Seeing this website is the best place to go for advice on the ford model T i figured this would be the place to ask.
So after the engine overheated it lost some power (missing that power, comes in handy) and makes some white smoke when revved after idling for a few minutes. The valve guides do not seem more worn than they were before it overheated so i guess the oil may not be getting in through there.
There was oil and carbon in the intake manifold? How does that happen?
In the oil pan i found some metal crunchy stuff (could be rust) in the dipper pans and less than a teaspoon of antifreeze.
The piston to cylinder wall clearance is about 20thousanths of an inch all the way around. The cylinder wall wear is only 2 thou' from the top to the bottom and across. This might not be too bad but the pistons might be bad.
Here are some pictures.
Cylinder walls have crosshatching showing at the bottom where the pistonrings do not contact the walls but the top half is shiny and scratched.
Worst piston. There are scratches that have been filed flat in the past but this one is fresh, The rest look a little better.
While i was here i thought i would ask about the babbit. How does it look? Not that i can afford to do much about it at the moment.
And this exhaust port. They all look like that so what clever backyard mechanic tricks are there to help this seal a little longer?
Does anyone see anything wrong with the way the piston rings are aligned? They came out of the engine like that.
Oil ring is wrong size, ring gaps should be should be 33degs from each other. With that oil ring flopping around like that, it could cause overheating and the engine to seize up. I see new pistons and rings in your future, block will need to taken to the shop honed or bored out and the correct size pistons/rings ordered. Sorry to be the bearer of bad/expensive news friend/mate.
George n L.A.
PS, keep us posted on this issue, we all learn from others.
Is there 0.020" clearance at the bottom of the skirts, 90 degrees from the wrist pin too? If so, it's a bit too large, time for new pistons - likely oversize and a rebore of the cylinders too, but it'a hard to tell without the actual measurements. Did it pump oil and smoke a lot when you were driving?
Do you have any shims left between the rods and the rod bearing caps?
As Roger says, piston clearance needs to be checked in the right spots.
George, the oil ring is OK, that type of piston has 2 steps at the oil ring level, the oil one is deeper to accommodate the ring.
Just a question, how did it over heat that badly? typically model Ts will run boiling and be just fine. maybe put together a little too tight?
your babbitt looks fine, maybe a little galled, but that will wear in and it looks like you have plenty of shims left.
definetly need to hone or bore and install new pistons of the correct size.
I have an engine where the #1 exhaust port looks worse than the one in your picture. It looked like the previous owner had used JB Weld to seal it but it had all burned out. About 20 years or so ago I was talking to an outboard motor mechanic about the problem and he suggested using hi-temp gasket sealant (the orange stuff). This has worked fairly well. I have used it twice (with the glands) and it is now time for a third shot at it. This time I plan to try those new style $35.00 rings sold by Macs and possibly other vendors.
Looks like it was too tight. IF it measures to have .020" piston clearance that is too loose. Something doesn't add up, maybe you misplaced a decimal point or did not make a correct measurement?
Royce is right, pistons will not score with .020 thousandths clearance, they will score with .002 thousandths, as piston instructions normally say, which is wrong!
The white smoke came from water and antifreeze being let go in the cylinder when it got hot, from a head gasket or a crack.
If the clearance turns out to be right, just the fact that antifreeze got in the cylinder will instantly remove cylinder oil, and score a piston, or pistons if all cylinders leak antifreeze.
The crunchy found in the crankcase is ground, and flaked Aluminum from the pistons.
I would not try to use any of the bearings over again, as they are all now impregnated with Aluminum fragments from the pistons. cam bearings, rods, and Mains!
You can see the Aluminum in the one bearing picture that you show!
The oil in the manifold came from the oil going past the piston's
I think Royce is correct. If it were mine, I would carefully measure pistons and bores and hone to the correct size. I would clean up the pistons, clean the rod bearings and reinstall them. Aluminum is softer than steel and makes a decent bearing if well oiled. I would check for cracks, put in a new head gasket, change the oil and give it a shot.
If the clearances check out, hone the cylinders just enough to get a good crosshatch, replace the rings and clean up everything else. Put it back together with new gaskets. Drive around for a while. If it doesn't knock or burn excessive oil, just keep driving it. If it knocks and after a few thousand miles burns a lot of oil, then pull and rebuild.
