Which TR6?

[chard]

Hi

I'm thinking of a TR6 (currently a Midget driver)
I do not need ultimate performance but would like the extra refinement of a "six" and the bigger car.

I will be looking for overdrive and reliability but should I go for, fuel injection or save a bit and buy the less powerfull carb model?

Any tips would be appreciated I've never owned Triumph six before but always fancied one.

[Combover]

Prices between them don't seem to differ all that much.

Also bear in mind that there was a PI that had 125bhp...

My advice would be to get a good solid car and think about the engine afterwards.

[chard]

Thanks

Solid car is a given.

I will be spending £7-£10k so expect to get a servicable solid car. Some dealer cars seem to attract a considerable premium which for me isnt a sensible investment for the use I will get from car.

(plus I enjoy a bit of tinkering, tidying and minor repairs, a bit sad I know but it helps me bond with the car)

[Combover]

Provided you can't wiggle the cranckshaft about too much, the engine would be near the bottom of my list of priorities.

Chessis first, then body, then suspension and diff, then gearbox etc etc...

[gt5r]

Uk cars were all PI models - either 124bhp or 142bhp block reference CR/CP (CP being the 142bhp model) - export versions ran on carbs so most UK cars running on carbs have been converted from saloon models - looses its rather burtal charm running on carbs too me

Don't be put off by all the horror stories about PI - its the fuel pump that causes the agro not the metering unit or injectors - you can replace the lucas pump with a bosch fuel pump

There arn't that many differences between the basic units in both 124 & 142 bhp models - a change of camshaft - emission control and a few other small difference is all

Also bear in mind the 2.5PI unit from the saloon @132bhp again different cam to the early 142bhp TR6 - but will drop straight in if you can find one

So its injection all the way for me - ditch the plenum chamber and stick some 45mm DCOE ram pipes on it and the induction noise is awsome - don't get that noise with carbs

[Combover]

gt5r said:

Uk cars were all PI models - either 124bhp or 142bhp block reference CR/CP (CP being the 142bhp model) - export versions ran on carbs so most UK cars running on carbs have been converted from saloon models - looses its rather burtal charm running on carbs too me

Don't be put off by all the horror stories about PI - its the fuel pump that causes the agro not the metering unit or injectors - you can replace the lucas pump with a bosch fuel pump

And even that isn't as bad as people say either!

gt5r said:

So its injection all the way for me - ditch the plenum chamber and stick some 45mm DCOE ram pipes on it and the induction noise is awsome - don't get that noise with carbs

Tell me more...

[gt5r]

Basically if you remove the plenum chamber and the 6 black rubber connectors from the manifolds and then take out the inserts from the throat on all 3 of the manifolds (the bit that the rubber fits on) you can then insert 6no 45mm webber DCOE ram pipes with no mods they are a nice snug fit (use a bit of loctite as well)

How do I upload a picture on this forum - am I missing something???

Edited by gt5r on Thursday 16th April 09:34

[Combover]

[img] www.tinypic.com [/img]

Just as above but without the spaces. Use a picture hosting website such as tinypic.

Edited by Combover on Thursday 16th April 12:52

[jellison]

Get a good solid (as has been said) car. Engine wise - don't get a twin carb car - well they were never sold here and there is a reason (crap) - slower than a PI. Pi is better and in most instances and good for big power if you want to tune up later.

[pits]

From what I remember of the old mans, the Lucas fuel pumps were crap, do have a Bosch one somewhere, becarefull of the inertia switch as they are very sensitive, buy a red one, as the fastest ones, also get rid of the black on the rear end and have it all red, looks so much better

TR6s rule, just dont buy a st one, as they are very expensive to restore

[Wacky Racer]

Ring Stalybridge MOT Centre and ask for owner Nigel Bancroft if you need any info on TR6's, probably knows as much about them and TR5's than anyone in the country......

[jellison]

Yellow is Fastest don't remove the black rear (they look worse that way). Each to there own!

Edited by jellison on Tuesday 30th June 10:42

[Yertis]

pits said:

also get rid of the black on the rear end and have it all red, looks so much better

That black rear panel is one of the defining characteristics of the TR6. Those without just look like unfinished restorations, only marginally worse than those few made by Triumph where only the centre panel was painted black.

