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Old 07-25-2020, 11:50 AM   #1
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Default Decided to pull the motor/trans

So, I had done the valves and guides (they were shot) in hopes of fixing an oil consumption problem (1qt in 60 miles) to no avail. It ran sweet but still uses the same amount of oil. So, I pulled the head and dropped the pan so I could pull the pistons and check them out. When I had the head off to do the valves, I noticed that the cylinders were glazed but there was no ridge so was thinking a deglazing and new rings should do the trick. Nope. Has .0100 over pistons (for a 3.975 bore) and the bores mic'ed 3.986 and the rings had a gap of 1/8-3/16". There was also some scoring on the walls and pistons, mostly at the bottom of the cylinders. So, after some pondering, I decided to hone the cylinders out to 4" and put .0125 over pistons in. I did #1 cylinder in the car but found that the amount of metal dust produced was such that there was NO WAY I would be able to clean the bottom end sufficiently so I pulled the engine/trans to do it on the stand. In so doing, I found a few other issues that need to be dealt with. The oddest one was that one motor mount was broken. The face that bolts to the block was broke straight across the middle then up and around the edge so that the top bolt was not holding anything, just the broken square from the mount. NO IDEA how that could/would break that way. Also, the pressure plate fingers wee WAY out of whack (possibly explaining the clutch chatter when taking off). Two fingers were 1/8" plus lower than the others. A screw was missing from the bottom generator mount and the other was loose. Also found that the teeth on the ring gear are chewed but they are chewed on the backside which suggests to me that the ring gear was turned around as I would think that any grinding should occur on the front edge of the teeth where the bendix engages. It never made any noise when cranking so I think I will just leave that for now. Cylinders also had a wicked taper which takes some doing to remover (about .008 tighter at the bottom). Anyway, I'm going to try to set my clearances with a micrometer since the engine is out and on the stand. Mic the journal, then mic the corresponding "circle" and adjust for .0015 difference. The cam shows, what looks to me like, a fair amount of wear. The clutch disc looks OK but is solid. Not sure if it's worth putting a new spring damped disc in or not.
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Old 07-25-2020, 12:03 PM   #2
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Default Re: Decided to pull the motor/trans

Valve guides in any engine will not cause that much oil consumption. Ringing it properly is a good thing. But, with .008" taper I would recommend sending it out for boring. I prefer to leave the piston clearances a bit on the wide/loose side. But, thats just me.
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Old 07-25-2020, 12:20 PM   #3
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Default Re: Decided to pull the motor/trans

At 37 bucks change the clutch disc every time,especially if it chatters.generally when the cylinder bores are worn and the valve guides are shot every other component is worn..bearings,distributor drive,oil pump,everything should get a full inspection.
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Old 07-25-2020, 01:51 PM   #4
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Default Re: Decided to pull the motor/trans

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Valve guides in any engine will not cause that much oil consumption. Ringing it properly is a good thing. But, with .008" taper I would recommend sending it out for boring. I prefer to leave the piston clearances a bit on the wide/loose side. But, thats just me.
I already removed the taper and brought the cylinders to 4" (the pistons mic 3.998). well, 3 are done, one to go.
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Old 07-25-2020, 01:59 PM   #5
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Default Re: Decided to pull the motor/trans

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At 37 bucks change the clutch disc every time,especially if it chatters.generally when the cylinder bores are worn and the valve guides are shot every other component is worn..bearings,distributor drive,oil pump,everything should get a full inspection.
already checked out the oil pump and distributor drive, all good. Bearings look good and of course will have the clearances set on assembly. Timing gears are good but cam shows wear. Cam bearings feel good. Release bearing and pilot bearing appear new. Good point on the disc. ordering it will delay assembly but I have a lot of detail work I can do while I wait. What I find odd is that the cylinders APPEAR to be worn (based on measurements) but there was zero ridge at the top of the cylinders leading me to think that maybe someone botched a bore job. I can't think of any way that a cylinder can wear that much and not leave a ridge.
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Old 07-25-2020, 02:08 PM   #6
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Default Re: Decided to pull the motor/trans

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I'll deal with only one item. The ring gear needs the rounded side of the teeth at the rear as it sits in the chassis. When you remove the starter the bendix goes past the ring gear and comes forward to engage, the rounded end of each tooth aids in engaging. same for the bendix, rounded end is the engage side.
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Old 07-25-2020, 03:25 PM   #7
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Default Re: Decided to pull the motor/trans

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I'll deal with only one item. The ring gear needs the rounded side of the teeth at the rear as it sits in the chassis. When you remove the starter the bendix goes past the ring gear and comes forward to engage, the rounded end of each tooth aids in engaging. same for the bendix, rounded end is the engage side.
Ah yes, I see that now. I never paid much attention. It's "backwards" from what I am used to. I'll change out the gear. Thanks
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Old 07-25-2020, 03:27 PM   #8
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Default Re: Decided to pull the motor/trans

