I had the engine of my 1914 touring completely rebuilt : new babbit, new pistons, reboring and new valves with oversized guide.
I first drove the car yesterday. I put two stroke oil in gas and drove very slowly. Engine start easily and run fine. After 5 miles the engine began to loose power and misfire. I stop immediately. With hand crank it was hard to turn. After 10 minutes of cooling, it was free and I restarted it but after 5 minutes of slow moving same problem. Went back home on a trailer and the engine is free now.
I don't think it is something in transmission because I have and additional gear box that give me a free neutral and there is no starter. It must be "only" the pistons (aluminium) too tight in the bore.
What should I do ? Go on and trying to running it in gradually ? Take the head off and pistons out to hone the bores ?
Sounds like the rebuilders responsibility. Tell him about the problem before you ruin the engine and he then says it's your fault. If you continue to try to break it in but the engine is damaged from the attempt, he'll say it's your fault. If the builder tries to "break it in" by running and it seizes up it's his fault and his responsibility.
Sounds like just a tight motor. Not too uncommon after a rebuild. Don't drive like that. Just start it up, run it for a few minutes, (not until it seizes), then let it cool down. Several runs like that should loosen it up. I had the same thing happen. The engine now has over 25,000 miles on it.
You may have aluminum pistons that are fitted with too little clearance. Talk to your rebuilder and see what he has to say.
I had that happen to a "new" engine on an engine stand. Long story short, the rear cam bearing was too tight and caused the engine to "seize"
The engine was at low RPM so there was no damage to the cam.
My 1911 motor is getting a couplet over haul by Ross Lilleker . He told me he would connect my motor to his tractor with a PTO and let turn the motor until it is easy to hand crank . Grate ideal, I had a motor rebuilt that I had the same problem you are having ,a 1915 . I finely broke it in just by running it . Good luck
Il y avait quelques nouveaux pistons étant que furent marquées incorrectement. Le fabricant recommande un trop - dimension de jeu serré. Suggérer que vous arrêtez. Discutez avec le motoriste. Envisager de tirer un piston pour vérifier
What? How about those of us who don't remember the
French we tried to learn in school?
There's software that will translate a sentence in one language to gibberish in another.
Don't even need software. www.translate.google.com does as good a job as anything else I've seen. According to Google Royce's post says
"that were marked incorrectly. The manufacturer recommends a too - tight play dimension. Suggest you stop . Discuss with the engine manufacturer. Consider taking a piston to vér"
If nothing else you get the gist of it.
Non, je suis désolé, je ne parle pas français
No, I'm sorry, I don't speak French
Thanks guys, don't want to go off topic, I thought I heard of such, just didn't know where to find it. I see it works real handy!
The most common problem with seized engines is that the piston clearance is too close. Egge says clearance should be 0.0025. What they don't say is that that clearance should be on both sides of the piston, or 0.005 total clearance. This is a stupid way of specifying clearance that has caused a lot of frozen engines. No aluminium piston can run very long at 0.0025 total clearance. The clearance should be set at 0.0045-0.005 in clearance. I'd be willing to bet that that is your problem.
Glen is 100% right. The Egge pistons are excellent. Follow the instructions an you fail.
Yes, I agree that the T requires that extra clearance.
By piston engineering specs and measuring a piston clearance, is, the piston with the thrust side against the bore wall and at right angle the required feeler gauge thickness, no wider than 1/2", and the thickness set by the manufacture, correct reading is by the pull required to remove, from as low as 4 lbs to as high as 19lbs, varies with different engine/piston manufacturers.
You need to be careful doubling the clearance as piston slap can start with as little as .006" clearance.
I would agree that the clearance is tight. Two possibilities, the aluminum pistons themselves are too tight , or the rings do not have enough gap.
This will also happen if the engine severely overheats. Unfortunately, when it is just rebuilt, it will tend to run hotter than normal.
This is how I start and run a rebuilt T engine: I start it up and run for just a minute or two. This will get the oil to flowing in the oil lines. After a minute or two I turn it off and wait about 5 minutes. Then start it up and run in neutral or run with wheels jacked up in neutral so it minimizes the drag caused by the clutch. It will also be easier to crank in that position. I run it until it reaches normal operating temperature. If I have a steel head, I re-torque the head and manifold while hot. If the head is aluminum, I wait until it cools off to re-torque the head. Then after it cools off completely, I start the engine and drive about a mile and let it cool off. Each time I warm up the engine, I re-torque the head until it remains at 50 ft lbs. Next I start the engine and drive slowly about 2 miles and let it cool off. After I have about 100 miles on the engine, I drive slowly as far as I want to drive it. Just keep an eye on the cooling. Do not let it overheat.
If it still seizes when using these precautions, it is too tight.
Anyway, that's how I do it.
I bought the pistons and rings from Lang's in 2012, there are 0.06 oversize.
Reboring was done by who I think is the better workshop for old and very old engines in France but I didn't check the clearance when I received the block back. I checked the rings and gap was OK.
In the first miles, engine ran a little bit hot because of not enough advance but it was correct when engine seized. For this first run, I added 2%oil in gas to avoid seizure.
I think I will take out one piston (witch is best ?) and measure piston and bore.
Were do you live in France. Next weekend we are going to Beaune, If it is on our way I will be glad to stop and try to help.
My suggestion would be to remove the pan plate and have a look at what may be happening, there's plenty of room to check piston clearance from the bottom, see what .000" gauge size you can get in between the piston and bore at 90degrees from the wrist pin, see if you have any scoring as well, if you find things seem to be to tight then remove pistons and hone your clearance of choice.
