.031" Dykes or .043" Rings ?

[trmnatr]

Gonna put new lighter pistons in the 331 (327) , I know im gonna go with a 3mm oil ring. I know im gonna go with a .043" napier second ring

Here the thing, Should i go with an .031" Pressure Back Dykes Top Ring or an .043" .155" radial ring with lateral gas ports ?

Engine Combo..........
- 4.030" bore GM block, filled with Hardblok, Milodon Splayed Main Caps with Milodon Main Studs, using ARP head studs too
-Bryant billet 4340 3.26" stroke 40 pound crankshaft , 350 main size with 2" rod pin and big block chevy snout
-GRP aluminum rods 478grams 349grams big end 129grams beam end , ARP 3/8" 8740 rod bolts
-Crane Solid Roller Cam 308/314 @.020" 278/284 @.050" 200/206 @.200" .670"/.670" 106 lobe seperation, Mikronite processed, 1-8-7-2-6-5-4-3 (4/7 & 2/3 firing order swap)
-Shaft Rockers with 5/8" shaft
-Jesel Belt Drive

Pistons will be 2618, They will be lightweight plus they will have some work done to them by Rebco Machine to lighten them up

Here are my options on rings, give me your opinions
1) .031" Dykes
2) .043" .155" radial moly ring with gas ports
3) .043" .134" radial AP ring with gas ports
4) Other, make suggestion

Piston weight should be around 400grams plus wrist pin which should be around 95grams. Pistons will use a pretty good dome size due to 62cc heads and .040" quench

[Bub Whitaker]

NO to Dykes
.043 lateral gasports wins hands down, AP will last longer, But make sure you make the backspace correct for whatever ring you use...

[trmnatr]

Originally Posted by Bub Whitaker

NO to Dykes
.043 lateral gasports wins hands down, AP will last longer, But make sure you make the backspace correct for whatever ring you use...

The pistons will be cut so there is .005" back space

Why dont you like the .031" Dykes ring ?

[Bub Whitaker]

too heavy / ring flutter... also dont really start working till high RPM and then we have the flutter...

[trmnatr]

Originally Posted by Bub Whitaker

too heavy / ring flutter... also dont really start working till high RPM and then we have the flutter...

I have never had any issues with them, maybe thats because the leave rpm has always been 6,000rpm and up

Yes they do smoke some until gas loading at higher rpm, have noticed this

[Jim Cimarolli]

I have tried just about everything out there, and for my money I choose the 5/64 back-cut top and second ring with the low tension oil ring by Tri-City Competition Service, for a stocker motor that is with the 5/64 ring lands. Call Greg Luneack @ 760-630-9094 He will fix you up, and he is a great guy to deal with.

[trmnatr]

Originally Posted by Jim Cimarolli

I have tried just about everything out there, and for my money I choose the 5/64 back-cut top and second ring with the low tension oil ring by Tri-City Competition Service, for a stocker motor that is with the 5/64 ring lands. Call Greg Luneack @ 760-630-9094 He will fix you up, and he is a great guy to deal with.

Jim,

Thats the kit with the gas ported spacers and thin narrow rings below the spacer , all in the 5/64" groove ?

Anyways the engine im doing is not a stocker so i can go with any ring i wish. You use the .8mm or 1.2mm ring with the spacers ?

The 3 rings i listed were what i thought about going with

Hey, maybe the 5/64" groove with gas ported spacer will knock some weight out ?????????

Thanks for the contact info

[RPinoski1]

.043 With lateral gas ports.
.043Napier second ring.
3mm oil is good
The key to the whole package is a good straight hone with the correct profile.

Good Luck

[Jim Cimarolli]

Sorrt trmnatr, I should have completely read your post before I jumped in with my 2 cents worth.
I was talking about a stocker motor that had to use 5/64 ring lands.
I'm sure you would probably want to use something different for what you are building.
Good luck.

[trmnatr]

Originally Posted by RPinoski1

.043 With no lateral gas ports. Lateral ports create a vacuum leak on the intake stroke so now not the way to go anymore.

Napier second ring with twice the end gap as the top ring. Eliminates top ring flutter.
Remember: This type of ring as with all secong rings is for oil control only hence the larger end gap.


3mm oil is good

Use fish scale and drag the whole package @ 7 lbs.

The key to the whole package is a good straight hone with the correct profile.

Good Luck

Vertical gas ports ?