help with lean carb.

[sst4356]

ok here is my problem other than not having enough cash to buy a apd carb. Iam running a 1050 hp holly carb. on alcohol . 540 inch BB chevy. and it is way lean even with 200 jets. is there any way I can fatten up this carb.

[cepx111]

Is this a alky carb or a gas carb with just bigger jets? I'm no alky carb man but I'm sure there's more to it than just throwing some bigger jets in the carb, maybe some of the alky carb guys will chime in here and give you the low down.
Goodluck, Charles

[hammertime]

ok here is my problem other than not having enough cash to buy a apd carb. Iam running a 1050 hp holly carb. on alcohol . 540 inch BB chevy. and it is way lean even with 200 jets. is there any way I can fatten up this carb.

Going to need a few more things, has anything else been done to this carb ? who converted it to alky holley ? You are sure its lean and not so rich that its giving you lean conditions ? Tell me more about the motor, fuel system, fuel pressure maybe we can come up with something.

[hammertime]

Also would like to know timing you are running.

[sst4356]

This is a out the box hp holly ach. carb. Friend has a apd and I tryed it on my engine and ran just like it is suppose to do. fuel pump is a blp belt pump with 9lbs pressure. power valves has been removed and block offs installed. timing is at 32 . engine will heat up just idling, with apd carb. almost impossible to build heat. Thanks for help

[hammertime]

You can get jets over the 200 range for a alky carb its not common to use them if the carbs are right but its for sure been done. Where are your idle mixture screws set at ?

[OneBadGMC]

This is a out the box hp holly ach. carb. Friend has a apd and I tryed it on my engine and ran just like it is suppose to do. fuel pump is a blp belt pump with 9lbs pressure. power valves has been removed and block offs installed. timing is at 32 . engine will heat up just idling, with apd carb. almost impossible to build heat. Thanks for help

Sounds like it's too lean on the idle circuits, and that it has the wrong air bleeds in it.

Holly shows the 0-80586 is the only 1050 carb calibrated for methanol out of the box. Is that the p/n you have?

http://www.holley.com/types/4500%20Dominator%20HP.asp

[sst4356]

I was told that 200 jets is the max jets that stock metering plates flow. yes that is the same part no. that I have . it also gains heat thru the run also, leave at 140 degrees 180 at finish line 1/8 mile. before you say not enough rad. ok with apd carb.

[hammertime]

I was told that 200 jets is the max jets that stock metering plates flow. yes that is the same part no. that I have . it also gains heat thru the run also, leave at 140 degrees 180 at finish line 1/8 mile. before you say not enough rad. ok with apd carb.

Might be worth saving up to send to apd, I've seen very few holley out of box alky carbs that work right. Sounds terrible lean but maybe its so rich that its giving you a lean condition. You run a egt ?

[lively]

DUUUUH---YOU KNOW IF THE CARB IS LEANING TO MUCH --[YOU COULD ALWAYS JACK UP ONE SIDE OF THE CAR TO MAKE IT LEVEL!!!!]--DUUUUUH :shock: :roll: 8) :lol: :lol: --LOL LOL---LIVELY

[OneBadGMC]

I was told that 200 jets is the max jets that stock metering plates flow. yes that is the same part no. that I have . it also gains heat thru the run also, leave at 140 degrees 180 at finish line 1/8 mile. before you say not enough rad. ok with apd carb.

Doesn't sound like there's anything wrong to me. In fact, it sounds too cold. I like to see around 210 crossing the line (whether 1/8 or 1/4).

[hammertime]

210 can I ask why ?

I go into the burnout @ 165 and am 175 when i get back to the trailer, I just the car off and fuel it and ready to go for next round. If i were to get it to 210 I'd never make next round without being to warm.

[OneBadGMC]

210 can I ask why ?

I go into the burnout @ 165 and am 175 when i get back to the trailer, I just the car off and fuel it and ready to go for next round. If i were to get it to 210 I'd never make next round without being to warm.

It has always had a better et at the higher temperature.

I run an electric water pump and fan, so cooling it isn't an issue. If I'm under pressure between rounds, we simply use a bug sprayer on the radiator while the pump/fan is on.

[sst4356]

Thanks for everybodys in put . I think hammertime is right it needs to go to apd.

[hammertime]

Thanks for everybodys in put . I think hammertime is right it needs to go to apd.

Its amazing what Randy can do with a carb !! I was totally amazed when I stepped in the shop and seen all the carbs and all the brands. I've known several people who have switched from good carbs to apd and only 1 of them didnt like it, but he didnt give it much of a chance either.

[cncmotorsports]

ok here is my problem other than not having enough cash to buy a apd carb. Iam running a 1050 hp holly carb. on alcohol . 540 inch BB chevy. and it is way lean even with 200 jets. is there any way I can fatten up this carb.

Have you changed the air bleeds ?

[altune]

It is my experiance that when the engine gets too much alcohol it runs hot, if you pull fuel back the engine gets colder. It is an oxigenated fuel. It works almost opposite of race fuel.
If one carb is working and another of the same size is not then as the other guy stated, you need to change the main air bleed to the venturi's
remember the smaller the air bleed the more fuel you will flow. ( siphon effect ) do youself a favor and get a egt sensor and guage installed.
you can tune and figure a bench mark wide open 1200 degrees. thats what we run at. Be carefull to not have too much alcohol cause it will start to burn in the header and show a hotter temp.

[oncearacer52]

Do yourself a big favor and get some type of O2 analizer. It will tell you exactly where it is going lean and you will be able to immediately see what effect any changes you make are. Spend the money ($100 and up). I have an Altronics that I gave $450.00 for and it will make an induction expert out of you in no time. One con is tho at idle your reading may not be true.