1914 Touring Low Compression/Engine Rebuild

E

Ed in Maine

Well-known member
Some of you may remember some of my posts on my 1914 T that has low compression and is difficult to start. I lapped the valves and put in new valve springs and the compression came up a little. I was able to use the car over the summer but I didn't trust it. Sometimes it was hard to start when it was hot. I think it is time to look into a rebuild of some level.

The bearings are quiet. The valves looked very good. I would like to change the rings. Is this a job that could be done with the block in the car or should I plan to remove the engine. I don't know the condition of the cylinders other than that they are not scored or rusted. What is the best course of action at this point? I would like to do as much work myself as possible but if necessary would have the block bored out for new pistons. Your suggestions are appreciated. Ed
 
We'll call this an in frame overhaul. Before deciding for sure which course of action to take, consider the condition of the cooling system, magneto operation, transmission operation, and heaven forbid, oil leaks. If any of this stuff is in the least problematic, pull it out and go through it. When you get to that point, look deeper into each component.
In answer to your question, a re-ring with a hone job in frame is not difficult. Mark the heck out of EVERYTHING for re-assembly; direction of rods and caps AND ESPECIALLY shims. pistons to cylinders etc etc... Do a real compression test BEFORE you start pulling it apart. 50-60 psi would be good to have. Ts can and will run on 25 psi but be pretty low on power. ws

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I am no T expert but I think if you have hardstarting when hot I would be looking for something in the electrical system .Does it use oil ?? .
Ed in Maine said:
Some of you may remember some of my posts on my 1914 T that has low compression and is difficult to start. I lapped the valves and put in new valve springs and the compression came up a little. I was able to use the car over the summer but I didn't trust it. Sometimes it was hard to start when it was hot. I think it is time to look into a rebuild of some level.

The bearings are quiet. The valves looked very good. I would like to change the rings. Is this a job that could be done with the block in the car or should I plan to remove the engine. I don't know the condition of the cylinders other than that they are not scored or rusted. What is the best course of action at this point? I would like to do as much work myself as possible but if necessary would have the block bored out for new pistons. Your suggestions are appreciated. Ed
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As bill suggested, do a real compression test. All plugs out, test each cylinder. Then put a little motor oil in each cylinder & test again. ( A rag over the open plug holes will help keep you from wearing the extra oil.) If the readings are low but the same the problem would lean toward the valves, if the oiled readings are higher it would indicate a ring/piston problem.

Have you checked the valve clearance? If it is too tight it might run fine cold but when hot things expand enough to close up the gap between the lifter & the valve stem causing loss of compression.
 
If its piston clearance then when it gets hot pistons should expand and tighten up so starting should improve ,We had a 38 Ford that used buckets of oil but started and ran like a train .I would change out the coils .Timer etc for known good ones .Test the spark when hot , run a jump wire from battery ,
 
For your problem or at least to find out the condition of the rings a proper compression test as stated earlier, will tell all. Do it cold. This will eliminate problems that could develop from parts expanding (as stated: loss of valve clearence). Pull the plugs. Make sure the throttle and choke are fully open. Take compression of each cylinder. 1 thru 4. WRITE IT DOWN! Don't trust to memory. Dump about a teaspoon of engine oil into #1 cyl. and take compression again. Repeat with the remaining 3 cyls. If the readings don't change it usually means valves leaking. If it goes up it's because the oil has temporarily sealed the rings and they are the culprits. Rings are do-able without removing the motor. If you have 40 Lbs. or better with a cold engine and no oil added to the cyls. you have another problem like fuel or ignition. The T is fairly low compression with 55/60 being marvelous. That's why I do them cold. You get a true cold engine/starting condition result. 10 lbs loss on a T could spell hard starting/low power. Not so much on a modern with say 150 Lbs normal comp. per cyl. You wouldn't notice a 10 Lb. loss in that case. A comp. test is without a doubt the best, easiest and cheapest way to tell you engines condition.
 
Thank you for your input. My compression values range from 25 up to 35 cold, car being cranked. I used to get "free starts" when I purchased the car in 2006 and start promptly with the crank. This spring before I take it apart I will try your suggestions with oil. Yes, the transmission is noisey in second and reverse. I will check in from time to time to tell how it is working out. Happy New Year to all, Ed
 
Not to ad to your' woes, but a noisy high and reverse in the trans may be rear end noise resonating up the torque tube (drive shaft). That noise could be as little as inadequate oil level, or, the dreaded imminent thrust washer failure rumble. When the motor is out, half the battle of pulling the rear end is done. Id finish it off with one shot to the back of the head and inspect the rear end while youre in there.
When those thrust washers fail, you lose the "whoaa" as well as the "go"! Not a pleasant scenario! ws
 
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