Does anyone know what a standard aluminum piston
Measures thanks philip
3 3/4" (3.750")
Actually that is the bore size. the piston will come in .0025 shy of that for clearance on thrust skirts, and by the way is not enough .0035 to .004 is safer. I did double check that with a new aluminium piston.
Factory specs for cast piston was 3.748-3.749" for 3.750" bore.
This "piston diameter" thing is confusing to me. I thought aluminum pistons were "cam ground",....no? And if so, I would think it a bit "tricky" to measure piston diameter! Not trying to complicate the issue here, but I KNOW that SOME aluminum pistons are cam ground, but not aluminum pistons for Model T's? Just wondering,.....harold
Very early T aluminium pistons, say from the 60's/70's were not cam ground. Every thing available today is cam ground, that's why I say clearance is checked at the thrust skirts.
ok here is the story and my options.car is pumping oil. pulled the pistons and the rings are worn out
the bores are in good shape with telescope gauges
i measure 3.753 at the bottom 3.755 mid way and 3.757 at the top and they are round. i ordered a set of rings only to find out that no body has any
standard rings in stock and have no idea when they will get any. i can order a set of aluminum pistons
do you guys think they will work ok in the bores.
First, whoarer the "no bodies"? Did you try Lang's, Snyders's, Chaiffin's, Bob's, Gas Light, or Mac's? There are others. Pistons do not come with rings so if you were going to stay with standard you would still be in the same boat.
i called langs snyders and chaffins i stopped there.
they are factory back ordered. if i go with new alum. pistons those are different rings that they do have. philip
No, they would use the same narrow rings. Check with Mac's, they will have the same brand of rings as the others.
Go .010 over on the bore’s. Install new aluminum pistons and rings. Never worry about it again and have yourself some fun. If you want to get crazy, do a valve train restoration while you are at it. Maybe the transmission too.
Your bores have exceeded allowable taper. Best bet would be to bore cylinders and replace pistons and rings. However if you are looking for a cheap fix, do the vendors have the next size rings that you could file the gap to spec. Just food for thought.
mark i have a hand held ridgid hone are you saying
hone the taper out [i could stop at .007 over] and
install standard aluminum pistons and rings?
Mark has stated to bore to .010" oversize pistons. But you need to follow Franks advise on skirt clearance of .0035" to .004". So you need to have the pistons on hand and measure it ID for proper fit.
Philip, I have done what Mike Bender suggested on two motors. It works real good. I didn't have the taper you do but if you can't afford the bore job and new pistons this is next best. I've got about 6,000 miles on one of these motors now and it still running strong and not burning oil.
i dont think they make .010 over pistons
after all of the other things you have done to this engine, in the car, to improve it. I see you're being steered to a total rebuild. That's ok if you have the time and money, and is the best advice from a mechanical point of view. But I wonder what was wrong with advice on another thread to simply fit oversize rings on your CI pistons and be done with it?
Understand that arguably, the best advice on a system that has worn, is always to overhaul. And yet, millions of T's ran with worn out rear ends, and just got outer bearings and sleeves; millions of T's ran with worn out cam shafts and were perked up with setting valve lash to piston clearance; and these days, thousands of T engines get the Full Monte, when they could have survived "as is" at 29MPH for another 20 years. It's your choice, but a full rebuild is not necessarily the only choice for a car which burns oil.
Thanks for all the help. Chaffins had the .010
Rings and I have a ring gap grinder so that will be easy. Philip