1925 model t question

[kwisor]

hello we have a 1925 model t we are getting smoke from where the throttle rod pass through the engine to the carburetor it is real bad we thought it may be the head gasket but no water in oil any ideas
thank you
kevin

[Jack Innes]

About the only thing that could cause smoke in that area would be a severe valve guide problem. You could run the engine with the valve cover removed to see exactly where the smoke is coming from. The head gasket would have no effect on that area.

[Royce P]

Maybe it is over filled with oil?

To check the oil in your Model T the car should be parked in a level place for at least 30 minutes. Open the upper petcock. Remove the oil filler cap. Pour in a small amount of oil. Wait 30 seconds. If oil starts to dribble out of the upper petcock the engine is completely full of oil.

More here:
https://modeltfordfix.com/the-model-...cation-system/

Originally Posted by kwisor

hello we have a 1925 model t we are getting smoke from where the throttle rod pass through the engine to the carburetor it is real bad we thought it may be the head gasket but no water in oil any ideas
thank you
kevin

[CharlieB]

Could be valve guides as suggested could also be blow-by from the rings. Pull the valve cover and make sure the drain holes are open. An oil build-up in the gallery could cause some smoke. Are you getting any from the oil fill cap or just the valve cover hole? From the cap too could be that blow-by from just the cover hole is something else.

[redmodelt]

2X this one; Pull the valve cover and make sure the drain holes are open.
Have a drip pan under the car when you do this. Good chances are there WILL be oil leaking out. Some gets trapped behind the gasket esp if the gasket drain holes are in the wrong place.

[kwisor]

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thank you for the replys this weekend i will be pulling the valve cover to look at the valve guides and clean out the drain holes how many are there and where do i find them the engine has only been run with non detueangt oil so may have a build up if we where to change to rotilla would there be any harm to the Babbitt
thank you kevin

[Jack Innes]

Originally Posted by kwisor

thank you for the replys this weekend i will be pulling the valve cover to look at the valve guides and clean out the drain holes how many are there and where do i find them the engine has only been run with non detueangt oil so may have a build up if we where to change to rotilla would there be any harm to the Babbitt
thank you kevin

YES! You will loosen all of the sludge in the engine & circulate it through the bearings. If the engine is completely dismantled & cleaned, you can get away with detergent oil if you change it often.

Originally the theory was that non detergent oil let the sludge settle to be cleaned out at the time of an overhaul. Then oil filters were invented & detergent oil would suspend the sludge to be removed as it passed through the filter. No filter - then the sludge just keeps going through the bearings.

I am currently working on a 471 cid 1927 MACK AC engine that has had detergent oil introduced after many years of non detergent oil. I am facing some very costly Babbitt work.

[J Franklin]

If you want to run detergent oil, remove the valve covers as well as the inspection cover on the crankcase and hogshead. Clean out everything with some good solvent like kerosene or you can use oven cleaner and water (my favorite) to get all the areas free of anything that will come loose. Clean and blow out the oil pipe too. Now you might not have trouble using detergent oil.

[Royce P]

Unfortunately there is an old wives tale that persists about detergent oil loosening up sludge and somehow destroying your engine. It's a myth, it never happened, and it is really silly that it carries on until today.

I've used nothing but detergent oil in Model A's, Model T's and all manner of old cars and trucks during my lifetime. It's the best thing that you can use, and it is sold everywhere, often the cheapest oil that you can buy. It's detergent oil. Use it.

[redmodelt]

There are two drain holes, each end, bottom center of each group of 4 valves.

[kwisor]

got a look at the valve chamber it was clean what i found was # 3 was not firing the coil is bad and the exhaust manifold has no threads to screw the nut on was held on with a clamp. i have another coil and manifold i will be shipping them to fla so my brother can get his car back on the road i will let you know how it turns out
kevin

[kwisor]

hello my brother put the manifold on and replaced the bad coil all 4 cycl are firing now he said it is still back firing and has no power where do we look from here I told him to ck the fuel line and sediment bowel to see if clogged he is going to look at that today also he has a drain in the battery if not disconnected it will drain it in 30 mins. if it is not running. if he turns the key to the battery side of the ing switch he said it will die any thoughts
kevin

[J Franklin]

Could it have a bad switch? If it has bad internal connections it could cause trouble. Maybe as a test jump around the switch.

[daren007]

Backfiring?

[J Franklin]

Depending on where the backfire occurs it could be electrical or a valve problem.

[Jack Innes]

The switch problem sounds strange - often a T will stop when switched to mag. due to common mag. problems, rarely will it run on mag. & stop on bat. It sounds like part of the trouble may be a mixed up wiring system. Trace all of the wiring & make sure it is correct.

The backfiring & lack of power could be from a leaking manifold gasket. If it has paper like gaskets it is likely to leak. The proper copper rings & glands usually work well.