Author Topic: factory appearing stock tire drag racing  (Read 10509 times)

Offline 69 stingray

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factory appearing stock tire drag racing
« on: September 25, 2012, 09:45:29 PM »
hi, new here and i have some questions, i have a 1969 corvette coupe originally a 427ci 390hp L-36 automatic car non power brakes, and non air conditioning. i was wondering if a correct numbered qjet carb. can be modified to work on a 520ci engine to run low 10's high 9's? i will have to use the correct intake manifold and correct cast iron exhaust manifolds and cylinder heads as far as casting numbers go, and we have to run a full 2 1/2 exhaust and stock tires. no power adder, no traction devices, and gas only, i wanted to use the L-88 engine parts (intake,carb. and heads since they are designed for higher rpm hp) and my goal is to run low 10's high nines. is this even possible? for the F.A.S.T. rules you can visit the F.A.S.T. website... i have seen a 69 L-88 corvette go 10.30's @ 130 in the FAST drags. so far they have 2 guys in the high nines dave dudak hemi and lane carey 71 mustang. thanks for any help  :)

Offline Cliff Ruggles

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Re: factory appearing stock tire drag racing
« Reply #1 on: September 26, 2012, 04:36:52 AM »
Yes, we built the carburetors that power Rick Mahoney's 68 FB's in both FAST and Stock. 

The early Chevy carb will work fine, needs some help as they are the smaller CFM models.  For FAST there are no limitations as to what we can do with them, just has to be "politically" correct for the application.

I have a few Super Stock cars in the mid 9's with those carbs (legal), so they are capable of keeping up with great power......Cliff

Offline 69 stingray

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Re: factory appearing stock tire drag racing
« Reply #2 on: September 26, 2012, 08:15:52 AM »
hi cliff thanks for the quick reply, i think it would be so cool to run in the low 10's high nines with a quadrajet carb. because alot of people just wouldn't believe it. i just bought this car and it needs alot of work and a chassis replacement which i'm in the process of changing, my donor car is a 73 corvette automatic small block car, no rust on the frame at all. the current engine in the 69 is a 76 454 with an E4M carb. the motor i'll build for FAST is a dart block 4.5 std. bore, 4in. stroke 4340 crank, comp. cams #288-CR-8 mech. roller .714 lift, 254/262 duration @ 0.050 good torque, rpm range is 3,200-6,200. i don't have this cam yet but just one i'm looking at, maybe someone has a better idea? i want to build this right the first time. thanks for any help.... cliff do you have any older carbs. that will be "politically" correct for my application?

Offline Cliff Ruggles

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Re: factory appearing stock tire drag racing
« Reply #3 on: September 27, 2012, 03:45:46 AM »
I may have one big block 69 carb left in the inventory, but pretty sure it's the 7029200 for the low perf big block with auto trans.  Not sure how specific they want it to be for FAST?  Any carb from 69-74 would work equally as well, as they are all the same basic castings.

The biggest obstacle to running really quick with a q-jet is not the carburetor, it's the fuel delivery system.  Having only one needle/seat assembly you simply have to take steps to keep the bowl full on hard runs.  Getting the carb to do it's deal is easy.

My 455 cid powered "daily driver" runs low 11's with ease, stock intake, q-jet, HEI, 10" converter and 3.42 gears.  Full quiet exhaust on DOT's, pump gas only.  Here's a clip of a run year in August.  Even at near 4000' DA I have to retard the timing to 26 degrees, add weight, and shift at 5000rpm's to stay roll bar legal:


http://www.youtube.com/watch?v=6zVdoLR-VzM&feature=plcp

....Cliff

Offline 69 stingray

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Re: factory appearing stock tire drag racing
« Reply #4 on: October 01, 2012, 10:40:07 PM »
hi cliff, i think you can change from different year carbs. as long as the cfm's are the same, nice video too! how small of a float can you use to help keep more fuel in the bowl? and are all the bowls the same size? i really need to contact the board members for F.A.S.T. so i know exactly what i can run. thanks cliff for your time and help and i'll be getting back here often  :)

Offline Cliff Ruggles

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Re: factory appearing stock tire drag racing
« Reply #5 on: October 02, 2012, 03:51:13 AM »
The 69 and later carbs will take a smaller float.  It really doesn't help.  The key is to improve fuel delivery to keep the carb full at all times.  Pretty easy for FAST, much harder for Stock.....Cliff

Offline 69 stingray

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Re: factory appearing stock tire drag racing
« Reply #6 on: October 03, 2012, 08:07:36 AM »
i see, i need a fuel pump, fuel pump lines, and fuel inlet needle and seat big enough to meet the demands of my engine. any idea what cfm carb. came on my 427/390hp engine?

