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View Full Version : TR6 TR6 fan in TR3A question



Jim Lee
11-04-2003, 12:41 PM
I'm about to go where I ain't been before and remove the front apron of my TR3A to replace my motor mounts, remove the radiator to recore and replace the lame original fan that is hanging on with way too much play. My question has to do with the fan I am hoping to use as a replacement. As far as I can tell it is an 8 blade TR6, 1969 plastic deal that measures about 1.75" thick and 13" in diameter. It looks to be the same fan as I see on the Moss Motors site on this URL:
https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=32732
Key number 1. Part #835-260.

The bloke I got it from knows and works on TR's so I know it is going to fit but I am just wondering if anyone else has had first hand experience fitting this fan on a TR3A. I have all new bushings and all the assorted rubber and metal fittings to replace the very worn out stuff that is now just barely hanging on to the original fan. Unlike others on the forum I haven't had problems with overheating but figured that as long as I am going to the trouble of removing the apron to do the front motor mounts and I have this fan and fittings on hand I might as well replace this more than ready to be replaced original fan. This TR6 one is definitely going to be pushing alot more air and I wouldn't be surprised if it is lighter to boot.

Another question I had was what other things I should think about doing as long as I have the apron off? I'm thinking steering box maintenance and/or upgrades? I don't have any up and down movement in the wheel or any great amount of side to side play but as long as I am in there I would think there is something I should at least check on while I have the opportunity. I remember vaguely reading about some sort of steering box cover with a spring that can help compensate for a worn worn drive shaft? Any opinions or experience with this? I don't think I am ready to go for the full blown rack and pinion conversion at this point but just for kicks how much of a hurt would that put on my wallet?

Thanks very much,
Jim Lee
1959 TR3A

Russ Austin
11-04-2003, 12:52 PM
Hey Jim; You may need to trim a bit on the fan (easy to do). As far as the steering box goes if you have little to no play don't mess with it. You may want to top off with lube. The cost for Rack and Pinion is about $900. I switch over to a rack two years ago. (like it very much) They have always said it takes a man to drive a TR3.

Thanks and Good Luck

MGTF1250Dave
11-06-2003, 05:39 PM
Aloha Jim Lee,

I've had experience with both items. Removing the front apron is not that difficult, before you start you may want to use some liquid wrench on the bolts under the fenders a day or two before you start. Having a helper or two when you lift the apron out will minimize the chance of paint work damage. I found the plastic fan was a very tight fit (I didn't try trimming it) and did not want to risk damaging the radiator. I choose to remove the stock fan and use an electric fan instead. My car always ran at normal temperature at highway speed, but would heat up very fast in stop and go traffic with the stock fan. The electric fan solved this problem. You didn't mention if you had the air dam installed to direct air flow through the radiator. If you don't have it I would recommend you get one, they are inexpensive and available from most of the major resoration parts suppliers. You can easily make one with heavy poster board and a pop rivet gun. Coat it with a water proofer like Thompson's Waterseal and it will last longer. With the apron off this is a good time to check the hoses for wear and the condition of your radiator.

The steering box cover can be removed for inspection of the worm gear. With the front wheels off the ground, you should be able to easily turn the wheels from lock to lock. On my first TR3, it took great effort to steer, and if in a turn you let go of the steering wheel, the car would continue to turn in a circle. The main problem was the shaft bushing was badly scored, probably a combination of lack of maintenance and a failed oil seal above the drop arm (pitman arm). The idler arm can also freeze up due to lack of grease and make steering difficult. I removed the entire steering column to work on the steering gearbox, I replaced the oilseal, the bushing and replaced the peg that follows the worm gear. I use 90W EP Hypoid gear oil, filled through a plugged hole in the steering column above the gearbox. You can use what ever you use in the differentail. Other sources of oil leaks are the gasket at the front of the box and the compression sleeve on the control head conduit also at the front of the box. Once the steering was overhauled, the car steered well with little effort.

Good luck with your TR3.

Safety Fast,
Dave

Paul W.
11-07-2003, 11:52 PM
I have heard, although I have no first hand experience, that you need to mount the plastic fan backwards for clearance. It will fit mounted frontwards, but the fit is extremely tight. The first time you hit a bump or suffer chassis flex in a hard turn, the blades hit the radiator core, causing quite a mess.