I see I have some up and down movement in the input shaft in the trans. Don't know what that means But I'm going to tear the tranny down and look things over while everything is out.
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Old 07-25-2020, 03:57 PM   #9
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Default Re: Decided to pull the motor/trans

Engine doesn't have cam bearings,up and down play on the trans input shaft is normal,the pilot bearing in the flywheel supports it. Good news about the bearings,thats expensive work saved
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Old 07-25-2020, 06:46 PM   #10
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Default Re: Decided to pull the motor/trans

Tore the tranny down. Gears are rounded on the tips and one tooth on one (don't recall which one) has a small chip. Not sure what to do there. $1000 for all new guts for a car that will see MAYBE 1000 miles a year???. Trans works well but would jump out of second when pulling. Hate to put it back together as is but...........I've got tomorrow to ponder and look them over again. Interesting note, Rather than two roller bearings and a spacer in the cluster it had three roller bearings. two short and one long. Also, rather than snap rings to hold the main bearings, there is a ridge cast into the case. Sure this is a model year thing just don't know enough about these to know what year.
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Old 07-26-2020, 02:51 AM   #11
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Default Re: Decided to pull the motor/trans

Jumping out of gear will only get worse. Fix it while it is out.
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Old 07-26-2020, 07:39 AM   #12
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Default Re: Decided to pull the motor/trans

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Jumping out of gear will only get worse. Fix it while it is out.
I can't seem to see anything that will cause it. Makes it hard to "fix".
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Old 07-26-2020, 09:48 AM   #13
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Default Re: Decided to pull the motor/trans

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I can't think of any way that a cylinder can wear that much and not leave a ridge.
Model T's do that, the top ring comes right to the top of the cylinder w/the piston sticking up above the block. Maybe the pistons you removed are like that?

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I already removed the taper and brought the cylinders to 4" (the pistons mic 3.998). well, 3 are done, one to go.
Is .002" piston clearance enough on these engines?
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Last edited by katy; 07-26-2020 at 09:49 AM. Reason: Corrected typo
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Old 07-26-2020, 10:06 AM   #14
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Default Re: Decided to pull the motor/trans

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Model T's do that, the top ring comes right to the top of the cylinder w/the piston sticking up above the block. Maybe the pistons you removed are like that?



Is .002" piston clearance enough on these engines?
The pistons are level with the deck @TDC so the top ring will be down a bit from that. I thought .002 was a bit tight also but that is the spec that I found and I looked for verification from a few different sources. All say .002.
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Old 07-26-2020, 12:23 PM   #15
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Default Re: Decided to pull the motor/trans

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I can't seem to see anything that will cause it. Makes it hard to "fix".
Check the dent plungers and spring, the plungers need to slide freely.
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Old 07-26-2020, 12:31 PM   #16
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Default Re: Decided to pull the motor/trans

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Model T's do that, the top ring comes right to the top of the cylinder w/the piston sticking up above the block. Maybe the pistons you removed are like that?



Is .002" piston clearance enough on these engines?
NO! #3&#4 with the larger bores at 4inches need .004 clearance. The two back clylinders run hotter than the front two. I would make all four .004 clearance, Someone had problems with his engine seizing, after several tear downs he increased the bore clearances to .004 and his problem was solved.
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Old 07-26-2020, 12:34 PM   #17
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Default Re: Decided to pull the motor/trans

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NO! #3 with the larger bores at 4inches need .004 clearance. The two back clylinders run hotter than the front two. I would make all four .004 clearance, Someone had problems with his engine seizing, after several tear downs he increased the bore clearances to .004 and his problem was solved.
Sounds reasonable. I haven't done the final finish hone yet so can easily add a thou or two. It would actually make me feel better anyway as .002 seems pretty tight to me. Thanks
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Old 07-26-2020, 09:18 PM   #18
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Default Re: Decided to pull the motor/trans

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NO! #3 with the larger bores at 4inches need .004 clearance. The two back clylinders run hotter than the front two. I would make all four .004 clearance, Someone had problems with his engine seizing, after several tear downs he increased the bore clearances to .004 and his problem was solved.
That's what I was thinking about as the water jacket on these engines doesn't go all the way down on the cylinder, just the top part is liquid cooled.
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Old 07-26-2020, 11:15 PM   #19
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Default Re: Decided to pull the motor/trans

Input shaft of tranny will wiggle a little. Since you have it apart, verify bearing is good, ie smooth. I would be tempted to replace all the bearings while it’s apart, but at least a thorough examination.
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Old 08-04-2020, 11:00 PM   #20
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Default Re: Decided to pull the motor/trans

Update. Motor and trans are back together and in the car. The motor got new pistons and rings, {.0125 over), cylinders honed to .004 piston/wall clearance, checked bearing clearances, all but one were between -0015 and .002, the other was about .0025 so I removed one shim, replaced head studs and replaced the ring gear. Trans was disassembled and inspected, replaced both shafts and rebuilt the shifter ball. Trans case and tower powder coated black as well as the clam shell halves. Motor and bell housing painted ford green. Have put on about 180 miles, runs great and no sign of oil use. far cry from the 1qt per 60 miles before.
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