Most powerful stock Vette
Race Director
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Hmmmmm, none ever sold? In 1974, I bought a M.Maroon, 1970 Coupe. It had a soild lifter BB with alloy heads and intake, with Holley carb and transitor ignition. Also had the THM-400 tranny with 3:08 posi. This car was purchased from E.B.Smith Chevrolet in Nashville, and I was told it was Mr. Smiths' son's car. Had about 17k miles on it. It was totally stock and looked as if there had never been a bolt turned on it. I was told that it was an LS7, and the air cleaner had a 454/465HP sticker on it. It had the A.I.R. pump, ps, pb, even a/c. I installed a set of Hooker headers, a 4:10 gear, and slicks, and the car ran 7:40's at Union Hill, 1/8 mile track near Nashville. When Jimmy Carters' distorted gas crisis hit in the late 70's, I was newly wedded, and traded it in on a '78 'Datsun' 280Z. I'm such a fool!!!! NOW, the wife wants to find it and re-buy it back, as that's the car we went on our honeymoon in. HA, if I could find it, I know I couldn't afford it, unless it's a pos.
Racer
Joined: Apr 2006
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Rotary boy is merely a disgruntled misfit who is unrelenting in his desire to convince everyone that a ZL1 is a 13 second 1/4 mile car. For whatever reason, it pains him immensely that an L88 might have as much or more power than the new Z06 motor. This does not make sense to me, since he does not have a Z06, instead plopping around in a ricer.
Thread Starter
Pro
Joined: Nov 2004
Posts: 575
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From: Nice Lake Ontario
Turbo wrote "You don't like the 13 and 14 second articles? The 13 and 14 second 1/4's tell you those motors aren't making big hp #'s you guys want to claim.
I watched the Speed channel this morning and a 427 Copo Camaro with headers and tweaking could only run 13's. "
And that may well be true but he must be seriously confused
if he thinks a Copo 427 which uses a standard production 427 BB is anywhere close to the same Hp motor specs as a L-88, ZL-1 or an over the counter 70s LS-7 
Wonderful read EuroRod ...Thank-you
I watched the Speed channel this morning and a 427 Copo Camaro with headers and tweaking could only run 13's. "
And that may well be true but he must be seriously confused
if he thinks a Copo 427 which uses a standard production 427 BB is anywhere close to the same Hp motor specs as a L-88, ZL-1 or an over the counter 70s LS-7 Wonderful read EuroRod ...Thank-you
Le Mans Master
Joined: Oct 2001
Posts: 6,798
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From: Pine Bluff Arkansas
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-‘19-'20-'21
Originally Posted by RHD '68 L89
Sorry Barry,
Todays ratings are NOT taken at the rear wheels, they are taken on an engine dyno with all accesories and pollution equipment fitted. If they were taken at the rear wheels then the transmission and diff would have to be taken into account as well. They are SAE NET measurements taken at the flywheel. It is still more power that the 60's ratings which were no accessories and open exhaust.
Todays ratings are NOT taken at the rear wheels, they are taken on an engine dyno with all accesories and pollution equipment fitted. If they were taken at the rear wheels then the transmission and diff would have to be taken into account as well. They are SAE NET measurements taken at the flywheel. It is still more power that the 60's ratings which were no accessories and open exhaust.
Larry
Team Owner
Joined: Sep 2000
Posts: 46,788
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From: Va. Beach Va.
Originally Posted by Chuck Harmon
Mr. Turbo Rotary is all wet!
My L88 engine was bought over the counter at Spedding Chevrolet in Denver Colorado. The factory pistons, rods, cam, heads, valves, springs, etc. were all used. I found a numbers correct 69 L88 intake manifold that was absolutely unmodified. Neither the runners in the factory open chamber aluminum heads nor the manifold were ported or polished. I did uses steel wool and some emory cloth to hand polish the chambers to keep carbon from sticking to them as easily. Anyone who thinks this mod would even make 5 more hp is probably getting their stuff from JC Whitney along with magnets on fuel lines, tornado air vanes for intake, etc.
I did purchase a new 4150 mechanical carb before I heard about Holley’s factory rebuild option, if it even existed at the time. I ran the carb as it came from the box other than using the same jetting numbers as my manual said the L88's used.
