Running on the Dyno with my LS6 on Friday
 

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I am taking the car to a local dyno shop on Friday to "see what she can do." Never been on a dyno or in a dyno shop. I am also not an accomplished wrench. What's going to happen and what can I do to make the most of this experience? Your thoughts are appreciated. I am going to video the dyno runs, and may post the files as I'll be using a digital camcorder.

Re: Running on the Dyno with my LS6 on Friday
 

What's gonna happen? It's gonna be LOUD! Seriously, this is one of the coolest things I've ever done. There is a LOT to be learned from spending time on the dyno, so take your time, and ask lots of questions.

So, you gonna pull it through exhaust manifolds or headers?

Re: Running on the Dyno with my LS6 on Friday
 

[ QUOTE ]
What's gonna happen? It's gonna be LOUD! Seriously, this is one of the coolest things I've ever done. There is a LOT to be learned from spending time on the dyno, so take your time, and ask lots of questions.

So, you gonna pull it through exhaust manifolds or headers?

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Manifolds and mufflers, as that's how I drive the car and that's how it's set up...totally stock. I positively can't wait.

[img]/ubbthreads/images/graemlins/burnout.gif[/img]

Re: Running on the Dyno with my LS6 on Friday
 

It would be great to do one dyno pull through open headers on the LS6 just to feel the raw power and know what your motor really can do......looking forward to your results....... [img]/ubbthreads/images/graemlins/beers.gif[/img]

Re: Running on the Dyno with my LS6 on Friday
 

mmcporter,
Give your drivetrain the once over under the car make sure there is no excessive play anywhere--and just smile for the camera. [img]/ubbthreads/images/graemlins/grin.gif[/img]

Re: Running on the Dyno with my LS6 on Friday
 

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mmcporter,
Give your drivetrain the once over under the car make sure there is no excessive play anywhere--and just smile for the camera. [img]/ubbthreads/images/graemlins/grin.gif[/img]

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Thanks Joe...everything's dry and tight under there...

Re: Running on the Dyno with my LS6 on Friday
 

Manifolds and mufflers, as that's how I drive the car and that's how it's set up...totally stock. I positively can't wait.

There are others out here that are VERY interested in your numbers!!! [img]/ubbthreads/images/graemlins/naughty.gif[/img] [img]/ubbthreads/images/graemlins/naughty.gif[/img]

[img]/ubbthreads/images/graemlins/burnout.gif[/img]

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Re: Running on the Dyno with my LS6 on Friday
 

I just read an old article from a '71 hot cars I believe,where they dyno tested a bone stock '70 ls6, 220 hp/450 lb torque at the rear wheels, after a dist recurve, new intake, 850 dbl pumper and headers they got 370 at the rear wheels and over 600 ft lbs of tq, I'll dig the article out and give your more info if you guys want?

Re: Running on the Dyno with my LS6 on Friday
 

[ QUOTE ]
Manifolds and mufflers, as that's how I drive the car and that's how it's set up...totally stock. I positively can't wait.

There are others out here that are VERY interested in your numbers!!! [img]/ubbthreads/images/graemlins/naughty.gif[/img] [img]/ubbthreads/images/graemlins/naughty.gif[/img]

[img]/ubbthreads/images/graemlins/burnout.gif[/img]

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Thanks Dennis. I am purchasing one hour of Dyno Time [img]/ubbthreads/images/graemlins/shocked.gif[/img] which should be fun and informative. Luckily I just got a digital camcorder, so I will be able to document the runs for posterity. I'll scan the sheets and post the results...hopefully it will do the LS6 community proud!! [img]/ubbthreads/images/graemlins/flag.gif[/img]

Re: Running on the Dyno with my LS6 on Friday
 

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after a dist recurve, new intake, 850 dbl pumper and headers they got 370 at the rear wheels and over 600 ft lbs of tq,

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We know these things like to breathe and that running them through stock intake and exhaust systems equates to having a restrictor plate at both ends. BUT.........they're still FUN! [img]/ubbthreads/images/graemlins/burnout.gif[/img] [img]/ubbthreads/images/graemlins/grin.gif[/img]

Can't wait to see your results.

Re: Running on the Dyno with my LS6 on Friday
 

The LS-6 for my Chevelle bettered the factory 450hp mark through the manifolds (an engine dyno), and I believe Muscle Car Review dynoed one and it did the same. And, you wouldn't believe what Dan Jensen's Pure Stock LS-6 is doing...

