750 does seem like a monster on a 289. doesrunning a double change thingsthat much?im curious what else you got there as well.

 

390 - forged pistons, aftermarket cam, solid lifters, roller rockers, Edelbrock alum.. heads, Edelbrock manifold, Hooker long tube headers with 770 Avenger on top,
soon to be replaced with a 750 double pumper and maybe in the future, a supercharger/engine rebuild,if I can find the right solution.

Jav

 

Carter AFB 600

performer 289 intake

Unknown cam but had a pretty good lope to it.

 

Hello Jav!

Where can you go to romp on that thing? When I think of Japanese streets I imagine the very busy roads barely wide enough to fit a big car like a Mustang! I envision you never being able to get out of first gear! I am sure that stereotyping and cinema have altered my view of realitythough!

 

There are many small streets in Tokyo, hence my change to power rack and pinion. Turning back and forth down small streets soon gets tiring.
But I plan to usethe carmainly in the countryside ( 1hr outside Tokyo ). We have a major selection of highways to speed on. Then there are race
track quality twisty roads though the mountains. Lastly there are the track day at race circuits like Motegi, Fuji Speedway, Suzuka and Tsukuba circuit.
So it not such a bad place to have a mustang. When it is drivenon the road, it attracts a lot of attention. I usually get kids on scooters following me
taking pictures on their phones, and truck drivers starting down at the beast. All good....

Jav

 

67mustang302:
very nice thoughts and facts in your article. Enjoyed reading it.
yes. a lot of points are often overlooked. I keep adjusting on my carb like a madman.
Never changed jets as the carb is a complete rebuild (autolite2100). But I can't see any end in me turning the screws.
Thanks a lot for the info about the HG values on 2barrell/4barrell carbs. at least I understand that now (measured in rating).

I still believe that I need a bigger carb (i know i know), but I'm the one with a 300cfm 2barrell :-)
great throttle response, but I have to switch at 3500 as there's no more power anymore. and unless I know better I'll go for a 4barrell.

I fell in love with those autolites, but even though I might go for a holley instead of their 4100. just because of the price (mass production ....) and I don't feel comfortable with overhauling an old rotten piece (i'll never get that right)

Kalli

 

I've got a Road Demon JR 625 on my 67 289.

Runs Perfectly with:
-280h comp cam
-performer
-headers


[IMG]local://upfiles/67579/816226F77E7C43C298E3B60826C39E51.jpg[/IMG]

 

750 is HUGE on a 289. It'd work well if you turned over 7,000rpm with at least 100% VE though. Double pumpers can help for throttle reponse. The job of the accelertor pump is to provide fuel to cover the dead spot between throttle opening and metering signal coming in. With 2 accelerator pumps and one linked to the secondaries you can greatly fine tune the fuel delivery volume and timing, but you have to know what you're doing. They suck for mileage though if you can't keep your foot out of it.

 

67mustang302,
Very interesting stuff. Would love to pick your brain more. I have a 429 with 10.5:1 and a SCJ cam grind. It has an Edelbrock Performer dual plane intake and a 770 cfm Street Avenger. It seems to run well but the plugs look like it runs rich when I check them. Would this indicate the carb is too large or just needs some tuning?
Craig

 

Jet it down maybe. If anything the carbmay betoo small, the reason it's running rich is it's pulling a stronger signal than it's tuned for, so it's delivering more fuel. Got a picture of the plugs? If they're just a little bit black/sooty you could try jetting it down a tad. But if it runs on pump fuel at 10.5:1 compression a bit rich might be a good safety margin to prevent detonation.

Remember that it's (CID*RPM/2820)*VE to get approx the right CFM needed. 429 is large, and with a good cam and 10.5:1 it's prolly got some decent VE, so depending on what RPM you turn, it might want a larger carb. But again, the tune depends on what fuel you run, cam timing, what the plugs look like etc.