Ring gap help

[SMOKEDYA]

I am getting ready to instal my new piston and ring set on the cylinder that i blew out.I need to know what to set the ring gap at?If i understand it right?I make sure the rings are square in the cylinder and then use feeler gauges to check the gap.Them pull the ring out of the cylinder then file the gap if needed.Then install the rings on the piston and install it in the cylinder.But i need to know what the gap should be? Also besides the fat ring,what ring goes where on the piston?My cylinders are 40 over. BTW and i'm working on a 1974 351w that is still flat tappet.The rings are these ones Sealed Power ZWE251K40 - Sealed Power Performance Piston Ring Sets - Overview - SummitRacing.com
also i also was told to just run a honer threw the piston to make sure the rings seat correctly??peace









john

 

[oz]

Check the ring gap with the ring square in the bore near the top - since the bore will be biggest near the top (if you didn't just have the cylinder bored out - in which case it should all be the same diameter).

Use the piston itself to get the ring square in the bore by loading the ring and then inserting the piston (w/o rings) into the bore.

I would think the piston rings would come with a diagram showing how to install the rings. If not, try finding it on the ring makers website.

As for size, allow .004" per 1" of bore end gap - or .016" on your 351W.

 

[Rick 91GT]

You want the rings square in the bore about 1" down, using a piston will work just pushod down and use the pin boss or ring groove as a visual to make sure your square.

Yes a nice hone with a ball hone will deglaze the cylinders and aid in ring sealing.

Since your boosted I would go (assuming a standard 4.0" bore) I'd go .020" top, .024" second

Like mentioned look at the instructions that came with the rings, they are installed by looking at the bevel or in many cases a "dot" on the ring. You want to file the rings from the outside to inside, deburr all edges or youll mess up the bore. The rings are a different material from the top to bottom, make sure you gap and install correctly! Wipe the bores down with a thin coating of oil (std 30w is fine) before installing the pistons...

 

[S351Saleen77]

John,
The link to Summit for your rings shows that they are NOT file fit rings which means that they might already have a bigger gap than you would have done for a file to fit.

 

[SMOKEDYA]

John,
The link to Summit for your rings shows that they are NOT file fit rings which means that they might already have a bigger gap than you would have done for a file to fit.

Thats what i was kinda thinking also....but my buddy said theres no such thing as file fit....The rings came with NO instructions.Just a box with rings..There is a dot on one of the rings.peace










john

 

[Rick 91GT]

File fit rings are usually the bore size plus .005", sometimes a standard set that comes with a generic gap has to be adjusted to the application.

Are the box flaps marked, top, second and oil...you need to id what ring is the top compression ring and what ring is the second ring

 

[Rick 91GT]

Typically the top ring has the dot and a inside champher

 

[SMOKEDYA]

Typically the top ring has the dot and a inside champher

Yes the one ring has a "dot" on it and is champher on it.The other one looks the same just no champher or dot.The 3 of them came in the same box not seperated by anything. The bore size is 40 over.The one with a dot on it,does the dot go towards the top or bottom of the piston? peace












john

 

[Rick 91GT]

John all depends on what ring it is, id call speedpro

 

[SMOKEDYA]

Ok I got it all figured out now, I think? Does this sound correct? I talked with summit tech.They say to put the ring with the dot in the middle groove on the piston with the dot faceing to the top of the piston.The ring with the champher goes in the top groove with the champher faceing the bottom of the piston.Another question....rick you say use a ball hone to "deglaze" the cylinder.All i have is one that has 3 bars on it,will that work fine?Or should i buy the ball one?peace








john

 

[Rick 91GT]

Yes that sounds correct for the rings...depends on the ring design, some have a napier second ring one reason I didn't want to tell you which was which without seeing them.

Yes the 3 hone stone will work, the ball hone is much more forgiving and easier to use, I use them on cheap rebuilds or to deglaze a cylinder.

 

[SMOKEDYA]

Cool thinksfor all the help!! peace











john

 

[SMOKEDYA]

Another question. Do I run the honer in the cylinder dry? Or a light coat of oil? peace




John

 

[Rick 91GT]

John I have honing oil I use, this keeps the stone from clogging. You could use WD40 in a pinch....make sure you clean it really well after your done!

 

[SMOKEDYA]

Thanks that's what I did!peace




John