I have a 1929 Ford Model A engine that was built by Ron Kelly. After putting about 25 miles on the engine (plus a lot of idling) I pulled the plugs and #4 cylinder plug was coated in oil. Unfortunately, Mr. Kelly is deceased so I'm uncertain as to whether putting more miles on the engine will eventually seat the rings or am I going to have to replace the rings. Any input is appreciated.
Rebuilt Engine Oil in Cylinder
- Thread starter sidthecpa
- Start date
The first step is a compression test. If the rings are broken, you should see it in the test. Model A engines have a loonnnnngg break in period. My rebuilt engine took like two thousand miles to get up near full compression. I now have another thousand and the compression is 100 across the board (high compression head). When I first checked, it was running in the 82-87 range across the 4 cylinders.
CWPASADENA
Well-known member
The worst thing you can do to a new engine is "a lot of idling".
The rings are not yet seated and just idling the engine will prolong the process. Running the engine at a higher speed will also help insure all the internal components are getting well lubricated. The cam and lifters depend on the splash from the rods for lubrication so if you must run the engine without actually driving the car is to set the idle up so it "idles" at a minimum of 800 rpm or so.
If possible, drive the car and get some miles on it. The rings should seat in and everything should be fine.
My opinion,
Chris W.
The rings are not yet seated and just idling the engine will prolong the process. Running the engine at a higher speed will also help insure all the internal components are getting well lubricated. The cam and lifters depend on the splash from the rods for lubrication so if you must run the engine without actually driving the car is to set the idle up so it "idles" at a minimum of 800 rpm or so.
If possible, drive the car and get some miles on it. The rings should seat in and everything should be fine.
My opinion,
Chris W.
Fullraceflathead
Well-known member
Most likely what you’re seeing is oil being pulled up past the rings because of the extensive idling. The vacuum is highest with an engine idling. If the rings are not completely seated which they most likely are not yet you may see some oiling on the spark plugs.
I doubt you have any serious problems.
Make it a point to warm up the engine a few minutes then drive it for 25 miles or so at various speeds and loads.
Try to put 500 miles on it like this and watch the oil level closely.
The oil consumption should only get better meaning less as you put more miles on it and the ring seat.
A leak down test will tell you exactly the condition of the engine but I don’t think it’s necessary.
I think you need to just drive it and don’t do any more unnecessary idling.
I doubt you have any serious problems.
Make it a point to warm up the engine a few minutes then drive it for 25 miles or so at various speeds and loads.
Try to put 500 miles on it like this and watch the oil level closely.
The oil consumption should only get better meaning less as you put more miles on it and the ring seat.
A leak down test will tell you exactly the condition of the engine but I don’t think it’s necessary.
I think you need to just drive it and don’t do any more unnecessary idling.
Last edited:
Richard Knight
Senior Member
I think flathead has it right. Just get out and drive it. Normal secondary roads. No sustained high speed. I would not be concerned until I had 1000 miles.
Big hammer
Well-known member
Kinda sounds like the engine has been sitting around before installed and run ? Drive it easy but don’t lug it, when new I believe you where to not to drive over 35 mph for 500 miles
There are a lot of viewpoints on engine break-in that have been passed down over the years, but I tend to go with what trusted engine builders say. I was once told "drive it like you normally would, just not a lot of idling or lugging". I would check with other Model A engine builders to see what they recommend, but as others have stated above - drive it normally and the rings will seat in and all will be well. As was also previously mentioned, a compression check and leak-down test would certainly be in order before making any further assumptions.
*Disclaimer...if you are using 100% synthetic oil, you can just about double the normal break-in mileage/time before the rings begin to seat properly. This is a fact with Amsoil and perhaps some others synthetic oils.
*Disclaimer...if you are using 100% synthetic oil, you can just about double the normal break-in mileage/time before the rings begin to seat properly. This is a fact with Amsoil and perhaps some others synthetic oils.
BRENT in 10-uh-C
Well-known member
Is there a reason why you are concerned at this very moment? For example, is the engine smoking blue smoke? If not, I am taking a shot in the dark here but with it idling and not building a lot of heat, sooty carbon caused by a 'fat' mixture will often look like wet oil. Unless there is a reason you need to open the engine immediately, I'd suggest starting the engine and allow it to get good and warm (almost to the point of boiling). Then allow it to cool and check head gasket torque. Then restart and allow the process to repeat so as to allow thermal expansion to happen to all internal parts. A lean carburetor mixture will be your friend on allowing it to build temps. You may just find your 'oily' spark plug cleaned-up.
BTW, seeing this is your first post on Fordbarn, ...Welcome.
mctim64
Junior Member
I would agree with the other builders who posted, take it out and drive it! I tell all my customers " don't be too rough with a new engine but don't be too kind either. And definitely don't let it idle for long periods of time"
Clean or replace the fouled plug (s) first of course.
Clean or replace the fouled plug (s) first of course.