Pistons: 3 ring vs 4 ring?

[Curt in AZ]

Rebuilding stock merc (3rd generation) for 53 F100. Any advice on best piston choice? Basically stock, just two 97s and headers. Also I see engine stands that support along the sides, usually at exh ports: why not from the back of the block in the more traditional manner? Thanks for advice.

[40 Deluxe]

Originally Posted by carbonarc

Rebuilding stock merc (3rd generation) for 53 F100. Any advice on best piston choice? Basically stock, just two 97s and headers. Also I see engine stands that support along the sides, usually at exh ports: why not from the back of the block in the more traditional manner? Thanks for advice.

Use a three ring piston with the modern three piece oil ring. This way you do not need the lower fourth ring. With new style rings, a fourth ring only adds friction/drag. It does not stabilize/support the piston in any way, contrary to popular myth.

[V8COOPMAN]

Originally Posted by carbonarc

Also I see engine stands that support along the sides, usually at exh ports: why not from the back of the block in the more traditional manner? Thanks for advice.

Because on '32-'48 blocks with the extended cast bell, and with the additional leverage and the thin casting in that part of the block, the bells CAN break under the weight and drop your engine to the floor........BLAMMO! It only matters when it happens to YOUR engine. DD

[tubman]

Coopman,

Thanks for posting that. I think it is the first one I've actually seen busted. I think I am going to spring for one of those sidemounts, however, because it looks like it would make engine assembly easier, even though I only mess with 8BA's.

Also, I hope to finish my 258" engine next spring. One of the reasons I built the engine is that I got a spectacular deal on a set of new 3 5/16 4-ring pistons. After posting here and a discussion with my engine builder, we decided to leave out the bottom rings because the ring set has the modern 3 piece oil rings. From everything I have found, it is a better choice than using them.

[super flat]

Originally Posted by carbonarc

Rebuilding stock merc (3rd generation) for 53 F100. Any advice on best piston choice? Basically stock, just two 97s and headers. Also I see engine stands that support along the sides, usually at exh ports: why not from the back of the block in the more traditional manner? Thanks for advice.

You don't need them if your block is a post extended bellhousing block. Gary

[flatjack9]

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I think the exhaust mount is the only way to go. Lets you install the oil drive and cover as well as the flywheel, disc and pressure plate.

[V8COOPMAN]

Originally Posted by tubman

Coopman,

Thanks for posting that. I think it is the first one I've actually seen busted.

This is what YOUR engine looks like after you hear the........BLAMMO! DD

[Curt in AZ]

Thanks for the helpful info. Are side mounts for sale or home built?

[Dodge]

Yes, on the early block as soon as one turns the motor upside down the bellhousing
breaks. I have had to repair two of these that customers broke.

[JSeery]

Originally Posted by carbonarc

Thanks for the helpful info. Are side mounts for sale or home built?

Both, there are a number of past threads on this topic.

[tubman]

Originally Posted by Dodge

Yes, on the early block as soon as one turns the motor upside down the bellhousing
breaks. I have had to repair two of these that customers broke.

I find this very interesting.

[V8COOPMAN]

Originally Posted by carbonarc

Thanks for the helpful info. Are side mounts for sale or home built?

Click this link for a side mount you can purchase. DD

http://www.fordbarn.com/forum/showthread.php?t=164965

804-245-1959 Dave Havlir

[Bored&Stroked]

Here is another link to Stumpys . . . I've used quite a few of his products - really good guy!

http://www.stumpysfabworks.com/store..._Products.html

[petehoovie]

I see that this thread has evolved from 3 vs. 4 ring pistons to engine stands. Is there anymore that can be said about the original topic? I like to hear more about the 3 ring versus 4 ring comparison for a stock street flathead. Is the difference really going to be that significant?....

[tubman]

Originally Posted by petehoovie

I see that this thread has evolved from 3 vs. 4 ring pistons to engine stands. Is there anymore that can be said about the original topic? I like to hear more about the 3 ring versus 4 ring comparison for a stock street flathead. Is the difference really going to be that significant?....

This was posted on the H.A.M.B. and influenced my decision :

"It is better to run a three ring piston than run a four without the lower oil control ring. The skirt will be slightly less stable. Having said that, I have built many flatheads and left of(f) the lower ring set. Ford had oil control problems and hired some former Olds (engineers) to cure the consumption problem. Their solution was the four ring configuration. That cured the oil consumption problem but caused a new problem of causing the top compression ring to run too dry and overheating. Anyone that has torn down a later flathead and seen the top ring broken and segmented crawling over bits of each other an attest to the dry ring damage. Leave of(f) the bottom ring and live with the minuscule piston rock and oil consumption and not cook the top ring. I learned all this from a couple of old Ford mechanics when I was just starting out in the early 60's. Believe me the pluses far out weigh the minus'(s). Or if you haven't purchased pistons yet, get three (ring) pistons to start with."

As others have said, the rings "float" in the piston and have no role in supporting it, so this posters one worry seems unfounded.

[petehoovie]

[QUOTE=tubman;1210730]This was posted on the H.A.M.B. and influenced my decision :"Ford had oil control problems and hired some former Olds (engineers) to cure the consumption problem. Their solution was the four ring configuration. That cured the oil consumption problem but caused a new problem of causing the top compression ring to run too dry and overheating."

It would seem that MMO in the fuel would resolve this problem....

[flatjack9]

You'd have to put a lot of MMO in the fuel to show any lubricating quality for the rings.