[MrSurly]

1. compression test. (low compression can mimic a rich condition)
2. swap the injector with another on the same side just to test it OR
3. pull the injectors and have them tested OR
4. replace all of them for peace of mind and keep an eye on the plugs

(don't read this part) a flat cam lobe can ALSO mimic a rich condition... but you'd have noises and other symptoms, so that's not likely...aren't you glad you didn't read this part?

 

[FLOORED]

just swapped injectors 2 and 4. will report back with results

 

[subaru335i]

Did your friend do compression or leakdown in diagnosis? Did he take the valve cover off?
I agree with others, this didn't just heal on its own and you had extreme oil consumption so something is wrong, not just the tune.

 

[subaru335i]

1. compression test. (low compression can mimic a rich condition)
2. swap the injector with another on the same side just to test it OR
3. pull the injectors and have them tested OR
4. replace all of them for peace of mind and keep an eye on the plugs

(don't read this part) a flat cam lobe can ALSO mimic a rich condition... but you'd have noises and other symptoms, so that's not likely...aren't you glad you didn't read this part?

Did we all forget about the 1/2 quart per 200 mile oil consumption? haha

I agree the plug could be caused by these things or just running rich for some reason but that amount of oil consumption doesn't just heal itself.

I doubt its injector related. My money is still on valve guides or worse.

 

[Sudderth]

I worked at a Chevrolet dealership back in the early 1980's and we used Bon Ami and it worked to get rings to set. Worth a try before you tear it down. We had a duster we filled up and sprayed the dust in the carburetor. I suppose you could remove one of the intake lines that connect to the main inlet duct. Dusted a quarter of a can into the engine and ran it around the block a couple of miles and it really would stop oil burning. I apprenticed under a guy that started at the dealership when it opened up in 1955. He was the master. He could rebuild an engine, set the rockers, timing and carburetor and shut the hood before he started it and it worked flawlessly. Anyway, if Roger used it back in the day its worth a try...

 

[Rubber Duck]

Did we all forget about the 1/2 quart per 200 mile oil consumption? haha

I agree the plug could be caused by these things or just running rich for some reason but that amount of oil consumption doesn't just heal itself.

I doubt its injector related. My money is still on valve guides or worse.

..

-continually fouling a spark plug-
The causality. . .
If that cylinder is not firing properly, then rings can get washed out.

And as I explained above. . .
You might not see any blue smoke coming out the tailpipe.

Then. . .
Adding boost to the issue generates another causality.

Oil in any cylinder can and will lower the octane level
sufficiently to generate self detonation.

Preheated 'end gasses' that hide, unburnt within the backside of the upper ring, by themselves generate self-detonation.

Now, add boost along with oil and you have a 'ticking time-bomb'. . .

Cheers

 

[Rubber Duck]

I worked at a Chevrolet dealership back in the early 1980's and we used Bon Ami and it worked to get rings to set. Worth a try before you tear it down. We had a duster we filled up and sprayed the dust in the carburetor. I suppose you could remove one of the intake lines that connect to the main inlet duct. Dusted a quarter of a can into the engine and ran it around the block a couple of miles and it really would stop oil burning. I apprenticed under a guy that started at the dealership when it opened up in 1955. He was the master. He could rebuild an engine, set the rockers, timing and carburetor and shut the hood before he started it and it worked flawlessly. Anyway, if Roger used it back in the day its worth a try...

Your Master Mechanic you apprenticed under most likely learned that technique when Chevrolet released the 1955 Chevrolet 265 cid. That is exactly what the tech note from GM explained what to do, as those engine blocks were made of Nickle, where hard and the cross hatch pattern was wrong. So rings did not seat.

Interestingly. . .
When I was asked to become a service writer at a GM Dealership, back in the early 1960's, I was taught by an older individual who had been a Service Rep for Chevrolet back in 1955. Because I was now making more money I decided to build out my 1955 Chevrolet 265 cid engine.

He told me to get a later 283 cid engine block.
I asked why(?) and he showed me the original tech note from GM.

But that tech note, as I recall, only stated to put about
a tablespoon of Bon Ami down the carb???

Cheers

 

[Rubber Duck]

Regardless I would still change it. I would also put a new plug in it and go clear out the cylinder before performing your leak down …..I almost guarantee it would be low if you were to just test as is now.

Good Advice..

Tell us a little about your B-15 with the ported blower. . .

Cheers,
Bruce

 

[kittyboy]

hows your valve stem seals ? not sure if yours are held down with the spring or if they push on, if they are the push on style then they can pop up over time, easiest way is to remove rocker covers and look at the springs see if any are sitting up where they shouldnt be

Attached is an image of my #8 cylinder that I felt had a leaking valve seal, I replaced them all when I pulled the heads. At the time I was not fouling plugs and had no misfires. I can't say what your issue is, but based on these images prior to replacing the valve seals, it appears bad valve seals can make a difference.

 

[07GTS]

Attached is an image of my #8 cylinder that I felt had a leaking valve seal, I replaced them all when I pulled the heads. At the time I was not fouling plugs and had no misfires. I can't say what your issue is, but based on these images prior to replacing the valve seals, it appears bad valve seals can make a difference.

View attachment 165703

View attachment 165702

only time i noticed i had a valve seal issue was when engine was stopped over night and i removed plugs as i do just as a check now and then and one had some oil on the thread and tip looked like it was running rich, i then used pore scope to look at the piston top and it was also more black then others and then i lifted the rocker covers and see some of the valve seals had lifted up and were allowing oil thru, i didnt notice any smoke or anything just luck that i checked the plugs regularly

 

[07GTS]

got this pic of mine as u can see middle valve the seal has popped up and just sits up within the spring

 

[kittyboy]

only time i noticed i had a valve seal issue was when engine was stopped over night and i removed plugs as i do just as a check now and then and one had some oil on the thread and tip looked like it was running rich, i then used pore scope to look at the piston top and it was also more black then others and then i lifted the rocker covers and see some of the valve seals had lifted up and were allowing oil thru, i didnt notice any smoke or anything just luck that i checked the plugs regularly

A few valve seals blew, slight rear main seal leak after my bank two head lifted running aggressive timing and inadequate case pressure relief. I was 17lbs boost, 2.0 cylinder air at 22*, 6500rpm, 98 octane gas. Everything runs fine since less some compression loss due to accelerated ring wear caused during the event. I am just keeping things tame for now until I get the motivation to replace the rings and bearings. Live and learn I guess...

 

[kittyboy]

got this pic of mine as u can see middle valve the seal has popped up and just sits up within the spring

Mine are the hat seal types.

 

[NVscout]

Good Advice..

Tell us a little about your B-15 with the ported blower. . .

Cheers,
Bruce

Was a ported blower … now 2650 rabbit hole! Haha , just getting the tune finished up running a 3.5/9.2 pulley setup on pump gas that makes 17 psi. The plan is to run a 3.25/9.55 and land somewhere in the 20-21psi range !

 

[kittyboy]

Was a ported blower … now 2650 rabbit hole! Haha , just getting the tune finished up running a 3.5/9.2 pulley setup on pump gas that makes 17 psi. The plan is to run a 3.25/9.55 and land somewhere in the 20-21psi range !

If you don't mind, will you post your timing table after the tune?