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Triumph TR6 - help with compression test

Hi Folks

I am on line in the garage. I have the engine and gearbox fitted to the frame, nothing else connected, plugs are removed, starter checks out ok.

I want to do a compression test as is. So I connected a battery direct across the starter, well negative to the engine and positive to the WR connector on solenoid, the solenoid engages and that it the motor does not turn over. I have manually turned the engine and thats ok. I guess that I need to apply power somewhere else...looking for help...I am having a cup of tea while I wait......

Les
lw gilholme

Tis I again

I shorted the soleniod to the +ve terminal on the starter, now it cranks.

Marvelous what a cup of tea does
Les
lw gilholme

Hi folks

I finished the compression test, first dry and the second test(wet) with a little oil in each spark plug entry.

The first reading is dry. second reading wet

Cyl 1 130 psi 170 psi
Cyl 2 110 psi 142 psi
Cyl 3 103 psi 144 psi
Cyl 4 80 psi 105 psi
Cyl 5 110 psi 155 psi
Cyl 6 113 psi 146 psi

So what does the team think?

Thanks

Les
lw gilholme

Hi Les,

I agree that a cup of tea can solve many-a-problem. I also think that you may be in for an engine rebuild. Drinking tea will be mush easier but not nearly as exciting.

The balance of pressures between cylinders should not exceed about 10psi and the lowest pressures should be above 120psi. Do check that the valves are correctly adjusted and redo the test. If the imbalances are still as defined, then a leak-down test is in order to determine if the problem is the valves, head gasket, pistons, etc.

What do you know of the history of your motor... mileage, partial rebuild, etc.???

Cheers, Rob
Rob Gibbs

Thanks Rob

As far as history of the engine....I believe was last run in 1992-3 that was when the car was last road registered. Milage/KM? 49000.

How do you check the valves?

Les
lw gilholme

Les,

set the valve lash to .010" for both intake and exhaust using a feeler blade set, bladed driver, and 1/2" wrench. If you are uncertain in this procedure, have a fiend help out who has done it before or read up on the procedure... very simple.

The one poor cylinder may have extensive corrosion causing the poor compression... due to moicture / improper storage over the years.

Hope this helps,

Rob
Rob Gibbs

Thank Bob,

The tale goes on, just set the valves to .010", some were way off.

So the readings are now (1st number dry 2nd number wet)

Cyl 1 120 ps1 133 psi

Cyl 2 130 psi 155 psi

Cyl 3 135 psi 160 psi

Cyl 4 110 psi 120 psi

Cyl 5 120 psi 135 psi

Cyl 6 130 psi 150 psi

So number all have improved No.4 low in comparison. Thoughts please. Bob you mentioned a leak down test? is that on the CD 2?

Les

I am off for a bath & a single malt.
lw gilholme

Lss- Not spot on but livable. I say drive the bodily fluids out of it until it breaks.
DON KELLY

Don/Rob

Thanks for the valuable information, I have an excellent machine shop in our local town "old school" trained with a wealth of knowledge. So its off with the head and to his shop for checking. I will let you know how I get on.

Les
lw gilholme

Hi Les

Those are not bad #s for for an engine that hasn't been run hard for that long. As Rob points out a bit of corrosion or sticky rings will give odd #s after long storage. Not always a good idea to open them up untless your going to do the whole deal. I would try using a bit of diesel fuel and an oil can to soak down the cylinder walls and loosen up corrosion. Put the plugs back in and turn over a couple of times then let sit a day or two. Change oil and check. Cheap trick may work.

Instead of shorting the solenoid buy a ten dollar remote starter switch. Work great and save the arc marks on the screw drivers.<G>

By the way are you close to Greenwich Rd.? And a nice drive to look over?

Bill
Bill Brayford

Les,

follow Don's advice re. the soaking of the cylinders in diesel for a few days. This will help in releasing sticking rings. However, DO NOT turn the engine over with more than a tablespoon of liquid in the bores unless the plugs have been removed... or you will be doing an engine build for sure! "Hydraulicing" the engine may bend rods and mush bearings. After the soak, then run it up for a while and finally do a recheck on the compression. Repeat several times if improvement is initially found.

A leak-down test is performed to determine where the loss in compression is coming from: valves, head-gasket, cracked block/head, pistons and rings, etc. and is carried out on each cylinder individually through the introduction of compressed air (10-15 lbs)into the cylinder through the plug hole using an adapter. An examination through site and sound is made ( and even rapidity of pressure drop) at all possible exit points... radiator, tail pipe, carburetors, oil dip stick hole/ filler hole, etc.

Rob
Rob Gibbs

oops, I meant Bill's good advice.
Rob Gibbs

Dang, I'll take prompts anyway I can even if I don't own them
DON KELLY

I have a train type oil can that I give a couple of good squirts. You need to get enough in but not fill up of course. I suggest putting the plugs back in because diesel fumes do take a long time to dispel if they get on the floor.
Bill Brayford

It looks like its already coming around just turning it over for the compression tests. Give 'er a good run and she might be fine.

And a hearty hello to Bill. It s been a while. Good to hear from you.

A. J. Koschinsky

Bill

I live in Coldbrook and work in Wolfville at Acadia Univeristy (Building/Grounds Maintenance). I do travel on the Greenwich Rd.

I took this picture of my drive to work this morning showing Port Williams in the background, cant wait until I do this in the 6. With the promising outlook on the motor the dream maybe one year earlier.

Enjoy the view.

Les

lw gilholme

Hi Les

We stayed at the orchard June 4 to 8 this year. Flew down and took a 2 week renta car tour of that area and PEI. Probably drove by you a dozen times. If we didn't have 8 grandkids spread from this area to the west coast you would have new nieghbours. Beutiful!

Can't guarantee that trick will work but from past experience its worth the try.

Hey Tony, Thanks. Yep its been a few years. Been on any good prairie tours lately.

Bill
Bill Brayford

Our club was invited to tour the Corner Gas set last summer. Here's a pic (I hope) of me in the V12 VDP gassing up at Brent's place. I wish I'd taken the TR, but sometimes the spouse gets to vote.

Getting back to TR6's, it might help Les to know what might be considered normal compression numbers. Testing the engine cold, without adding oil to the cylinders, I get 160 across the board.

Tony

A. J. Koschinsky

This thread was discussed between 20/09/2008 and 24/09/2008

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