GTOTitoLS1

AS a tech for GM for the past 8 years, the engine still uses the same simple set up, and that coment you made about GM not selling a car since 1998, what planet are you living in. Last year GM closed the year with the Hightest sales this year they are far ahead, for more info on this go to GM.com derectly don't listen to news they been trying to put GM down ever since our gas guzzlers tahoe became the #####1 selling SUV in the US. about the motor still has same basic set up, 90degree block single cam,
push rod, 16 valves, driven by a single chain . in 2004 the small block celebrated its 50 long years in production. Why you think all those Honda lovers hate us Gm fans, specialy the V8 camaro's now GTO's and THe trans , with GM it's still simple mathematics, and still kicking ***, I've also worked on Honda's it will take 2x the time just to do a simple timing belt, I do mines on my 383. in about 45min., no power tools.

foryorent

racer7088, GTOTitlLS1:

What would you guys recommend for an LS2 or LS7 setup that can rev as high as you want and make great power through the whole rpm band? I am pretty sure I want to go with the LS7 bloc, as you have more to work with. Correct? But if you can make an LS2 setup similar for a lot less I would consider that as well.

I know you need all upgraded internals, but I dont know too much about specific engine internals, so would you guys help me out identifying all the parts I would need?

I have talked to Jesel and they said they have a valve train setup for the LS7 that "has no maximum engine limitations" so I guess they are good for any rpm I want. I have heard that Crower makes the best rotating assemblies. I need forged pistons, what else?

GTOTitoLS1

foryrent, you have to remember LS7 block has already been tricked out a little, in order to get a lot more you would need alot of money. I don't think people realize what a LS7 is, is not an actual 427. it's realy a LS2 bored out to a 427. 7 liters. Why do you want it to rev higher than 7000rpm? Unless you're doing seriuos racing I woulden't mess with the rpm. I have two LS1 motors for my GTO the stock with a little mods. and a race motor that I don't even know what displacement it has. All I know is that I started with a LS1 but I bored , shorten up the crank, lower coppression, made it into a twin turbo. I get about 8500 rpm, but I usually won't go over 7200rpm, Haltec computer sistem lets you adjust your power band, I drive it with that motor almost every day to work, 35min comute each way. I've driving it to florida, miami and raced it,to this day there hasn't been anyone that has beat me in a street race, not even a 911GT2 or a Lambo Cala, Honda's don't even want to, mazda's Rx7 twin turbo's only one and I beat him by 5 cars, supra's twin turbo's almost any street racers, and I'll race anyone , I know some day someone might beat me but then I have a camaro waiting with 1350HP revs to 10,100rpm . Both LS2 and LS7 come with forged pistons, but if you get a bare block You will need forged pistons, try to get a stroked crank made out of forged steel , it's a little expensive but it will hold higher rpm's, also at least a 9000rpm cam same try to get forged steel, same with valves , sping and retainers titanium, roller rockers and lifters to 10000rpm. that's just parts . If you realy want to see for your self go to DevilRay and Lmperformance

GTOTitoLS1

devil rays 427 vette , lm performance dot com

speedracerz

iTrader: (8)

Bret im not looking to argue with you, at least we agree that there is an ideal ratio, and yes the ideal number does vary by setup, a link from your post i found this, read the portion about rod lentgh vs intake
http://victorylibrary.com/mopar/rod-tech-c.htm

critter

iTrader: (9)

I don't understand why everyone is so afraid to spin an LSx. We were taking SBCs beyond 8000 40 years ago. My 370 inch short block from FFHP pulls hard to 8000 ....

DavidNJ

There are three things holding the LS1/2/6s back. First, the hydraulic lifter/small spring valve train. Those SBCs had big springs and solid lifters.

Second is the bottom end. Just like ans SBC, a change of rod bolt, rod, piston, pin, and maybe crank is necessary for a safe 8000 rpm engine.

Third is electronics. Not an issue with an SBC, however the standard ECU on the EFI/EEC engines doesn't map to 8000. So tuning isn't as good unless you go aftermarket.