I disassembled the motor because I noticed a slight scratch on the one of the cylinder walls. One of the rings was broken when the factory installed the piston. I replaced the ring with a new set for that piston and made sure that all the others were OK before I re-assembled the motor using my Chilton's manual for torque specs and clearances. For the record I taught Smokey Yunick and Grumpy Jenkins everything they know in my two car garage.
My tuning consisted of a timing gun and the seat of my pants before my dyno session. I used 36 degrees total advance by 3000 rpm as the factory suggests and filled the car with 100 octane fuel sold at a local 76 station down the road. The price then was about $4.25 per gallon when regular was about $1.50 per gallon.
The only difference between my cars specs and one coming down the assembly line in St. Louis was that mine had the factory design off road headers similar to the Kustom Headers supplied to Chevrolet as an over the counter option in ’69 and/or delivered with the car in the trunk to be installed at the dealership. Kustom is no more, but Hooker has a set that is the same 2.125” primary tubes into 4” collectors. Any new owner of a L88 that didn’t immediately install headers would have been looked upon as crazy. Open headers was what the car was designed for with the factory cam. All 69 Vettes, big block and small had 2” exhaust pipes. For the L88, this was like a sprinter breathing in through his mouth but only being allowed to exhale through his nose.
My motivation for this project was to personally experience what was to me a legend, not just build a big hp motor which would have been much easier to do. When I started this project, chassis dynos were quite rare. But once it was finally finished, I took the car to the Speed Merchant in San Jose where they use a DynaPak chassis dyno. As it happened, there was another guy who also had a blue 69 L88 that was a factory original with 4.56 gears and the Kustom factory headers. His engine had been rebuilt using all factory spec parts and the ZL1 cam which has slightly higher lift and was thought to be used on some of the L88 engines in 69 as this was the latest cam for the new open chamber heads. Guys ordering this car would have been knowledgeable of the latest and greatest of the factory performance parts. This was a time when the factory was the source for the best parts, the aftermarket really hadn’t taken off yet. Anyway, his car had a slight miss at high rpm and only made about 475rwhp without mufflers. Mine did not miss and made 483rwhp without mufflers. What I was also very pleased with was that with the JCL muffler inserts I still made 477rwhp and the car was much quieter.
The new LS7 engines are incredible, but from the factory they are making about 450rwhp. With headers they are making about the same as my L88 which is pretty amazing on two counts. One that such incredible power levels are back once again. I for one never thought that we would see them again. Number two, that such power can be made and still get 26 mpg on the highway and idle all day at 800rpm. Horsepower is really pretty easy to make. Gas mileage together with smog requirements are not.
With simple mods, the new LS7 is well into the mid 500’s at the rear wheels. With simple mods, so would the L88. Head porting, modern roller cam, modern intake or FI would have easily added over 100hp. The biggest difference today is in tire technology. Old tires couldn’t begin to put all the power an L88 had down to the ground. Tires are a pretty simple thing to change, but if you insist that the L88 had to have the skinny bias belts, the L88 will lose. But that is like claiming a modern skier is better because he can beat a 1968 Olympic Ski champ because the old champ can’t use new skis. Let the new ZO6 run with headers and the best tires, likewise the L88.That would be a real test.
I recently put a new 402 LS2 with AFR225 heads along with a modest cam and headers in my 2002 ZO6. The car now has phenomenal power. I made 481rwhp on the same model DynaPak dyno at Synergy Motorsports. My original LS6, rated at 405net only made 350rwhp. The car now has virtually the same feel as my much lamented L88. In more than a small way I fell like I have my L88 back, but with air conditioning, power steering, cruise control, cd stereo, power windows, incredible handling & braking, etc. But my L88 was not as streetable as my new 402. But if I didn’t live with city driving, the L88 was a fine package for the open road.
I don’t know what Mr. Turbo’s agenda is. I leave that for others to decide. I don’t really care. To anyone else who is interested, I just explained what I had done and why. I have owned 5 Vettes and numerous other high performance cars. I satisfied my desire to experience what the L88’s were like to drive. I don’t consider it any difference in performance to create an L88 clone vs. one built as an L88 from the factory. If you do, fine; but, the very close numbers made by a factory car dynoing with mine show this to be not very realistic. But then some may believe that the guy with the factory L88 was a liar and rebuilt his car with extra special pieces. Convincing such doubting Thomases is not worth my time.
