Divorce Valley Cover From RPM Air Gap Intake - Gen1 SBC

[Guest Mike]

I'm thinking of divorcing the valley cover from my RPM Air Gap intake so I can install wet N2O via direct injection on the underside of the runners.

 

1. Can this be done?

2. Any advice on how to do this without damaging the intake.

3. Is there an existing aftermarket divorced valley pan available for Gen1 SBC?

4. If answer to #3 is "no", then any suggestions on how to make one?

 

THANKS!!

[blueovalz]

Could you cut a large hole (or several smaller holes more ideally located) on the lifter over so that you could attach overlaping aluminum from the bottom as "covers" once the installation is completed?

[Guest Mike]

blueovalz,

 

Hmm... that's a good idea. Perhaps I could tap large holes to accept 3/4 inch or larger threaded plugs? That should provide wide enough access to drill and tap the runners. These won't be seen easily under the intake so I doubt appearance is much of an issue. However, if bosses must be added, this isn't enough room to work.

 

I've read where people have cut away the webbing from their intakes to clean up the appearance. However, this is different since the valley cover is an integral part of the intake. I was thinking that I could buy some really nice reusable metal gaskets and rivet them to a piece of heavy-guage SS sheet metal bent to fit the lifter valley. Between the gaskets being held on with the intake bolts and some good high-temp silicone sealer, there should be no valley leaks. What do you think?

[blueovalz]

I thought of that as well. Back in the 80's there was a similar pan that covered the bottom of the OEM intake made by Ford for the 351W.

[Guest Mike]

The engines in my old Pontiac Firebirds (400's and 455's) had separate valley pans with an integrated air space to minimize heat transfer from the lifter area. These were made of fairly thick steel and held on with two bolts through the center and into the block, if I remember correctly. I wonder if there's anything aftermarket similar for a SBC... I think I'll search a bit before I leap. No... I don't want to drill/tap the block

[Guest Mike]

Here's another thought. I could simply cut one large hole from the underside of the intake so I can plumb for N2O and methanol injection, then cover it with an aluminum or SS plate a quarter inch larger all the way around. If I can seal and screw the plate from the top... no real problem. However, if I must attached the plate to the top, I'll have cleaning issues. Also, water could accumulate in the recess and if the seal isn't perfect, the water could drain into the lifter valley.

 

What do you think?

[HarrisonTX]

You mean like this?

[HarrisonTX]

Here ya go

 

 

 

[Guest Mike]

HarrisonTX... Yes, plumbed like that. However, I have a dual plane dual quad air gap intake and the lower runners extend very low. Without a lot of cutting, this won't work on mine. Perhaps if I could find a separate valley cover, I could make this work.

 

QUESTIONS:

1. Did you make a valley cover for your SBC? If so, what method did you use?

2. Did you plumb your N2O through the block?

[HarrisonTX]

sadly, i did not perform this, is an old, old carcraft article, heres the link!

a dual quad airgap... bad ass man, just take a measurment with the intake on. Make like a 2 or 3 inch cone out some play-dough or something, and install the intake, the remove the intake, and measure the height of the now flattened play-dough

I bet youll have room..

Heres the link, they mention exiting thro the intake, but i think someone would see that, i think exititing thro the back of the block would be best.

also mike, that metering block has gotta be the lowest part of the system, and that dosnt seem to be too thick, i think you should be okay.

This is sold as a kit, and it comes out to like $900 OUCH!!!

Heres the original article

http://www.carcraft.com/howto/95718/index1.html

 

 

Theres also this neat little trick

 

http://www.carcraft.com/techarticles/116_0504_hidden_nitrous_kit/

[Guest Mike]

I'll probably just plumb for N2O/alky on the outside of the runners. I'd be removing a rather large section from the underside of the intake in order to have access to the inner runner area. Then I'd have to make a sheet metal cover for the hole. Also, the heat from the oil may affect performance if I plumb under the valley cover. Here's a pic of the intake... notice the rather thick solid plate under the runners.