TR6 compression problems

[rubberburner]

Help, I'm looking at buying my first TR6 which has had a new reconditioned engine fitted 2 years ago. The problem with the engine is that the compression is about 240 and I have checked technical specs and it should be around the 150 mark. The only conclusions I can draw from this is that the head has been skimmed too much, gasket is too thin or the head is the wrong type??!!!. I have no details of the cylinder head, could it be something simple that we have missed or is it a replacement head and how much would that be. Any info would be great. ??) ??) :'(

[Jason]

My first thoughts - your readings are wrong. If you've got that much compression you'd get serious running problems immediately - take if for a test drive, find a hill and select a gear that's too high, make it work going up the hill - if you've got any problems you'll hear the engine pinking.
The big issue with compression is that the readings from all cylinders should be in the same general area - one low and you've got a ring problem, two low and you've got a gasket problem between those cylinders - all low and the engine may be worn (or could have gummed up rings due to under use) To check for a worn engine do a compression test dry note your readings now do it "wet" by putting some oil (we're talking a teaspoon of oil, not half a pint) into the spark plug hole. Give it a minute to seep around the piston, do your test. This will create a better seal and give a higher reading - amazingly higher and you've got worn rings.
Rings are about £50 plus you'll need a head gasket and a few odds and sods to do the job - you can pop the pistons out with the engine in situ - call it a weekends work and £100 - jobs a good 'un - unless you fins problems  ;D
For REAL piece of mind, take the car to a specialist and get an inspection - £50 well spent and a good baragining chip if the car needs work.

[rubberburner]

Jason thanks for the info, the readings may indeed be incorrect as the compression test gauge was a very cheap one. I shall investigate further. Many thanks again.

[Jason]

I think it fair to say that a compression test can help diagnose problems but shouldn't be your only investigation - use it in conjunction with a proper test drive, I mean don't just jump in the car and drive round the block. Put the car under load in all gears, accelerate up hills, use the engine to brake you going down hills then watch for white smoke (means worn valve guides) take it round roundabouts at speed, listening for groans in the suspension etc. Find some small pot holes or dips in the road and drive over them - listen for bangs, crashes, scuttle shake etc.
As a general rule of thumb, mechanical wear is easier to rectify than body work and usually easier to price and do on a DIY basis so always buy the best body you can afford (unless you work in a body shop!)
Triumph engines, with the exception of the Stag, can stand a lot of abuse and wear - the 6 cylinder is a strong old lump and goes on for many thousands of miles - the things that usually kills it is lubrication or the lack thereof - the oil filter/pump set up is not the best design and after standing for a few hours much of the oil drains back into the sump so when you start it p the bearings are starved of oil creating an intense period of wear - not good. You can get anti-drain filter kits to reduce this problem.

[rubberburner]

Jason thanks for the test drive tips, I shall be taking a copy of these when I take it out for a test drive in a couple of weeks time. The anti drain filter kit is something I have never heard off but is an exellent idea especially if the car sits for prolonged periods with out running. I suppose oils that are magnetic help reduce wear also as they tend to cling to the engine parts thus providing lubrication as soon as the key is turned. Do you know of any suitable for the TR6?

Thanks again.  :)

[Jason]

No worries, advice here is free, that's why it's such a good place to hang out! I think the accepted wisdom is use a fully synthetic oil rather than an oil for a modern engine. Regular use of the car is the best way to prolong engine life - these cars don't like being sat for long periods. The TR6 engine is in the 2.5 PI big saloons and the tuning guru is Chris Witor - he sells a good oil filter kit - check that it will fit in a TR6 though, clearnace for some of these things can be an issue.
Avoid just going to the TR specialist for your parts - they charge a premium as the cars are thought of highly, more highly than the saloons but the main engine components are the same - avoid Rimmers and Moss unless you like paying through the nose. Best to ask for recommendations here before committing to any big spend on bits or when pricing any remedial work. Some traders are not known for their TR work but are very capable - a personal receommendation is worth a lot here. I think it fair to say that the TR fraternity is usually better off financially than the Saloon people so they tend to get charged a little more - just be aware of the alternatives  ;)

