I'm building my 1st engine, and it's a stroker, so I figured where else is best to ask than the Advanced Gearheads ??? Anywho, I'm starting with a 78 K2500 Block ( 4 bolt) been bores, pressure checked, align honed, ect. I purchased a Speed-O-Motive 383 Mighty Mouse kit, and have already installed the crank. Now my questions are, the kit came with KB Claim pistons, which reccomend the top ring gap be bore x 0.0065, which comes out to be .026 gap, mine are reading about .020, do I need to file them ??? Next, cam selection, I'd like to use a Roller cam, but my block is a non-roller, can I just purchase the retro-fit cam, retro-fit roller lifters, roller chain, roller rockers, or is there more to it ??? Lastly, if I do have to go with a solid or hyd. flat tappet, what do you reccomend, I'm thinking a Lunati Bracket Master 00012LK ??? .515/.515, anyways, all help is appreciated, thanks.

 

.020 should be fine for the top ring if you aren't going to spray it. Yes, you can retro fit a hyd roller if someone has a kit for your block,or use a mech roller which will fit right in if the lifter bore size is stock..847 If I remember right.

 

So a mechanical roller will fit with out any mods, just buy the mech. roller lifters, roller cam, and roller timing chain, and I can go, wow, this saves me about $500 doesnt it compared to Lunati and comps retro fit kits !!! Thanks for the info, I do want to spray, only 100 shot at the most though, what do ya think there ???

 

If you want to spray it I would talk to the ring manufacturer to get proper gap.Don't put molly rings in if you are going to spray it,they won't last.Get some plain ductile iron rings and they will be there after 50,000 miles.Even Total Seal doesn't recommend molly for spray.
Call Crower Cam's and talk to Dave Crower and see what he recommends for your set up.Have all your info ready-head flow number's, comp ratio,CID,rocker ratio and the like because he will need it.My guess is 250-260 on a 108 to 112 LSA and 4* advance on the ICL with .650 or so lift.Just a guess on my part see what Dave says. They have your complete set up cam,lifters,springs,retainer',and locks and he may give you a good price if you buy it all from him.You can go wiyh the Cloyes extreme duty chain for the LT-4 or a conventional SBC double roller chain set and some timing cover mods and electric water pump .Both will be OK.

 

In my opinion, plain old moly rings are fine with a small nitrous shot. I've been doing it for years. However, the "claimer" pistons are not a very good choice for N2O. So, if you go the nitrous route I'd say stick with a very small shot.

LR: it looks like a gen I, so he can use a regular SBC timing set with a conventional water pump. The kits can be a good way to get all the needed parts, but I certainly have no problem with your advice to call Crower.

Rich

 

Rich,
I just haven't had good look with molly rings.All the molly winds up in the pan.They can't take heat,dirt or pressure.I have tried everything from C&A to Seal Power and can't keep them in the low % when leak tested.Total Seal said not to put there molly rings in a blower or NO engine.I tried the first set in '67 thats when they were "trick".Couldn't make them work then or now in a HP application.Some people swear by them,but they don't leak test their engines or customer engines as much as I do.

 

People place too much faith in leakdown %. The only thing we should be concerned about are how well the rings seat when the engine's actually running.

I do know we lost 3 tenths of a second with nothing more than a ring swap going to Total Seal gapless seconds. Put Speed Pro moly rings back in and picked it back up. I don't doubt the TS rings had lower leakdown numbers too.

Go figure.

Only 100hp shot? It won't make much difference which material you go with (no cast) for rings IMO.

-Mindgame