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Discussion Starter · #1 ·
After diving off the deep in into a racing project several years ago (and taking the engine out of my street 69 vette and donating it to my race car) I have finally got the 69 back on the road.

The important stuff:

69 corvette (original 4 speed, 427 car)
New engine;
4.310 x 4.25 (496 cu in.) Eagle rods and crank, Ross nitrous pistons, Hellfire rings
Oval port Rpm Air gap with center divider cut out
Ported Edelbrock ovals (330 cfm at .650)
HP 1000
10.75 to 1 compression
Solid roller 255 / 262 at .050 .651 lift on a 112. Isky lifters.

Richmond road race 5 speed with .75 5th gear overdrive.

I also have a Victor Jr intake that I thought about running, but since I am serious (this time LOL) about making this car a 1-2 times a week 35 mile to work communter car (and I want to keep it all under a L-88 hood) I will almost certianly stick with the Air gap. I plan on a chassis dyno run in a few weeks to see what this combination will make at the wheels. Also planning on a couple trips to the track to see what the car will mph (not hoping for any great et's, ran 11.87 at 124 in street trim as a 454 in 2002) but a 125+ trap speed would be cool. Outside chance of a little better than that maybe. I am sure if I really worked on it I could do a little better than that, but this is a driver and I have a dedicated race car. The car has no roll bar.

If you see a bright yellow 69 corvette with stock wheels and a L-88 hood at Fontana or Irwindale that will be me, come say hi.

For you guys that have similar combinations any HP guesses? might this engine make 600 + hp. Tq?

It felt great to take the car out for a test drive this weekend.

John
 

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Hey congrats John, sounds like a fun car....I'll be lookin' for ya.....:thumbsup:
 

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How the hell did you get a Richie RR 5 speed box with .75OD?
 

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Discussion Starter · #4 ·

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Well, learn something new every day. I liked my Richmond box for the ability to shift at 7400 rpm w/o drama.
 

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Congrats, John. Sounds like a really nice car/combo. I would think 600hp/tq would be a done deal with the parts you've put together. Got any pics?
 

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Discussion Starter · #9 ·
Ken, I will see if I can get a few pics.

Todd, arg......I am TRYING to keep this thing a street car. Truthfully; when I was putting the engine together the plan was to mini-backhalf the car, full cage, Jeffco 4 speed, and a LOT of nitrous. I wanted to make it into a mid 8 second street car. I then came to the conclusion that all I was doing was building another race car, so I sold the Jeffco (that was hard to do those things are SWEET) and bought the Richmond. I already had the pistons and rings so I used them. I really want to be able to drive this car and not have to speed a lot of time messing with shifter tower pressure (Jeffco) and all the stuff that would have gone with an 8 second street car......but man would it be cool to dump the clutch on a Jeffco and yank those handles !!
 

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Ya know John, my daily driver 70 Elky became my street-strip beast and my 68 Vette 427 is still just a very fast cruiser. Strange is that I take the Elky EVERYWHERE and the Vette is an occasional driver.
I keep thinking about a trip down the coast in the RatVette but damn-stupid fuel costs bring me back to reality.

The RPM intake clears the L-88 hood no issues



I'm from Carson/Torrance/Gardena long ago mid 70s. :cool:
 

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For you guys that have similar combinations any HP guesses? might this engine make 600 + hp. Tq?

John
John,
Sound like a real nice combo. :thumbsup:

Your combo is very close to mine and mine made 523 rwhp on the first pull with zero tuning. With a little work I think I could squeeze a little more out of it. I'm guessing with a good tune, mine would be in the low-600 to 620 fhp range.
 

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Discussion Starter · #12 ·
Ya know John, my daily driver 70 Elky became my street-strip beast and my 68 Vette 427 is still just a very fast cruiser. Strange is that I take the Elky EVERYWHERE and the Vette is an occasional driver.
I keep thinking about a trip down the coast in the RatVette but damn-stupid fuel costs bring me back to reality.

The RPM intake clears the L-88 hood no issues



I'm from Carson/Torrance/Gardena long ago mid 70s. :cool:
Slap some 69 Stingray badges on that car and it looks just like mine. When I first saw the pic I thought someone saw my car at a car show and posted the pic, took me a sec to realize it was not my car !

Darren,

You are right, combos are very close. I will post up my results......where in the rpm range did yours make max power and tq?. Your heads are a little better than mine and a little more cam, 108 LSA comparred to my 112 might be interesting.
 

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Awesome build! Cool to see another hot rod Vette in here. I bet you break 625hp with that combo, if not more. If you can get that thing to hook at all in 1st gear, you will run 130mph....but you will have to get some use out of 1st/2nd. I am curious to see the chassis dyno results. Are you running the stock clutch fan? If so, there goes 15rwhp. Also if you are running the L88 drop base air cleaner with the small lid and chicken wire, there goes another 7rwhp. Having the hood closed with no air cleaner lid and filter on even kills 5rwhp. Hit me up before you dyno, I will give you some "Vette" dyno data/tricks.

