440 /super charger add on ?

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flathead31coupe

flathead31coupe

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I have a 1972 440 30 over flat top pistons,steel crank little over stock cam, and six pack rods. I wanted to know if I use 1.25 thousandths thick head gaskets' and that's it could I run a low boost dyrer roots blower.
not gonna race just looks and drive..any help in the right direction would be appreciated thanks.
 
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I don't know what your static compression is right now but a .125 gasket is only going to lower it about .5 to 1. That's a bit of a guess. It would have to be a multilayered gasket to work. The other option is to underdrive the blower and retard the timing to keep detonation under control. You could always add a water/meth system as well.

Jack
 
Coyote Jack said:
I don't know what your static compression is right now but a .125 gasket is only going to lower it about .5 to 1. That's a bit of a guess. It would have to be a multilayered gasket to work. The other option is to underdrive the blower and retard the timing to keep detonation under control. You could always add a water/meth system as well.

Jack
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was told that with the 906 heads..they have 88 or 91cc chambers I don't remember,and with the 30 over flattop pistons,its right around 9 and a half to one compression if I stay around 5 to 7 psi boost, shouldn't be to much of an issue but lowering the compression would help
 
Like Coyote Jack said, underdrive some if necessary to keep dynamic compression under control and you'll be fine. I run 5-7 lbs. @ 8.5:1 no prob with premium pump gas.
 
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I have another ? I was told you have to cut the intake valley pan and use two peice intake gaskets...anyone have a thought iam using a dyer setup.
 
If you use an actual blower intake rather than one adapted/modifed from a 4 barrel intake, it's a bolt-on that eliminates the valley pan gasket. You just use port gaskets and RTV on the end rails. They're around $500 but the way to go. Usually have a provision for a pop-off valve built in.

Dyers is good, Good Vibrations Motorsports (who I really like) or RBS for other parts. BDS is okay. There are other suppliers like The Blower Shop who are pretty proud ($$) or their stuff.
 
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i
70Duster440 said:
If you use an actual blower intake rather than one adapted/modifed from a 4 barrel intake, it's a bolt-on that eliminates the valley pan gasket. You just use port gaskets and RTV on the end rails. They're around $500 but the way to go. Usually have a provision for a pop-off valve built in.

Dyers is good, Good Vibrations Motorsports (who I really like) or RBS for other parts. BDS is okay. There are other suppliers like The Blower Shop who are pretty proud ($$) or their stuff.
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t is a actual dyer blower intake for a rb 440... So do I use the Valley Pan Intake Combo One piece.. Or do I cut the Valley pan used 2 side pieces.
 
No, just paper gaskets on the ports. Everything about the bathtub gasket goes bye-bye.
 
No, I don't believe so. You might see if Dyers includes the gaskets with their intake. If not, they may have a recommendation.
 
So just intake port gaskets and rtv on the in rails.... Are all blower intakes made like that my buddy has one he cut the port gaskets off of the metal gasket and left the pan in place and use the separate port gasket.and rtv where he cut off. The metal port gasket meets the paper ones..
 
He must have an old vintage intake. Some were fabbed from aluminum 4 barrel intakes with an adapter plate welded on. Not uncommon back in the day. If you buy a new blower intake for a 440 these days it's all one piece that seals the top of the motor. No part of the old metal gasket is used, period.

8366%20440%20chry%20003%20(1024x768).jpg


Dyers photo below....

intake-440Mopar-1.jpg


Here's an old school one that would require a valley pan...

12657785_10207484197839308_7094642768669909036_o-jpg.jpg
 
70Duster440 said:
He must have an old vintage intake. Some were fabbed from aluminum 4 barrel intakes with an adapter plate welded on. Not uncommon back in the day. If you buy a new blower intake for a 440 these days it's all one piece that seals the top of the motor. No part of the old metal gasket is used, period.

View attachment 1715085557

Dyers photo below....

View attachment 1715085558

Here's an old school one that would require a valley pan...

View attachment 1715085559
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cool thanks for the info..so i see studs for the blower...so just use bolts for the intake to block? Last question the ends of the block just use rtv... Do tha make gaskets or just rtv
 
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Racers use aluminum studs to shear off if there's an intake explosion. I used steel ones. You could also bolt it to the manifold but studs work and look nicer. The torque spec for blower to intake is very low and specific. Will cause problems if over-tightened.

Blower intake bolts to the heads just like the stock intake. They don't make end gaskets because normally the valley pan gasket is held down on the ends with flat metal retainers. So, yes, a thick bead of Permatex Ultra-Gray on the ends will do it. Set the intake, tighten to specs, tool the excess RTV than squishes out with your finger for a nice clean finish.
 
70Duster440 said:
Racers use aluminum studs to shear off if there's an intake explosion. I used steel ones. You could also bolt it to the manifold but studs work and look nicer. The torque spec for blower to intake is very low and specific. Will cause problems if over-tightened.

Blower intake bolts to the heads just like the stock intake. They don't make end gaskets because normally the valley pan gasket is held down on the ends with flat metal retainers. So, yes, a thick bead of Permatex Ultra-Gray on the ends will do it. Set the intake, tighten to specs, tool the excess RTV than squishes out with your finger for a nice clean finish.
Click to expand...
 
thanks again....on to the next ? my blower is a 871 upper pulley is a 36 and lower is a 33 I think its -8.3 drive ratio...if this is correct what does it mean...thanks
 
You'll need to consult some charts for reference, either on the BDS or Dyers site. There are many factors you need to compare to arrive at an appropriate drive ratio: Engine displacement, static compression ratio, blower size (6-71, 8-71), dynamic compression ratio at a given boost level, etc. The pulley combination (or drive ratio) affects how much boost you'll potentially generate. Too much, you grenade things.

In a nutshell, with a 6-71 on a 440 you need to overdrive or spin it faster (bigger pulley at crank, smaller at blower) to make boost. An 8-71 moves more air per revolution so it doesn't need to spin as fast. So, if you put the smaller pulley on the crank and the bigger one on the blower it will spin slower or be under driven. If you swap pulleys it will be over driven by the same amount. If you do the math, the difference between the two pulleys you have is 8.3%. So, installed correctly, you can under drive your blower by 8.3%. Whether that will give you the safe and sane boost level you desire, you'll need to determine.

You have some homework to do.
 
Looking at the 8-71 chart, and by my estimation based on the info you've supplied so far, if you under drive by 20% you'd be in the 4-6 lbs of boost range.

Guessing you have 1/2" pitch pulleys (I'm using 8mm pitch with vastly different tooth count). As an example, if you use your 36 tooth on top and buy a 29 tooth for the bottom you'll be a little more than -19%

Again, from Dyers....

blower-gilmer-ratio-1.jpg


Running the pulleys you have might put you in the 10 lb range - or the land of detonation for your combination. The charts serve as guidelines.
 
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