3 ring pistons
 

I have a stash of 3 ring aluminum 3-3/16 pistons Ford part # 09A6110- G .060 over. are these suitable for a stock engine , I realize ford went to a 4 ring design and some of us are using 4 ring pistons and leaving off the fourth ring ,the ring lands are 3/32 compression and 5/32 oil ring, also I'll need wrist pins and retainer clips, who sells new old stock wrist pins ? and is there an alternative to the wire clips such as an internal flat double eye (common hardware store ) steel snap ring ? these pistons have the side slots, is there a clearance spec for the slotted type or is .0015-.002 wall to piston skirt clearance acceptable? also there are two steel pieces inside just below the ring lands with cut outs that look as if they are for piston expanders, are piston expanders required on these New pistons ? I have found that there are quite a few surprises on these early fords when it comes to unusual design and maybe product field testing, I was thinking maybe the 3 ring pistons were a discontinued for some failure reason?
Thanks

Re: 3 ring pistons
 

Do you have any idea of the vintage? Can it be determined from the part number?

Re: 3 ring pistons
 

Thes pistons are of the auto thermic design and are designed to have a tight fit in the cylinder. .oo15/.002. Nice pistons for a street engine, mild cam hi compression heads. 2gc carb/

Re: 3 ring pistons
 

Since they are ford pistons they came without pins installed...should be pins available from several of the big parts vendors and the piston manufacturers like Egge.
They are early non offset pistonpins...puts them in the up to -48 era...starting out as a mercury part.
Ford pistons are made to fit a bore size...bore .060 and they should work just fine..
Ford went to 4-ring pistons to handle oil control issues...are we worried about oilconsumption ?...are modern piston rings better...is it a real problem to worry about in a hobby car...

Re: 3 ring pistons
 

09A is a 40 Mercury part #

Re: 3 ring pistons
 

The advent of "modern" three piece oil ring design has made four ring pistons antiquated.

Re: 3 ring pistons
 

The Pistons may have a color near the pins . If it does it represents the pin size . If my brain is working correctly. I've got the color to size chart somewhere.

Re: 3 ring pistons
 

Thanks all , Ggmac I see a red mark on the pistons ,that had me curiouse as well , I thought mabe they were a ford failure design or something of that nature , I am going to go ahead and use them , I hated to waste a new set of pistons or mabe set up for failure , never seen a Ford brand three ring aluminum 3-3/16 bore piston till now. I gave away a couple sets of pins a year or so back ,they must have been for these pistons ( shame on me) I never checked these out, I thought all three ring pistons were for 3 1/6 bore, appreciate the input. Flathead murre, I agree with you on the ring and oil cons; I found a couple sets new old replacement (aftermarket rings) to fit the pistons , Do you recommend the tapered heavy pins over the early style pins? or does it really matter? I have an exceptionally heavy accelerator foot at times and don't need any parts flying out the crankcase . Thanks again all .

Re: 3 ring pistons
 

If you are balancing the rotating assembly...sometimes choosing a lighter pin avoids adding heavy metal and that´s a bonus...drilling out metal balancing is one thing..adding weight is less fun.
Otherwise if it´s not heavily hot rodded the pins will survive std.

Re: 3 ring pistons
 

Find the correct size pins ( usually available on eBay ) I'm pretty sure they'll be available only in one weight .

Re: 3 ring pistons
 

I went to look for the green book with the pin color sizes and , well , cant remember where I put it ! I'll probably remember at midnight.

Re: 3 ring pistons
 

I appreciate it , If it wasn't for you letting me know about the color codes I would not have ever realized it till I got all standard size pins, then I would have been pulling what hair I have left on my bald head. I 'll try and see what I can find , if you happen to find the info I will be grateful , I see the color codes you spoke of but didn't realize what they meant , that is why I asked about the pistons , never ran across this before. Many thanks to you and all the fordbarners.
D.Estes

Re: 3 ring pistons
 

I can't find red but pink denotes a standard size and listed as 39-41.

Re: 3 ring pistons
 

Re the piston pin sizes. The pistons and pins that I took out of the crusty flatty I'm currently working on had pins that were .004" down from standard. (.75") I had to open the rod bushings out to .75" to fit a different set of pistons. I didn't know different sizes were available.

Re: 3 ring pistons
 

I never heard of under .750. But as I stated these engines sometimes are full of surprises, a gracious Fordbarn member Tim Ayers is sending me some to fit to my piston Rod assemblies, and at no charge at that , Many thanks to you Tim.
Fordestes