Chuck
My L88 engine was bought over the counter at Spedding Chevrolet in Denver Colorado. The factory pistons, rods, cam, heads, valves, springs, etc. were all used. I found a numbers correct 69 L88 intake manifold that was absolutely unmodified. Neither the runners in the factory open chamber aluminum heads nor the manifold were ported or polished. I did uses steel wool and some emory cloth to hand polish the chambers to keep carbon from sticking to them as easily. Anyone who thinks this mod would even make 5 more hp is probably getting their stuff from JC Whitney along with magnets on fuel lines, tornado air vanes for intake, etc.
I did purchase a new 4150 mechanical carb before I heard about Holley’s factory rebuild option, if it even existed at the time. I ran the carb as it came from the box other than using the same jetting numbers as my manual said the L88's used.
I disassembled the motor because I noticed a slight scratch on the one of the cylinder walls. One of the rings was broken when the factory installed the piston. I replaced the ring with a new set for that piston and made sure that all the others were OK before I re-assembled the motor using my Chilton's manual for torque specs and clearances. For the record I taught Smokey Yunick and Grumpy Jenkins everything they know in my two car garage.
My tuning consisted of a timing gun and the seat of my pants before my dyno session. I used 36 degrees total advance by 3000 rpm as the factory suggests and filled the car with 100 octane fuel sold at a local 76 station down the road. The price then was about $4.25 per gallon when regular was about $1.50 per gallon.
The only difference between my cars specs and one coming down the assembly line in St. Louis was that mine had the factory design off road headers similar to the Kustom Headers supplied to Chevrolet as an over the counter option in ’69 and/or delivered with the car in the trunk to be installed at the dealership. Kustom is no more, but Hooker has a set that is the same 2.125” primary tubes into 4” collectors. Any new owner of a L88 that didn’t immediately install headers would have been looked upon as crazy. Open headers was what the car was designed for with the factory cam. All 69 Vettes, big block and small had 2” exhaust pipes. For the L88, this was like a sprinter breathing in through his mouth but only being allowed to exhale through his nose.
My motivation for this project was to personally experience what was to me a legend, not just build a big hp motor which would have been much easier to do. When I started this project, chassis dynos were quite rare. But once it was finally finished, I took the car to the Speed Merchant in San Jose where they use a DynaPak chassis dyno. As it happened, there was another guy who also had a blue 69 L88 that was a factory original with 4.56 gears and the Kustom factory headers. His engine had been rebuilt using all factory spec parts and the ZL1 cam which has slightly higher lift and was thought to be used on some of the L88 engines in 69 as this was the latest cam for the new open chamber heads. Guys ordering this car would have been knowledgeable of the latest and greatest of the factory performance parts. This was a time when the factory was the source for the best parts, the aftermarket really hadn’t taken off yet. Anyway, his car had a slight miss at high rpm and only made about 475rwhp without mufflers. Mine did not miss and made 483rwhp without mufflers. What I was also very pleased with was that with the JCL muffler inserts I still made 477rwhp and the car was much quieter.
The new LS7 engines are incredible, but from the factory they are making about 450rwhp. With headers they are making about the same as my L88 which is pretty amazing on two counts. One that such incredible power levels are back once again. I for one never thought that we would see them again. Number two, that such power can be made and still get 26 mpg on the highway and idle all day at 800rpm. Horsepower is really pretty easy to make. Gas mileage together with smog requirements are not.
With simple mods, the new LS7 is well into the mid 500’s at the rear wheels. With simple mods, so would the L88. Head porting, modern roller cam, modern intake or FI would have easily added over 100hp. The biggest difference today is in tire technology. Old tires couldn’t begin to put all the power an L88 had down to the ground. Tires are a pretty simple thing to change, but if you insist that the L88 had to have the skinny bias belts, the L88 will lose. But that is like claiming a modern skier is better because he can beat a 1968 Olympic Ski champ because the old champ can’t use new skis. Let the new ZO6 run with headers and the best tires, likewise the L88.That would be a real test.
