What size jets are you running?

[DUCKY]

Just curious of what size jets some of you are running. I have a Holley HP950 (80496-1) on a 8:1 468 chev with a little cam and headers. It came with 78's all the way around. I am up to 84's in the primaries and 90's in the secondaries and my friggin plugs are still white, and I have what sounds like a lean miss at WOT (which is only 4600rpm). I have a 6-valve mechanical pump at 6psi at WOT so delivery isn't an issue.
Oh yeah, I run at 500 ft alt. :confused:

[502procharger]

i know this probably will not help but i am running a blow through nickerson built 750 with 86 pri. 100 sec. 7lbs at idle. 502 with a procharger

[Thunderbutt]

I have 80's & 92's in 2- 750's 468 W/ a 650 lift cam and at normal running 2m to 3m rpm it runs fat, at 4500 to 6200 it runs just gray.

[DUCKY]

Geez, 92's and 100's in 750 cfm carbs? I guess since I have a 950, I'm not there yet! I'm wondering why Holley would have installed 78's from the factory though...
Where will I end up. .110's in the secondaries???

[77charger]

I am running 75 pri 79 sec in a holley 750 vac secondary.motor is a 429 w/cam,intake,11-1 comp.Also have a plate w/47 and 53 jets too :p

[Hotcrusader76]

What size air-bleeds are you running? High speed and idle? Who built the carb? Are the metering blocks adjustable with air-correctors or are they drilled? Type of boosters?
Did you check your float settings? With knowing the type of calibration performed to your metering blocks, this will determine proper float height and jet selection.
What type of pwr.valves do you have? Size of PCVR bleeds?
Contact me if ya need some assistance...
Note- when asking which size jets are proper on a HP950 is like asking what is the best timing for a small block engine... :D
~Ty
[ December 29, 2002, 06:53 PM: Message edited by: Hotcrusader76 ]

[DUCKY]

I have no clue what air bleeds are in it. What ever came from the factory. The boosters are the "down leg" units, also factory. The floats are about level with the bowls off, I set them just to dribble a little with the sight plugs out. It has #6 p-valves, and I don't know what a PCVR bleed is. My scoop is a bear to get off, I'll see what I can do. I wasn't so much asking for a recommendation, I just wanted so see where some other people were. It seems like I am getting awfully far from factory jetting, with no improvement.
[ December 29, 2002, 07:02 PM: Message edited by: DUCKY ]

[DUCKY]

Okay, 32's and 74's on the air bleeds.
Thank God for GearWrenches!!!!!!!
It runs awesome all the way up to nearly full throttle, but that last little bit of throttle and it starts missing and falls on it's face. WTF!!!!!!!
[ December 29, 2002, 07:23 PM: Message edited by: DUCKY ]

[sdba069]

Hey Ducky..........The jetting on that carb will be pretty close from the factory.I think you are probably okay on the jets you have in it.I would be looking elsewhere for the problem.What about timing and are you running that HEI piece of,well you know what I think of them.
Garry

[DUCKY]

I would think that factory jets would be close too. I would also normally blame the ignition, but my plugs are dry and white. How could an ignition issue cause that?

[502procharger]

my boat was doing the same thing and it ended up not being fuel related at all. plugs and wires were breaking down up top, or my cap and rotor were carbon tracking at high rpm. i messed around with the carb and fuel system for 3 weeks before i replaced(again) plugs, wires,cap rotor. fixed it. not that that is your problem, but i am making a point that your problem may not be fuel related even though you feel it is. just a thought

[DUCKY]

I changed the cap and rotor, on a hunch. They were not new, but were in better shape than the ones I took off. The wires are nearly new MSD super conductors. I run Autolite 26's right now (Cheap) New this morning. I may go back to my old dual point just for a test.

[502procharger]

i changed eberything also, ran it about an hr and put it away. next time i went to run it it started to have those problems. i finnaly changed it all again and it was fixed. not sure what part or parts did it, but it worked. i even tried a new coil, thunderbolt brain box, ect before i finaly re-replaced the cap,rotor,plugs,wires. good luck

[Infomaniac]

Sounds like it is running out of gas to me.
I would check the fuel system starting from the size of the tank outlets.
If you raise the float level 2 flats and it runs better chances are you have fuel delivery problems.
You can do this only a few times before it will dribble over all the time.

[DUCKY]

I also thought about wiring up my fuel solenoid for the nitrous separately to dump a little raw fuel down it. Same idea. I will keep yall posted. Can't hit the water again until Wednesday. Gotta work cry

[stressedout]

Autolite 26's are too hot, go with 24's.
Double check that timing keeping total advance under 36.

