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TR2/3/3A compression numbers & smoking engine

Kleykamp

Jedi Trainee
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History is that I discovered a cracked block on TR3 engine that was a fairly good running engine. I bought a used TR4 short block. I know it's fool hardy to buy a used engine and not rebuild it , but what can I say, I gambled on it,because it looked pretty good,i.e cylinder walls,timing chain/tensioner,etc. I transferred all ancillary parts and head to the TR 4 block and shoved it in the car. Started with the first push of the button in a cloud of blue smoke. I expected smoke from a engine that had been sitting for who knows how long. The heavy smoke cleared after a few starts over the next couple of days, each time with less smoking. Now the engine idles with no smoking. Although,When I rev the engine and hold it around 2000 or more rpms blue smoke shows up from the exhaust. Not a smoke screen but more than I have experienced in other 3's and 4's. I checked compression, engine warmed to running temp, thottle full open, 5 cranks each cylinder and got ( 1 = 150, 2 = 155, 3 = 155, 4 = 155 ) That seems pretty good to me, right? Now for the smoke. Carbs have had seals installed twice trying to stop leaking from the bottom. I discovered that the front carb piston does not hit bottom which would result in a very rich mixture. Could the rich fuel be floating enough oil off the cylinder walls to create oil burning in the chamber? I have a new set of the cork jet seals which I am going to put in and re-center the jets. Any thing else I should be looking at? I certainly don't see giving up on this engine. Once warmed up it is running very well except for the smoke. Appreciate the input. ( Pat, there are the compression numbers you were curious about. )
 

TR3driver

Great Pumpkin - R.I.P
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Could the rich fuel be floating enough oil off the cylinder walls to create oil burning in the chamber?
If so, it would be because the excess fuel has been washing away the lubrication and now the rings are badly worn. So fixing the mixture is not likely to help the oil burning.

I would be wondering if the oil is going past the intake valve guides. I also wouldn't worry too much until having driven the engine for awhile. Might be just a stuck ring or something, that will work loose. If it does need rings and/or valve guides, those can both be replaced without pulling the engine.
 

PKPoole

Senior Member
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Joe,
I'm with Randall on this one. Initially, I was thinking valve guides, but if you didn't have similar problems with the same head on the other engine I doubt you would have it here. I'm guessing it is the oil rings 'glommed up' (a technical term). I know when I was a kid (the dark ages) the old timers would pour STP gas treatment straight into the carbs to clean valves and rings. Makes a real smoking mess when you do it but always seemed to work. The compression readings look good, and the sleeves certainly looked fine when we looked at them. Are you sure it is oil smoking and not water vapor? Pat
 
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Kleykamp

Kleykamp

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Randall, I later did a "wet" compression test...two squirts of oil...per your instruction in another post I found on search. Difference was about 10 psi on each cylinder. Does that indicate any room for concern with the rings. Valve guides? It doesn't smoke on start up, just when I rev the engine. I thought valve guides typically caused smoking on start up which went away after the "settled oil" burned off. I have not had the car out on the road yet, only running in the garage. It may be a mute point, as the blue smoke has all but disappeared. I wouldn't know about the car having been run rich or lean previously, as I just put it in with my carbs on it, but I definitely need to address the sticky piston in the front carb. I'll put it the rest of the way together and drive for a while. I remember my first TR3( worse than a barn find) smoked some for several drives, and ended up running really good. This one has cleared up significantly already. I may need to buy a lottery ticket. Thanks for the input.
 
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Kleykamp

Kleykamp

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Pat, It's all but quit smoking. I suspected the "glommed up" issue may be the cause. There was alot of sludge in the bottom of the oil pan. Thought it might be oil that jelled around the rings and would just take some time to re-seat. Not water vapor though. The first day it was like a smoke screen. Yep, I didn't have that issue with the same head on a different block. I run it a while and change the oil and I think it will be good. Like I mention....probably need to buy a lottery ticket with this kind of luck. Maybe I'll drive over when I get confidence in it and make you even more proud of your two nice 3's.
 
Last edited:

PKPoole

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Joe, come by anytime. The beer's cold and we can celebrate you getting back on the road. Pat
 

TR3driver

Great Pumpkin - R.I.P
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Randall, I later did a "wet" compression test...two squirts of oil...per your instruction in another post I found on search. Difference was about 10 psi on each cylinder. Does that indicate any room for concern with the rings.
Sounds like you are good to go; but I just wanted to explain that a compression test is not the comprehensive diagnostic that many people assume that it it. Your results sound perfectly normal; but you would get the same results if the 3rd "oil control" ring was missing entirely!

If there was visible sludge in the pan, then I would suggest frequent oil changes for awhile, with a good high quality oil. Also wouldn't hurt to double-check that the rockers are getting oil.

The classic symptom of worn valve guides is a puff of blue smoke every time you shift. But they can be bad enough to cause smoke almost any time.

Many years ago, a buddy of mine owned a Ford Pinto station wagon that had some serious wear issues. Around town, it burned an incredible amount of oil, almost more oil than gas! I used it briefly to run parts and it would be a quart low after just 15 or 20 miles around town. He was going to drive it from TX to CA and back; and I just couldn't understand why he wasn't stocking up on cheap oil before the trip. But what I learned was that, at constant freeway speeds, it used almost no oil at all! It also carried almost no intake manifold vacuum, even the vacuum operated cruise control would quit working if you started up a slight grade. So I surmise that most of the oil was being sucked past the guides by intake vacuum. We left Spring, TX with 6 quarts of spare oil, and ISTR still had two of them when we got to Los Angeles.