Offline von

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Re: factory appearing stock tire drag racing
« Reply #7 on: October 04, 2012, 04:02:02 AM »
69 Stingray I think you have to use a factory block in FAST. In the late 70's and early 80's I had a '69 Vette 390 hp 427 automatic I built into an NHRA B/SA class racer. I ran it as the 400 hp tri-power version. It ran a best of 11.28 in 1982. Won a couple class wallys and briefly held the 1/8 mile record. Sammy Pizzolato has it now. I used a 1/2" fuel line from tank to carb with elect pump at the back and a dummy (gutted) mech pump. It had no fuel pressure or volume problem. I'm not sure if you can change the fuel line diameter in FAST.

Offline 69 stingray

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Re: factory appearing stock tire drag racing
« Reply #8 on: October 06, 2012, 04:27:57 PM »
hi von, thanks for the reply. yes you can change the fuel line diameter and run the electric fuel pump as long as it's hidden and appears stock. did you run the3931063 cast iron heads? i think pure stock you have to use the OEM block but in F.A.S.T. you can use an aftermarket block but not with siamesed cylinders and cubic inch limit is 560 unless you have a 429/460 BB ford which is 604 ci limit. 11.28 is very good what was the m.p.h.? i just picked up the aluminum Q-jet intake #3947801 for my engine, i have a 512 casting engine block but i really don't want to use it for racing since they are getting expensive to replace. please send me any and all information i need to get my car competitive, thanks again...

Offline Cliff Ruggles

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Re: factory appearing stock tire drag racing
« Reply #9 on: October 07, 2012, 02:11:43 AM »
Pretty sure that aftermarket blocks are not allowed in FAST.

Just got an email yesterday from my good friend and customer Jay Delaigle.  His 74 Pontiac Firebird is pictured on our website.

It's a legal FAST class car, using crappy Pontiac 4X heads, EGR iron intake, Q-jet, and "log" exhaust manifolds.

He went 10.89 @ 125mph yesterday.

The must run on 7" wide bias ply tires.....just amazing.

My contribution to the project are the carburetor, distributor, and transmission......Cliff

Offline von

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Re: factory appearing stock tire drag racing
« Reply #10 on: October 07, 2012, 03:14:15 AM »
69 stingray, yes I used the 063 oval port heads (had to). You have a PM. Cliff, 10.89 is very good in FAST for that car. Do you do anything to the race Q jets to increase bowl capacity (like use some of the adjacent cavities for fuel storage)? Any tricks other than what's in your book?

Offline 69 stingray

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Re: factory appearing stock tire drag racing
« Reply #11 on: October 07, 2012, 09:36:37 AM »
very impressive cliff! thanks for the pm von  :) i'll keep you posted on my project...

Offline Cliff Ruggles

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Re: factory appearing stock tire drag racing
« Reply #12 on: October 09, 2012, 05:57:15 AM »
Complete waste of time/funds to increase bowl capacity.  Set the carb and fuel system up so it stays full on hard runs instead.....Cliff

Offline 69 stingray

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Re: factory appearing stock tire drag racing
« Reply #13 on: February 17, 2013, 08:50:27 PM »
well i got a quadrajet for my 427 ci 390hp automatic, my car was built around mid to late september of 1969, so some 69 corvette's had parts for the 1970 model as well. this is the carb. i bought.... ( This is a rare 1970 Chevrolet big block quadrajet carb number 7040200 EE dated 2039...roughly its about July 22nd of 1969 for 1970 production...the number on the carb shows 40200 EE 2039...omitting the "70" prefix which is sometimes how they numbered them..really nice carb..came off a running engine but I would give it a simple rebuild to freshen it up )...... is it a carter? and what's a fair price for this carb? thanks for any help.... i also have been getting parts to build a L-88 clone engine for F.A.S.T. i found some 074 aluminum heads which need work, a real deal #3955205 holley 850cfm double pumper carb, new aluminum water pump # 3975928, and a new reproduction intake #3933198, new chrome valve covers/oil cap/breather hose, and a older used corvette distributor which will be upgraded. i can use a dart block as long as it's Not a tall deck. what do you think about a big bore short stroke engine? maybe a 477 ci?

Offline 69 stingray

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Re: factory appearing stock tire drag racing
« Reply #14 on: February 17, 2013, 09:04:29 PM »
i also called your shop and put my name on the waiting list  ;D