I will go too but infortunately not with my T but with "Anatole" one'
The rebuilder put the clearance that came with the piston box
he suggest that if I take the pistons apart to reduce a little the pistons but not hone the cylinders inside the car
That does not sound like good advise to me. Aluminum pistons are "cam ground",....in other words, they are not round. You said,...."reduce a little the pistons". Assuming you meant "reduce" by turning pistons in a lathe,.....don't do it! Again, aluminum pistons are not manufactured round,....they are cam ground to allow for uneven expansion from heat. To me, honing cylinders is the only logical solution, but I don't understand why the engine builder does not seem to feel any responsibility for doing this,.....???
I should have added that if you remove much material from the pistons by turning down in a lathe, you will destroy, or, at least significantly reduce the cam ground shape of the pistons and almost certainly end up with an engine with "piston slap",....for what it's worth,.....harold
Just do not touch the engine. It is freshly rebuild so the rebuilder should take care of it for free. I should only take of the head and the inspection cover of the oil pan and look for seize marks on the cylinders and crankshaft.
As Harold said:"DO NOT REDUCE THE PISTONS". If the problem is in the cylinder the only solution is honing the cylinders till the pistons fit with the right clearance.
We will talk about it in Beaune??
My French is in the form of four-letter words
I find the instructions that came with the pistons:
"recommended cylinder clearance is .002 to .003"
also on the box "Packed 02 19 2008" and "made in Taiwan"
These pistons came from Lang's in 2012
The clearance was set for .002 to .003 by the workshop.
Would a careful run in be enough or should I take the block apart for a rebore with a clearance of .0045 to .005 ?
Philippe - Re-read Glen Chaffin's post of June 21, 7:23pm:
He has said exactly what you just said - .0045" to .005" total clearance. Glen's post has explained exactly what the problem is, which is insufficient clearance due to the engine rebuilder's misunderstanding of the piston manufacturers confusing printed instructions that came with the new pistons.
From what you have said Philippe, I don't think your engine rebuilder understands that the new pistons are NOT perfectly round, and that they are "cam-ground" and why, and how and why he needs to take this into consideration when measuring for adequate total clearance of .0045" to .005".
Hope this helps,.....harold
Pour rendre nos amis au US jaloux un peu de Français.
Est-ce que le jeux a été messuré les deux cotés des pistons?
Avant tout il faut ouvrir le moteur et chercher les traces du grippage. Ci la cause sont les cilindres il faut très bien controller les pistons. On en parlera à Beaune.
To make our friends in the US a little jealous we will talk a little French.
Did the clearance be checked on both sides of the pistons?
First you need to open the engine and look for the place were the engine sized. If the reason is the cylinder bore, you need to check very well the pistons for damage. We will discuss about it in Beaune.
There would be no misunderstanding or blame on the machine shops behalf, the piston clearance is not meant to be doubled, that's only something we find needs to be done on a T with aluminium pistons.
Okay Frank - When I read the very first line of Philippes original post when he started this thread, he said,...."I had the engine of my 1914 Touring completely rebuilt : new babbitt, new pistons, reboring and new valves with oversize guides."
From that, I guess I made some "assumptions". Because he said he'd "HAD" the engine rebuilt, I assumed a "rebuilder". Because he said "NEW" pistons, I assumed aluminum pistons, because I figured than no rebuilder nowadays would use anything but aluminum pistons, and quality aluminum pistons are cam-ground. So,...did I miss something?
Was just thinking, if the re-builder thinks these pistons are round, and measured them under the pin area, the bore would definitely be too small!
And,...Glen and Royce assumed that the aluminum pistons used were Egge pistons, which have the confusing clearance instructions with the pistons which I assumed probably to the machinists (rebuilders) possible misinterpretation which several of us are assuming lead to the too tight clearances which is why many of us said to STOP messing with the engine and go and talk to the rebuilder. Whew!!! Maybe I'm sorry I tried to help here at all! ha,ha,.....harold ( ;^)
No you didn't miss anything.I gave the machining that I cannot do myself to the rebuilder but I reassembled the engine myself. When he told me yesterday he can adjust the pistons, I assume he will not only put them in a lace he must have some cam-grounding machine. As he is not T specialised he just put the clearance that was on the piston box and for what I know here when a clearance is stated for piston, it is the total clearance, not the half. I cannot blame the guy.
Ahaaa...haaa!!! Now I understand Philippe! Thank you for explaining that! Well, you're getting lots of advise here, the best of which is by smarter guys than me, but now that you're clear on the proper TOTAL clearance, I think all you need to do is hone the cylinders for the necessary additional clearance. And apparently from what's been suggested by those who know, less than .0045" is too tight, but more than .005" is too much! How you do that, I'm not sure, but I've been lead to believe that skillful use of the modern type power hone will do it! (....I've never used one but that's what I've been told,...)
Harold, You are right, the pistons are cam ground and are not round. All clearance measurements should be made at 90 degree from the piston pin end of the piston, or half way around from one pin end to the other. This is the widest point and exactly where the measurement should be made. If you make the clearance at the end of the pin you will have no clearance at the 90 degree point. All piston manufacturers specs are screwed up. No piston can run in a Model T with 0.002 0r 0.003 in clearance. They will seize every time. It is the same problem as with the triple gear pin clearance. Ford said set the clearance to 0.002 running fit. He didn't say clearance, he said running fit which means 0.004 in or 0.002 on each side. I believe that the piston spec is just the same but they don't say running fit. Any way, any fool that sets his piston clearance to 0.002 , even at 90 degrees to the end of the pin will have a seized engine.