1/4 Mile Times Stock LS-6 [Archive] - Chevelle Tech

: 1/4 Mile Times Stock LS-6


GOSFAST
Jul 23rd, 06, 11:13 PM
This is a quick follow up post on the LS-6 we delivered a few weeks back. If you do a search you'll get a rundown on the unit. They made a few passes the previous weekend and just called me the with the numbers. The car ran 12.6's at 107 MPH, I have to double check the MPH number, he had a bad connection on his cell phone. The car weighs 4000# with the driver and has factory tires in the rear. This is the first one we set up for the F.A.S.T. class drags. Thanks, Gary in N.Y.

P.S. The unit is 99.9% stock. The only non-stock parts are the 6.385 rods and a set of Probe "slugs". It uses a 10:1 C.R. and a 238 @ .050" cam. The cam has less duration than stock but more lift. Unit runs with 13 inches vacuum. Power brakes work fine. Stock intake manifold, exhaust manifolds, and carb. Runs on 93 with all 36 degrees of timing up front, no starting issues even with the hot weather. Should do slightly better in cooler weather also!

Bomber '67
Jul 23rd, 06, 11:56 PM
That is pretty good, but its not stock. With the newer parts and minor changes, it also benefits from a more careful assembly than the factory LS6's of 36 years ago. Many long years ago when I worked the parts counter at a big Chevy dealer I had one customer who regularly bought LS6 engines to install in his customers cars. I was surprised when visiting his shop one day to see that he had completely disassembled a brand new engine that I had sold him. He told me that he always disassembled these engines and checked and adjusted clearances, ring gaps. etc.

Congrats to your customer for a good first showing at the drags - where do you think the car's performance will end up at e.t. & mph?

Thomas

68chevelle533
Jul 24th, 06, 12:58 AM
Nice times. Automatic car? Repo tires (coker)? Cool seeing someone race a rare and expensive car.

mr 4 speed
Jul 24th, 06, 9:06 AM
Gary,what is the advantage of the 6.385 rods and the Probe pistons?
I'm guessing they are alot lighter than stock
Pretty impressive performance considering stock intake,manifolds,etc.
original post:
http://www.chevelles.com/forums/showthread.php?t=133209

GOSFAST
Jul 24th, 06, 10:03 AM
Gary,what is the advantage of the 6.385 rods and the Probe pistons?
I'm guessing they are alot lighter than stock
Pretty impressive performance considering stock intake,manifolds,etc.
original post:
http://www.chevelles.com/forums/showthread.php?t=133209

Hi Chris, the long rod gives a more efficient "burn" and the "Probes" are actually part of an ongoing test of their pistons. We chose them for a number of reasons, first they have a decent price, second, they came in 540 grams with some dome removed, and third, they're forged on the 2618 blanks. They did come without pin-oilers and at first we were going to install them but changed our minds as part of the piston "test". The unit is already scheduled to be redone over the winter season with an upgrade on the cam from the 238/248 x .550-.570 to a 248/258 x .570-.600.

The E.T.'s are not too bad considering the street tires but we're dissappointed in the mile-per-hour. We need more upstairs. As of today we feel the cam is the deterrent. But you have to remember the power-brakes MUST be functional. They work good with the existing cam and we want to try the next one up! The larger cam will do 2 services, it'll give more power in the upper band AND kill some low-end Torque where we don't need it with the street tires. The 4000# weight is a benefit with "hooking".

A "key" item to remember here is it runs fine on 93 with all the timing up front, the C.R. as I stated has been knocked back to exactly 10:1. this is NOT a stroker, these units get "pumped-up" for size at the meets.

I have a 402" '70 Nova headed to the dyno this week for the same class racing. A square port head and ALL stock inside pieces. No lightweight parts whatsoever, no "tricks". This one has the stock 242 x.500 cam AND stock rocker arms. Thanks, Gary in N.Y.

P.S. 68chevelle533: Car is automatic with stock convertor and I'm not sure about the tires, but I believe the "rules" for his class must have the identical ones there when the car was delivered new. To the best of my knowledge,
no radials allowed. Strict rules for his class, no MSD's, stock coil, stock wires, stock valve covers, etc.

garhate
Jul 24th, 06, 11:24 AM
hey gosfast, where are you located on long island. i too am on long island thanks gary

kstanbach
Jul 24th, 06, 11:30 AM
are you allowed to put a better torque converter in it? would it hook with a better torque converter?

mr 4 speed
Jul 24th, 06, 11:53 AM
are you allowed to put a better torque converter in it? would it hook with a better torque converter?