Re: Running on the Dyno with my LS6 on Friday
 

Rob,

I've seen Dan's car and read the numbers but just how close is he to "Pure Stock"? I've always suspected he rides the fence between "Pure Stock" and "Stock Appearing". I know he plays with Dist. curves, etc. and carb tuning, and that's acceptable. Just wondered what else goes on under that hood. Still.........pretty impressive! And much better than what I could do.

Dennis

Re: Running on the Dyno with my LS6 on Friday
 

[ QUOTE ]
Rob,

I've seen Dan's car and read the numbers but just how close is he to "Pure Stock"? I've always suspected he rides the fence between "Pure Stock" and "Stock Appearing". I know he plays with Dist. curves, etc. and carb tuning, and that's acceptable. Just wondered what else goes on under that hood. Still.........pretty impressive! And much better than what I could do.

Dennis

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It would be interesting to know what he has for valves, valve springs, cam, lifters, etc. They are all little things but they do add up to a radically different picture. Just look at the killer "L89" Nova run by the Brewers from Georgia. 12's on polyglass with a Turbo 400 tranny. Stock? Ummm errrr....not really...stock appearing? Yes.

Re: Running on the Dyno with my LS6 on Friday
 

I tell ya, there's a lot to be said for sweating the little stuff, but Dan's stuff is for sure "Pure Stock". His LS-6 is nothing trick by normal racing standards, just a "blue printed" LS-6...much like the L-72 we're putting together. When you blue print these big blocks to factory specs, you put 'em up in the 12:1 neighborhood compression-wise, which really seems to wake them up. But the key to the whole deal is the cam...and I don't mean a trick grind. Just the stock GM cam, but retarded. What people don't relize is the stock cams are ground 6 degrees advances...good for bottom end power, but makes it a booger to launch on skinny tires. Also, in a "from the factory" engine there isn't enough compression to work "well" with the cam. I've seen 9.8-10.2 compression ratios on stock L-72s! That was the norm, not the "11:1" advertised ratio we'd all like to believe we have. So, when you retard the cam, you basically put it back to "straight up", which kills a little bit of the bottom end (better for launches), but more importantly puts the IVC right where it needs to be with the higher compression (12:1) of the blue printed engine. Simple stuff, but it makes HUGE gains!

(Note: to read more about the IVC & compression, do a search on "comression mapping" on this forum. Some good info posted there.)

Re: Running on the Dyno with my LS6 on Friday
 

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Just look at the killer "L89" Nova run by the Brewers from Georgia. 12's on polyglass with a Turbo 400 tranny. Stock? Ummm errrr....not really...stock appearing? Yes.

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If you liked Brewers Nova, you just gotta see what Terry Penningtons Orange 69 ZL-1 clone (S/A) does on white lettered Polys. How about 11.30's ! [img]/ubbthreads/images/graemlins/3gears.gif[/img]

Re: Running on the Dyno with my LS6 on Friday
 

I was admittedly one of the ones who said "no way" when Brewer was dropping low-mid 12s on people. Heck, I ran Phil in my first Pure Stock event ever and he dropped a 12.5 on me. I immediately said "no way", as I was running a 427 Camaro and was only running low 13s...of course, I didn't know jack squat about tuning a car, but I figured since I had a 427 and he had a 396 that I should be able to take him. O'contrare mon frere! Granted, he had his engine set back and was admittedly "stock appearing", but my eyes have since been opened, if only a wee bit.

So, we built an engine the way Tonowanda would have back in '69, with the specs way off of what was advertised, just to see what would happen. Well, I've since gone 12.7s@108 with it...if I could hook it, it's got .6s in it, no doubt in my mind. And mind you, this is with 10.2:1 compression, the stock cam put in as original (not retarded), and a heavy automatic Camaro (3700 with me in the seat). That particular engine put up 425+ on the dyno through the manifolds, and I feel better about the timing/jetting I have now than when it spun up the dyno. We basically did it to see if it was possible, and it is, and then some. Pete tried to tell us, but we're Missourians, so you gotta "Show-Me" it can happen.

A lot of what works on your typical "race engine" won't work for what we (Pure Stock guys) do. We're running stock manifolds and 2.5" pipes, so big flow numbers only hurt us because we can't get rid of it. And since we're running the stock cam, heavy duty springs only hurt the cam and add unneeded friction. That's why cam timing and distributor timing are so crucial...we try to sacrifice the bottom end just so we can get rolling and bring it back in on the big end. It's definitely a different mind set, and most engine builders can't comprehend it...I know mine sure has a hard time!

