TSP 454 LSx, what cam?
Launching!
Joined: Dec 2003
Posts: 251
Likes: 2
From: Portland OR
There was a Super Chevy article earlier this month on GM's buildup of a 454 LSx for a Reggie Jackson '69 Camaro. With a carb intake and Holley 950 (4150 series) carb, the motor made 641 hp at 6400, 611 tq at 4900 on an engine dyno (flywheel horsepower).
Those numbers were achieved using "prototype LSx heads", which by all indications are just 6 bolt versions of the LS7 head. The cam was a 236/246/110, .630/.630 grind from Crane. 11-1 compression. 1.75 long tube headers.
Considering that a 950 carb is probably costing 20 HP or so at this power level, those are stout numbers for a pretty mild cam. It would seem to show that LS7 heads can feed this many inches, and that huge cams aren't necessary to get very good results.
Those numbers were achieved using "prototype LSx heads", which by all indications are just 6 bolt versions of the LS7 head. The cam was a 236/246/110, .630/.630 grind from Crane. 11-1 compression. 1.75 long tube headers.
Considering that a 950 carb is probably costing 20 HP or so at this power level, those are stout numbers for a pretty mild cam. It would seem to show that LS7 heads can feed this many inches, and that huge cams aren't necessary to get very good results.
Launching!
Joined: Dec 2003
Posts: 251
Likes: 2
From: Portland OR
Originally Posted by Hennytime
not impressive
Sorry for the sarcasm. But the point is, in a controlled head to head comparison between motors (that is to say, on an engine dyno) 640 HP on a mild cam is really quite remarkable when you step back and think about it. I'd bet dollars to donuts that none of those 600+ rwhp LS7s with huge cams actually makes 700 on an engine dyno - probably not all that close to 700, actually. Not knocking LG at all - they make some great combos - but using the 15% "drivetrain loss" to calculate a big "flywheel horsepower" is simply bogus.
The 15% number is what accountants like to call a "plug number" - a rough number based on a combination of parasitic losses between an engine on a dyno and an engine in a car, with full accessories, exhaust, and drivetrain. You can reduce those parasitic losses through many means - underdrive pulleys, electric water pump, lightweight flywheel, lightweight small diameter clutch, uncorked exhaust, etc. The increase at the rear wheels is real, and will make a difference in the 1/4 mile or other measurements, but you can't multiply reductions in parasitic losses by 15% and claim that the engine now makes more on an engine dyno.
Engine dynos, if honestly calibrated and used, are much better for comparing two different engines in two different locations. Maybe someday the top tuners will actually agree to test their best combos against each other on a controlled basis on the same engine dyno - but I'm not holding my breath.
Last edited by 71CamaroLS1; Apr 22, 2007 at 08:54 PM.
Teching In
Joined: Apr 2006
Posts: 16
Likes: 0
Originally Posted by SDB
$5095 for basic shortblock from TSP...
with upgraded Callies crank and Oliver billet rods, $6100.
VERY good price for 454 cubes.
Why choke this motor with L92 heads? Get some ETP's or LS7's that are ported to 390-400 cfm. Make sure to get killer valvetrain, and spin it to 7500 rpm and make 750 crank hp!!!!!!!!!!!!!!!
with upgraded Callies crank and Oliver billet rods, $6100.
VERY good price for 454 cubes.
Why choke this motor with L92 heads? Get some ETP's or LS7's that are ported to 390-400 cfm. Make sure to get killer valvetrain, and spin it to 7500 rpm and make 750 crank hp!!!!!!!!!!!!!!!
Originally Posted by 71CamaroLS1
How so? Because you can multiply somebody else's Dynojet number by a magical correction factor and come up with a fictitious "flywheel horsepower" number in the 700s?
Sorry for the sarcasm. But the point is, in a controlled head to head comparison between motors (that is to say, on an engine dyno) 640 HP on a mild cam is really quite remarkable when you step back and think about it. I'd bet dollars to donuts that none of those 600+ rwhp LS7s with huge cams actually makes 700 on an engine dyno - probably not all that close to 700, actually. Not knocking LG at all - they make some great combos - but using the 15% "drivetrain loss" to calculate a big "flywheel horsepower" is simply bogus.
