stevewix

i've been doing the math on the motor i'm building, and i keep coming up with a peak hp at 8350rpm. my question is; how much is too much in an ls1? the solid roller valvetrain will be as light as i can get it; and i will be running a 347 with the longest rod possible, and highest compression i can make.

what are the limiting factors? help! i only want to change valvesprings once per season, or 25-40 runs. am i asking too much?

PS this is a race motor, that may see 10 miles of street duty each year.

RyanJ

It can be done. Are you looking to rebuild every season? How much cash are you sinking into this? Where did you get 8350rpm?

Classic

iTrader: (3)

There are LS1s that have spun or do spin that high. However the main concern is not the valvetrain but the oiling capabilities of the block itself.

stevewix

the cam that i've come up with making the best power from 6100-7800 just happens to keep pulling- past 8500; it's on performance trends' engine analyzer pro. i'm trying to stay as cheep as possible, BUT i am not messing around at the same time, i'm doing it right the first time.

it makes good power, but i'm afraid this motor will want to rev hard -way hard.

i know these software dyno programs are a joke, obviously nothing works like dyno time, but so far this program has been dead-nuts right on the money; as long as a guy knows how to use it.

EDIT the motor will more than likely be out for a rebuild each season.

MUSTANGEATER

iTrader: (10)

You're going to want great control so lightest pieces isn't always going to work. I'd go Jesel Rockers, Manton Puhrods, & Morel Lifters. Hollow Stem or Ti valves would be a good idea too. For a valve spring you could get people argueing until they are blue in the face about it, but I'd go with a Bee-hive style spring, and that's just my opinion so take it for what it's worth.

DAPSUPRSLO

iTrader: (14)

The oiling system is the biggest factor in the ls motors and is the only reason I'm keeping my 434 to 7500 or less rpms. Dry sump will let you do anything you want though.

Question, what cam, head, and intake combonation did you use to arrive at the 8300rpm figure?

Classic

iTrader: (3)

The dry sump setup will solve some problems however it will not solve the oiling issues inside the block. You can do some things to smooth the path of oil flow however that still will probably not be enough. I have seen an external wetsump fail plumbed directly into the block -- where you would plumb a dry sump.

RyanJ

So you are basing the 8350 figure on the cam alone? Be aware that if you do that you'll spend a lot more money getting the rest of the motor to keep up with the cam, rather than spending $400 on a different cam. But anywho.

Go with what MUSTANGEATER posts, they are good pieces (but I would really go with what Ed at FTI recommends...because I'd just call him with my head/intake/bottom end/rpm specs and have him spec a cam that will work). Also, if you have the cash for Ti valves, get some aluminum rods...you'll spin higher and faster easier, but you'll probably need to rebuild every season and at least check the rods. Technology is getting better, but you never know with rod stretch. Jager makes a ceramic/aluminum rod that is supposed to survive street car stuff but still weight much less than steel rods. Good stuff, but expensive. Call Ed Curtis at FTI (EDC on here).

Oh yeah, if you are gonna spin that high, go to www.drysump.com and start buying.

Classic

iTrader: (3)

A behive isn't going to keep up with a big solid roller. You are going to need a good set of duals (PSI/Manley Nextex/Isky) and a light valve.

MUSTANGEATER

iTrader: (10)

Ed's a good guy to call about Camshaft and valvetrain stuff, for sure.