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Compression results and additive question


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Hi,

Just joined.

I have done my homework for several weeks, so this is not just a lazy question.

Since 1969, I have had my TR3 and driven it occasionally over those years. But, I was lazy in setting my carbs and for several years I used starter spray rather than fix my choke cable. I know, I deserve punishment!

The result is my compression is bad due to what I call "washed my cylinders clean - syndrome."

I need new rings at least and maybe new liners and pistons.

My question today is should I buy some time and just add some of the miracle oil additives?  And if so, which one do you recommend?

Thanks from North Carolina!

Opie (pic below of my compression tests)

https://ibb.co/vDNc8Bg

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The numbers in that table look a bit variable from test to test. I think the only set that mean anything are those with the throttle wide open - but did you also raise the carb pistons? 

The actual numbers are not that important as that will depend on various factors like cranking speed - what you should be looking for is variation between cylinders. 

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RobH,

On the test today, after advice I found in your archives here, I not only opened the throttle but I removed the carb piston assembly to allow all the air possible.

I have no way of predicting, but for the first time in many years, my plugs are clean after a run, so maybe I won't make things worse with the too-rich issue and I have years of service left.  It starts fine.

And I spent a day on getting the choke linkage perfect.

My question about engine restorer additives is because there are some eye-popping claims on YouTube but I think many folks on YouTube are really seeking product commissions, so a recommendation from a TR owner would have weight with me.

Opie

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All together now.....

Snake Oil

 

 

Truthfully I do not know but as you remark the youtube stuff  is filled with get rich quick would be millionaires seeking approval of an unknown item.

Peter W

 

PS the low pressure on No3 might indicate a leaking valve.  Have you tried the' compressed air in the cylinder through the spark plug hole' trick and listened for air leaks through carb or exhaust?  Could guide you to perhaps removing the head and decoking/re-seating all the valves.  See Bob's recent post on this of this:-

 

Edited by BlueTR3A-5EKT
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15 hours ago, Opie said:

Hi,

Just joined.

I have done my homework for several weeks, so this is not just a lazy question.

Since 1969, I have had my TR3 and driven it occasionally over those years. But, I was lazy in setting my carbs and for several years I used starter spray rather than fix my choke cable. I know, I deserve punishment!

The result is my compression is bad due to what I call "washed my cylinders clean - syndrome."

I need new rings at least and maybe new liners and pistons.

My question today is should I buy some time and just add some of the miracle oil additives?  And if so, which one do you recommend?

Thanks from North Carolina!

Opie (pic below of my compression tests)

https://ibb.co/vDNc8Bg

I would suggest you are less likely to have washed oil off the bores with the ether  spray than by using the choke. It sounds as if you only use the car intermittently and I would think that if the rings are worn then it is because the oil has drained away from the bores during the periods of idleness.

If you have not already done it I would firstly check all valve clearances and if that was not the problem then lift the head and check valve seats, after all the head is going to have to come off to do the rings, but a valve job may sort it, and give you chance to look at the cylinder bores anyway.

As far as miracle oils go I am sceptical, however I did once sell a Mercedes diesel car because I was having trouble starting it from cold and suspected worn rings and bores. The new owner simply did an oil change and it was perfect thereafter. I am now a believer in good guality oil changed regularly in all my vehicles.

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