Good luck on the new build. I hope you have plans for an IRS rebuild in the works.....I can get you in touch with the right people for that stuff as well.
 

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Discussion Starter · #14 ·
Awesome build! Cool to see another hot rod Vette in here. I bet you break 625hp with that combo, if not more. If you can get that thing to hook at all in 1st gear, you will run 130mph....but you will have to get some use out of 1st/2nd. I am curious to see the chassis dyno results. Are you running the stock clutch fan? If so, there goes 15rwhp. Also if you are running the L88 drop base air cleaner with the small lid and chicken wire, there goes another 7rwhp. Having the hood closed with no air cleaner lid and filter on even kills 5rwhp. Hit me up before you dyno, I will give you some "Vette" dyno data/tricks.

Good luck on the new build. I hope you have plans for an IRS rebuild in the works.....I can get you in touch with the right people for that stuff as well.
I have electric fans on it, not using the L-88 air cleaner. I am aware of the hood issues, I did a lot of testing with my 454 and the airgap / hood open, closed, etc on a chassis dyno. The L-88 hood is not tall enough to run the Airgap without killing power unless you do some mods to the aircleaner assembly.

I have beefed up IRS stuff, but don't plan on the full Toms set up, etc. The car in its current form will never see slicks or hard launches, so it should live. If I ever decide to race the car more it will get a 9 in.

130 mph would be sweet.

I will post the chassis dyno results.
 

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Darren,

You are right, combos are very close. I will post up my results......where in the rpm range did yours make max power and tq?. Your heads are a little better than mine and a little more cam, 108 LSA comparred to my 112 might be interesting.
John peak HP was around 6100-6200 and only dropped about 15hp by 6500. Peak torque was 502 @ 4600rpm. The torque was very flat from about 4000 to 5200 rpm only varing from the peak +/- about 5 ft/lbs. Not sure if the tighter lsa has anything to do with the flat torque curve or not. I'm in the process of updating the cooling system with a little larger radiator and electric fans. Hopefully (like Alan stated) I'll pick up another 10-15 rwhp.

Also getting ready to install a new T-56 Magnum for a little better interstate driving and a beeier tranny for a little more "spirited driving". :D
 

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Discussion Starter · #17 ·
I would rather run the Vic Jr. but hood clearance will not allow for it unless I chop some off the Vic jr. or have some custom work done on the hood, neither of which I want to do. I hope the mods I made to the air gap will help. If I can make 500+ at the wheels and about the same amount of tq I will be happy.

I will probably replace the solid roller with a newer grind squishy roller down the road aways.
 

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Have been searching for a post where someone took the time to completely remove the plenum divider on an AirGap. Have a rec port here, have debated on doing the same thing and adding a short spacer in combination with opening the plenum.
I would rather run the Vic Jr. but hood clearance will not allow for it unless I chop some off the Vic jr. or have some custom work done on the hood, neither of which I want to do. I hope the mods I made to the air gap will help. If I can make 500+ at the wheels and about the same amount of tq I will be happy.

I will probably replace the solid roller with a newer grind squishy roller down the road aways.

Bryce at Dr. J's Performance performed a full porting on my RPM AirGap.

When I talked to him about my combo, he thought the Vic Jr was a better fit than the dual plane. I told him this was going to be primarily a street car that will be raced once in a while, wanted maximize mid-range torque and be able to hold on in the higher rpm's (6500). After stating that criteria, he thought the AirGap (with his porting) would probably work better than the single plane. Before porting the average port flow was around 320-330cfm, when finished it was just short of 400 cfm (390-something). He left in the divider, but thinned it signicantly. He thought that with his work and the spacer I am running (1 in. open with a 1/2 in. nos plate), this intake would supply enough for my motor to about 6800 rpm. It doesn't appear to drop off much up top so I think his work paid off. :yes:
 

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I just got in a Brodix HV2016 dual plane. Runners are huge, noteably larger than the AirGap rec. Looks like this intake will move some air. Have a Moroso wedge plate here to correct the carb pad angle from flat to a 5* forward tilt, averages to a .625" spacer and sets the carb pad equal to an AirGap rec port. Giving this intake serious consideration.
 

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FWIW....my out of the box RPM air gap supported almost 660hp on two different dynos with a 1" open spacer. On a chassis dyno removing the spacer hurt 7rwhp.....so I figure it's worth about 10-11 crank hp. BUT my engine is only revved to 6000-6100. The way i look at it is HP is HP, doesn't matter where it's made so......the air gap will feed 660hp...(just maybe not at 6500....who knows)

I know it makes some freaking low to midrange power for sure....
 
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