speed demon versus mighty demon

rblong · #1 (**permalink**) 05-17-2005, 09:28 PM

Well I will show my inexperience again! My son loves my Speed Demon 750 on by Fe. He went out and bought what he thought was a Speed Demon 650 from the local Hot Rod shop and installed it on his car. I went out to help him set it up and it is a Mighty Demon 650. The receipt showed Speed Demon and so did the box! Here is my question - is the Mighty Demon as good for street application as the Speed Demon? His SB is pretty hopped up so I am not worried about it taking the gas, but I don't want a carb we have to mess with all the time.

We are always learning and really appreciate everyone's help.

Bruce

Perf. Eng. Eric · #2 (**permalink**) 05-17-2005, 09:55 PM

The Mighty Demon is better suited for higher duration camshafts. What is your cams duration?

rblong · #3 (**permalink**) 05-17-2005, 10:23 PM

I believe it is a comp cam # XE262H.

Adv - in 262, ex 270

@.050 - in 218 ex 224

lift - in 462 ex 469

Headers w/3 inch pipes, single chamber flowmaster mufflers, 373 12 bolt possi, Muncey 4 speed, msd blaster, holley performer intake, 350 4 bolt bored 40 over

Thanks for your help
Bruce and Jordan

mj_duell · #4 (**permalink**) 05-18-2005, 05:06 AM

I think you may be just a bit over carbed. Mighty Demons are usually for radical cam applications with high durations. They are wonderful carbs when tuned right. I have a 428FE with a comp cams 292/.560 (244@.50)), the 750 Mighty Demon is perfect for this kind of set-up. However there are advantages to the Speed Demon if you run a milder cam. Look at the Demon Selection Guide for your cam and other specs:

http://www.barrygrant.com/demon/default.aspx?page=5

I'm not saying that you cannot get the Mighty Demon to work, but you may not be happy with the constant tuning or the lack of a choke.

--Mike

MidOHasp · #5 (**permalink**) 05-18-2005, 08:07 AM

Mighty Demon is definitely too much (even at 650cfm) for that kind of cam.

What size is his SB?

rblong · #6 (**permalink**) 05-18-2005, 10:38 AM

Thanks tons guys. It will go back. The last thing I want is a mis- application that we have to mess with all the time to keep it running correctly. This is about typical for this particular speed shop - not pay attention to what they are doing and leaving it up to the end user to check if what they gave you is correct. Unfortunately my son told them a Speed Demon 650 which is what they sold him, but thay handed him the Mighty Demon! He did not know enough to tell the difference and installed it on the car. It was a hard earned $450 for him and they better not give me any crap about swapping it out.

Thanks again,
Bruce