My friend's T is an oil burner. In addition, it has had some valve trouble lately. While we have the head off to address the valves it was my thought to scuff the cylinder walls with a Flex Hone, going down as far as possible without removing the pistons or replacing the rings. The theory/hope being that the scuffed cylinder walls will help to reseat the rings. As you've surmised, we're trying to avoid a full ring job. I know it's not a huge deal to put in new rings but it's got a 3 dip pan and I don't want the risk of dropping a nut or bolt inside while doing the fourth rod.
Anyway, have any of you ever done this simple scuff thing and had a successful result???
You might be wasting your time Jerry. Take a look at the valve guides. If they are shot the engine will draw a lot of oil in through there.
With regard to the ring question you are not going to make the situation better doing what you are suggesting. Best bet, save your energy and money for a proper repair.
You should have taken a compression test before you started what is now a guessing game about what's wrong. It would have told you the ring and valves condition. Forget the partial hone thing. That's a total joke. NG.
That won't accomplish anything Jerry. When an engine is built with new rings and a honed cylinder, the hone scratches hold oil for cooling of the new rings and to provide something for the edge of the ring to bite against. New rings if looked at closely appear like saw teeth and those high spots are white hot as they smear off and seal up to the cylinder. As rings wear, they loose tension against the wall and the engine starts using oil. They are still seated even though its using oil. There is no way to reseat them other than replace.
We did take a compression test before we started. It was practically zero, which is WHY we started...
As for the "total joke", thanks, I didn't realize I was being funny. Glad you're amused.
I hadn't really considered the loss of tension against the cylinder wall but that's a valid concern. Thank you.
Valve guides are pretty good and should be o.k. Thanks for your thoughts on the hone only thing. In all honesty, it's the advice I would probably give to anyone else thinking of doing this.
Jerry, I just pulled my motor down this winter because of smoking and oil consumption. I had good compression, 50 to 55 psi. After pulling the pistons I found the oil rings were worn smooth. The valve guides were also worn badly. Maybe pull one piston and see what you have. PK
Problem with worn rings is twofold. As the rings and cylinders wear, the gap gets larger causing oil to go in and compression to go out. The ring grooves get wider and the rings get narrower from wear causing the same problem. Need to at least remove the pistons and check for taper and roundness of cylinders. Also check the fit of the pistons and then either hone and replace the rings or rebore with new pistons and rings. New rings have a rough edge and together with the honed cylinders they will quickly seat. Used rings have a very smooth polished edge and will not seat.
Likewise the valves need to be at least reground, or replaced if the guides are too worn.
I know it's a lot of work, but from personal experience, it will save more work in the future.
Thanks. Valves have been reground & lapped. Guides are good.
Not too much point in measuring the bores as a bore & hone ain't gonna happen. Not my car, not my call. Looks like a hone & rings is probably in the works though.
If your cylinders are worn out of round a hone probably won't clean them up. New rings in an out of round bore will never seat. If you still don't have any compression after the valve job, you are going to have to get into it a little deeper if you want to fix it.
Most of the cylinder bores in any car of the age are out of round or need to be bored to get a good clean seal anyway. I have had lots of A model motors and only one block that didn't need to be bored. Thanks to Rich at Antique Engine Builders i have never had a problem with a rebuilt A model motor. He does not build T engines anymore, if he did my next T motor would go to Skokie Il. Just my 2 cents Tim
Not to beat a dead horse, but it would be impossible to wash all the abrasive swarf from the ring grooves. Even if you can get it all to flush down, it's going to go into the crankcase.
Then to the bearings!
Since you failed to mention such an important diagnostic step as a comp test in your original post + your asking about honing the top 1/3 of the cylinder walls I had to figure you or your friend might be a little light on experience and just pulled the head. It really seems to be a regular pass time for T people. "The car ran rough when I got home so I pulled the head". Don't tell me you haven't seen something similar posted here over the years. OK. You took a comp test. Both dry and wet? (oil)? That would have given a real indication of what's wrong. You took the test, pulled the head and you're still not sure what the problem is. You actually are guessing. Or not posting all the info. I wasn't amused about honing the cyls. with the pistons in place. Amazed is a better word. Never heard that one before.
Where did I say I didn't know what's wrong? Why must you be so abrasive? What have I done to you?
On a lighter note;
My Ford's cylinders and rings are worn out. The valves go up, tip over a little bit and then go back down to seat. True.
Two of the four cylinders (with enough compression) gets it started and it's so sweet running after that. Then the smoke comes.... :-)
I know it's getting oil.
Years ago, we'd run my T around the show grounds and we'd stop to look at the tools a guy had out on his tables.
When ready to move on, I'd look over my shoulder and say "John (not a member here), a little smoke for ya." I'd blip the throttle and drive away.
It left a cloud and still does. :-) God I love my T.
Successful result? Nah. I once honed the cylinders on a friends H Farmall and I have always hoped they cleaned the crankshaft hanging down below after I was done....
You know the answers but I get it. You're working with a friend. :-)
Thank you. I appreciate hearing about your T and your understanding of the situation. Enjoy your T!
If the cylinders are in bad shape, bore wise, deglaze them, not hone.