[Blown 472]

That would have been my guess on too hot a plug, also look at the ground strap to see where the discoloring is, I jet to keep the discolor in the center of the bend.
I had the same problem with my single four ford, jetted and jetted and still no color until I stepped down a heat range.
[ December 30, 2002, 06:57 AM: Message edited by: Blown 472 ]

[DUCKY]

See the "plugs still white" post for an update. :confused:

[DansBlown73Nordic]

I may be wrong but its worth checking. On my motor I had some similiar problems. A good friend of mine kept saying are the intake bolts tight. Id say YES...Well after calling him a few times he says I will be OVER in ten minutes.
Well he shows up. Takes a 9/16 wrench and every bolt was loose.... eek!
We did do a few other things that day. The motor has run better ever since. :D

[Blown 472]

Good point.,

[GofastRacer]

DUCKY:
Just curious of what size jets some of you are running. I have a Holley HP950 (80496-1) on a 8:1 468 chev with a little cam and headers. It came with 78's all the way around. I am up to 84's in the primaries and 90's in the secondaries and my friggin plugs are still white, and I have what sounds like a lean miss at WOT (which is only 4600rpm). I have a 6-valve mechanical pump at 6psi at WOT so delivery isn't an issue.
Oh yeah, I run at 500 ft alt. :confused: Sounds to me that you're running out of gas!, I just had a similar situation!!.If you're carb is the right size for the motor, you shouldn't need to go more than one or two sizes from factory jetting!..Are you running adequate size fuel lines?, you using a regulator or bypass?..I'm running a Victor454R and a 1050 on a 468. I have #12 line from the tank to one of George Streagle's high pressure mechanical pumps, #8 from the pump to the carb and a 8lbs bypass after the carb. Couldn't figure out at first why I couldn't pull more than 6000 even after dropping down in gears, raised the floats, up the jets, still 6000, plugs lean, WTF!, come to find out, the bypass was stuck open, popped a bowl, it was almost dry, wonder I didn't cook something!!.....Just my experience, something to look for!!...
:confused:

[DUCKY]

Dans66Stevens:
I may be wrong but its worth checking. On my motor I had some similiar problems. A good friend of mine kept saying are the intake bolts tight. Id say YES...Well after calling him a few times he says I will be OVER in ten minutes.
Well he shows up. Takes a 9/16 wrench and every bolt was loose.... eek!
We did do a few other things that day. The motor has run better ever since. :D I wish it was that easy, but I already checked that, and checked for vacuum leaks with propane.

[DUCKY]

GofastRacer:
DUCKY:
Just curious of what size jets some of you are running. I have a Holley HP950 (80496-1) on a 8:1 468 chev with a little cam and headers. It came with 78's all the way around. I am up to 84's in the primaries and 90's in the secondaries and my friggin plugs are still white, and I have what sounds like a lean miss at WOT (which is only 4600rpm). I have a 6-valve mechanical pump at 6psi at WOT so delivery isn't an issue.
Oh yeah, I run at 500 ft alt. :confused: Sounds to me that you're running out of gas!, I just had a similar situation!!.If you're carb is the right size for the motor, you shouldn't need to go more than one or two sizes from factory jetting!..Are you running adequate size fuel lines?, you using a regulator or bypass?..I'm running a Victor454R and a 1050 on a 468. I have #12 line from the tank to one of George Streagle's high pressure mechanical pumps, #8 from the pump to the carb and a 8lbs bypass after the carb. Couldn't figure out at first why I couldn't pull more than 6000 even after dropping down in gears, raised the floats, up the jets, still 6000, plugs lean, WTF!, come to find out, the bypass was stuck open, popped a bowl, it was almost dry, wonder I didn't cook something!!.....Just my experience, something to look for!!...
:confused: I am running 3/8" lines from the tanks to the selector valve, to the pump, through the water separator, and up the the carb. I am using a 6valve mechanical pump, probably similar to what you have, I think it's a Holley, with a Holley regulator set at 7psi. I have a hand-held fuel pressure gauge ran up to the driver seat, and fuel pressure is fine, and both bowls are full when I go to change jets. :mad:

[GofastRacer]

Well heck, just throw a set of injectors on there and end your problems!! :D wink :D

[DUCKY]

GofastRacer:
Well heck, just throw a set of injectors on there and end your problems!! :D wink :D Got an extra set? eek! I didn't think so.... :D

[GofastRacer]

DUCKY:
GofastRacer:
Well heck, just throw a set of injectors on there and end your problems!! :D wink :D Got an extra set? eek! I didn't think so.... :D Sorry, I need a set first!!... :D :D

[Hotcrusader76]

I thought you were getting me some injectors? :-)

[78Eliminator]

Infomaniac:
You can do this only a few times before it will dribble over all the time. INFO: Not a good suggestion. Want to know what happened to me last time my float levels were set to high? KABOOM!!!!!!!!!

[Hotcrusader76]

So do you have any flame paint job ideas in the future J? LOL

[GofastRacer]

Hotcrusader76:
I thought you were getting me some injectors? :-) OK, here ya go!.... :D
Injectors (http://www.racingjunk.com/classifieds/classified.php3?SHOW=35076)

[78Eliminator]

Hotcrusader76:
So do you have any flame paint job ideas in the future J? LOL Actually HBJet had a good idea that I am going to do one of these days. It's a flaming comet with "78" in the middle. It will go on the side of my scoop. You have any TPC stickers made up yet? I am still waiting to throw them on my ride.......

[Hotcrusader76]

I don't have any done in flame yet, but yes there are some things you and I have to still deal with....LOL....test drive again? I got my fire suit!
GoFastRacer......don't c*^k tease me with that injector shit!
[ January 03, 2003, 10:52 AM: Message edited by: Hotcrusader76 ]

[GofastRacer]

Hotcrusader76:
I don't have any done in flame yet, but yes there are some things you and I have to still deal with....LOL....test drive again? I got my fire suit!
GoFastRacer......don't c*^k tease me with that injector shit! Sorry, just couldn't resist!!.. http://64.207.13.28/mysmilies/contrib/lilly/hmm3grin2orange.gif