Triumph 2.5 P.I. in a Stag information please.

[Guest]

Hello. Sorry more questions.



I realise that to some that someone owning a Stag without the Triumph V8 is the Devil reincarnated and should be stripped naked and flogged with nettles.



Next week I am looking at three Stags. One of them has the Triumph straight six 2.5 P.I. Engine. Description of the car seems to suggest that this Stag has a lot going for it so I should not dismiss it. Has anyone experience of a Stag with this type of engine and if so could they please give their opinion, thoughts. I know about the Injection system requiring to be converted to unleaded ( problems with the seals with leaded petrol ) but is there anything else I should know about this system. I know they had a bad reputation when they first came out but like the Stag V8 any problems should have now been sorted. As advised this is one of three Stags I will be looking at and as this will involve a round trip of about 600 miles ( I must be mad ! ) I would like to know as much as I can about the 2.5 P.I. engine and fuel Injection.



Many thanks, Don Kennedy.

[Cheesy]

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I am just in the process of fitting a 2.5 straight six into my Stag!

The 2.5 engine is a very reliable unit, with one weakness with crank thrust washers. Check the crank endfloat (easier in a manual) and be wary if there is excessive movement; it is possible for very badly worn thrust washers to drop out into the sump, causing damage to the block.

That's pretty much it! It's a strong, torquey unit which in injection guise is as powerful as a Stag engine, but without the Stag V8's various and well documented problems.

Check the conversion has been well done. The engine weighs pretty much the same as the original Stag unit, so there are no issues with suspension mods to worry about, unlike with the lighter Rover V8.

I would say do not dismiss a Stag with this engine!

The Triumph Sports Six Club has an excellent forum which would provide valuable advice should you decide to go down the straight six route.

Good luck with your viewings!

[GATS]

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:dude:hi don, sorry but i don,t have any experience of this engine, but like to say it does not matter what engine is in the stag, as long as you enjoy the car , i am putting a rover 3.5 v8 in mine as i broke down three times last year and it became a car i did not enjoy taking out , always looking at the dials waiting for something to go wrong. i also understand i may be unlucky and that other people run their cars from year to year with no problems, it a matter of choice. good luck in finding your stag they are the best cars around. Paul

[stagstr]

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Hi Don,

My experience with this engine is in my TR5 on which I spent a good deal of time sorting the PI. As you say, like the Stag, once sorted it works and works well. The seals need to be Viton to be resistant to unleaded so make sure the metering unit has been converted. The metering unit for the 150bhp engine is calibrated differently than for the 125bhp engine. Make sure you've got the right one. Of more importance is to check which engine you have!I think a 150 bhp engine number starts with CP and a 125 bhp one starts with CR, if it came out of a TR. I don't know about 2500 saloon numbers. Worth checking in case I'm wrong, but you need to know which engine is in the Stag.

The other major problem was with the Lucas fuel pump arrangement - cavitation meant that fuel wasn't always delivered when neededespecially in hot weather. Many switched over to Bosch but there are also many whose Lucas system gives not one jot of trouble and those people are happy to stick with what Triumph furnished.

The Bosch system is not without its issues so I suggest you register with the TR Register Forum and read the archives. You do not have to be a member of the Register to read or post threads on their forum.

If I think of anything else I'llPM you, but in the meantime happy hunting

Ray

[Gresley]

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Hi Don

Don't be put off by the PI system - once set up properly it is fantastic! I have a Pi at the moment and now I have it sorted it runs really well. In my experience the main thin is to make sure that the fuel pump is delivering a good pressure, at least 100 psi. If it starts easily from cold then itis probably OK. They can sulk if not used regularly but, as I said if it has been set up properly then you should not have any trouble. If it is hesitant a little with the engine cold don't worry, this is normal on a PI. Good luck!

Brian

[Guest]

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Many thanks to all for your time replying. Looks like I should not rule out the 2.5 PI Engine. Off next weekend to have a look at the Car, maybe this is the one ?. With a round trip of about 500 miles I hope it is worth the effort.



Don Kennedy



P.S. There is a line between Enthusiasm, Dedication and Madness, I think I must be in the Madness area !.