1925 Master engine Issues

[dibarlaw]

I am still trying to come to grips as to what would need to be done with the engine on my 1925 Master Touring. The previous owner had replaced the riser sleeve. I had gone thru the carb, including a new nitrofil float. After replacing plugs, new wires, points and cond. Timing and re-timing it was still not running any better.

I recently did a compression check. Cylinders 1-5 were 50-55lbs. #6 was 10lbs. on a cold engine. With a bit of added oil in #6 up to 20lbs. After a good 15 mile drive it was 35lbs. hot. That is what I remember it being when I ran a compression check on it back in 2017. Working through the rebuild of my 1925 Standard engine in 2018-2019 the Master sat mostly idle for 2 years until I found out why that engine quit on me. (Stripped timing gear.) It was a while before I replaced the timing gear. Then started and ran he engine only sporadically while I did a radiator re-core, water pump, brakes and all until I got him back on the road in January. Previously the vacuum was barely at 17 in vu. After the last 15 mile run the vacuum was at a better 18-19 in. Very slight fluctuation at that reading. But that was to me at a too high an idle speed.  The only way to get it down to a reasonable idle speed is to drop down to full retard. No adjustment left on the butterfly stop. On another issue that cropped up after the good run was that it was blowing oil out of the road draft tube. (The previous owner installed a later oil filler with the conduit style road draft down tube.)

Oil all over the steering box side of engine and coming out the hood louvers.

A

Also oil from the bottom of the trunnion case indicating rear seal issue.

All this indicating an overfill condition. Oil pressure at the gage is 22 lbs. When I changed the oil after the timing gear replacement the level on the stick was at the full line.  It was now showing a bit higher. Using my suction gun, I pulled a pint of oil to get it back to the full mark. No indication of coolant in oil. But after several runs of over 10 miles of up to 50 MPH, there would be a several cup full puddle on the driveway or on the drip pan plus whatever was blown out along the way. 

I consider a possible over rich condition adding fuel to the oil. 

 

 Could the low #6 cylinder and blowby add that much fuel to the oil over the 59 miles and several hours of static running time over the last 4 months trying to sort things out?

 

 Could the vacuum tank vacuum line be also sending extra fuel to the manifold?

The uncontrollable too high idle speed as a symptom. 

 

 Thoughts???

Edited April 19 by dibarlaw
Added content (see edit history)

[Daves1940Buick56S]

Larry:

 

So you know I only work on newer stuff but I have 2 ideas.

1. Do a blowdown test on #6 to see if the leakage is thru the valves or rings/piston.

2. Get a quart bottle and hook it up to your carb IV-style in place of vac tank. That will at least tell you about the idle issue.

 

Cheers Dave

[Mark Shaw]

5 minutes ago, Daves1940Buick56S said:

1. Do a blowdown test on #6 to see if the leakage is thru the valves or rings/piston.

Hopefully you will find it is a burnt valve on #6.  Much easier to fix than a scored cylinder and/or broken rings.

[Oldtech]

Check the valve clearance first. Valve(s) may be being held open. 

 

[EmTee]

My thought is there are probably a combination of sticky and/or burnt valves (e.g., #6) and sticky rings (the blow-by).  In the past I've had reasonably good results adding Rislone to clean oil to help free sticky valves and lifters.  Stuck rings may be tougher to resolve without disassembly, depending upon how much carbon is fouling the ring grooves and the condition of the rings themselves.  You can certainly try lowering the oil level in the crankcase and driving the car. Exercising it should help loosen things up to a point.  Drive the car, monitor the compression, and see what happens.

[dibarlaw]

Thanks to all...

 Old tech...I have checked and rechecked valve clearance. .009 on #6. 

 

Dave.... Hugh has sugested a leak down test also. I would simply disconnect the vacuum tank from the manifold and plug the line using the fuel in the canister to check idling.

 

Mark.... The burnt valve was on top of my list as there was a sporatic variation of my vacuum readings. Not more than 1/2 inch point drop.

 

 EmTee...I am trying to get some more miles on the engine before I commit to drastic measures. 

[DonMicheletti]

With all those issues, I'd just tear it down and check everything out.

May be more than one issue

[Hubert_25-25]

If you are going to "drive the problem" out of the car, you need an additive that works on sticking rings.  Lots of snake oil out there.  Not sure what is better than another.  

 

A leak down test will tell you if #6 is a valve or piston problem.  That would determine if you pull the oil pan (pistons come out the bottom) or pull the head for a valve job. 

 

I am in the court with Don.  I would not drive the problem out, but rather do the leak down and follow up on that data.   If it's a piston, then it is an opportunity to inspect the oil lines and the oil screen.  There is also no loss in pulling the cylinder head and cleaning all the carbon out and dressing the valves.   Hugh 

 

[Oldtech]

 

Quote: If you are going to "drive the problem" out of the car, you need an additive that works on sticking rings.  Lots of snake oil out there.  Not sure what is better than another.  

 

Just put a cupful of ATF in the gas tank with at least a half full tank and see what happens .

[EmTee]

6 hours ago, Hubert_25-25 said:

If you are going to "drive the problem" out of the car, you need an additive that works on sticking rings.

I'm not saying the issue will be resolved by driving but, driving it a couple hundred miles may change the severity and buy some time.  A sticky (not bent or galled) valve may be completely resolved by driving.  Stuck rings are less likely to free-up by just driving, but compression may still improve enough to mitigate some of the current blow-by issue.  If you have one of those inexpensive borescopes you could attempt to look at the #6 cylinder wall through the spark plug hole to look for any scoring, which would confirm the engine needs to come apart for repair ASAP.

[dibarlaw]

I will be trying to get some more miles on the car before making a final decision. As to how things evolved. I think the previous owner did an overhaul when resurected back in the 1960s -1970s. Very sporatic use over the next 30 years. Probably not accumulating more that several hundred miles in that time, then left to sit for nearly 10 years. We got the car running for the family in 2013 after the owner passed in 2012.

They ran the car a bit with probably not an hour on the engine untill they sold it to me in September 2016.

 Since my last post I have  put on another 6 miles since I pulled the extra pint of oil out. At the same time I had changed out the Oil/Amp gage since the gage was leaking. On this gage the pointer was at 5lbs. so now the pressure is showing 28lbs.  The old leaking gage that would zero at rest was showing 22lbs. I had the oil pump rebuilt and installed a new screen as well as resoldering the joints of the oil delivery manifold. Now very little noticeable blow by smoke coming out of the road draft (there had been a lot before) and no excesive drips of oil. But I have kept it down to no faster than 35 mph. Stay Tuned.....

[EmTee]

5 hours ago, dibarlaw said:

Since my last post I have  put on another 6 miles since I pulled the extra pint of oil out.

 

5 hours ago, dibarlaw said:

Now very little noticeable blow by smoke coming out of the road draft (there had been a lot before) and no excesive drips of oil.

Could the dipstick be incorrect and "FULL" actually overfills the crankcase?  Maybe try sticking a wire (e.g. coat hanger or welding rod) into the dipstick hole and measure the distance to the bottom of the pan.  Compare with the dipstick and distance to the crankshaft centerline.