Pete has gone 12.0s in his Pure Stock ZL-1 Camaro, and I watched him put that thing back together at the Certified Stock tech, and you'd be amazed at how tame that engine is. And like John said, Terry's car is a freakin' animal!

Re: Running on the Dyno with my LS6 on Friday
 

I found the article that I was refering to.... It's from Super Street Cars Feb '71. At 1st the bone stock LS-6 owned then by Eddie Fitzpatrick, showed 220 hp at 4800 rpm at the rear wheels and 460 lbs of tq. After removing the smog equipment,installing headers, aftermarket intake, 850 dbl pumper with carb spacer, .080 jets all of the way around,ACR43T plugs gapped at .035 and a distributor curve the engine showed 310 rear wheel power and 700 ft lbs of tq at an engine speed of 6000 rpm.They then put in .082 jets all of the way around and got 350 hp and 720 ft lbs of tq.Lastly they closed the headers and put on the air cleaner and got 290 hp and 670 ft lbs of tq!!! With 7" slicks and open headers it ran a 12.51 at 111 mph. ALSO, concerning the dyno test in muscle car review,they had headers on that mill and had to play with the timing a lot and it had an after market cam to get the numbers that they got.Expecting 450 plus hp out of a STOCK ls-6 is wishful thinking.Dont get me wrong, I'm not knocking the ls6, I have 1, but the hype about their power, amongst other things, has caused part prices to balloon out of this world!!!

Re: Running on the Dyno with my LS6 on Friday
 

I picked up a 1970 Chevrolet engine Dyno test booklet.
It shows the ACTUAL RPM/Horse Power ratings for all the 1970 Engines.Graphic charts and tech. notes,etc.
The LS6 engine shows it making a Max. of 446HP.
I don't remember the RPM range at that percise moment,but I can look it up if anyone is interested.
Good book,I just had to have.

Re: Running on the Dyno with my LS6 on Friday
 

4800? That's seems awfully low to me. I'm thinking my LS-6 peaked around 5300-5500, while my L-72 peaked at 5800...both of these numbers are through exhaust manifolds. (Edit: I found my dyno sheet and the LS-6 peaked at 5400.)

That dyno test in MCR has always bothered me, because a the square port BBCs should ALWAYS be able to equal their displacement in horsepower, even through manifolds. My LS-6 and L-72 did, as have Pete and JJ's engines. And Moparts can vouch for my L-72, as he walked me through building it...there's nothing trick about that thing! Not that we couldn't, but we didn't. I see no reason an LS-6 shouldn't be over the 450hp mark through manifolds (on an engine dyno of course). That would be 1hp per cube, which is pretty conservative. An interesting side note is that Jensen is running his full smog setup and dated wires on his LS-6.

Rick: I've heard you speak of this book before, but have NEVER seen one! I'd love any info you'd care to share.

Re: Running on the Dyno with my LS6 on Friday
 

I can honestly say that I've seen Dan's cylinder heads before they were put on the motor. Nothing but a very good valve job. Dans car is like alot of the cars that go really quick at the Pure Stock Drags........attention to details. I asked Dan what his leak down was on his car and he gets 1 to 2% on all 8 cylinders. The cam is stock from GM. He retarded it 5 degrees because that is all the timing chain would allow. He wanted 1 more degree out of it but couldn't. The motor is 12:1 compression and idles like a pussy cat!

JIM [img]/ubbthreads/images/graemlins/flag.gif[/img]

Re: Running on the Dyno with my LS6 on Friday
 

I was hoping you'd stop by! I tried to get my heads done at the same place, but never could get it set up...plus, getting them to Michigan and back would have been a chore.

I know it's hard for people to understand, especially when you see all these magazine articles hyping this and that. Unfortunately I think a lot of the articles are just "info-mercials". It doesn't take voo-doo to get a BBC running through stock (read: unported) manifolds to get 1hp per cube. Heck, if I can do it, I know it can't be THAT hard!

So, Jim, got that LS-6 squared away? Find out what wiped out the cam?

Re: Running on the Dyno with my LS6 on Friday
 

Their are so many lessons to be learned from my motor build up and it makes me cry. lesson number...............


1. Don't take your motor to someone that doesn't believe what you do even if they are a well known machine shop.

2. Don't take their word it is done the way you want when they have a different falocify.

3. Make sure you go to someone that understands the events you run. Because as stated the shop doesn't beleive for a second that you can run low 12's with a blue printed motor on Wide Ovals at 3800lbs.