New rings in tapered ring grooves won't make for much improvement.
Either have the pistons regrooved for new, wider, rings or for standard rings and spacers.
At the price of T piston sets I'd go with a set of new pistons which would probably close up the bore/piston clearance anyway.
Sorry I didn't read all the posts on your thread but I'll tell you how I solved the oil burning/smoking problem on mine last year.
The bore is a little O/S and my 0.80" rings had too much end gap. I installed new O/S rings from Grants the next size bigger and gapped them properly in the bore. Now my engine doesn't burn any oil or have any blue smoke taking off from those lights or an idling period.
I did not know it was possible to use a bigger size ring but the guys at Grant said its OK.
I'm not looking to start anything here, but let me just say that I know of no one who knows more about the mechanics of a Model Ts, engines, motors and, just about anything else, than Jerry Van. He is very knowledgeable about anything mechanical -- not to mention one heck of a fabricator in wood, metal and many other things.
I agree with you and have the highest respect for Jerry. I wasn't questioning his ability with my comment but was only pointing out the rings can't be reseated and once worn to the point that tension is lost there isn't any thing that will bring it back.
I know if it were Jerry's car, the Pistons would already be out and the bores examined to see if rings only would work and if not, he would send it out for rebore.
I also understand about helping others and sometimes they may not have the funds at that given time to do it right. Many of us have made a repair that is temporary and I understand that is what they were after. The guy receiving help from Jerry is a lucky guy.
I certainly didn't mean to question his abilities either but the idea of honing the upper 1/3rd of the cylinders with the pistons in place was so far out that I felt the need to try to stop him from trying it. There's no way it could have helped. Now as to testing before tearing it up is concerned: The engine ran so a vacuum gauge could have told him the condition of the intake valve guides. A vibrating needle at idle shows that their worn and you'll smoke like hell if their really shot. As to the comp test: do both dry & wet (oil) tests. An increase in pressure with oil added indicates worn rings but no increase usually indicates burned valves. My rant is only meant to tell that there's testing to do before tearing into an engine when your not sure what the problem is and I've read of guys here on the Forum that just pull the head without finding out what's what. That usually shows 2 things 1: I want to do it and 2 a lack of knowledge concerning available and cheap test procedures. The only things pulling the head straight off will tell you is damaged (scored) cyl. walls or if you have 2 piece valves. The point is then moot. There is work needed to do. Test, diagnose then open your tool box.
Back in another life when I worked for the railroad, we would use bon-ami scouring powder to put on friction bearing journals to polish them up if they weren't too badly scored. It is an organic powder so it soon goes away with out harming anything like timesaver yellow won't imbed in the bearings. Tight budget? you bet I'd try either one in a heart beat. KGB
Keith - Not sure if they still recommend it, but years ago, Caterpillar Tractor Co. also used to recommend the use of Bon-Ami in cylinders as part of their break-in procedure to help seat piston rings.
Didn't know that Harold but makes sense, lot of the old tricks worked fine. KGB
I didn't go into why the head was removed, or how the compression test was conducted because at least one cylinder had zero compression. I didn't think wet or dry would change "zero" to anything acceptable. As it turned out, a hunk of carbon had gotten between the exhaust valve and the seat and was holding the valve open maybe a 1/16". The leak had gone on long enough to burn the valve. Luckily, the seats were o.k., needing only a cleaning, light touch up and lapping. The other valves weren't so great either so they were all addressed. The honing thing was just a thought. Wondered if anyone had tried it. I wasn't suggesting or endorsing the procedure. Anyway, thanks for clarifying your thoughts.
Thank you for your kind words. I appreciate it!
Thanks to you as well!
Jerry - There might be a lesson here in what you just explained. I am very much a proponent of the modern "3-angle valve job". One of several good reasons for the narrow valve seat that is the main feature of the 3-angle valve seat is the fact that theoretically, the narrow seat has a much better chance of allowing the valve to break something like a piece of carbon that might otherwise hold an exhaust valve open and thus cause a burned valve. If even a very tiny piece of carbon trapped between valve face and valve seat holds the valve open even as little as a thousandth or two, the valve will then leak ever so slightly, but then "ever so slightly" is all it will take to eventually burn the valve. I guess what has to be considered here is what it is that is "leaking" as even the slightest leak is leaking "FIRE"! And of course, even the slightest tiny leak of fire due to even the tiniest piece of carbon holding the valve open can result in a burned valve as you described. (....also, consider that the only time a valve cools is for the little instant of time that the valve is FIRMLY SEATED against the valve seat, allowing momentary heat transfer from valve face to cooler engine block). Can't help but wonder if the burned valve you described might have been prevented by the very narrow valve seat that would have been afforded by a modern 3-angle seat,...??? Guess we'll never know, huh? For what it's worth,.....harold
I remember as a kid, my Dad, after doing compression testing would throw a t spoon of Vim (Bonami?) down the carburettor of a fast idling motor. He would run it for a while then retest. Mostly on 1950's English cars but it seemed to work a treat.
I was thinking of suggesting the Bon-Ami trick; it's been "in the books" a loooong time!