Had a lot of fun on that trip, in spite of (or perhaps because of) all the mechanical problems. I had bought a 56 TR3 through him, and he had drug it to his home in Spring and gone through the brakes for me. I flew down there with my wife to drive the TR3 back to LA and Gary agreed to accompany me (in his Pinto). We didn't even make it out of the subdivision before the TR3 quit the first time! But after that, it ran like a champ, except for some overheating issues that were ultimately solved by tightening a hose clamp. The original thermostat housing was unusable, so I had found a water outlet at a local auto parts store that would kind of work. But it had no provision for the bypass hose, so I had to cap off the bypass fitting on the water pump housing. Apparently my cap would suck air on the road, and force water out the overflow. Or it may have just been the big traffic jam in Houston, which had more or less cleared while I was fiddling with the cooling system.

Then somewhere in western Texas, the Pinto lost a front wheel bearing. We both remembered the "Next services 104 miles" sign, but couldn't agree on whether it had been more or less than 50 miles ago! We finally went back (I was right, it was only 46 miles) and were able to find the parts he needed to continue.

BTW, both wives were smart; they insisted on flying to LA :smile:
 

MDCanaday

Jedi Knight
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The best ever fix for the no valve seal on the intake valve is to install new guides and have
them knurled to make up for wear on the old valve.This is like magic and can easily take the oil consumption
down to less than a quart per 1200miles. It has tha advantige of being cheap too....
MD(mad dog)
 
OP
Kleykamp

Kleykamp

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DSCI6582.JPGI've run and driven the car and the smoke has stopped completely. 3-4 weeks ago, I sat out to replace a head gasket...now I have a new/old short block and much better running car. I have a clean and color matched engine bay, rather than ratty black, I have a wiring harness that is completely wrapped and neatly tucked into the tabs, I have shiney brake,clutch and fuel lines, rather than ratty black. I'm a happy man for a day or two.DSCI6583.JPG
 

leslie_choo

Freshman Member
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I have overhauled and changed to new valve, springs set and new valve guide from moss motors . Alot of smoke hence I installed valve seal and the problems gone. It took me a while to find the right size of valve seals though. Not too sure what's the impact of having valve seals but the smoke problem is gone .
 

TomMull

Luke Skywalker
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I have overhauled and changed to new valve, springs set and new valve guide from moss motors . Alot of smoke hence I installed valve seal and the problems gone. It took me a while to find the right size of valve seals though. Not too sure what's the impact of having valve seals but the smoke problem is gone .

Interesting. I'd be interested in other experiences. Perhaps food for thought: https://www.tr3a.info/Net_TRvalveGuide.htm


Tom
 

Don Elliott

Obi Wan
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I have never had valve seals on my 1958 TR3A. I changed the guides and valves about 1995 (about 70,000 miles ago) when I had my head converted for lead-free fuel and have driven over 193,000 miles on this original engine. I think a expert will advise against valve seals because we need to get lubricant between the valve stem and the guides.
 

TFB

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I have never had valve seals on my 1958 TR3A. I changed the guides and valves about 1995 (about 70,000 miles ago) when I had my head converted for lead-free fuel and have driven over 193,000 miles on this original engine. I think a expert will advise against valve seals because we need to get lubricant between the valve stem and the guides.

The subject of valve guide seals on motors not origianally equipped comes up often in the vintage motorcycle community.It seems the misconception is that the seal keeps oil off the stem,when in fact it is actually wiping a thin layer of oil on the stem each stroke.The hole in this argument seems to be that the seal only contacts a small portion of the stem,and never contacts the majority of the stem in the guide .Tom
 

leslie_choo

Freshman Member
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from my experience it does help alot. without valve seal my car is producing smoke. when i overhauled my car i change to the bronze guide, so both intake and exhaust have 5/16 stainless steel valve stem. I got them from Moss Europe. Believe me, the clearance gap in between the guide and stem enough to produce alot of smoke from the car.
I should have stayed with my old 3 spring, old guide and stem. but i thought bronze guide, stainless steel stem and 2 springs are better.
anyway, if seals are needed make sure you get the right size seal, we need to make sure the guilde diam and stem size (both intake and exhaust) are correct
 

TR3driver

Great Pumpkin - R.I.P
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Well, I'll sure never use them again. This was the result of my only experience with valve seals on a TRactor motor. I had put them on only as a band-aid to cover up the severe wear in the valve guides. One of them popped apart during service, causing that one cylinder to go back to burning lots of oil under cruise conditions and, apparently, detonating from the octane-destroying effect of the oil.

BrokenTR3piston.jpg
 

MDCanaday

Jedi Knight
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Has anybody tried my fix(mentioned earlier in this thread)?? it does it all for almost no $$
Your machinist will think you quite mad, but it works great and lasts.
MD(mad dog)
 

TR3driver

Great Pumpkin - R.I.P
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Nope, I went for new guides and new valves, plus fixing the original oil supply to the head and losing the external oil feed. Got my oil consumption down to about 1 qt/3000 miles, which was mostly leakage at the rear main seal.

Kas Kastner once wrote of having the guide cut to accept a spiral of copper wire inside, which was then reamed to fit the valve stem. Anyone tried that method?
 

TomMull

Luke Skywalker
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Has anybody tried my fix(mentioned earlier in this thread)?? it does it all for almost no $$
Your machinist will think you quite mad, but it works great and lasts.
MD(mad dog)
Never done it but I wonder how knurling the guides will compensate for worn valve stems. The stems, like the guides, do not wear evenly so if you knurl to the largest valve stem diameter it will still be loose at the ends.
On the other hand, I worked in a shop once where just about anything that didn't fit was knurled, and with considerable success.
Tom
 
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