I recently put a new 402 LS2 with AFR225 heads along with a modest cam and headers in my 2002 ZO6. The car now has phenomenal power. I made 481rwhp on the same model DynaPak dyno at Synergy Motorsports. My original LS6, rated at 405net only made 350rwhp. The car now has virtually the same feel as my much lamented L88. In more than a small way I fell like I have my L88 back, but with air conditioning, power steering, cruise control, cd stereo, power windows, incredible handling & braking, etc. But my L88 was not as streetable as my new 402. But if I didn’t live with city driving, the L88 was a fine package for the open road.
I don’t know what Mr. Turbo’s agenda is. I leave that for others to decide. I don’t really care. To anyone else who is interested, I just explained what I had done and why. I have owned 5 Vettes and numerous other high performance cars. I satisfied my desire to experience what the L88’s were like to drive. I don’t consider it any difference in performance to create an L88 clone vs. one built as an L88 from the factory. If you do, fine; but, the very close numbers made by a factory car dynoing with mine show this to be not very realistic. But then some may believe that the guy with the factory L88 was a liar and rebuilt his car with extra special pieces. Convincing such doubting Thomases is not worth my time.
Chuck
We went round and round with this before.
1) Your car was not an original L-88, period.
I posted an ORIGNAL ZL-1 DYNO, ORIGINAL and it even had some mods. You guys all run from that why is that?
2) Post pictures of the heads, they were polished, I saw them. You used "steel wool and "emory cloth" to keep carbon from sticking to them?
You just admitted they weren't stock.
3) The engine had a "scratched bore"? What did you do about that? Must have bored/honed it?
4) TRW pistons were original factory?
5) Headers aren't STOCK. Especially AFTERMARKET ones. The car came with IRON MANIFOLDS and you could purchase headers from GM.Not street legal from the factory. That's TWO MODS you have stated.
6) You made 411 RWHP even with polished heads, tweaking and some aftermarket heads with iron manifolds.
7) The tire argument is bs Chuck and you know it. The cars have been tested over and over since 1969 with new tires and guess what? No 10 second slips.
You have the corvette magazine with the L-88 s 427 side oiler cobra. POST IT!
The L-88 with a 4:56 rear gear, Open headers and exhaust with SLICKS ran mid 12's at 114!
BTW: I can't really get mad at Chuck because of his politics!
Last edited by Mr turbo rotary; May 28, 2006 at 01:11 PM.
Team Owner
Joined: Jul 2002
Posts: 37,053
Likes: 69
From: This city NEVER sleeps! Frank's back yard!
Originally Posted by 84rzv500r
This is all very interesting....
But can that ZO6 drive throught the wheel spinner/fart muffler part of town and set of car alarms idling down the street in 4th.
My wimpy 502 can through mufflers.... It's great fun.
But can that ZO6 drive throught the wheel spinner/fart muffler part of town and set of car alarms idling down the street in 4th.
My wimpy 502 can through mufflers.... It's great fun.
Funny! My buddys Cadillac CTS-V with the B+B exhaust does this! Not exclusive to big blocks afterall.
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Joined: Jul 2002
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From: This city NEVER sleeps! Frank's back yard!
Originally Posted by EuroRod
Hmmmmm, none ever sold? In 1974, I bought a M.Maroon, 1970 Coupe. It had a soild lifter BB with alloy heads and intake, with Holley carb and transitor ignition. Also had the THM-400 tranny with 3:08 posi. This car was purchased from E.B.Smith Chevrolet in Nashville, and I was told it was Mr. Smiths' son's car. Had about 17k miles on it. It was totally stock and looked as if there had never been a bolt turned on it. I was told that it was an LS7, and the air cleaner had a 454/465HP sticker on it. It had the A.I.R. pump, ps, pb, even a/c. I installed a set of Hooker headers, a 4:10 gear, and slicks, and the car ran 7:40's at Union Hill, 1/8 mile track near Nashville. When Jimmy Carters' distorted gas crisis hit in the late 70's, I was newly wedded, and traded it in on a '78 'Datsun' 280Z. I'm such a fool!!!! NOW, the wife wants to find it and re-buy it back, as that's the car we went on our honeymoon in. HA, if I could find it, I know I couldn't afford it, unless it's a pos.
That is an LS6 my friend! My cousin had one too -and they are SUPER rare!!! You should have kept it -worth big bucks today!
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
Originally Posted by sxr6
Originally Posted by sxr6
Ironcross is that Black 62 yours too
Now I'm really envious
Checked the pics out!
But are you happy???
