Got my 383 on the ground a couple of weeks ago. First engine build and install, all by myself, EXCEPT for the numerous hours and help recieved from THIRDGEN.ORG. Thankyou! A terrific site.

I should let that statement ride on it's own but instead of cluttering the board I'd like your opinion on my idle vaccum.

Off idle the engine runs just fine. At idle it feels more like a Hot Rod. Not really that bad but far from the comfort of my Riviera.

At about 650-700 RPM with the air screws at 1 1/2 turns I'm seeing no more than 10" of Vaccum. Timing set at 12/33*.

See my Sig. Just looking for your opinion. Does that seem to be in the ballpark? (Seems kind of low to me).

Thanks again,
Bruce



------------------
87 Camaro with 700R4 and 2.73(3.23 posi in the driveway), 383cid, 4-bolt #010, Int. Balanced Eagle crank assembly, 4340 crank and H-Bean 6.0 rods with SRP flat tops.
DART IE 200/72cc heads (10:1 C/R) with Harland Sharp 1.5 full roller rockers and Guide Plates
Comp Cams XE274H (230/236 .487/.490 110LSA 1,800-6,000 RPM).
Edelbrock RPM manifold with Holley 750 (Vac/Electric).
MSD Pro-Billet (Vac) with 6AL box and Blaster2 coil.
Hooker SC LT headers, 3" pipe to Dynomax muffler and 2 1/2" dual outlets.
My best guess (Dyno 2000) is about 400HP and 430TQ??

 

i'd say it's "kinda" low too, but not that odd for a preformance cam/engine. you can tune the carb and timing by making the adjustments while watching a vacumn gauge and go for the highest readings.

------------------
ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

I'd say that vacuum sounds pretty reasonable for a 650-700 rpm idle speed. If it runs 'OK' enough for you like that and you have the carb tuned well so it isn't loading up the plugs you will prolly just make it with power brakes.
If you have problems you could always bring the idle speed up 1-200 rpms.

 

I'm not sure if you have enough initial timing for all those goodies. I'd try about 15 and play with it.

Bear Tracks