Kaikkien LSX projektien joukosta löytyy aina välillä jotain häivähdyksiä vanhoilta hyviltä ajoilta, kun GJ:täkään ei ollut lanseerattukaan.
Kaikki lähtee siitä kaikkein kauneimmasta Corvette korimallista, eli Mid Yearista ja kauneimmasta moottorista mitä mihinkään Corvetteen on koskaan työnnetty. Eli 4twenty7 ja 3x2bbl Tri Power. Perus konsepti on jo niin hilloinen, ettei sitä viitsisi oikein mitenkään pilata, mutta mutta...
Mitäs jos kuitenkin pikkuisen sitä kuutio kapasiteettiä nostettaisiin johonkin... mmm... 542ci korville? Menisikö auto jo ihan munilleen? Ainakaan sitä kaunista kuorrutusta moottorin päällä ei voisi enää käyttää, kun se ei kuulemma toimi vakioissakaan kunnolla.
Olisi naurettavaa edes ajatella, että tollaisesta malmikasasta otettaisiin jokapäiväiseen kruisailuun sopivat 671 takafillarikaakkia, se nyt vaatisi ainakin jo vaikka mitä hot rod ja ralli race osien istuttamista konehuoneeseen? Ja kunnon peltisarjat ja suorat putket?
Siis yli 670hevosen voimaa takapalloilta, orkkis tri powerilla, valusarjoilla ja konehuone ei näytä 90-luvun NasCar moottorilta? Hmmm... Vähän enemmän koneen sielun elämää omistajan kertomana:
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The car is a 1967 Corvette convertible.
All of the runs were made with the factory 1967 tri-power intake manifold, factory cast iron exhaust manifolds, a custom fabricated 3” exhaust system, all accessories connected (including clutch fan), and power steering.
Here are the numbers from the DynoJet:
STD: 671.05 rwhp / 633.45 rwtq
SAE: 652.77 rwhp / 616.20 rwtq
Uncorrected: 671.87 rwhp / 634.23 rwtq
Some of my friends want to know what that equates to in flywheel horsepower. I hear a lot of people talk about 15%-20% for manual transmission cars.
If you take 15% the numbers become the following:
STD: 789.47 flywheel hp / 745.24 flywheel tq
SAE: 767.96 flywheel hp / 724.94 flywheel tq
Uncorrected: 790.43 flywheel hp / 746.15 flywheel tq
If you take 20% the numbers become the following:
STD: 838.81 flywheel hp / 791.81 flywheel tq
SAE: 815.96 flywheel hp / 770.25 flywheel tq
Uncorrected: 839.84 flywheel hp / 792.79 flywheel tq
There are some people on this forum that insist Corvettes eat up well over 20% due to the independent rear axle.
For any purists out there, I am not trying to pass the car off as an original 435 hp 427 Corvette. It is a 327 car pure and simple. I will freely admit this to anyone who asks. The more I thought about trying to make a tri-power setup produce big numbers, the more I wanted the challenge. Making this combination run with factory exhaust manifolds just added to the challenge.
My goal with this combination is to have it appear factory correct under the hood. I also happen to have a 1967 Corvette coupe with a 632" motor that looks nothing like stock under the hood. I wanted to do something different this time. I have taken a great deal of time trying to make things appear stock. Most everything for this conversion was purchased from Paragon Corvette Reproductions.
This car originally came with a 350 hp 327. I put a 383” motor in it around January of 2006. With cast iron exhaust manifolds and 2-1/2” exhaust, that motor made 416.47 rwhp / 430.4 rwtq and went 11.93 at 114.99 mph in the quarter. (BTW, the 383” motor is for sale.)
The gold color you see on the top of the exhaust manifolds are a result of the exhaust manifold paint I purchased from Paragon. I painted the entire exhaust manifold with this product. It starts out gold and then as they heat up they change to a cast iron color. Since the temperature of the exhaust manifold is lower the closer you are to the exhaust flange of the head, the longer it will take to change colors.
The motor consists of the following: Chevrolet Bowtie block, Dart *highly disguised* 335 CNC heads, Jesel valvetrain, Mike Jones solid roller cam, Isky EZX roller lifters and valve springs, BRC crank, Howards I-Beam rods, J&E pistons, Total Seal rings, Clevite 77 bearings, Dan Olson oil pan, Holley fuel pump, and a trio of *SPECIAL* Holley 2-barrel carburetors.