Never mind I can guess
Ironcross is that Black 62 yours too
Now I'm really envious
Checked the pics out!
But are you happy???
Never mind I can guess
Heres one I left out but since the discussion has centered to the engine in a Vette. My answer is this 68 that I parked when the Jews kicked the Arabs in 1973 and the gas went crazy with only 28086 miles on the meter. An yes, it has and contains a real "IT" 427 L88. For those who think a late model can get by it are definately wrong and have never driven or felt this raw HP. They are strictly awsome for a single 4 bore engine including in this classification only the 427 ZL1 and the 454 LS7 as almost identical HP except for weight. This Vettes only problem was not with other hot rods, but the fact it only gets 7 MPG and couldn`t pass a gas station.
I see this as the ONLY advantage a 2007 505HP ZO6 could ever have besides cold air. Basically a new Vette is not on the same page as far as HP 
Team Owner
Joined: Sep 2000
Posts: 46,788
Likes: 37
From: Va. Beach Va.
Originally Posted by mandm1200
I think he should go back to the Rotary Forum and stay there with his BS.
What are you going to tell the other vette drivers here who know better and disagree with you to leave? Facts are facts no matter who states them. Interesting concept.
Team Owner
Joined: Sep 2000
Posts: 46,788
Likes: 37
From: Va. Beach Va.
Originally Posted by Bismarck
Rotary boy is merely a disgruntled misfit who is unrelenting in his desire to convince everyone that a ZL1 is a 13 second 1/4 mile car. For whatever reason, it pains him immensely that an L88 might have as much or more power than the new Z06 motor. This does not make sense to me, since he does not have a Z06, instead plopping around in a ricer.
I'm sure you have both an original L-88 and a new Z06 right? Brilliant logic.
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Thought some might be interested in seeing my ZO6's new 402 dyno run. Pretty amazing for 11:1 compression on 91 octane! Using the same loss ratio as my LS6 motor (350rwhp vs 405 sae net) this puts the SAE net somewhere around 556hp. Gross would surely be close to 600, just about where many of the old chassis dyno's showed the L88 to be. The torque of the new motor is quite a bit better though. The roller cam really makes a difference. My regret is that I never made a dyno run after I installed the solid roller in my L88. It sure did smooth it out though. For streetability and even road racing where pulling from loower revs out of a corner is important this is a huge advantage over the old L88. For drag racing where the ehgine never drops below 5000rpm once the car leaves the line, not as much difference, but there is a difference.
.
Anyway, to address some of rotaries points:
1) Neither the runners in the heads or intake were polished
2) The factory pistons, possibly TRW which was a supplier to Chevrolet, supplied with the factory engine were used. A ball hone with an electric drill took care of the minor scratches. There were no magic or special techniques used in the assembly of the motor.
3) The 411 rwhp quoted was an disappointing earlier dyno session. The post mortem revealed that the throttle cable bracket had slipped and was only getting about 3/4 throttle. The engine had peaked at approximately 5000rpm, extremely low for a long duration L88 cam.
4) As for magazines with published times, there are certainly interesting, but hardly conclusive proof of a car's potential. Are you suggesting that just because you climbed into a top fuel dragster and ran it down the quarter mile, this is what I should believe is the best it could do. More likely, you would be pulled from charred wreckage.
The article you attempt to use against me that I placed on the forum is also a good example of this. The owner of the car made much faster times, in the high 11's, when he drove. His friend's times were considerably slower. It is convenient for you to quote the slower times but dismiss the faster ones. This does not strike me as very forthcoming or honorable on your part.
5) Regarding 10 second times, I am not aware of any 10 second postings with street tires for the new ZO6 either, so what is your point?
To accuse someone of lying is a very serious act. Mr. T. Rotary has essentially accused me of this. Any knowledgeable and very fortunate owner of other extraordinary performance cars such as a solid lifter 426 Hemi or Boss 429 sohc knows what I say is true. Headers and tires were essential to getting the power to the pavement. If others are so certain that the engines were grossly overrated and that this wouldn't make much difference, they shouldn't mind running against such old tech with such modest concessions. Saying that I can run a foot race with you but I can wear cleats and you can't would not be a very impressive victory.
It is a shame Mr. TR and I have not had the chance to meet face to face. He is probably not bottom dwelling specimen I sometimes visualize him to be. But then again...
