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View Full Version : Beating a dead horse again.



junkyardjohn
07-28-10, 09:53 AM
Horsepower TV show, a few weeks ago bought an over the counter corvette LS3 engine, changed only the exhaust manifolds to camaro manifolds dyno'd the engine and got 495 h.p. out of the other wise bone stock motor. ( no dry sump ). Question: Would the power of been the same or more if it were using a dry sump system? :D

Tuna
07-28-10, 11:25 AM
I can't see a dry sump making any more horsepower than a regular oil pan on a dyno unless the 'windage' in the pan of the wet sump engine is churning up oil and causing resistance to the crank shaft rotation. Most modern performance have windage trays and other things in the pan to keep the oil in the bottom of the pan versus getting all around the crankshaft.

Now for racing purposes, the dry sump has advantages like getting the oil away from the crankshaft where it can cause loss of power it high "G" corners.

SnakeOiler
08-22-10, 09:14 PM
Did they dyno it before the manifold change? I would hope so, for baseline reference. If so, what was the baseline?

junkyardjohn
08-23-10, 12:56 PM
Horsepower T.V. didn't say anything about any baseline. They simply took an over the counter LS3 crate motor, used camaro exhaust manifolds, dyno'd the motor and came up with the said horsepower at the flywheel.

VettinFan
08-23-10, 03:16 PM
WoW. It's hard to believe they could get that much extra HP out of a stock LS3, with just the Camaro exhaust add-on. :confused

catbert
08-23-10, 03:54 PM
WoW. It's hard to believe they could get that much extra HP out of a stock LS3, with just the Camaro exhaust add-on. :confused

Right. If Chevy could get that kind of horsepower, they wouldn't be advertising 430. I didn't think the SAE horsepower regimen was 50 hp tougher than a simple dyno pull. Something isn't right.

SnakeOiler
08-23-10, 08:37 PM
Accessories rob a lot of power. Look at the different ratings back when they switched to SAE.

I think the test would have been better if, say, they tested different stock exhaust manifolds on the LS3: truck vs. camaro vs vette

make it at least interesting.

junkyardjohn
08-24-10, 01:05 PM
Back in the late 1960's and 1970 the crysler 426 hemi was factory rated at 425 horsepower when in reality it produced over 650 h.p. The chevy 454 ( LS-7) over the counter was factory rated at 465 H.P. again in reality it produced 600 +H.P. Don't forget the ford boss 429 motor ( the highest) under rated motor yet. The factory horsepower rating then were to fall under the insurance companies radar as far as rates. Today, who knows.

korvettekarl
11-10-10, 02:01 PM
I don't know about the numbers, but I know there is definitely a difference between the LS7 and the LS3. My Z06 was A LOT faster and had A Lot more torque than the LS3 that is residing in my GS right now. I will be adding a supercharger as soon as I can get the $ without the little woman noticing. I probably should have gotten another Z06 when the 07 was wrecked but boy that GS sure was pretty and had everything the Z had except the ponies. Live and learn. Anybody want to buy a 57 Bel Air?

Hib Halverson
11-10-10, 03:39 PM
Before you can address this issue you first need to know...

1) Was the test on Horsepower TV run to the same SAE standard as is the stock engine, ie: in SAE test configuration which is, basically, the engine as run in the car--with cats and a full exhaust and the production ECM cal?

2) Was the dyno correction data SAE net?

3) Was it the same kind of dyno that GM uses to certify it's engines?

Hib Halverson
11-10-10, 03:50 PM
Back in the late 1960's and 1970 the crysler 426 hemi was factory rated at 425 horsepower when in reality it produced over 650 h.p. The chevy 454 ( LS-7) over the counter was factory rated at 465 H.P. again in reality it produced 600 +H.P. Don't forget the ford boss 429 motor ( the highest) under rated motor yet. The factory horsepower rating then were to fall under the insurance companies radar as far as rates. Today, who knows.

It is true that some muscle car era engines were underrated but the idea that the Street Hemi made 650 hp and the LS7, sold by GM Parts in the 70s and early 80s, made 600 is fantasy.

A production L88, with headers, tuned for racing and running racing gasoline produced 620-hp at 6800 rpm.