The first is the cheap way to go, but you are not out very much if you decide to rebuild. If you do decide to rebuild, then go through everything and replace or regrind everything which is not in good condition including the transmission and magneto.
Kep, I think George means the ring gaps should be staggered around the piston at 120 degrees. He has it mixed with 33% or 1/3. In easy terms, put one gap at 12 o'clock the next at 4, and the last at 8.
Do you think your overheating was caused by the pistons lacking clearance and seizing up, or did the overheating cause the pistons to heat up and sieze/score? Either way, you have the same route for a fix, but the root cause may need to be identified to avoid a repeat.
Hope this helps.
Allan from down under.
Do all four cylinders show rust damage like the one in your picture? You can see where the rings sat and rusted. Rust particles could have caused or added to your scoring problem. If all four cylinders are pitted, it's probably a storage problem. If it's one or two cylinders its a crack or a gasket.
Isn't the oily buildup in the intake ports more likely from loose valve stems letting oil get sucked up into that area?
If that is one of the problems and the head is coming off anyway, may be a great time to ream the valves to the next larger size and replace with stainless valves, new springs/keepers, seat them well (grind if needed), etc.
You've got some work on your hands Kep. Even your good pistons don't look that good and that cylinder kind of sucks too. Agree white smoke is most likely anti-freeze. Must have got good & hot. It's kind of beat all around. Do some checking and ask questions before you try an economy re-build.
i would reccomend checking your bore, honing the score marks out with a RIGID hone, not a spring hone or a dingle ball hone. a little pitting wont hurt. I would also replace the pistons, they are only like 80 bucks a set, who knows what happend to the ring grooves when all that happened.
as far as bearings go, i wouldnt worry about contamination, like ted says aluminum is a good bearing surface when oiled, but also i doubt much happened to them.
if your clearence with new pistons is going to be .002 more than reccomended dont worry about it, if its more go he next size up.
It was climbing a steep hill when it steamed up to a halt. Only needs to go for another year or so before i can get enough coins to rebuild it properly (i hope!) as long as i can keep my job that is.
Strange this is it never made oil smoke before and that was when a 15thou' feeler gauge would fit between the pistons and the bore.
The bore is only worn 2thou' overall so i was hoping to keep it going for a while yet. What i can't understand is if air flows up the intake manifold constantly how burnt carbon and oil would build up in it when it almost never runs backward.
Believe it or not that engine ran like a top with those bores, They always had rust like that. But where did all the power go?
I'd really question those pistons based on the clearances you are kicking around 'cause you certainly don't have skirt clearance in those pictures. Mental math isn't working right now (end of the day Ultracet Semper Gumby moment), but you'd need a real quick huge temperature rise to even think about losing 0.015"
If your intake is burnt carbon, you have an intake valve that is not doing what it is supposed to be doing and thats where 'all the power go'. The pushing down may be offsetting the sucking up and in fact you may be firing 2 at once, not in waste spark mode but in the opposite. (I think that makes sense )
Good point George of cherry hill. So i measured the skirt clearance. 0.006 Kind of proves i should not be allowed near a car.
So now i have another question. After removing a fibre timing gear with not a lot of wear should i install a steel timing gear with pointy teeth that might be fairly worn? Not really the sort of job i would like to do in the future on the roadside. The steel one might rattle but not break right? No generator if that makes a difference.
if its he old style phenolic gear, hey are reliable. the new ones suck.
the steel one will turn the the cam.
Any indication from this picture whether the gear is the old kind of hobbed from wheatbix? Guess i could break it and find out but rather not..
Would removing it with a cold chisel possibly have stressed the teeth? Or is the answer to that "If the teeth are still on it then no"
Lucky i am not a lawyer that was supposed to say "or carved from wheatbix"
Aye Kep, now you've gone and loaded up the tricky bag. Wheatabix...that's the best darned description I've ever heard for the composite gears!
I think you might get a 50/50 concensus here as to that one. One the one hand, you are torn down far enough that if you could find a steel/iron one at a reasonable price, I'd say go for it myself. As you say, once the piggy bank get's ahead of the game you want to redo the whole engine from scratch anyway...so just call that a buy forward.
On the other hand if looking at the tooth wear surface under a glass you see what looks like polished glove leather as to surface finish and it feels smooth as glass, and you can get the backlash set right on reassembly to not change the real surface form in use...you just might be able to get away with it. My belief or rather opinion is that when these do fail they start as a gall and not a flexure crack from millions of pressure cracks in their root, but thats only a guess as when they go, boy do they shred and apparently shred quickly.