Good luck.

Jim Lee
11-08-2003, 12:15 AM
That sounds very familiar. I got the fan a few years ago and I am thinking that is what the guy said, that I would have to put it on backwards.
So of course my next question is how effective is the fan going to be if, regardless of how well it moves air with all its blades pitched so well, when I assume it would be pulling air from the engine and pushing it into the radiator instead of the normal pulling cooler outside air through the radiator and then into the engine. I guess its possible that if it is moving enough air quickly enough it could suck new cold air into the engine compartment but I'm getting anxious just thinking about sitting in traffic on a hot day with the fan blowing the heat off the engine directly into my radiator.

Has seen, felt or heard of a backwards fan installation like this? I'm beginning to wonder if it would not be worth doing unless I can trim it way down so that I could install it frontwards and not have to worry about it chopping up my radiator which I am hoping will be newly recored at the same time this fan is mounted. I'm willing to do all the trimming it takes if it is possible.

Thanks very much.
Jim Lee

Jim Lee
11-08-2003, 12:20 AM
Russ,
Did you trim enough off the fan to mount it the way it was meant to mount? If so what did you use to cut it evenly? For some reason when you mentioned trimming I was thinking of the radius and trimming the fan blades not the roughly 2 and 3/4" depth of it.

Thanks,
Jim Lee

Dave Russell
11-08-2003, 02:14 AM
<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Jim Lee:
guy said, that I would have to put it on backwards.
when I assume it would be pulling air from the engine and pushing it into the radiator instead of the normal pulling cooler outside air through the radiator and then into the engine.
Jim Lee[/QB]<hr></blockquote>

Mounting a fan blade backward does not reverse the direction of air flow. Try it & see. It can reduce the efficiency however. It will still be pulling air through from the outside.

If you experiment with resizing the blades make sure that everything is perfectly balanced & that it doesn't weaken things structurally. A fan that breaks can make a BIG mess.
D

Jim Lee
11-08-2003, 09:17 PM
That is great news. I was thinking about the electric fans that feature the ability to reverse the direction by reverse mounting the fan. I would think that even a less efficient TR6 8 blade fan is going to blow away the original TR3 4 blader that I have on there now.
Another related question I have is as the current original fan is loose as a goose as far as the attaching hardware goes...for example if I grab one of the blades there is much more than a little play though not enough to worry about it ruining my radiator, and my two front motor mounts are soft as the inside of a jelly donut, I am thinking that my engine will be doing alot less rock and rolling once I replace the fan and get the new motor mounts in. Right now it shakes around so much I keep the idle up to like 12 or 1300 rpm just because I hate to see it in such turmoil. I thought it was primarily due to the motor mounts being so mushy but that the centrifugal force of the fan would make up for the loosened hardware but now that I read all this stuff about balancing at the fan area I'm beginning to wonder if that might be as much or more of a problem than my mushy motor mounts.
By the by I believe that I have a good working regulator in there now and was running all around today without any of the 'running out of gas/spark' problems of before. Time to stumble across new Little British Car learning opportunities.

Thanks much,
Jim Lee
59 TR3

Paul W.
11-09-2003, 04:02 AM
Jim, that's what I thought too. But in reality, as it was explained to me, Dave is right. It will still be a puller fan. You would have to run it the other direction for it to become a pusher. I don't have a fan in front of me, but try this: Take a look at the blade pitch. If it's 45 degrees, then I believe it will be exactly the same 45 degrees when you flip it over. Of course, if it's less or more than 45 degrees, then you would lose (or possibly gain) that much effiency.

I also agree with Dave that you need to be very careful if you remove any material. The fan should be balanced. A little extra weight on one side may cause an unwanted vibration or worse.

Dave Russell
11-09-2003, 04:26 AM
Paul,
You are exactly right. A straight blade at 45 would be the same either way. In reality, the blades are usually not straight but curved or otherwise shaped to optimize efficiency in a particular direction.
D

[ 11-08-2003: Message edited by: Dave Russell ]</p>