[jellison]

Yertis said:

pits said:

also get rid of the black on the rear end and have it all red, looks so much better

That black rear panel is one of the defining characteristics of the TR6. Those without just look like unfinished restorations, only marginally worse than those few made by Triumph where only the centre panel was painted black.

EXACTLY

[Seight_Returns]

Why were the later UK PI cars less powerful than the earlier ones ? Was it an emissions thing ?

[Yertis]

Seight_Returns said:

Why were the later UK PI cars less powerful than the earlier ones ? Was it an emissions thing ?

Different cam, but mainly a different measuring technique (net and gross or something, I forget which now.) Anyway the real difference in bhp is much smaller than the 150 vs 125 figures suggest. However, the earlier throttle set up is better than the later one, and note also that the later cars have a J-type overdrive which is active only on 3rd and 4th, rather than the A-type overdrive on the earlier cars which also acts on 2nd and therefore makes for good fun.

The changes were made to make the car more tractable in low speed situations, idle more smoothly etc. Perversely the throttle linkage designed to make this so goes out of adjustment more than the original when worn so has the opposite effect as time goes by (or rather as the miles mount).

[Seight_Returns]

Thanks. So can you simply change the cam from the CR engine to that from the CP to get the increased peak power of the earlier cars ? Is it actually noticeable in real world driving ? I see that people advertising earlier cars make a big thing of "150 bhp model" - on paper 124 vs 150 bhp sounds like a big deal, but seeing as how much time a 40 year old car is actually going to spend doing 5000+ rpm does it really matter ?

Where in the throttle linkage does the wear occur that spoils the responsiveness of the later cars ? Is it an easy fix ?

Sorry for the inquisition. Genuinely interested.

[jellison]

Some of the reason for change was emission as even though the Terribly strangled TR250's (125bhp TR6's with twin carbas and even less power sold in the states. Thee later cars had the cam and a head (plus different fuelling or the crap carb setup in the US). The earlier head had a tad bigger valves as std and was skimmed for more compression. SO you can change a cam and alter the fuelling from the pump, but to get back to full 150 power (they did not actually make 150bhp anyway!!!!!!), you would need to skim the head and pop in the larger valves, but just skimming the head for about 10.5CR and running on 97+ octane should have a similar effect.

Or you can go way beyond the 150 engine if you through cash at the head and a fast road cam. We used to run like this, skimmed 125 head made better than a std 150 one with tad bigger valves than the 150 but 10.5 CR, changed meetering and fast road cam for a true 175-180bhp. This is real world 45-50up on a std 150 which on the (corrected) rollers makes about a true 140+ at the flywheel. Past this get alot more expensive. But this level of grunt can be done for a moderate price.

Best performance mod is to bin the 3.45 diff and pop in a US (TR250) spec 3.7 (cos they had so little power then needed this ratio to get some of the accleration back) or better still get a 3.9. If you do the above mods and a 3.9 Crown wheel and pinion (does not kill top end much and you have the over drive for the high speed stuuf and cruising)it makes for a damn fast ride a moderate cost.

Hope that helps.

[Seight_Returns]

Thanks very much indeed.

I know that the twin carb (SUs?) US setup was pants - but have heard people running TR5s and 6s on triple Webers - how does that compare to the PI setup with tweeked metering - I understand Webers but am a bit wary of the PI setup.

[//j17]

Seight_Returns said:

I know that the twin carb (SUs?) US setup was pants - but have heard people running TR5s and 6s on triple Webers - how does that compare to the PI setup with tweeked metering - I understand Webers but am a bit wary of the PI setup.

The US cars pants set-up wasn't strictly down to the carbs them selves but the whole set of emissions kit (low overlap cam/low compression/lean carb needles/etc). In the later saloons the 2.5 engine on twin SUs made almost the same power as the PI cars.

As usual Webers will give more out and out power than SUs but only a few BHP at the very top-end and with noticably lower MPG across the range.

The PI set-up isn't inherently bad - it was just often missunderstood by mechanics that knew carbs and refused to read the manual! The big problem with PI is fuel pressure where you need to maintain something like 140PSI - much higher than modern EFi and only achieved with the Lucas (windscreen wiper) motor in top condition.

If you follow the book and ensure you have the correct fuel pressure the PI system is usually reliable. Or if you prefer you can have the PI throttle bodies remachined to take EFi injectors and with a few other mods get the increased performance AND higher MPG of EFi.