piston ring ?????

[h2ojet001]

I am going thru the process of gapping the rings(very time consuming) and have several questions. Is it better to gap them a little on the big side than to small and if this is true how much over is too much. I am using speed pro file fit and the piston manufacturer(srp) told me .022 for the top ring and .023 for the second. How much over would be to much. Next ? I tried fitting the oil expansion ring in the cylinder and found it to be very tight with the ends butted together. What is the recommended procedure to decrease the circumference of this ring. Also the expansion ring has two small plastic blocks on each end one pink and the other yellow do these remain or are they removed.
Thanks for any info.
Barry

[Fiat48]

There should be a chart with the speed pro rings to figure ring end gap. Looser is always better. The idea is the rings can never butt. The more heat the cylinder makes..the looser the ring manufacturer wants the gap. Recent years the ring manufacturers are calling for wider gaps yet. And they are also increasing the gap on 2nd rings. Many time the 2nd ring will be wider gap than the top.
Oil expander rings depend on design. Many times they even lap over on the ends. You don't file that ring. All that info should be with the instructions that came with the rings.
The little plastic blocks in the oil expanders are there so you can see that you have the ring ends butted when installed on the piston. On hard running alcohol deals I remove them (have seen them try to melt) but on gas dealios you just leave them alone.
If you have no ring instructions..that should be available on line at Speed Pro. Also remember to deburr all sharp edges after filing the rings.

[h2ojet001]

thanks fiat for the response. I was just concerned about how tight the oil expansion ring should feel in the cylinder. From what I can tell due to the design of the ring when it is installed on the piston it will rub against the cylinder wall with some tension. I talked to the speed pro tech line and they weren't much help, they said just install it and it should work.
Barry

[Fiat48]

I can remember Speed pro's oil ring used to actually lap the ends when checked in the cylinder bore. And C&A's oil ring used to do the same thing. But recently (with Ineedav's deal) the C&A's butted in the bore when checked. So there has been some changes in the oil expansion dept. The C&A rings had a note in the box that the oil expansion ring had a lot of flexability as far as how it fit in the cylinder bore.
Speed Pro has done tons of testing on ring end gaps. Read this info: http://www.federal-mogul.com/cda/content/front/0,2194,2442_897063_8682,00.html

[Jordy]

I just got the new pistons and rings for the yellow boat and was looking at the top file fit rings (the second's are gapless) and had the same question.
Should I just go to the top end of the manufacturer's reccomendation or should I go a little bigger than that? I believe (it's not in front of me at the moment and after fighting double spiral locks all night, I'm not going back out there) that the range went from .012 to .024 on the top ring. Should I run them to .024 or go a little bigger for marine style piston and ring expansion with little cylinder wall growth??? :confused:

[Hotcrusader76]

Originally posted by h2ojet001
I am going thru the process of gapping the rings(very time consuming) and have several questions. Is it better to gap them a little on the big side than to small and if this is true how much over is too much.
As it was mentioned above, more is "safer" than tighter. Just remember that the Hypereutectic pistons normally run larger ring gap factors. For example, KB recommends a gap factor of 0.008" per inch of bore on a N/A Marine set-up, where as the Forged slugs may be around 0.004" or 0.005". Check with the piston manufacturer for "recommendations ONLY"! Just some food for thought.
I am using speed pro file fit and the piston manufacturer(srp) told me .022 for the top ring and .023 for the second. How much over would be to much. .
Assuming you have a 4.028" bore that would be a gap factor of 0.0055" for the top and 0.0058", which is a little tight for Hyp.pistons but since it looks to be that you have SRP(Forged) you're in the safe zone. (assuming this is a N/A Marine set-up with a 4.028" bore)
I tried fitting the oil expansion ring in the cylinder and found it to be very tight with the ends butted together. .
This has happened twice to me so far, second time being exactly this afternoon. The ring expanders were not the correct ones for the application. Against my own will and as per the client's request I purchased the components cheaply from Summit Racing and I honestly believe that's where the problem existed. They fit the bores just fine, but the their width is a little too much for the ring land. Maybe we recieved somebody's return order despite the fact those ring boxes are suppose to be sealed. Who knows but be forewarned when you recieve Speed Pro products.
I've only found this on the expander where as it doesn't allow the other two oil rings to seat completely. Long story short I ended up using to two ring sets to complete this SBC I was working on today. Boy was I tempted to step up to Total Seal after this whole ordeal. Not once this has happened but twice in three months.
~Ty

[h2ojet001]

Assuming you have a 4.028" bore that would be a gap factor of 0.0055" for the top and 0.0058", which is a little tight for Hyp.pistons but since it looks to be that you have SRP(Forged) you're in the safe zone. (assuming this is a N/A Marine set-up with a 4.028" bore)
Back to the rings again. My bore is 4.28. The gap size I used was .022 on the top and .024 on the second. I am using srp forged pistons and this is a N/A marine setup. SRP recommended these gaps to me. I was able to get all but a couple gaps set exactly to those specs. On one cylinder the top ring came out to be .024 and another cylinder the second came out to be .026. I just wanted to know if this is good to go and what the tolerances were I had to work with. Will this affect the performance and if so should I order a couple of new rings and start over.
Barry