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TR4/4A TR4 Radiator over flow bottle?

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I have a similar question on the 8. Will post later when able to down load photos
 
There was a thread not too long ago that I can't find. Someone who knows more than me said the bottle is more than for overflow, should have coolant in it as it will be drawn up to the radiator as the engine warms.
 
While I could be mistaken, it's my belief that the bottle was not added until the 'neckless' radiator with the short-reach cap came in.

Installing a bottle would be optional, IMO, but only if you can find a cap that properly seals so the radiator can suck water back out of the bottle as it cools. The original cap was not sealed for a recovery bottle, so it just lets air into the radiator and negates any benefit of the bottle.

IMO, the advantage of the bottle on a long-neck radiator is slight, since the early radiator has a large upper tank (and of course that extended neck) that serve to allow expansion/contraction of the water. But the bottle does provide some small theoretical advantage, by reducing air bubbles in the coolant. I could never get a cap (and water pump) to stay sealed well enough to pull water back up from the bottle, so my TR3A doesn't have one and I'll likely remove the one my TR3 DPO added.

ISTR the original routing of the overflow hose on a TR4 had a clip to the radiator frame or brace. TR3 clipped to the inner fender I think. After that, it just hangs down loosely.
 
TR3driver said:
While I could be mistaken, it's my belief that the bottle was not added until the 'neckless' radiator with the short-reach cap came in...
Click to expand...

I think the 'neckless' TR4s still lacked the bottle, I believe it was added with the TR4A. That's what the Moss catalog indicates (not that they are the last word) and my late TR4 had no bottle.

I added a TR4A bottle to the TR4 and found that the original radiator cap does indeed allow coolant to be drawn back in as things cooled down.

Seemed like a worthwhile addition on that system rather than having air in the top couple of inches of the radiator at start-up. I too don't bother with the bottle on the TR3A, just fill until the bottom of neck has about a quarter inch of coolant in it.
 
Geo is correct - neckless TR4's did not have bottles, which can be a pain with no expansion room and the occasional coolant puddle even though overheating is not occurring. I recently purchased a brass MG expansion tank (I think someone recommended it on an earlier thread) - I haven't installed it but it definitely looks period correct and will be an easy install next to the radiator. I think it may also be better than the plastic version because it has its own cap so will retain pressure and allow fluid to get back into the radiator a bit easier.

Randy
 
My late '64 TR4 had the bottle as original equipment. I believe the late TR4's had the same radiator as the TR4a's did. That would be late '64 and those made in early '65 until the TR4a's began production. It functioned the same as those on the TR6 do.
 
Tom-

I can't be positive about the overflow bottle, but I don't think you had a 4a radiator as it would have been too wide for the TR4 frame.

Randy
 
Hi Randy, Could be about the radiator. I just remember it looked the same when parked next to my buddy's 4a. But it was over 40 years ago. Come to think of it there was some other difference with the 4a, maybe the position for the hose to the engine on top tank?
Definitely had the bottle though. I remember thinking it would be a good thing for American cars to have too. Our LBC's were leaders with several features.
 
Larry, my '63 (no filler neck) did not have an overflow bottle when I got it many years ago. It did have an overflow hose that was routed along the top of the tank and then down the right side (passenger side) of the radiator frame. The hose was retained to the radiator frame by some clips that were part of the frame. I don't believe that any of the TR4s (long or no filler neck) ever came from the factory with overflow bottles, I think that started with the TR4A.

I have added a TR4A overflow bottle to my TR4 (TRF sells them) and it works great, I did have to change the radiator cap to a sealed one (Stant SP28) so that the coolant would be sucked back.

The long neck radiator needs a longer reach cap (1" vs 3/4") than the latter radiators, so the cap I used will not work for you, but one out of a Volvo 122S should work, but verify the working pressure before you use it, or check the Stant catalog at you local FLAPS to see if they have a cap that will work.
 
Merlin63Tr4 said:
or check the Stant catalog at you local FLAPS to see if they have a cap that will work.
Click to expand...
But beware of misprints. Some years ago they had a cap listed that did not, in fact, fit. Last time I checked though, they listed nothing at all.
 
The cap you want is a NAPA 703-1411. It is a 7 lb 1" deep neck cap set up for over flow tank applications. It has seals for both just below the cap and at the 1" deep and around all internal shafts. I used the MG Midget brass expansion tank as an over flow tank by removing the 5/8" seal out of the center of it's radiator cap, removing all pressure control capacity from it. It now keeps the antifreeze from splashing out of the over flow tank. The ultimate set up would be radiator to expansion tank to over flow tank, but the radiator to over flow tank has proven to be adequate and takes less room. I also added an electric fan, with thermostatic control, in front of the radiator of my TR3, leaving the crank mounted mechanical fan. The results are no over heating and no more drips on the floor.

This summer will be the elimination or reduction of the oil drips. PCV will be required to eliminate the draft tube.
 
startech47 said:
...PCV will be required to eliminate the draft tube...
Click to expand...

That's what Triumph did to this engine in 1964. I added a draft tube to mine because of pressure in the crankcase causing oil to ooze from many sources. Just a thought if you plan on sealing that thing up.
 
I am not planning on sealing it up, but routing it to a PCV valve to the intake manifold or to the exhaust manifold through an extraction valve. If anyone has done this successfully please let me know. I always like to ride on the coat tails of sucess.
 
startech47 said:
I am not planning on sealing it up, but routing it to a PCV valve to the intake manifold or to the exhaust manifold through an extraction valve. If anyone has done this successfully please let me know. I always like to ride on the coat tails of sucess.
Click to expand...

I setup my 71 Z-28 with extraction valves. I used a valve cover breather that had a nipple for 1/2" hose; I welded pipe nipples to the header collectors and screwed in the valve and attached the hoses. Surprisingly the rubber hose never melted. The valve are GM air pump valve. I still have one if you want the numers off it but they are common.

See valve numbers here:
https://cgi.ebay.com/ebaymotors/79-96-GM-...sspagenameZWD1V
 
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