an argument against oil coolers in general, not just thermostats. William's book (which, I agree w/you, contains a few errors and even opinions I sometimes have to disagree with, but is generally quite good) does present Neil's case: He prefers to add oil cooling in a more passive way by modifying the stock sump pan with a couple sizeable tubes running front to rear and welded in, increasing air flow and cooling.

However, done right this also means cutting holes in the structural frame cross member just ahead of the sump, in order to route air into those sump tubes. Since the large cross member supports the weight of the engine and the stresses of the front suspension, punching holes in it makes me a little nervous! And, while I would guess there's not enough cooling added by this method to cause a problem, there is no control over how much cooling is effected (as a thermostat would do). So perhaps in some situations over-cooling might occur. Finally, this method also reduces the amount of oil in the sump (unless it's bumped out to the side to add some capacity back, also).

Keep in mind that Neil's emphasis is on rally cars. He owns two of the four original factory rally TR4s, and has regularly competed in historic events with at least one of them. Rally cars are often driven on gravel and rough dirt roads, where an oil cooler that gets holed by a rock can knock the car completely out of the running. So, for this sort of competition, an oil cooler might not be the best option. Neil's exhaust systems and many of his other parts also tend to be designed from this particular point of view. I'm not suggesting this design and development perspective is a bad thing, just that it's something to think about in relation to how you will be using your car.

For example, folks like Kas Kastner, Ken Gillanders and many, many others - some of whom who have probably been building and working on TRs about twice as long as Neil Revington - all use oil coolers on these cars on a regular basis. Lessons learned while rallying might be very applicable to the typical driving experience on the narrow lanes and roundabouts throughout Neil's England.

The guys on this side of the big pond (Kas, Ken, etc.) generally built cars for endurance (Sebring) and SCCA road racing, which I would argue might be more applicable to driving in the U.S.

In really broad terms, I think there's a lot more cruising at sustained mid-to-high rpms in U.S. driving, while there's more working up and down the gears, accelerating and decelerating in Britain. Note: Although some have no posted speed limit, by comparison the "M" motorways in England are relatively new and nowhere near as extensive as the U.S. system of freeways and fairly high-speed secondary highways.

Also, ambient summer temperatures across most of the U.S. tend to be higher than in England. A *lot* higher in some cases.

All this steers me toward using an oil cooler (w/thermostat), but I would certainly agree with Revington on one issue: The older and still most common style of oil cooler thermostat is mounted inline requiring 4 additional hose connections in the cooler's hose circuit (for a total of 8, minimum).

Each added connection is an opportunity for something to loosen and leak. This is one reason I personally like the combined take-off and thermostat now offered by Mocal (part SP1T at www.racerpartswholesale.com (https://www.racerpartswholesale.com)) which doesn't add any connection points, because the thermostat and bypass do their thing ahead of any of the hoses. Perhaps some other manufacturers offer something similar, I dunno. The Mocal is just the only one I'm familiar with.

Best case scenario, the thermostat works correctly and oil temps are kept within a more ideal operating range, helping maintain optimal oil viscosity, extend oil life and even moderate general engine temps to some degree. Middling case, an oil cooler thermostat fails closed: The oil bypasses the cooler and runs at the same temp it would have done without any oil cooler installed. Worst case, the thermostat fails partly or fully open and there might be some over-cooling of the oil for a while until the thermostat is fixed.

Oil coolers were factory/dealer options on all TR models, and are options or standard equipment on all manner of cars and trucks, both new and old. The technology has been around quite a while and is pretty well proven.

My biggest concern about an oil cooler is effecting a complete oil change. There will be some old oil trapped in the cooler all of the time (especially as it's now mounted on my car). But, on the bright side, the cooler increases the total oil system capacity a bit, which is never a bad thing.

...the engine frequently ran too hot.... made an aluminum shroud to fit it, added an electric fan and punched louvers in the bonnet.

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Very interesting! So, in other words, improved shrouding, an electric fan and engine compartment venting worked well enough that the oil cooler (w/o a thermostat) was "overkill", even with a hotter/modified engine.... I'm making similar engine mods in my TR4, and will be going through the same sort of efforts to keep engine compartment temps under control. Glad to hear I'm on track!

Maybe when I get my TR4 back on the road, I'll buy one of those laser thermometer thingies and temporarily disconnect the oil cooler to measure the differences, and be able to give a more real-life comparison.


07-19-2006, 11:32 PM
Hi Alan,

Very informative post! However, I pointed out that Neil Revington's opinion was regarding oil cooler thermostats, not oil coolers per se. You can go to the RevingtonTR web site and see that. I think he does sell oil coolers, but not thermostats, and he gives the reasons that I listed in my earlier post. I am in complete agreement with you regarding the efficacy of an oil cooler on a TR, and I run one myself. I don't run an oil cooler thermostat, in part because it seems many folks who know more about it than I (including Neil Revington) think it is not needed and perhaps even detrimental.

Another point on the thermostat, the way I see it is without one, you have an oil line going to the cooler and one coming back. If you cut both lines and insert the thermostatic valve, you now have four total hoses, not the eight that you mention (perhaps I misunderstood).