There maybe a fourth. If using the stock tach (a kinda nice thing to do on a vette), it doesn't go to 8000 and I don't know of any aftermarket mods to make it do that. By contrast, I have a 10k tach for my Supra on the shelf. From Toyota. Is and looks factory.

Chuck Harmon

HMMMMMMMMMMMMMMMM, very interesting!


Chuck
(pun intended)

racer7088

Been there. Done that!

airflowdevelop

sorry to break the party up

Piston speed has been related to engine potential RPM for years. Believe it or not, Myth-Busters ought to run a special....BUSTED!

the problem is keeping the intake charge GLUED to the induction system at the velocities required to feed the cylinder at those speeds (in lamens terms).

8k ls7? no problem.. 650BHP --> Only if you are retarded, handicapable and drunk/high!

airflowdevelop

Bret,
Sorry to cut in....but you are 100% half correct. Rod ratio is BS --- TO A POINT! just like a humans diet..everything is good, but extremes of one thing are BAD!

Many have asked why we are working on our new flowbench/testbench...Now you know WHY! This has taken the ability away from me to help customers in a timely fashion...but will help us provide a quality product in the end.

Also, I have heard that you are trying to get ahold of me... I will be in the shop tomorrow afternoon if you wish (working on Sundays SUCKS!)

Dennis

airflowdevelop

Speedracerz,

As my father taught me (who was the best conventional physicist I have known). "Understand 100% of what you read, Believe 5%. Understand 110% of what you prove, believe 50%".

The document you are refering to, would be correct within the theories of 1977. Today they hold about as much water as broken glass.

OldStroker...Please don't pick on my gramatical errrs!

Dennis

DAPSUPRSLO

iTrader: (14)

Does the ls7 computer not map 8000? That doesn't sound right to me as the ls1/ls6 does. Also, I think alot of the reason people don't spin these motors 8000 is the oiling issues that become a problem with the wet sump setup of the ls motors. Then again if you have $3000+ laying around you can solve that with a dry sump!

racer7088

Remember the LS7 is dry sump now right from Chevy!

DAPSUPRSLO

iTrader: (14)

Yeah, definately! I was more responding to critter's post about why people are afraid to spin the lsx motors. Erik, I remember seeing something in where you talked about the drysump of the ls7 and how it still allows for aeration of the oil? Obviously its not a 5 stage deal or anything. Would you mind elaborating on that? I've gotta keep these things in mind when I attempt to convince the old man to put that special suprslo grind in his, lol, riiiiiiiiiiiiiiiiiiiiight!

MadBill

When I model an all-out 427 in Dynomation, using 0.750" intake lift, optimum duration & LCA cam, ETPs 265 cc C5R heads, 14:1 CR, Harrop intake, 2" to 2-1/4" stepped primaries with Burns merge/meg collectors, etc., it makes well over 850 HP, but peak power is ~7,300 RPM. I don't think even say 0.900" lift would raise the peak to 8,000 RPM. I'd be surprised if you could do it with existing parts, N/A.

foryorent

just want to clarify some things.

I don't care if peak power is at 7k, I just want to be able to spin up to 8k without the power dropping off like crazy.

airflowdevelop: what do you mean by: 650BHP --> Only if you are retarded, handicapable and drunk/high

That 650hp is a no brainer with this setup? Or its asking for too much?

DAPSUPRSLO

iTrader: (14)

No brainer!

Old SStroker

Dennis,

Are you saying intake manifold/port velocity is the limiting factor? If so, given a cylinder volume (300 cc in F1 or 1000 cc in ProStock) both making about the same BMEP @ power peak, wouldn't increasing the intake conduit area give a lower velocity for the same flow?

Average intake velocity of 240 ft/sec is 14400 ft/min, about twice the max PS and 2-1/2 to 3 times the mean PS of those high-end engines.

Would you elaborate, please?



Only one...OldSStroker.

YlwGTO4m3

have you ever heard of nascar? Those are pushrod v8s. and they rev to 9000 to 10k no problem. it can be done and it's not terribly hard, you're gonna need some special (expensive) and custom (more expensive) parts tho. As far as feasibility goes, it's absolutely possible.