Chuck
By the way, please remember what this weekend is all about. It is not just another 3 day weekend!
Thread Starter
Pro
Joined: Nov 2004
Posts: 575
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From: Nice Lake Ontario
Couple reads from the early-mid 70s "Chevrolet" car book for you Turbo.
"So, when we talk about L-88 performance, we have to qualify things, Chev engineers were cagey when they rated the L-88, quoting 430 hp gross--but at only 5,200rpm, which was well down on the power curve. The engineers admit that the engine would not even develop 430hp at the clutch when installed in the car WITH the street exhaust system. Just to much restriction & the cam wasn't designed to work like this. True output was more like 400hp on the street, which was very little better than a standard high-performance 427.
And the performance with headers & open exhaust was something else again. Chevrolet engineers said the dyno output would jump to 560hp a 6,400rpm as soon as you took of the cast iron manifolds & mufflers. That's a gain of 150hp!
From latter in the same book.
"While at the General Motors Proving Grounds for the 1969 & 1970 new car presentations, we were fortunate enough to both ride in & drive a ZL-1 engined Corvettes. One was a 3000-lb road-race type model with four speed & 3.70 cogs. We were able to pick up 115 mph / 12 sec time slips after a few trial blasts. A 70 Vette with 4.88 gears & a highly reworked Turbo-Hydro shifter consistantly ran under 11 seconds for the quarter-mile trek."
This same mag also rated the ZL-1 Camaro as a 420 net hp thru the stock exhaust, revealing times in the mid 13's @113. They also noted the ZL-1 motor suffered the same "just won't run" thru stock exhaust!
Just in case turbo understands cam basics here's the L-88 cam specs as quoted " the L-88 featured the first true racing camshaft developed for the BB engine, 337* & 340* duration for intake & exhaust with corresponding lifts of .540 & .560. The cam was designed primarily for the range from 5,500 to 7,000 rpm.
& the motor was rated 430 hp @ 4,400rpm
"So, when we talk about L-88 performance, we have to qualify things, Chev engineers were cagey when they rated the L-88, quoting 430 hp gross--but at only 5,200rpm, which was well down on the power curve. The engineers admit that the engine would not even develop 430hp at the clutch when installed in the car WITH the street exhaust system. Just to much restriction & the cam wasn't designed to work like this. True output was more like 400hp on the street, which was very little better than a standard high-performance 427.
And the performance with headers & open exhaust was something else again. Chevrolet engineers said the dyno output would jump to 560hp a 6,400rpm as soon as you took of the cast iron manifolds & mufflers. That's a gain of 150hp!
From latter in the same book.
"While at the General Motors Proving Grounds for the 1969 & 1970 new car presentations, we were fortunate enough to both ride in & drive a ZL-1 engined Corvettes. One was a 3000-lb road-race type model with four speed & 3.70 cogs. We were able to pick up 115 mph / 12 sec time slips after a few trial blasts. A 70 Vette with 4.88 gears & a highly reworked Turbo-Hydro shifter consistantly ran under 11 seconds for the quarter-mile trek."
This same mag also rated the ZL-1 Camaro as a 420 net hp thru the stock exhaust, revealing times in the mid 13's @113. They also noted the ZL-1 motor suffered the same "just won't run" thru stock exhaust!
Just in case turbo understands cam basics here's the L-88 cam specs as quoted " the L-88 featured the first true racing camshaft developed for the BB engine, 337* & 340* duration for intake & exhaust with corresponding lifts of .540 & .560. The cam was designed primarily for the range from 5,500 to 7,000 rpm.
& the motor was rated 430 hp @ 4,400rpm
Drifting
Joined: Sep 2004
Posts: 1,959
Likes: 1
From: North Bend Ohio
I don't know what this would equate to in horse power but Jimmy Johnston's 69 L88 ran an 11.62 last year. His car has been certified Pure Stock, meaning the engine has been opened up and measured and there is no porting allowed and it must run stock specs on the camshaft. That is plenty quick considering this car rides on G70 street tires. Here is a link.
http://www.fastraces.org/members/fas...nu-items/ghp24
Look at the second article, Car Craft Nov. 2005.
BigBlockk
Later.....
http://www.fastraces.org/members/fas...nu-items/ghp24
Look at the second article, Car Craft Nov. 2005.
BigBlockk
Later.....