[Keith]

Hi Mr Rubberburner,
I agree with Jason about cheap compression testers, I've got one that gives 220 on my 4A which I'm sure is nowhere near the truth, the important thing is that they should all be equal.
Re oils, I've gone off synthetics as I had a bad experience with camshaft failures a few years ago, I can't be sure that the oil was the the only factor here, but I haven't used them since.
Nowadays I use Duckhams Q 20/50, which is cheap and I change it regularly - every 3000miles.
Does the car have injection?
If so does it have a bosch or lucas pump? The bosch is a common non origonal replacement which gives greater reliability.
Also check the car has been converted for unleaded. It should have hardened exhaust valve seats, and the seals in the metering unit and injectors need to be suitable.

Keith

[rubberburner]

Jason, Keith, The TR6 is non injection and is able to use unleaded, the comment about Rimmers is a valid one, this is where the £2k recon engine came from, these guys are expensive!
Keith, ok my name is Gavin, just other forums they tend to stick to their user id, must be more friendly on this forum ;) Cheers guys

[Jason]

A friend of mine once priced up a basket of stuff for his TR - service items, some trim a panel or two - total cost at Rimmers was £2250, that same list of parts were bought from TRGB and Canley Classics for a total of £1700! Admittedly that was a couple of years ago but things haven't changed that much. A quick look at Canley's site http://www.canleyclassics.com/partfinder.asp?partnumber=E17UR shows an unleaded engine at £1275 and I know Dave himself does the engines, uses them in his own cars and they are worth every penny.
Shame you don't have the injection on there, it's by far the best thing about a TR6 :-)

[Tim Bancroft]

Re:Compression testing.
Also ensure that the valve clearances are correct.
I've got a Gunson compression tester that has proved to be fine over the years.
Re: Engine oil.
I am of a similar line of thought as Keith, I prefer to use good quality 20/50 and change it regularly. I also worry about it leaking
Also whilst fitting an anti-drain filter I reckon it is essential to also fit an oil cooler kit: including a 22 row rad. and a oil stat. Always difficult to find a good position to fit the rad in, on my GT6 I used to have it in front of my water rad. but found that the oil rad blocked air flow, now moved to behind the anti-roll bar- which is bit vulnerable- but does the job.

[Raider]

I'll just add my two penneth worth.

I use Duckhams 20/50 too! I used to sell lubricants years ago and I know that the spec on the Duckhams is fine for the cars I run.

Fitting anti-drain filter - yes done that on my Vitesse and will do on my TR7. Never fitted an oil cooler though Tim and as I have never got round to fitting an oil tamp gauge I don't know if I need one either!

Regarding Rimmers - they are a on the pricey side but they have always been knowledgable and when I have bought anything it turns up on time, it's the right part and it fits! When I used to rally Minis I always used Minispares in London for the same reasons - it's a real pain when suppliers aren't as good as this.
For this reason I would be very surprised if a Rimmer Brothers supplied engine had a fault on it.

[v8dean]

Quote:

I used to sell lubricants years ago

well there's a turn up for the books!

[Raider]

Stop it!!!!!! :P :P :P

[Jason]

You know being old a cynical I rarely smile when reading message boards but that little "lubricant" exchange made me chuckle, in fact I'm still chuckling as I write this - Mr Raider, you have become a smut magnet!

Back to the thread or it will have been hijacked like so many in here! As far as lubricants generally are concerned you can get away with a cheap oil if you change it regularly and to be honest I see little point in trying to extend the service intervals for the sake of a few quid - you've got to make a hell of a saving on oil to pay for an engine rebuild!

It's like the perpetual Herald chassis question - "Do I grease or oil my trunnions?" I usually answer "It doesn't matter as long as you chuck some lubricant in there every 3000 miles or so!"

:D

[rubberburner]

Lots of good tips, thanks guys.  :)