...not in that class

Whittaker
Jul 24th, 06, 1:25 PM
A "key" item to remember here is it runs fine on 93 with all the timing up front, the C.R. as I stated has been knocked back to exactly 10:1. this is NOT a stroker, these units get "pumped-up" for size at the meets.




Gary, I have always wondered how they pump these things up at a track? They do this right to check the displacement?

Are they allowed to port the intake, heads, and exhaust manifolds? Would they benifit from extrude (I think this is what its called) honing/porting on the stock exhaust manifolds?

How do they know what is in there for a cam at the track? Could a solid roller be hidden inside one of these beasts?

Pretty impressive for stock tires of what 14" or15" bias plys on a 7" or 8" rim.

artmalibu
Jul 24th, 06, 2:20 PM
That alot faster than stock!! http://www.ls-6.com/1970_chevelle_454_ls6.htm

novadude
Jul 24th, 06, 2:47 PM
Intersting... that AHRA record holder kind of proves that a true STOCK LS-6 - the biggest and baddest muscle car ever - wasn't much faster than a modern chevelle with a steetable warmed over 383 small block. We've come a long way! :)

BillsCamino
Jul 24th, 06, 3:09 PM
Intersting... that AHRA record holder kind of proves that a true STOCK LS-6 - the biggest and baddest muscle car ever - wasn't much faster than a modern chevelle with a steetable warmed over 383 small block. We've come a long way! :)
Exactly what crossed my mind. My bro-in-law's '69 Malibu with a mild 383 runs mid 12.60s.

mr 4 speed
Jul 24th, 06, 3:15 PM
That alot faster than stock!! http://www.ls-6.com/1970_chevelle_454_ls6.htm


Not faster..but quicker,and that's all due to the 60 ft.
If you notice,both the AHRA record holder and the motor Gary built both have basically the same MPH,but the AHRA car certainly wasn't hooking up back in the day..in fact,none of them did.
Pay attention to the MPH,not the ET :) (I don't mean to sound like a jerk)

dreis454
Jul 24th, 06, 3:24 PM
106 is the mph for a mid 12 second car...

Rob G
Jul 24th, 06, 4:49 PM
106 is the mph for a mid 12 second car...
even at 107 its still in the "hooking" up range. my chevelle runs in the area of 105-107 to 12.6-12.4

-SS454-
Jul 24th, 06, 5:04 PM
the F.A.S.T cars are hardly stock at all. 99.9% stock, not quite at all. He hooked up pretty good though.

novadude
Jul 24th, 06, 8:26 PM
Pay attention to the MPH,not the ET

Yessir... I will not argue that one bit. MPH is more indicative of hp / weight ratio. However, 107 was the BEST mph for that record holder. If you snoop around that site, you will see that most runs were in the 103-106 range. I would argue that that is well within the range of a 383 Chevelle w/ good heads and a 270-280 degree hyd cam.

I won't even mention the fact that the 346 ci LS1 routinely hits that MPH (usually better) bone stock. ;) Howver, we all know that the LS6 is a lot more fun to drive, and with bolt-ons, one could easily trap 110+. Point is, STOCK LS6 cars were not that fast compared to todays street cars. :)

Harold Sutton
Jul 24th, 06, 8:29 PM
That alot faster than stock!! http://www.ls-6.com/1970_chevelle_454_ls6.htm That might have been a AHRA record but one of the magazines tested a pure stock LS-6 and got a 13.12 @ 107 or 108 out of it back when they first came out. I saw one run at Fort Smith in 1970 from Muskogee and it ran 12.80 with slicks and headers.

Neal Wright
Jul 25th, 06, 9:27 AM
Fast car for sure! Iím kind of surprised the engine was never set up on a dyno though Ö almost all of those cars are dyno-tuned. That would surely give you an indication of how fast it would run. Itís amazing how fast the cars actually will run, when people realized that a suspension 2feet high and tires sticking out of the wheel well wonít cut it. A complete teardown and blueprint will usually bring a lot more power out, and was pretty much standard fare on any of the factory stock racers of the 60ís. Production assembly really isnít that great, when you look at with a microscope Ö and, one of the reasons Iím in complete awe of the new ĎVette LS7 engines!

Personally, I am really excited about the FAST cars. With the guidelines set in place, I think it will remain a pretty neat/fun class for a while to come Ö unlike the 10.5 rules, that have gotten extremely wild from when they started. I donít participate in either, and still enjoy watching the 10.5 classes Ö they just seem like Pro Stockerís now though.