So hows your luck been running?
To each his own but if it was mine, I'd just go and find a metal gear. There are some decent reports as to the plastic replacements and as to aluminium replacements, but myself am just a little old school on them as they add a new variable and that is having the proper backlash to begin with. My own view is that the plastic or aluminum needs a little more initial clearance than a metal one when cold but I have yet to be able to prove that.
Just one guys view.
Once before, I wrote extensively on why I do not like fiber timing gears. Suffice to say, a steel gear would have to be pretty bad for me to choose a fiber gear over it.
What year is the block/car? I suspect you will be needing a replacement.
What is the cost to ship something like that to NZ? Although I do know I paid about $80.US to ship one halfway across the 48 states. Ouch.
Drive carefully, and enjoy the holidays! W2
Replacement? i will keep this block running as long as i can. It only survived floods, partial burial, rod through the pan and whatever else happened to it in the past 90 years so i doubt i will do it much harm in mending it.
anything can be repaired, just check out what the California gold marine engine collectors will do to save a block.
If anybody searches the archives and wants to know what a molded type timing gear looks like i think this is it. See the fibres run outward toward the teeth tips, i think it might be ok.
This following picture will learn me for my confidence. Dropped something heavy down the bore and it made that long mark on the crank journal thing. Is this something i can fix at home? polish out with a magic fix in a can?
aye aye aye! things just keep gettin worse!
if you are refering to lapping compound, NO.
make sure there are no high spots in the dinged area, best to use a fine honing stone like what machinists use, run it over the affected area, all the high spots will show up, rub the stone around until all the high spots are gone. then polish with fine sand paper,
seeing as you are planning on doing a full rebuild in the future put the fiber gear in it and run it. then in a year or two when you rebuild it replace with bronze or aluminum.
Cheers i will try looking for some fine stones tomorrow. Meantime here is some pictures of a timer with only 1 year of wear for you to laugh at.
Not sure how that happens. Filled with grease.
wow, thats incredible, build it up with weld beads then file back to shape.
Build up the timer or the pin? Because i was thinking of cutting a nail for the pin.
Once again i pester your forum in my hopes of finding out which grade of sandpaper to try to remove this mark from the crankshaft. i have found some 1200 grit but think this might be too coarse. Should i go out and buy some 3000 grit? Or is something even finer available readily?
Use a fine file to remove any raised portions then do a little honing to smooth it more.
What is a honing for crankshafts? Or was that a recommendation for the bores?
Like Craig said, use a fine 1/2 inch wide file, and clean the high spot, following the curve of the crank.
When you can't feel any raised metal anymore, use some wore 600 lightly, always going around the crank pin, never side ways.
Finish up with your 1000, 1200, and 1500 paper.
When you can't feel a raised spot, there is none.
Yikes! i guess you know best, Thankyou, wish me luck!
Kep, the wear on the pin is probably the from a loose rotor, you either need to tighten the nut or shim the rotor . The wear from the movable flapper could be accelerated because you "Filled with grease." The only place any grease should be put is on the axle of the flapper. The grease acts as an insulator and will encourage arcing at the contacts and increase wear.
I left one thing out Kep, when using the paper, fold a piece around the file, and you will be using the file in the same manner, but you will have the paper between the file, and crank pin, making it a lot more accurate.
Good luck, Kep! And it is "your" forum also.
(Back with more massive pictures to tire dialup users, sorry)
The polishing the crank with paper worked as near as i can see. Kind of difficult to do through the bore or the dipper pan cover, No stones so i used a file wrapped with 2000 grit soaked in kerosene. Guess the true test would be how round it remained.
So how i hope to post a picture of my improvised exhaust port repair for anyone interested in trying it at home.
It is actually pipe cut to a short length and shoved in the port with a hammer and sealed with some exhaust sealer. Doubt it will last the whole year or so but worth a shot.
So this headgasket is probably beyond repairing but the other one is used and about 50 years old and looks like it was sealed with shellac? Is that possible? (instead of using a new gasket on an engine that might blow up after 5 minutes) Can i retry it with shellac?
Last day of the year, Last opportunity to update this i guess. If anyone is interested to know i scraped the grey alloy looking stuff off the bearings with a bearing scraper, right wrong or otherwise it has been done. If it would start i could tell you if it knocks.
Happy New Year!