Team Owner
Joined: Sep 2000
Posts: 46,788
Likes: 37
From: Va. Beach Va.
Originally Posted by Chuck Harmon
Dyno sheet 483 rwhp
Originally Posted by Chuck Harmon
Thought some might be interested in seeing my ZO6's new 402 dyno run. Pretty amazing for 11:1 compression on 91 octane! Using the same loss ratio as my LS6 motor (350rwhp vs 405 sae net) this puts the SAE net somewhere around 556hp. Gross would surely be close to 600, just about where many of the old chassis dyno's showed the L88 to be.
http://members.***.net/harddrivin1le/ZL1DYNOTEST.JPG
It made less hp than an 02-04 Z06 engine.
Originally Posted by Chuck Harmon
1) Neither the runners in the heads or intake were polished
Originally Posted by CHUCK
"I did uses steel wool and some emory cloth to hand polish the chambers"
Originally Posted by Chuck Harmon
2) The factory pistons, possibly TRW which was a supplier to Chevrolet, supplied with the factory engine were used. A ball hone with an electric drill took care of the minor scratches. There were no magic or special techniques used in the assembly of the motor.
Originally Posted by Chuck Harmon
3) The 411 hp quoted was an disappointing earlier dyno session. The post mortem revealed that the throttle cable bracket had slipped and was only getting about 3/4 throttle. The engine had peaked at approximately 5000rpm, extremely low for a long duration L88 cam.
Originally Posted by Chuck Harmon
4) As for magazines with published times, there are certainly interesting, but hardly conclusive proof of a car's potential. Are you suggesting that just because you climbed into a top fuel dragster and ran it down the quarter mile, this is what I should believe is the best it could do. More likely, you would be pulled from charred wreckage.
The car was a modified L-88 with gears, full race exhaust and SLICKS. Not even a stock example.
Originally Posted by Chuck Harmon
The article you attempt to use against me that I placed on the forum is also a good example of this. The owner of the car made much faster times, in the high 11's, when he drove. His friend's times were considerably slower. It is convenient for you to quote the slower times but dismiss the faster ones. This does not strike me as very forthcoming or honorable on your part.
Originally Posted by Chuck Harmon
5) Regarding 10 second times, I am not aware of any 10 second postings with street tires for the new ZO6 either, so what is your point?
Originally Posted by Chuck Harmon
To accuse someone of lying is a very serious act. Mr. T. Rotary has essentially accused me of this.
I did notice you have no problem telling me I am not "forthcoming" and "dishonest" though?
Originally Posted by Chuck Harmon
Any knowledgeable and very fortunate owner of other extraordinary performance cars such as a solid lifter 426 Hemi or Boss 429 sohc knows what I say is true. Headers and tires were essential to getting the power to the pavement. If others are so certain that the engines were grossly overrated and that this wouldn't make much difference, they shouldn't mind running against such old tech with such modest concessions. Saying that I can run a foot race with you but I can wear cleats and you can't would not be a very impressive victory.
Originally Posted by Chuck Harmon
It is a shame Mr. TR and I have not had the chance to meet face to face. He is probably not bottom dwelling specimen I sometimes visualize him to be. But then again.
Last edited by Mr turbo rotary; May 28, 2006 at 06:26 PM.
Team Owner
Joined: Sep 2000
Posts: 46,788
Likes: 37
From: Va. Beach Va.
Originally Posted by sxr6
Couple reads from the early-mid 70s "Chevrolet" car book for you Turbo.
"So, when we talk about L-88 performance, we have to qualify things, Chev engineers were cagey when they rated the L-88, quoting 430 hp gross--but at only 5,200rpm, which was well down on the power curve. The engineers admit that the engine would not even develop 430hp at the clutch when installed in the car WITH the street exhaust system. Just to much restriction & the cam wasn't designed to work like this. True output was more like 400hp on the street, which was very little better than a standard high-performance 427.
And the performance with headers & open exhaust was something else again. Chevrolet engineers said the dyno output would jump to 560hp a 6,400rpm as soon as you took of the cast iron manifolds & mufflers. That's a gain of 150hp!
From latter in the same book.
