the22driver

I am building my LS1 for road racing, it is completely stock at this point with the exception of some 26918-16 Comp Cam Valve springs. It dynoed at 311hp and 330tq with a full exhaust and no headers. I have long tubes, a 2into1 dr gas boom tube, ARP rod bolts and an Improved Racing Baffle set up for the oil pan all ready to go in.
My question is, I am looking for stone cold reliability and around 1000rpm more out of the car (i need it for stretching gears out from corner to corner).

What besides moving the rev-limiter with the tune will I need to do this? I am willing to change whatever to get there, I am sure that with what I have I will be close to my desired 345hp and 355tq, So I am afraid of a cam (these things make so much power stock, poor little mustangs) but do I need one for the RPM I desire or are the valve springs enough?

What about rotating assembly? It seems that most people think it will be fine, any thought?

Thanks for the help

garygnu

consider pac 1518 springs and harden push rods.also look at swapping in some compcam trunnion bearings .TSP has these parts.what cam are you using?what cam dose rules allow?

the22driver

It is stock, I can use any cam I want I am just limited by hp/tq to wieght. I like the characteristics of the stock cam, good power under the curve, I just need to move that rev-limit up. And not worry about the engine staying in one piece.

the22driver

Is there something wrong with the springs I have?

Darkman

iTrader: (2)

OEM springs are not intended for sustained high rpm and will cause valve float and/or will break. What rpm are trying to sustain?

the22driver

Sorry, I am currently running 26918-16 Comp Cam Valve Springs.

I am not sure on RPM maybe 6500-7k would be perfect. What is the stock revlimiter set at 5500? I am looking for another 1000 +/- over stock.

Does the cam affect valve float?

Darkman

iTrader: (2)

My fault, you reported your valve springs in the first post.

I think you could get the valve train to sustain 7k rpm levels with the following:

Morel lifters,
Comp Cam Hardened Push Rods or the eqivalent,
Comp Cam 921 valve springs (or PAC 1221s, or the TFS equivalent),
Upgraded OEM rockers using either the Comp Cam or Harland Sharp trunion upgrade).

As for a cam, the stock might work but I would be tempted to have PatrickG spec one on EPS lobes, which make for a stable valve train.

I will defer to others concerning the bottom end of the motor. I suspect that sustaining 7k rpm will require at least setting up the rods and crank for that. The ARP bolt upgrade, which does not work for everyone, is more for "visiting" 7k rpm, such as in drag racing as opposed to living there as in road racing.

TurboBuick6

iTrader: (2)

Yeah I am thinking the same thing about the bottom end.
Cam, lifters roller rockers pushrods 1518's (depending what type of cam may need 1521's). That will get you a pretty solid valve train.

THENASCAR

iTrader: (19)

ive never road raced or anything but if i had any valve springs to suggest, ive been using patriot gold extreme springs , cryo-treated and have had great luck , we will see how much spring pressure i have lost in a few thousand miles but i bet not much, and with a double spring valve floating is less likely

SOMbitch

iTrader: (8)

Yes a cam with a more intense lobe rate and higher lift will affect valve float and require more spring pressure.

It would be pointless spin the stock cam to 65-7000k because it is done making power at 5800. You need more cam to make power at those RPM's

the22driver

Yes I agree and the lost time on a shift seems to be worse than a losing out on couple of horse power? Maybe not, I am talking 10ths of a second.

Could a cam be done that would give me those extra rpm with out a ton more peak horsepower? Maybe 7k is too far what is the stock rev limit?

the22driver

That has been my thought on the bottom end, yet you hear over and over that the at least the crank can handle a lot of abuse. I have all winter to work this thing over. Last thing I need is to lose a motor mid season cause I got cheap now.
I will take your advice and get with TSP for the rockers, valve springs and pushrods maybe they can get me some numbers for a bulletproof bottom end.

Thanks for the input.

SOMbitch

iTrader: (8)

How much power can you make?

You can get cam that will make much better torque up high than the stock cam and help you cut down on your shifts. Even if you keep your stock cam if you plan to spin it like you want to you need springs and hardened pushrods minimum or we will eventually see you posting another another "LS1 carnage threads"

Get Geoff at EPS or Patrick G to spec you a custom cam to suit your needs.....

the22driver

Yeah kinda want to stay out of there! Lol I can make around 345-350 depends on how heavy I keep the car? I will get with both of those guys and sound like pushrods and better springs for sure. I need to read up on those trunion bearings. Any threads for that?

Darkman

iTrader: (2)

https://ls1tech.com/forums/generatio...n-upgrade.html

A search on "trunion" will yield many more.

01ssreda4

iTrader: (96)

Don't know if I would trust the bottom end to repeated 7k runs. All the valve-train upgrades listed here are good suggestions, however, I don't think duals are needed for a stock cam. The 918s are already a big improvement over the stock weak springs.

slt200mph

iTrader: (42)

918 springs do not have what you would call a stellar reliability record to say the least. There are lots better springs with much better reliability than the 918s. If you want long lasting reliability Comp 921s are the ticket.

GIVE EM' THE BIRD

iTrader: (1)

I would say an overall upgrade will be needed for prolonged runs up really high. I understand that the HP up high is not what u are concerned with, just spinning her. I would recommend a bottom end build as well tho just to fret on the safe side...

If u just want to spin the hell out of the thing that just getting a good top end component setup would be the ticket. Hardened push rods, rockers, GOOD springs, litters, etc... The stock cam along with all of the components will turn the RPM u need, but won't make power much after 5900 or so. That will get you your desired RPM range, but u will be running on a ticking time bomb...

How long will your bottom end hold while pushing 7k for prolonged periods of time??? 1k miles... 20kkk? Who knows, but it's going to end bad even if your tune is damn good.

Have u considered gearing changes??? Instead of needing more RPM to sustain power through a corner, how about changing the gearing to accommodate, and allow you to keep your engine in the 6000-6200RPM range(or lower). That way you will be stressing the bottom less, and you will be keeping your car closer to is peak with the stock cam and a good top end setup.

Just a thought... But either way I'd say at least get a good rotating assembly.

vette0009

Call ECS

They are experts in road racing

Ask them about a Solid roller cam

and a new valve train

You can run higher rpm with a solid roller

vettetrickcom

the22driver

Ahh..now I see! Thanks, seems easy enough (has to be easier than doing the valve springs)? Would some aftermarket rockers be even better or are they overkill?