Couple things, and I donít know much about their rules Ö but, Iím pretty sure theyíll let you run a radial tire. I donít think any track wants a bias-ply out there. Radials have to stay stock dimensions though. A car doesnít have to prove itís an all original LS6 car either Ö just has to run an engine combination that was dealer-optioned that year/model. I am told many of the cars are ďrealĒ though Ö again, I just think itís one of the neatest classes running out there.

Not for sure why heís stuck on power brakes though (except for cruising?). If so, I donít know if they would allow a HydroBoost but that would eliminate the problem Ö manual brakes really are not as bad as people make out, and in some ways a lot nicer. The 93 octane is definitely a winner though, especially with a true 10:1 and iron heads I assume. Much more fun that staying within a 60 mile radius of the closest TurboBlue station you know of!

mr 4 speed
Jul 25th, 06, 9:53 AM
You can run radials as long as they are the stock dimensions
http://www.musclecardrags.com/

Harold Sutton
Jul 25th, 06, 10:40 AM
Fast car for sure! Iím kind of surprised the engine was never set up on a dyno though Ö almost all of those cars are dyno-tuned. That would surely give you an indication of how fast it would run. Itís amazing how fast the cars actually will run, when people realized that a suspension 2feet high and tires sticking out of the wheel well wonít cut it. A complete teardown and blueprint will usually bring a lot more power out, and was pretty much standard fare on any of the factory stock racers of the 60ís. Production assembly really isnít that great, when you look at with a microscope Ö and, one of the reasons Iím in complete awe of the new ĎVette LS7 engines!

Personally, I am really excited about the FAST cars. With the guidelines set in place, I think it will remain a pretty neat/fun class for a while to come Ö unlike the 10.5 rules, that have gotten extremely wild from when they started. I donít participate in either, and still enjoy watching the 10.5 classes Ö they just seem like Pro Stockerís now though.

Couple things, and I donít know much about their rules Ö but, Iím pretty sure theyíll let you run a radial tire. I donít think any track wants a bias-ply out there. Radials have to stay stock dimensions though. A car doesnít have to prove itís an all original LS6 car either Ö just has to run an engine combination that was dealer-optioned that year/model. I am told many of the cars are ďrealĒ though Ö again, I just think itís one of the neatest classes running out there.

Not for sure why heís stuck on power brakes though (except for cruising?). If so, I donít know if they would allow a HydroBoost but that would eliminate the problem Ö manual brakes really are not as bad as people make out, and in some ways a lot nicer. The 93 octane is definitely a winner though, especially with a true 10:1 and iron heads I assume. Much more fun that staying within a 60 mile radius of the closest TurboBlue station you know of! There are two different classes in the F.A.S.T. racing series that i know of, the pure stock one, and the Factory Appearing Stock Tire one and yes they do require the stock type bias ply tires. Contrary to what you may think a bias ply glass belted tire is very safe, unlike many of the steel belted radials which heat up and seperate the belts. I had a friend that tried to drive about 90 MPH with early steel belted radials and wound up sitting beside the road after the third blowout in thirty miles. (he had two spares when he started). They even went back to bias ply tires after having several blowouts on Hiway Patrol cars using steel belted radials around here. They have finally fixed the tread separation problems but they were big trouble in their early days. The FAST cars all use reproduction polyglas bias ply tires which i have had to well over 140 MPH back when i was "young and dumb" without ever having one tire failure.

Whittaker
Jul 25th, 06, 10:52 AM
Is the surface or tread compound the same on bias ply and radials?

One of my first cars was a $75.00 Pontiac 2 door Catalina, the 74-75 vintage. I can't remeber if it had hei or not.

It proudly displayed a little dash emblem that proclaimed "Radial Tuned Suspension." Which I assume meant it came with radial tires and was built with that in mind.

For some reason with that Poncho would really burn the bias plys that my dad had laying around. Not as much using the worn out radials. I remember pushing that car as fast as it would go with blown shocks bad tires and wet pavement. Definitely had a higher power looking out for us that day.

So radials I'm assuming here don't give as much as a bias ply tire might. Like the wrinkle on slicks. Less support in the sidewall of the tire or is that a misconception?

Also do repro-bias tires have better tread patterns than the ones made in 70?

Hi-po SS 454
Jul 25th, 06, 11:38 AM
hey gosfast, where are you located on long island. i too am on long island thanks gary
Gary will not tell, but I still LIKE his Threads and Post's and help.