"While at the General Motors Proving Grounds for the 1969 & 1970 new car presentations, we were fortunate enough to both ride in & drive a ZL-1 engined Corvettes. One was a 3000-lb road-race type model with four speed & 3.70 cogs. We were able to pick up 115 mph / 12 sec time slips after a few trial blasts. A 70 Vette with 4.88 gears & a highly reworked Turbo-Hydro shifter consistantly ran under 11 seconds for the quarter-mile trek."
This same mag also rated the ZL-1 Camaro as a 420 net hp thru the stock exhaust, revealing times in the mid 13's @113. They also noted the ZL-1 motor suffered the same "just won't run" thru stock exhaust!
Just in case turbo understands cam basics here's the L-88 cam specs as quoted " the L-88 featured the first true racing camshaft developed for the BB engine, 337* & 340* duration for intake & exhaust with corresponding lifts of .540 & .560. The cam was designed primarily for the range from 5,500 to 7,000 rpm.
& the motor was rated 430 hp @ 4,400rpm
"So, when we talk about L-88 performance, we have to qualify things, Chev engineers were cagey when they rated the L-88, quoting 430 hp gross--but at only 5,200rpm, which was well down on the power curve. The engineers admit that the engine would not even develop 430hp at the clutch when installed in the car WITH the street exhaust system. Just to much restriction & the cam wasn't designed to work like this. True output was more like 400hp on the street, which was very little better than a standard high-performance 427.
And the performance with headers & open exhaust was something else again. Chevrolet engineers said the dyno output would jump to 560hp a 6,400rpm as soon as you took of the cast iron manifolds & mufflers. That's a gain of 150hp!
From latter in the same book.
"While at the General Motors Proving Grounds for the 1969 & 1970 new car presentations, we were fortunate enough to both ride in & drive a ZL-1 engined Corvettes. One was a 3000-lb road-race type model with four speed & 3.70 cogs. We were able to pick up 115 mph / 12 sec time slips after a few trial blasts. A 70 Vette with 4.88 gears & a highly reworked Turbo-Hydro shifter consistantly ran under 11 seconds for the quarter-mile trek."
This same mag also rated the ZL-1 Camaro as a 420 net hp thru the stock exhaust, revealing times in the mid 13's @113. They also noted the ZL-1 motor suffered the same "just won't run" thru stock exhaust!
Just in case turbo understands cam basics here's the L-88 cam specs as quoted " the L-88 featured the first true racing camshaft developed for the BB engine, 337* & 340* duration for intake & exhaust with corresponding lifts of .540 & .560. The cam was designed primarily for the range from 5,500 to 7,000 rpm.
& the motor was rated 430 hp @ 4,400rpm
I would suggest you read about gross hp ratings here's an article.
Team Owner
Joined: Sep 2000
Posts: 46,788
Likes: 37
From: Va. Beach Va.
How about this?
An ORIGNAL, NOT CLONED, Original L-88 owner. He also owns a new Z06.
http://forums.corvetteforum.com/show...4&postcount=13
"My Z06 will dust it"
An ORIGNAL, NOT CLONED, Original L-88 owner. He also owns a new Z06.
http://forums.corvetteforum.com/show...4&postcount=13
Originally Posted by Everett Ogilvie
I owned both (still own my Z06). Had one of the most well-known '69 L88 convertibles in the country. It recently sold for one quarter of a million dollars. It was a frame off restoration by the best L88 expert in the country. It had completely original parts throughout the engine, in exact original configuration. I ran 108 leaded racing fuel. It had 4.11 gears.
My Z06 will dust it.
My Z06 will dust it.
Last edited by Mr turbo rotary; May 28, 2006 at 06:42 PM.
Team Owner
Joined: Sep 2000
Posts: 46,788
Likes: 37
From: Va. Beach Va.
Originally Posted by BigBlockk
I don't know what this would equate to in horse power but Jimmy Johnston's 69 L88 ran an 11.62 last year. His car has been certified Pure Stock, meaning the engine has been opened up and measured and there is no porting allowed and it must run stock specs on the camshaft. That is plenty quick considering this car rides on G70 street tires. Here is a link.
http://www.fastraces.org/members/fas...nu-items/ghp24
Look at the second article, Car Craft Nov. 2005.
BigBlockk
Later.....
http://www.fastraces.org/members/fas...nu-items/ghp24
Look at the second article, Car Craft Nov. 2005.
BigBlockk
Later.....
Tom Clary
Yenko Sportscar Club "