Please Help with my Weber Jetting!!!!

tonyt · #1 (**permalink**) 12-28-2001, 11:34 PM

OK, ford 392 crate motor, 16 degrees initial timing, 18 advance for 34 total. 55 idle jets, 80 idle jet holder, 165 mains, 140 air corrector, 40 mm venturies.
Idles well, pulls clean and strong from 1k up to about 3800-4000, then starts to run poorly (almost like a miss) through 4500, and wont pull past 5k. Anyone have any ideas?

Denis Bouchard · #2 (**permalink**) 12-29-2001, 06:29 AM

G'Day tonyt,

I'm sure you're probably already aware, but the article at

http://www.inglese.com/tech.htm

offers insight into a variety of performance-related Weber gremlins.

By the way, very 'purdy' system.

Good luck with the fix.....Denis

cobrajeff · #3 (**permalink**) 12-29-2001, 07:21 AM

Tony -

SWEET looking set-up! Is that an Accusump forward of your expansion tank?

You're CHOKIN' your carbs for air! Two things - I think your air correctors should be more like 185 or 195; and you're losing probably 25-30 ponies thru the air cleaners.

My engine runs so poorly with air cleaners on, I don't use them. I believe that if you want to run the air cleaners, the carbs should be jetted and tuned to run with them, otherwise, it runs too fat and loads up.

There are lots of guys here that know more about them than me, but, I think you'd be headed in the right direction by upping your air correctors. Good luck!

regards,
cobrajeff

tonyt · #4 (**permalink**) 12-29-2001, 09:17 AM

Thanks for the input guys... Ill try larger air correctors and see what happens, I have some 180's laying around.. What about air cleaners? I s there anything that can be run without choking the engine down?
That is an accusump mounted on the crossbar, the superformance cars have an ideal location for them, but my oil pressure has always seemed a little low with this engine ~30 at idle, 45-50 from 2k up. Does this seem normal?

Thanks...

Cal Metal · #5 (**permalink**) 12-29-2001, 07:15 PM

Move your air correctors up to 200. The idle holder should, optimally, be around 65/70 with a 120 holder. Make sure the etubes are F 7s. The problem is with the air cleaners, I think, because a loss at top end would be due to a too lean (higher) air corrector. 140s are pretty rich. I think you are losing all your power because of the CFM demand when you approach the higher r's and the air cleaners are restricting air flow.