LevonH
Aug 11th, 06, 12:03 PM
I know these LS-6's will make power!. I have an Over the counter 10.25 Comp one that propels my 73 Camaro to 11.00's We will bet it in the 10's.
The only non stock parts are the carb(Holley 830)/headers. I don't push this thing because it is the spare motor for my 70.

Not bad for 3200 lbs :-)

Whittaker
Aug 11th, 06, 1:52 PM
SO it seems like on the LS-6 the rectangular heads are not hurting it much down low. With those et.s on stock or even on slicks they seem to do well.

Were the LS-6 heads open or closed chambers?

LevonH
Aug 11th, 06, 2:01 PM
My LS-6 is the open chamber version with the tall intake. 6100RPM is all it spins:hurray: .

mr 4 speed
Aug 11th, 06, 2:37 PM
Were the LS-6 heads open or closed chambers?

1970 LS6 came with closed chamber heads
1971 LS6 came with open chamber aluminum heads (1971 Corvette only)
All LS6 crate motors came with open chamber cast iron heads

JLerum
Aug 12th, 06, 12:20 PM
Intersting... that AHRA record holder kind of proves that a true STOCK LS-6 - the biggest and baddest muscle car ever - wasn't much faster than a modern chevelle with a steetable warmed over 383 small block. We've come a long way! :)


I think you have an apples to oranges comparision. I don't know of the 383's that are being put together that have to get throught emissions with the government. Just the castings now days are much more of a quality peice from the foundry. Yes, technology has gotten better and just so many more choices for that right combination. No doubt in my mind that cars that made power in the 60's and early 70's put together under todays quality control would have gone considerably faster yet.

Carburation from the factory was jetted for all seasons and driving senarios. If you live in Denver at 5600ft or sea level the tune was compairable. Fuel injection gives you the right measure no matter where you drive. Set them up right (carbs) and it works............................

Jim

71malibu406
Aug 12th, 06, 11:21 PM
I think you have an apples to oranges comparision. I don't know of the 383's that are being put together that have to get throught emissions with the government. Just the castings now days are much more of a quality peice from the foundry. Yes, technology has gotten better and just so many more choices for that right combination. No doubt in my mind that cars that made power in the 60's and early 70's put together under todays quality control would have gone considerably faster yet.

Carburation from the factory was jetted for all seasons and driving senarios. If you live in Denver at 5600ft or sea level the tune was compairable. Fuel injection gives you the right measure no matter where you drive. Set them up right (carbs) and it works............................

Jim
as far as all out dragrace performance i'd just as soon have the carb, especially if i am building from scratch, it's just so much cheaper. one other thing is that back in '70 there weren't the emissions requirements that there are today and fuel was way better back then too. imagine what the new cars could do if they had no emissions components and there was 100 octane fuel at the pump.;)

Harold Sutton
Aug 12th, 06, 11:29 PM
My LS-6 is the open chamber version with the tall intake. 6100RPM is all it spins:hurray: . The original '70, LS-6 was a closed chambered motor. In 1971 G.M. lowered the compression and the '71 motor is open chambered and was derated to 425 H.P. All '70 and later motors had the low rise manifolds to clear the lower hoods. Obviously the taller manifolds will fit also but they didn't come from the factory that way.

LevonH
Aug 13th, 06, 12:56 AM
I agree. Mine is the over the counter version from the late 70's.

Harold Sutton
Aug 13th, 06, 10:07 AM
The high rise manifold from the earlier cars when added to a '70 - 454 would add 20 H.P. with the same carburetor. My old '67 ran 107.7 on a reasonably cool day at Tulsa but due to the fact that no traction could be had it only ran an E.T. of 14.21. On real cool nights with a concrete surface it was a full second quicker. Over in Arkansas at an old concrete strip it ran 11.6 across a distance of 1120 ft. I think that would be somewhere in the vicinity of 12.90 to 13.10. A S/S Camaro with lots of gear went 9.96 on that same day and was the fastest car there. On concrete the car's starting line RPM could be raised to 3500 and then just let the clutch out quickly. It lit the tires but was moving real good too and edged out a 435 H.P. 'Vette. It easily downed two different street Hemi cars on seperate occasions.

427L88
Aug 13th, 06, 11:10 PM
I think the F.A.S.T. racing is neat. We should accept a less rigid definition of "stock" and not quibble about it.The rules are quite stringent.


"ANYONE USING NITROUS OXIDE WILL BE BANNED FROM PARTICIPATING FOR LIFE!"

:)