I think that you started a good thread as long as it stays on track (guess that it's my job to keep it that way, but I have to keep myself from trailing off first ) But like you said, you've got people thinking, and guys like myself run straight to google and start looking around for more info (that's where I found the Isky info).

With that being said, I'm gonna get a little off topic The 2.5 collectors actually work perfectly with my current setup (mods in sig), but I have an LQ9 shortblock that needs a freshen up and some WCCH StageII 317's ready to go on after a little milling (maybe .030 -.040), and that's the direction that my minds going when I'm thinking of cam specs

I like the 113, like you said, if you can't decide on 112 or 114, split the difference . Seems like guys have had good results with GENIII's with 111, 112, 113, 114, 115,etc...it all depends on the combo

Yeah, I noticed that too...curious as to why that is...they do offer custom grinds also, and they show all of their available lobes on their site. It isn't as extensive as say what Comp (barf) offers, but it looks like one could spec out a decent Isky cam if they wanted to

 

GEN III vortec heads flow much better than vortec SBC heads on the exhaust port. In my tiny brain I'm curious why we need a large exhaust duration split? All their off the shelf grinds have fairly low lift too.

Maybe they designed them for newbies who want to throw shorty headers and a cam on their truck? Or maybe split pattern cams just tend to sell better, who knows?

People seem to have good results running the TR or TSP 220 and 224 I'm just kinda curious how it'd work in bigger and smaller packages. Like would the 212/212 be better than or comparable to a low lift 212/218?

 

That's the thought I had too. I'm going to try and email Isky and get his thoughts on this.

 

I'm curious to hear Isky's response myself

 

In the larger cams the single pattern is often the way to go in a heavy truck, but in cams below 218 @.050'' I like to run a short split in most NA applications, especially when running cats. Often times you can get away with less exhaust duration as LSA tightens, but opposite is true when center increases due to the reduced scavanging effects. If you are running headers and good exhaust system you want a tighter lsa, and single pattern, to low forward split. When running exh manifolds or shorty headers the tight LSA and single pattern can hurt you... A ISKY 212/215 112 would work well in most applications. I wouldn't go past 112lsa unless you are running stock manifolds, or shorty headers. JMO

 

218/221 110+4

 

Indeed

Ive got an isky 208/214 112 that i cant wait to get in the hoe

 

ok let me make sure I'm reading this right

so with some exhaust restriction (ie cats, shorties, manifolds) you want a small split pattern

but with an open exhaust (longtubes ORY) you want single patterns and a tighter LSA

smaller lsa you can go less exhaust duration

what do you mean when center increases?

when you say go past 112 LSA do you mean higher or lower?

sorry if I seem like a