I waited 9 months to have someone set me up with 148lbs of seat pressure on a cam that requires 120 and refussed to setup a cam retarded unbenounced to me. The list goes on. After over pressuring these people to get the job done and $1500.00 later I'm the looser. FASTIMES MOTOR works did me s**t work.

The motor on a dyno(not FASTIMES) pulled 420hp@4900RPM and 518 ft/lbs@3600RPM. After some pulls it was obvious the moter was loosing power and high oil temps made us stop. The leak down was 15-20% and the exhaust lobs on #7 and #8 were going down.

After disassemly the cam was 6 degrees advanced 148lbs on the vavle springs. (max spring pressure for non single spring breakin is 130lbs). Their is more but I'm not going to go there. I can not stress lesson #3 enough. The motor should make 470 to 480 HP and around 535lbs of torque to my best estimations. Yes compression is important. It makes big ports work and give strong signals to the induction system.

JIM

Re: Running on the Dyno with my LS6 on Friday
 

Boy, Jim, reading you post made me even more nervous about putting the finishing touches on the L-72! I'm *suppsoed* to pick it up Tuesday...

Re: Running on the Dyno with my LS6 on Friday
 

The only thing that could of gone worse is a rod through the block and the heads getting damaged. If you beleive in your machine shop and no previous problems before I would say you're good to go. Don't look back now!!!!!!!!!

JIM

Re: Running on the Dyno with my LS6 on Friday
 

Is Dan Jensens LS6 the Fathom Blue one that Gilbert Probst restored for Floyd Garret?
I have a Videotape of an Old "My Classic car" segment with Dennis Gage and Dan at the dragstrip running this Chevelle 3X with a Camerman in the backseat to boot!
Pretty impresive times..

Re: Running on the Dyno with my LS6 on Friday
 

Mr70,
Would you share the peak hp @rpm and peak tq @rpm for the 1970 L78? Are these numbers through cast iron manifolds, open exhaust, or??

TIA!
-Sam

Re: Running on the Dyno with my LS6 on Friday
 

Yes, that is Dans car before he did his rebuild. I should say that he has an x-pipe and the long 25 inch DynoMax ultra flow SS mufflers on the car now.

JIM [img]/ubbthreads/images/graemlins/biggthumpup.gif[/img]

Re: Running on the Dyno with my LS6 on Friday
 

I had my LS5 on the Dyno at Superior Engineering in Anaheim, Ca last year. The numbers showed 287.6 peak HP at the rear wheels with 415.7 max torque. The engine is stock (balanced and blueprinted) running stock exhaust manifolds. The only upgrade from stock is 2 1/2 exhaust with Dynomax mufflers. Your LS6 should be better than that in proper tune and condition.

Re: Running on the Dyno with my LS6 on Friday
 

Those numbers are right on where an LS-5 should be, SS4! [img]/ubbthreads/images/graemlins/biggthumpup.gif[/img] That puts it in the 320 NET hp range, or 360 GROSS hp range...right on!

Re: Running on the Dyno with my LS6 on Friday
 

OK it's Saturday now, what did it do?? [img]/ubbthreads/images/graemlins/3gears.gif[/img]

Re: Running on the Dyno with my LS6 on Friday
 

Yeah, inquiring minds want to KNOOOOOOOOOOOOW!!!!

Re: Running on the Dyno with my LS6 on Friday
 

I am curious to!!!

Numbers??

NEW [img]/ubbthreads/images/graemlins/smile.gif[/img]

Re: Running on the Dyno with my LS6 on Friday
 

This is a great thread but we need closure.

Re: Running on the Dyno with my LS6 on Friday
 

What is done to the block when it is "blueprinted"?

Re: Running on the Dyno with my LS6 on Friday
 

I don't think there is a lot to do to the block for blueprinting, I would say align-hone the mains with caps torqued on, make sure the cylinders are round with torque plates bolted on, check the deck for flat and level, check the lifter bores for proper dimension, maybe the height and angle of the distributor boss to the cam gear engagement point? I guess I would expect casting clean-up as well, to remove any sharp edges that can serve as stress risers.
Most of the blue-printing is done on parts that move, I believe.
-Sam