The 15% number is what accountants like to call a "plug number" - a rough number based on a combination of parasitic losses between an engine on a dyno and an engine in a car, with full accessories, exhaust, and drivetrain. You can reduce those parasitic losses through many means - underdrive pulleys, electric water pump, lightweight flywheel, lightweight small diameter clutch, uncorked exhaust, etc. The increase at the rear wheels is real, and will make a difference in the 1/4 mile or other measurements, but you can't multiply reductions in parasitic losses by 15% and claim that the engine now makes more on an engine dyno.
Engine dynos, if honestly calibrated and used, are much better for comparing two different engines in two different locations. Maybe someday the top tuners will actually agree to test their best combos against each other on a controlled basis on the same engine dyno - but I'm not holding my breath.
Sorry for the sarcasm. But the point is, in a controlled head to head comparison between motors (that is to say, on an engine dyno) 640 HP on a mild cam is really quite remarkable when you step back and think about it. I'd bet dollars to donuts that none of those 600+ rwhp LS7s with huge cams actually makes 700 on an engine dyno - probably not all that close to 700, actually. Not knocking LG at all - they make some great combos - but using the 15% "drivetrain loss" to calculate a big "flywheel horsepower" is simply bogus.
The 15% number is what accountants like to call a "plug number" - a rough number based on a combination of parasitic losses between an engine on a dyno and an engine in a car, with full accessories, exhaust, and drivetrain. You can reduce those parasitic losses through many means - underdrive pulleys, electric water pump, lightweight flywheel, lightweight small diameter clutch, uncorked exhaust, etc. The increase at the rear wheels is real, and will make a difference in the 1/4 mile or other measurements, but you can't multiply reductions in parasitic losses by 15% and claim that the engine now makes more on an engine dyno.
Engine dynos, if honestly calibrated and used, are much better for comparing two different engines in two different locations. Maybe someday the top tuners will actually agree to test their best combos against each other on a controlled basis on the same engine dyno - but I'm not holding my breath.
Launching!
Joined: Dec 2003
Posts: 251
Likes: 2
From: Portland OR
Originally Posted by texada
I saw BBC Head flow numbers (ALL AFTERMARKET BBC HEADS) on AFR's website and fromthe way it looks STOCK LS7 heads flow more than those big block heads.
The price on the site is correct! I had previously put the wrong price in 
Jason
Texas Speed
Jason
Texas Speed
Originally Posted by 1fastbusa
check there site again they upped the price 900 bucks
__________________
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
TECH Fanatic
Joined: Mar 2004
Posts: 1,017
Likes: 0
From: Laguna Niguel, CA
I think that some people are forgetting about the low end torque that generally comes with more cubes. I do agree that for a RACE motor, the LS7 or L76 intakes are too small, but for a street torque monster they might just work.
And comparing the LS7 heads to the BBC heads above do the LS7's flow 300+ at .400 valve lift?
I think the low lift flow numbers have always been the key to the monster midrange power and torque that the 454 CI monsters from the 1960's and 70's made...
And comparing the LS7 heads to the BBC heads above do the LS7's flow 300+ at .400 valve lift?
I think the low lift flow numbers have always been the key to the monster midrange power and torque that the 454 CI monsters from the 1960's and 70's made...
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On The Tree
Joined: Dec 2005
Posts: 127
Likes: 0
From: North of California
interesting thread since I have been considering buying one of these from TSP as well ... SOOOO I know this is gonna be a flame fest but ...
exploded piston in my LS2 is forcing me to do something about it and this looks like an extremely good foundation to build on over time ... What about LS2 heads on the 454 with a mild to mid cam for primarily street and weekend strip usage ... I would be using my LS2 heads until I can get some better ones ... just hard to cough up all the cash at once
I can't see any reason this won't put down more power than a basically stock LS2 for the time being.
exploded piston in my LS2 is forcing me to do something about it and this looks like an extremely good foundation to build on over time ... What about LS2 heads on the 454 with a mild to mid cam for primarily street and weekend strip usage ... I would be using my LS2 heads until I can get some better ones ... just hard to cough up all the cash at once
I can't see any reason this won't put down more power than a basically stock LS2 for the time being. 