1BADWS6@STENOD

iTrader: (6)

I'm building a L92 based 427. I want to make 700 hp. He is what I have so far.

L92 block
Callies 4.125" crank
Using Howards steel rods 6.125"
Kooks 1 7/8"-2" stepped headers
D&D T56

He are the constraints I have. Must run on pump gas, so no higher than 12.0 cr. I would rather have it a hydraulic roller but not throwing out a solid. The only problem with the solid roller is the oiling. I don't want to run a dry sump system, so i want to stay under 7500rpms. I have a peterson external wet sump pump that I can use. The cam can be as big as needed...actually the bigger the better! It's a 6 speed so it won't be a problem on the street. I'm not sure what heads to use ET LS7, ET 265, Livernois L92...etc.

What do you guys think? Is it possible? Give me your input!

landstuhltaylor

iTrader: (6)

big difference between flywheel and rwhp

ls1 joe

iTrader: (37)

I have no problems at 8400 with my wet sump. It has a melling pump that about it on the oiling system.

DoesSpeedTurnUon

iTrader: (17)

jesus... what does something like that sound like at 8400rpms?!

mr2guru

iTrader: (16)

IMO to make 700hp it's going to take a solid roller, high compression and a lot of rpm.

Chances of doing it on pump gas with only a 427 are very slim.

Sean Collins

PM sent with info on who and where to get ahold of said information.

brad8266

iTrader: (23)

I was thinking the same thing.

Sean Collins

Its actually fiarlyu achievable with enough RPM and a single plane intake. Hell out of the box l92's should be really close with a single plane.

gator's 99TA

iTrader: (2)

intersting post. i like what i hear. nothing easy about 700 flywheel hp on pump gas and no methenol.

SSilverSSurfer

iTrader: (8)

yeah but you are solid roller

Sean Collins

It will require a rediculous camshaft lots of exhuast a big overlap happy camshaft with an early IVO maybe some cleanup on a set of l92 and a well ported single plane intake. that is if the flow numbers aren't pure BS and the heads aren't lazy. You could use the ETP 4inch bore heads and that number gets really easy with a 408 since I have seen the dyno sheet on a 408 running etp4$inch bore heads with a ls7 intake with a bit of work done to it and it made 640ish STP on the engien dyno. Just swapping to a single plane and revise the camspecs would have easily luanched that motor another 60 horse.

MUSTANGEATER

iTrader: (10)

With many folks doing near/over 600 RWHP on their LS7's on pump gas, which is nearing 700 Fly wheel HP I don't see it being a huge deal if you're wanting to get 700 FWHP.

airflowdevelop

I'm not seeing the problem here...the exhaust event that is required to make it really work, helps the whole situation....

is it possible...YES, with not so good induction, and non-engineered valvetrain...good luck!!

Dennis

Sean Collins

factory valvetrain has been proven to 7200rpm with the correct spring and a nice lightwieght sodium filled valve ( me regurgitating widely known info amongst engine builders again) and requires no exoctic hardware. I don't think it'll need to go more then say 7000rpm with the TQ potential of the ETP LS7 stuff. Honestly i don't think this particular build would be served by anything better then a stock rocker with maybe the bearing mod for durability. you can't beat those rockers for wieght and with RPM and zero maintence on pump gas soundling like the goals here hyduralic with ETP head with lightwieght $$$$ valves and beehives with ti retainers with resasonalbe lift and durations with a single plane and a fiarly standard header this is all doable if we are talking straight STP flywheel numbers. I don;t think exhuast is going to be the issue here.

Call Cary at ET he can help !

MUSTANGEATER

iTrader: (10)

I think what Dennis meant was exhaust timing event and how it works with a pump gas motor with a high SCR. Not reffering to exhaust itself.

Sean Collins

I don't think you need a really high SCR if you fill the cylinder correctly and don't overbleed the damn thing across the RPM range. I wasn't sure what he was talking about to be honest.

Mizfit MotorSports

iTrader: (11)

pm sent...

SStrokerAce

iTrader: (2)

Lets see.... who hear has seen 600rwhp SAE on 427 LS motors? I have. I don't think a single plane would greatly improve the peak HP numbers over a LS7 intake, and it's only helpfull if you need more RPM than 6500rpm. Even then it works well to 7200rpm, not perfect but well.

FWIW Sean, Dennis knows what he is talking about, DEFINATELY more than about 99.99% of the guys who are registered for this forum.

The compression is really the only thing that is going to change between a pump gas motor and a race motor in terms of this HP level. LS7 heads are surely capable of this on pump gas, no need to spend mega $$ on bling ETP's.

And for ***** and giggles people PLEASE stop thinking that overlap has anything to do with bleeding off compression!

Hell I think this is doable with LS7 castings and a hyd roller, but that's just me ;-)

Bret

Sean Collins

I am thinking defferently becuase ive seen motors 50hp shy of this goal. the Ls7 intake i a great piece but its got such a high runner impedence that it holds the head back a ton. I am sure another 200-300rpm with what already done with a mild cam change on the 408 i mentioned would easily break 700hp. Might be by just a few ponys but very very doable.

I don't think it'll take more then a 11.5:1 engine either.

Overlap can drop compression but it depends on where the EVO and IVC are you know that. When people stop obessing over DCR I will stop bringing it up. but if you let out the cylinder fill geuss what. you will have less DCR. its fiarly straight forward. Less cylinder fill less DCR. trap the cylinder fill and the DCR goes up. its dynamic compression. SCR is always there staying right on the number.

I just didn't get what he was saying. Yes the exhuast event could be critical.you could use it to lower pressure after TDC to help manage the ciritcal afterburn zone where detonation takes place. me i would keep that valve shut drop the SCR and worry aout keeping the burn on the piston dome. thats just me.

from what I have been privy to as far as whats been done a single plane/ls6/ls7 would bring Tq up 1000rpm and woul definately make this much more doable.

I don't think its doable with factory Ls7 casting to much runner volume for the flow rate. thats why i siad ETP ls7 heads. Now a proerply worked l92 head might be able to. the factory head with a ls7 intake might come close but no cigar.

Sean

chuntington101

700bhp NA has been done! lol it did take a 500cubic inch LS2 but they did do it on a very mild street setup!

the SAM went along and stuck 250bhp of n2o on there! lol

chris.