|
Author
|
Topic: More Carb Adjustment Talk...
|
Ryan Wilke
Gearhead Posts: 2289
From: Stanton, Michigan 49707
Registered: Oct 2000
|
posted 09-20-2004 10:30 AM
   
Morning, Folks: Looking for some advise here -- What are the symptoms of having a carb jetted too low?
I'm thinking mine is jetted too low but it isn't acting badly by coughing & sputtering.... it doesn't do that all. Although it is about .4sec slower in ET and less 4-MPH, it RUNS GREAT down 1/4.... I shift at 6.2K & go thru the eyes at about 5.8K rpms. A review of my combo: 302"+ 030 over; D0OE 351W heads with slight pocket porting & 1.94/1.6" valves; 252*/260*dur & 586"/608" solid cam; Stealth intake; 650DP Holley; to a 4-spd Toploader, 4.56 spool, 9" ET DRAGS; 3320# w/ driver. I realize that the Holley 650DP came OE with 67/76 jets. Earlier this summer when the weather was 20+ degrees warmer, I downsided my jets twice. It's currently at 64/71 jets, #28/#31 squirters & 2.5" power valve. The other night, it had cooled off to 66*F. Yet the car still ran great - no sputter or cough. AR-33 sparkplugs have ALWAYS BEEN clean......... Any thoughts?????
TIA,
Ryan  ------------------
'69 Mach I; 306"; 4-spd; drag racer.
'65 F100 Short box; 390"; 4-spd; Tow Truck.
'85 GT Convert.; last carb'd 5.0L; 5-spd; street cruiser.
'94 Ranger; commuter/parts hauler.
IP: Logged |
BLstangin
Gearhead Posts: 817
From: St. James, MN
Registered: Apr 2002
|
posted 09-20-2004 11:42 AM
Ryan, what does your car run, it is similar to my setup.------------------
1970 coupe restored with the help of my dad. 306 with 600 holley, Weiand Stealth intake, headers, mme custom roller cam, harland sharp roller rockers, kb pistons, 10.3:1 compression ratio, pertonix ignitor 2 with matched coil, lakewood bellhousing, 4-speed toploader, and 2.79 open 8" rear. Soon to be 9" 3.50 trac-lok
1986 f-150, 5.0, factory towing package with original c-6 trans
IP: Logged |
Ryan Wilke
Gearhead Posts: 2289
From: Stanton, Michigan 49707
Registered: Oct 2000
|
posted 09-20-2004 01:15 PM
quote:
Originally posted by BLstangin:
Ryan, what does your car run, it is similar to my setup.
Well - A year ago, on 9" ET STREETs, it's best run was a spinnning 12.99 @ 105.....However, in my attempt to get better traction, I installed some taller (29.5") 9" ET DRAGs. Now it has been running 13.2's - 13.3's without wheelspin.   I still think this combo should be a repeatable 12.8's @ 106 car.... Ryan P.S.
Frame connectors; 5-leaf rear springs; Cal-Tracs in lower hole; Rancho shocks @ #3 setting; 90/10 front shocks.
IP: Logged |
bluestreek
Gearhead Posts: 1724
From: Athens,GA
Registered: Jul 2001
|
posted 09-21-2004 01:47 AM
Mainjet leaness is sometimes hard to feel at WOT. What made you go down in jet size? That's a pretty big cam for a SBF. The carb may need some special tuning to run right with it.
I think you should go back up to stock jets and install new bowl/block gaskets while you at it. Then start from there. Seems like you should be much quicker. What rpm are you leaving at?------------------
1966 Mustang Coupe: Custom glass hood and BIG scoop sits atop a 289 stroked to 331 c.i., Steel crank, rods and girdle, TFS alum. heads, Stealth 8020 intake, Xtreme 268 Solid Roller, Holley 750 HP, long tubes, 4speed, 9" 3.50 posi.
11.86 @ 116 mph (7.62 @ 93 mph)daily driver!
DanH
IP: Logged |
Ryan Wilke
Gearhead Posts: 2289
From: Stanton, Michigan 49707
Registered: Oct 2000
|
posted 09-21-2004 08:38 AM
Thanks for the reply, Bluestreek!  Q#1) I went down in jet sizes because when it was sooo warm here, I figured that my air/fuel ratio needed to adjusted accordingly. My backwoods way of thinking tells me to change jets with every 10 degrees of temperature change - smaller for warmer\bigger for cooler. Q#2) I launch it at 5.7K rpms...... I also agree that the car should be quicker; However, as I mentioned earlier, my main challenge has been getting the car hooked up....so, hence, bigger, stickier rear skins. LAST NIGHT: Well, the weatherdude told me that Wed evening should be 78* cooling to 66* by 9pm......SO - I tore the 650DP apart, cleaned it and installed 70/78 jets and upped the squirters to #35/#37. I then re-installed it, fired it up, checked for leaks, checked/adjusted the float levels and checked the linkage. I'll take the car to the track tomorrow evening for some more TnT. I'm thinking I'll be making more power again & be back to, "Looking for Traction" once again...(not necessarily a bad problem)  . If I'm lucky, I'll be a bit faster than I've been lately; even with the bigger 'shoes'. Any other thoughts?? Thanks!
Ryan P.S.
By-the-way, not long ago I aquired a C90-X intake. Last night I thought about replacing the Stealth with the C90-X, but I didn't want to make too many changes at one time, so I didn't. Actually, I think a Victor Jr intake may also be interesting... 
IP: Logged | |
Mustangsandmore Forums