I have made 52 DynoJet runs to get to this point. My first run was on October 20th, 2011 and the final run was on November 20th, 2011. I have tried everything within reason including moving the cam timing 4 separate times. I am not talking about ignition timing here. Anyone who has moved the cam timing on a motor that doesn’t have a belt drive while the motor is in the car can attest to the amount of work it requires. The entire front end of the motor has to come off every time.
The cam specs are 254*/258* @ .050", .701"/.700", 114 LSA. It sounds as close to the stock cam in a 435 hp 427 as myself and a couple of friends can remember. Nothing radical in any way, shape, or form. This thing is shockingly smooth.
I will be running Mickey Thompson DOT radials. Hopefully they will get the job done.
I knew that the stock carburetors weren't going to be enough. The stock end carbs are #3659 and have a 1.75" base plate throttle bore, a 1.375" venturi, a straight leg booster, and a 466 cfm rating. I found that the Chrysler #4365-1 carbs have a 1.75" base plate throttle bore, a 1.57" venturi, a dog leg booster, and a 500 cfm rating. The Chrysler carbs also have a milled down air horn and idle mixture adjustment screws in the baseplate. So I picked up a pair of the 4365-1 carburetors. I modified them by replacing the thick aluminum throttle blades with the thinner steel throttle blades.
I decided to start my testing with the factory #3660 center carb. It has a 1.50" base plate throttle bore, a 1.1875" venturi, a dog leg booster, and a 350 cfm rating.
After a number of dyno runs I felt that I needed even more cfm. I purchased a #4412 500 cfm 2-barrel and machined it on my mill to fit. There is quite a bit of milling that has to be done to make this fit. I also milled down the air horn and machined a pickup point in the venturi for the vacuum signal that activates the end carbs. While it has a 500 cfm rating the base plate throttle bore is 1.6875 and the venturi is 1.375. Definitely larger than the #3660 350 cfm carb but not as large as the #4365-1 500 cfm carbs.
After a few more dyno runs I decided to install button head throttle plate screws on all three carbs and slabbed the throttle shaft on the end carbs.
Finally I enlarged the transition slot on the end carbs to remove most of the lean spot that occurs when they are activated.
Of course I had a number of jet and air bleed changes along the way but I am happy with where everything is at right now. Every time I have done something to increase the cfm of this combination, the horsepower has gone up.
I have not had the exhaust manifolds extrude honed. Just old-fashioned hand porting.
I'm sure I left a bunch of stuff out but this is a start. I have a friend that owns a machine shop that bored, torque plate honed, align-honed, and decked the block to my specifications. He also balanced the rotating assembly. Everything else was done by me. This includes the assembly and necessary massaging of the components in the motor. For instance, since I now have a mill and a lathe, I was able to flycut the pistons and machine my own pushrods. I also made significant modifications to the oil pan and fabricated the 3" exhaust system including making my own 'X' pipe. The exhaust system consists of (2) DynoMax bullet mufflers and (2) DynoMax Ultra Flo oval mufflers run in series.
One last thing. I will be drag racing this car this spring. (Sorry for the long-winded post.)
Steve
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Tietenkin pullistunut ojentaja saa paljon tuhoa aikaiseksi, joten tarvittavia apuja on istutettu hienosti, orkkis teemaan sopivasti auton alle.
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I recently got my 12-bolt differential conversion back from Mike Dyer(tracdogg2). This will be going in my red '67 convertible that I am putting a big block in. I was concerned about the strength of the factory diff so a Tom's was in order. I decided on the 1350 kit because I didn't want to have to cut the fiberglass on this car as you have to do with the 1480 kit that I currently have in my '67 632 car.
Tom recommended the HY-TUFF inner axles and Mike recommended the Billet Flanges.
I went with the following Tom's Differential components:
12V-KIT (12-bolt Corvette Conversion Parts Kit with 4.11 gears)
1350-VAK (1350 Vette Axle Kit with upgrade to HY-TUFF inner axles and Billet Flanges)
C10V-HDRC (H.D. Rear Cover)
Mike supplied his own custom left-side cap. At this point all of the work that Mike has performed is first class. Of course, the real test will be when I take it out to the drag strip.
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Tästä autosta tuli jotenkin niin hyvät vibat, että piti vähän haeskella taas hyviä kuvia kuuseiskoista:
http://forums.corvetteforum.com/c1-a...to-thread.html
Ottakaa rennosti ja nauttikaa itsenäisyyspäivästä!
06.12.2011, 12:39