I also appreciate the R. Williams "How to Restore Triumph TR4 & 4A" book. The problem with it for me as a TR4A owner is that he took a lot of info that he wrote for his similar title for TR250 & TR6 and assumed it applies to the TR4A. For example, he goes on about strengthening the lower wishbone attachments on the TR4A, and even shows photos. Problem is, the photos are for the six-cylinder cars and his notes in the text are not accurate for TR4A. Case in point: Front lower wishbone attachments. He advises to weld a reinforcement plate from the lower frame mounting bracket across to the nearby frame mounting for the rack and pinion steering unit. Sorry, wrong. The TR4A front lower wishbone bracket was integral with the steering rack mounts, and in fact the steering rack and mounts greatly strengthen and support that wishbone bracket. On the six cylinder cars, the steering rack mounts had to be moved further forward to accommodate the lengthier engine, and so the front lower wishbone bracket lost the strengthening aspect of being integral with the steering rack and its mounts. He should have researched his book better...it's an obvious difference between the 4A and TR250/6. I also think that the rear lower wishbone attachments on the 4A differed from the later cars with regard to factory gusseting (the 4A has it, the later one dropped it and then added it back in 72). And he seems to think that the 4A had the same spring & lever clutch that the 4 had, and of course we all know that with the 4A came the diaphragm clutch. There is also a myriad of other "issues" that make me think he wrote stuff on the TR4, then assumed the 4A was the same as the 250 and 6 and did a nice little copy/paste, and that's how you have a new title covering the 4/4A. Sloppy work, but the book does have good points in it otherwise and I do recommend it with caveats.

Sorry for the run on there!

07-19-2006, 11:39 PM
Thanks for the response.
I have a combined oil cooler feed/180 thermostat plate to put in place as even in Arizona our winters are too cool to go without.
In 100 degree plus weather my engine remains at about 180 degrees but the oil viscosity changes in hard driving. Other local TR3 drivers have added the oil cooler and noted a great increase in oil pressure (to normal) even in city stop and go driving at 110 degree in Phoenix.
I don't know that there is enough room in the small mouth Tr3 to mount the cooler flush with the radiator without carving into the 'apron funnel' but that option might be less drastic cosmetically than cutting vents below the mouth opening. I know you have a great deal more playing room in the Tr4.

07-21-2006, 02:06 PM
I have a combined oil cooler feed/180 thermostat plate to put in place

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Good. In spite of some arguments against it, I still personally wouldn't run an oil cooler on a street car without an oil thermostat. There's really no downside to using one in this application. Even if the t'stat fails to operate for some odd reason you are no worse off, the car is still driveable and the t'stat can simply be replaced in a reasonable amount of time.

Race cars that get fresh oil every 100 miles or so, have their engine's rebuilt every season, plus are looking for every last little bit of cooling anywhere they can find it, might not need an oil t'stat. (But a great many still use one).

Although your Arizona daytime Summer temps do make it bit less likely to happen, the downsides to not using a t'stat with an oil cooler are more serious and mostly have to do with overcooling (sludge in the engine leading to accelerated cylinder bore wear etc.; poor lubrication/restricted oil flow; and over-pressurizing, especially at startup, that can cause leaks or damage the oil cooler).

And... The new combined take-off/thermostat from Mocal eliminates the need for four extra hose fittings that the more common remote t'stats use, which I agree would increase the possibility of something loosening and leaking. (Not to mention, add to the cost of the installation!)

I don't know that there is enough room in the small mouth Tr3 to mount the cooler flush with the radiator without carving into the 'apron funnel' but that option might be less drastic cosmetically than cutting vents below the mouth opening. I know you have a great deal more playing room in the Tr4.

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If it helps, I can tell you the Mocal 10, 13 and 16 row units are all the same dimension along their longest side when mounted horizontally. And - including the oil cooler's mounting brackets - this happens to be almost exactly the same as the width of the TR2/3/4 radiator. The se coolers can also be mounted vertically, if you prefer. Lots of options.

Another thing, when mounting ahead of the radiator, I've found the hoses supplied by some vendors in their "oil cooler installation kits" simply aren't long enough. IMHO, it's better to buy the parts and make up your own hoses for a better fit (also can be cheaper).

Also, some of the oil coolers offered by the major Triumph vendors have British fittings (as did the original factory/dealer items, I would imagine.) That's okay, but hose ends and such to fit these are a lot harder to find in the U.S. (www.pegasusautoracing.com had some, last time I looked). AN-sized and/or US pipe threads on the coolers, hose fittings and take-off adpaters are a lot easier to work with here in the U.S. I don't have any detailed info about other brands, but do know that Mocal makes their oil coolers, adapters and remote thermostats with both British and U.S. sized fittings. (www.thinkautomotive.com)

Shoot! Rereading this, it almost sounds like I've got a financial interest in Mocal! I don't. Just familiar with their products. Other manufacturers might offer something similar. /ubbthreads/images/graemlins/wink.gif

07-22-2006, 01:43 AM
Maybe a thermostat is the way to go, but I will just point out that MGBs (and many other British cars) came with an oil cooler standard from 64-80, without a thermostat. Most have held up well! As a Triumph enthusiast, I should not think our engines are any less tough. Interesting that the Big 3 all sell oil cooler kits without thermostats, but I guess that will give them an upsell opportunity when they start carrying them. I can hear Charles' pitch already...