Re: Running on the Dyno with my LS6 on Friday
 

The main thing you're looking for from the block (other than you're normal bore and journal specs) is "deck height", or "piston to deck clearance". I've checked several AMA specs, several tune-up manuals, service manuals, you name it, and Chevrolet has never given a spec for this. My theory is that they had specs for the other components to get the "stacked height" (1/2 stroke+rod length+pin height) and let that determine where your deck height fell. This leaves a pretty wide range from about .010" to .025", below the deck...I'll have to grab my notes to see the actual range. Anyway, this is a pretty crucial spec in determining compression ratio, and is the main reason you won't find a factory engine with it's advertised compression ratio. NHRA allows .008" below deck on the L-71/L-72/L-78/LS-6, and -.008" (above deck) on the L-88/ZL-1. I have always heard the ZL-1 was hand built at the factory and was "blue printed" there (like the W-31 cars), and got the -.008" deck height, but I've never torn into one to see if that's true or not!

Re: Running on the Dyno with my LS6 on Friday
 

Thanks for the interest...we went away for a wedding right after the dyno session...just putting the kids to bed...I'll post the numbers tonight.

Re: Running on the Dyno with my LS6 on Friday
 

Hi sorry for the delay...when one plays at the dyno, one pays later on at home and work. Here are the results for my dyno pulls...keep in mind that the car is totally stock, NO HEAD WORK, original exhaust manifolds and stock-type exhaust and mufflers (no resonators) no balance and blue print, with >75K on the motor. Stock carb, no rejetting or optimization. Car is still running points, not HEI or Pertronix. M22. And I've never been to the dyno before. Temp was 96 degrees with 89% humidity. Not a good day to be running a high performance car.

The sound was incredible, it was just amazing to be doing > 90 MPH standing still. [img]/ubbthreads/images/graemlins/shocked.gif[/img] Here are the results of the runs:

Run#1: 305.8 HP, 374 LB Feet of Torque. [img]/ubbthreads/images/graemlins/no.gif[/img]

Cooldown [img]/ubbthreads/images/graemlins/cool.gif[/img]
Cooldown [img]/ubbthreads/images/graemlins/cool.gif[/img]

Run#2: 355 HP, 433 FT/LB of Torque [img]/ubbthreads/images/graemlins/rolleyes.gif[/img]

Go eat lunch, cool car, drink ice coffee, cool car down some more. [img]/ubbthreads/images/graemlins/cool.gif[/img] [img]/ubbthreads/images/graemlins/beers.gif[/img]

Run #3: 356 HP, 515 Ft/LB of torque [img]/ubbthreads/images/graemlins/biggthumpup.gif[/img]

I am happy with these results for now, although I think the car could have done better. I need to do the following:

1. Balance and blueprint the motor. Clearly there was more there. I gave up the ghost at 5500-5700 RPM, and clearly there was more there. Without going over the motor, I couldn't push any harder.

2. Add Pertronix points. No more points bounce and more consistent results.

3. Add 2.5 inch exhaust with 3 chamber flowmasters. Big difference in torque.

4. Carb work.

5. Maybe a multi-angle valve job. Heads are what really makes power.

6. Go back to the dyno on a dry cool day.

I took digital video of the runs and I will post them at a later date (translation: when I figure out how to manipulate the digital camcorder to the computer).

Thanks to everyone for their interest. The Dyno time was the best $70 I ever spent!!

Re: Running on the Dyno with my LS6 on Friday
 

I agree. [img]/ubbthreads/images/graemlins/biggthumpup.gif[/img] I'd be happy with those numbers from a totally stock set-up. Now you have me wondering.......should I; shouldn't I????

Re: Running on the Dyno with my LS6 on Friday
 

A few thoughts...

First off, those are really good numbers! Has anything been done to the engine? Any idea what cam?

That HP peak sounds about right for an LS-6 through manifolds. Mine peaked at 5400, and somewhere earlier in the thread I think someone posted that's about the neighborhood it's supposed to be in. An L-72 peaks about 300-500 higher due to it's shorter stroke, but doesn't make near the torque the LS-6 does.

As for mufflers, skip the Flowmasters and go with the Dynomax units. I've got the part number around here somewhere, but they make an AWESOME muffler for the A-bodies that will outflow that Flowmaster and will sound TONS better as well. It's what I've run on my L-78 and my LS-6, and is what the majority of the Pure Stock guys run. If I can find it, I've got an unbelievable exhaust test done by the Buick club that raves about this muffler...

You are correct in thinking all the little things (carb, valve job, etc.) will help, as it all adds up. Be careful and get the original type Pertronix unit and not the later model. Trust me, you don't want the newer style.

Again, AWESOME numbers, and I'd love to see what that thing would do on the track!