New Piston Rings

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration
Model T Ford Forum: Forum 2018: New Piston Rings
Top of pagePrevious messageNext messageBottom of page Link to this message  By John Aldrich Orting Wa on Sunday, April 08, 2018 - 01:31 pm:

Want to install new piston rings on stock pistons and then re-install the pistons. New valves going in to.

Is there a quick, down and dirty guide for ring installation and then piston re-installation (that I am unable to find) that will help us through this process???? Never done this before.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Tomaso - Longbranch,WA on Sunday, April 08, 2018 - 01:35 pm:

The packaging for the rings indicates which ring goes where - be sure to check/verify the end gap - piston wrist pin bolt goes towards the camshaft.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Frost on Sunday, April 08, 2018 - 01:52 pm:

Purchase a cheap pair of ring pliers too. Makes it easy to install rings on the pistons without breaking them.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les Schubert on Sunday, April 08, 2018 - 02:01 pm:

John. First a question, why new rings. Do you have a oil smoke/ consumption problem?
Things to do
1. Check top of cylinders for “ridge “ if you can feel it with your finger nail, it needs to be removed prior to piston removal with a “ridge reamer”.
2. When removing the rod caps it is VERY important to keep track of the caps and shims orientation and locations so everything can go back in the correct place!!!
3. It is good practice to gently hone the cylinders with a “glaze buster” once the pistons are removed and then clean the cylinders and crank to remove any debris.
4. I would also check the centre main , as usually it might need some adjustments.
This is all in addition to what has been suggested
Personally I would remove the engine and do this on the bench. A good opportunity to check some other things!!
A simple valve grind/replacement can be done over the fender easily
Best of luck


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Aldrich Orting Wa on Sunday, April 08, 2018 - 02:05 pm:

Thanks one and all!


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Aldrich Orting Wa on Sunday, April 08, 2018 - 02:09 pm:

Les,

Trying to increase compression.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Harold Schwendeman - Sumner,WA on Sunday, April 08, 2018 - 02:49 pm:

Les - I'm probably the wrong guy to bring this up, as there are engine rebuilders that know a lot more about it than me, and I hope someone more knowledgable will chime in here if they feel it's necessary, but I think you have to be careful about making "adjustments" in regard to the center main:

While the front and rear main bearings tend to wear in the caps, I think the center main can often wear in the block. It's more complicated than I could explain, but this has to do with the fact that the Model T engine/transmission assembly is not as rigid as it should be. "Henry" addressed this on the "new improved" '26 - '27 power plant by adding rigidity by bolting the top of the hogshead to the back of the engine block.

My whole point here is that "adjusting" the center main while doing nothing with the front and rear mains can actually cause a very slight "flexing" of the crankshaft with every revolution. Maybe only a thousandth or two, but eventually, a broken crankshaft! That's why I personally feel that if there is any "adjustment" necessary with the center main, a much better solution is to align bore, even if this means pouring new babbitt! Not what anybody wants to hear, I know,....but, there it is!

For what it's worth,.....harold


Top of pagePrevious messageNext messageBottom of page Link to this message  By Harold Schwendeman - Sumner,WA on Sunday, April 08, 2018 - 03:05 pm:

By the way,.... here's something I learned on this forum:

With a "stock" Model T engine, there will be no ridge at the top of the cylinders, because the top ring actually goes all the way up to the very top of the cylinders. Of course, if the engine was ever rebuilt with other than stock pistons, this might not be the case. In which case, there could be a ridge as Les says. And you'll sure know right away, because the pistons certainly won't come out if there's a ridge!

John Aldrich - I have a piston ring expander tool I'd lend you guys if you guys need one. It does make installation of rings a lot easier and much less chance of breaking a new ring when installing,....let me know,....harold


Top of pagePrevious messageNext messageBottom of page Link to this message  By George Andreasen on Sunday, April 08, 2018 - 03:08 pm:

A further note....it's a good idea to "warm" each ring before installing on the piston. A cold ring tends to snap easier. I use a little electric hot plate in my shop, set on low.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les Schubert on Sunday, April 08, 2018 - 03:57 pm:

Harold
Centre main wear in the block is almost exclusively caused by a bent pan or incorrectly assembled transmission or ball cap installation. This can only reasonably be dealt with on the bench. More often I have encountered wear in the cap as the center main is the most heavily loaded. I always begin with some basic dial indicator testing to see where the excess clearance is.
Obviously if in the block then a couple of options;
1 new main bearings
2. Scrape the front and rear until the crank is uniformly “bedded, and then adjust shims as needed. It appears that he wishes to go “low dollar “ approach.
With either of these approaches, checking and straightening the pan is important as well as verifying that the transmission is not wobbling and the ball cap is properly installed is important.
The symptoms I associate with a loose centre main is a not terrible knock at about 25 mph at about 1/3 throttle. It disappears at full throttle.
Cylinder ridge; you will note that I said to check for it, not that it would for sure exist


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Monday, April 09, 2018 - 07:35 am:

My machine shop guys refer to a ridge remover as a bore butcher. In the wrong hands and in a badly worn bore, results can be disastrous. They had a slant 6 Chrysler motor delivered to them for work. The fellow didn't like the quote, so he borrowed a bore butcher from a mate and removed the ridge himself, and fitted new rings, pistons and bearings.

The trouble was, he got a little enthusiastic with the bore butcher, cut a bit too deep and a little too far down the bore. The result on start-up was the tearing off of the top of two pistons. The top ring dropped into the too deeply cut ridge removal and on the downstroke the piston top stayed put at the top!

Allan from down under.


Add a Message


This is a private posting area. Only registered users and moderators may post messages here.
Username:  
Password:

Topics Last Day Last Week Tree View    Getting Started Formatting Troubleshooting Program Credits    New Messages Keyword Search Contact Moderators Edit Profile Administration