[TR] TR4 road draft tube plug

John Macartney john.macartney at ukpips.org.uk
Wed Sep 9 07:48:14 MDT 2015

The wet liner four was used in:

All TR models from TR2 to TR4A
Triumph Renown
Triumph Roadster
All Standard Vanguards from 1948-1959/60 before being replaced by the 2 litre six pot in the Vignale
There was also a Vanguard diesel variant in the mid 50's for car, van and pick-up
The Ferguson Tractor (in modified forms)
Standard Ensign in 1.6 and 2.1 litre variants
Leyland 15 and 20 revamps of the (ghastly) Standard Atlas van / pick-up / Minibus
Rover SD1 made in India
Swallow Doretti

And as an industrial power unit for trailer compressors, concrete mixers, stand-by generators and pedestrian controlled road rollers - all of which were as normally aspirated diesels.


-----Original Message-----
From: Triumphs [mailto:triumphs-bounces at autox.team.net] On Behalf Of Brad Kahler
Sent: 09 September 2015 14:02
To: Dave <dave1massey at cs.com>
Cc: Triumphs <Triumphs at autox.team.net>
Subject: Re: [TR] TR4 road draft tube plug

I forgot the TR3/4 engine was also used in a few other Triumph models.  Maybe Andy Mace will chime in with his knowledge of the other Triumph models.

On Tue, Sep 8, 2015 at 10:10 PM, Dave <dave1massey at cs.com <mailto:dave1massey at cs.com> > wrote:

	Well, of course the upper part isn't sealed from the lower.  The oil pumped to the rockers has to drain back down somehow.  As was mentioned previously, it goes through the push rod tubes.
	My guess is that the cover is used in other applications (Vanguard?) and whatever it was for was not implemented on the TR.  Not enough space under the hood.

	Dave Massey
	-----Original Message-----
	From: Brad Kahler <bkahler1 at gmail.com <mailto:bkahler1 at gmail.com> >
	Subject: Re: [TR] TR4 road draft tube plug

	So much for the official Triumph documentation!   

	Does anyone know why the real early TR4s (and I think late TR3Bs) had the brass plug in the top of the valve cover?  I've never seen anything relating to that plug written anywhere. 

	I don't think the bottom end can be completely sealed due to the openings for the push rods.  When the switch was made to the "sealed" system the draft tube went away for good. 



	On Tue, Sep 8, 2015 at 4:48 PM, Alan Myers <amfoto1 at aol.com <mailto:amfoto1 at aol.com> > wrote: 


			... Then at
			engine number CT14234E through end of TR4 production the
			cars had air
			filters with vent openings coming from a flame trap from the valve
			along with a "sealed" valve cover cap and no road draft tube.  TR4As had
			gulp valve with a vented (1/8" metered opening in the cap) valve cover
			and no road draft tube.  This information was found in Service

		I can tell you for certain that's incorrect. The change from open breathing to flame-trap, etc. came later than that. 
		CT17791E (fitted to CT17602L, built in late October, 1962) originally had the vented cap and the road draft tube. 
		The cap is the push on type, has big vents on the underside and filled with coarse  "steel wool" to reduce oil spray, I'm sure. 
		The road draft (or draught, I suppose) tube is large diameter, press fit into the side of the block and locked in place with two screws (maybe 1/4 or 5/16"). 
		The original valve cover has no vent, but it does have a large brass plug where one could be fitted. 
		Never had a problem with oil out of the push on cap or an unusual amount of leaks.... but the road draft tube kept most of the underside of the car rust free! 
		The car now has an aftermarket cast alu valve cover with a breather pipe and a low profile, twist-in filler cap (with a single, tiny breather hole). 
		I've replaced the road draft tube, but didn't plug it. It now has a nipple for a 1/2" or larger hose fitting. I don't think it's a good idea to completely seal up the bottom end of the engine. It needs to be able to breathe, same as the top end. 
		Car is not yet back on the road, but when it is the plan is  to have a catch tank or can fitted with a breather cap, with hoses running from both the valve cover and the fitting at the draft tube. 
		I intend to use a catch can similar to this: http://www.summitracing.com/parts/jrc-555-6402 
		Alan Myers 
		San Jose Calif. 
		'62 TR4 CT17602L 
		amfoto1 at aol.com <mailto:amfoto1 at aol.com>  


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