There is no way the Street Hemi or the LS7---at least in the form they were sold in cars or in crates, then installed in cars---made 650 and 600-hp respectively.

Now, the "Race Hemi"...the one supplied to drag racers like Sox&Martin, Ramchargers, etc and the NASCAR Grand National teams, may have been close to 650, but used parts not sold by Chrysler on the 425-hp Street Hemi.

An LS7, with headers, tuned for racing and on racing gasoline could have produced 600-hp.

In both cases, the engines were hardly streetable.

johnnyclassic
11-26-10, 02:35 PM
I did a little investigating on what you wrote and by running it past what I consider the most knowledgeable guy on the subject he says your correct. His name is Don "big daddy" Garlits. :L:L

junkyardjohn
11-26-10, 05:05 PM
I did a little investigating on what you wrote and by running it past what I consider the most knowledgeable guy on the subject he says your correct. His name is Don "big daddy" Garlits. :L:L
Hi, I'am glad that I'am your first post. Yes I, we all heard of Big Daddy Don Garlits. also I also own a Blue grand sport rag top.:rotfl

johnnyclassic
11-27-10, 11:25 AM
Junkyardjohn, wow same type of vette, same town, same name I guess, what else? How bout a picture? Mine will comming soon.:confused

Schrade
12-10-10, 10:59 PM
Junkyardjohn, wow same type of vette, same town, same name I guess, what else? How bout a picture? Mine will comming soon.:confused

Me too - I have a 2010 GS vette ragtop, and I'm gettin' a 2011 GS coupe for Christmas.

In fact, I think everybody has a 2010 GS on this forum board... Right?

Hog
01-25-11, 01:07 PM
It is true that some muscle car era engines were underrated but the idea that the Street Hemi made 650 hp and the LS7, sold by GM Parts in the 70s and early 80s, made 600 is fantasy.

A production L88, with headers, tuned for racing and running racing gasoline produced 620-hp at 6800 rpm.

There is no way the Street Hemi or the LS7---at least in the form they were sold in cars or in crates, then installed in cars---made 650 and 600-hp respectively.

Now, the "Race Hemi"...the one supplied to drag racers like Sox&Martin, Ramchargers, etc and the NASCAR Grand National teams, may have been close to 650, but used parts not sold by Chrysler on the 425-hp Street Hemi.

e.
I agree, my uncle's 1 of 22 1969 Dodge Charger "500" 426 Hemi, 4 speed, 4.10 Suregrip makes nowhere close to 650hp.
The "race" 426 Hemi he has on a stand using dual dominators flowed at 1350cfm apiece was dyno'd at 850 hp at the crank.

Exhaust was everything on the older bigblocks, irregardless of manufacturer. A ZL-1 dynoed with a stock 1969 Camaro exhaust made about 275hp on an engine dyno, when the same engine with headers would dyno at 500-525hp. In race trim, over 600hp was possible.
I saw a 1969 ZL-1 427 Camaro run a 12.2 in the 1/4, but cant remember the mph. After every pass teh car would disappear into an enclosed car trailer between each pass. There was a moment where I was able to eyeball the engine quickly, and sure enough the block was aluminum, as was the intake.

I love these old iron stories. I could listen to Hemi, DZ302, LT-1, LS-7, ZL-1 etc etc stories all day.

peace
Hog

BigJimZ16
01-25-11, 03:23 PM
Me too - I have a 2010 GS vette ragtop, and I'm gettin' a 2011 GS coupe for Christmas.

In fact, I think everybody has a 2010 GS on this forum board... Right?


You could be right...

2300

'04 Vert was history last Fall... guess I need to update the avitar.

Tuna
01-26-11, 11:14 AM
I drove a 'street hemi' '69 Runner for 12 years. 500 HP might be close but never 650.
The 'street hemi' came with a solid lifter cam with 292 degrees duration and .485 lift. It also had 2 "C" series AFB carbs and cast iron exhaust manifolds. Not the kind of stuff that makes 650 HP.

I actually lowered the duration using a Racer Brown hydralic cam with 286 degrees and .485 lift because I got tired of adjusting the valves every oil change and it worked better with the automatic and 3.54 gears.