Holley vs speed demon

[JimmyV]

HEY GUYS! So i am aquireing a speed demon 650 vaccum secondary carb and thinking about putting it on my car.. currenty running a holley 650 dp mechanical secondary. my question for you guys is what is the interchange on holley parts to a demon as far as jets gaskets power valves squirters all that stuff? if someone coudl let me know that would be great.. and also whast the deal with demons idle-eze adjustment? does it work? i know it allows you to change idle speeds with out adjusting butterflies witch is probably really good for throttle response and such..any way let me know!! thanks

 

[LXguy]

Hey:

First, I'd just stick with Holley if possible. I know Demon is just back from bankruptcy and all that, but before bankruptcy there were all kinds of problems with Demon carbs. If you do go demon, make sure you take it apart before you install. Make sure everything is as it should be and blow the aluminum shavings out.

Second, the metering plate and bowl gaskets are the same as holley. Squirters, power valves are the same. Fuel line is different.

The Idle thing is a gimmick unless you're running a gigantic camshaft.

What is your combo? What is the intended purpose? Street/strip? Race?

 

[JimmyV]

Hey:

First, I'd just stick with Holley if possible. I know Demon is just back from bankruptcy and all that, but before bankruptcy there were all kinds of problems with Demon carbs. If you do go demon, make sure you take it apart before you install. Make sure everything is as it should be and blow the aluminum shavings out.

Second, the metering plate and bowl gaskets are the same as holley. Squirters, power valves are the same. Fuel line is different.

The Idle thing is a gimmick unless you're running a gigantic camshaft.

What is your combo? What is the intended purpose? Street/strip? Race?

360 bored 60 over 525 290 duration cam eddy heads 10.5:1 pistons victor intake but looking to swap to air gap..mostly just a daily running a 650dp right now and love it not really wanting to swap but the guy is looking to trade holley for demon....idk kthough i like my holley just more curious then anything

 

[LXguy]

If you're happy with the Holley, I'd stick with it.

Around here, Demons bring exactly nothing on the used market, but you can sell a good used holley for $200-$300.

For street, you'll like the air gap a lot better. If you want a more fuel efficient carb, I highly recommend a Holley street avenger. I run a 750 Quickfuel double pumper in racing season and a 670 vac. sec. street avenger the rest of the time. Its great. Great throttle response, electric choke, good mileage.

My double pumper is .15 quicker on average, but with the SA I still have to take timing out and put weight in to slow it down to 12.00....so it will support some horsepower.

 

[JimmyV]

If you're happy with the Holley, I'd stick with it.

Around here, Demons bring exactly nothing on the used market, but you can sell a good used holley for $200-$300.

For street, you'll like the air gap a lot better. If you want a more fuel efficient carb, I highly recommend a Holley street avenger. I run a 750 Quickfuel double pumper in racing season and a 670 vac. sec. street avenger the rest of the time. Its great. Great throttle response, electric choke, good mileage.

My double pumper is .15 quicker on average, but with the SA I still have to take timing out and put weight in to slow it down to 12.00....so it will support some horsepower.

fuel economy is not really a concern..my main concern right now is that that victor is just too intense for the street..i love how it performes at 4-6 k but on the street i dont see that much :burnout: need some more streetable lowe end

 

[LXguy]

An LD340 or a regular Performer RPM wouldn't be a bad choice either. The only gripe I have about my air gap is cold starts. Once it gets heated up its fine, but it definitely takes longer to warm up with the air gap.

 

[JimmyV]

An LD340 or a regular Performer RPM wouldn't be a bad choice either. The only gripe I have about my air gap is cold starts. Once it gets heated up its fine, but it definitely takes longer to warm up with the air gap.

mine is a ***** to warm now..i wonder what the differnece woudl be in warm up time between victor and air gap i wouldnt think alot...... but i could be wrong

 

[Dubob]

Just my .02 cents. I would stay with the Holley and swap to whatever intake you want. With the Holley you know what you have and I personally wouldn't want to introduce too many unknowns at one time.