Well here's where I'm at- I want to pick everyones brain and tell me what you think about how I am deciding to try and bolt this thing onto the middle section.

What I am going to try is to drill the 8 remaining mount bolts "through" to the top side (red circles). note that 2 of the 10 are exposed and not a problem.

Now what I am thinking is to replace the longer bolts with studs. Then I can simply use a circular gaskit under each nut with a dab of sealant under the nut and thread to seal the top holes, and torque the lock nuts in place.

No before anyone comments further- Please look at the 2nd photo I am going to load and you can see how I engineered the sides walls of the plenum to be touching the studs thus giving as much strength and support under the nuts on top without yeilding the plenum to compress when I torque on them.

Please tell me what you think- any better ideas that don't involve brain surgery?

 

You can see in the picture below how the studs will be inserted and kiss the edge walls of the inner plenum. I built out the wall on the last one (each side- the other side not shown but is identical) so that the top will not flex when I torque down the nuts on top.

 

so this is going to slip over top of the lower plenum?

i think bolting it the way you say sounds like a great plan. let us know how that thing works

 

- Or - , cut the top off and make an access panel. Thus making the ability to torque the Upper to the middle from the inside with shorter allen head bolts.

 

So in essence, you'll have 8 studs running through the upper plenum (inside), sealed at the bottom (where the studs enter) and then sealed at the top (where they exit, with the nut holding it down)?

You should be ok with that - I'd use a rubber washer, to seal the entry/exit points of the studs....

 

Access panel, while it DOES sounds really cool, seems it would be inviting too much possible leak area, IMHO....

 

yes, biggest problem with putting something like that is the leaking. i think you'd have a hard time sealing it properly

 

Thats my thought also.
The underneath side would just require the standard gasket just as if I were installing the stock upper to middle. However, I plan to use sealant on both sides of the gasket surface also.

The top I have thought about metal washers with the rubber seal. I am just worried about heat and longevity of them + the fact they might loosen over time. I think just using the factory style GM flage head automotive nuts with sealant under them, or a flat washer with an exhaust style locknut on top with sealant on the washer surfaces? I just don't want things loosening from heat, but really don't think it will be too much of a problem- I'm leaning towards the flange head nuts.

 

keep it simple, don't put things in that aren't needed

 

how about flange head bolts with o-rings? shouldn't be to difficult to cut a small relief around the bolt holes to fit the o-ring. or even better, perhaps you can find a washer withthe right id to leave room for an oring? you would then be able to torque the bolts against the solid plenum instead of another compressible gasket.

 

It works w/injectors, and how many times do you plan on removing the intake (after it's perfected)

worried about loosening, how about safety wire

 

Laiky, I like the idea. Just a wider recessed hole just deep enough for the "oring to stay in place but stand taller than the deck for adequate squish.

 

You got the right idea, Dean.

 

It never hurts to ask others, Especially those that have curious interest and are willing to help see it work.

Thank you everyone.

 

I just water tested it for leaks as it stands before I drill and tap any fitting holes.

Turns out I have 4 tiny pinhole leaks around the entire top area. Three of them drip once ever 10 mins, one of them is dripping about once a minute. Aluminum is so damn hard to weld without having pores leftover.

Before I go any further, I am going to have to wait till I can get back over to the family garage (hopefully this weekend) and touch up these spots and then water test it again.

After that I'll need to tap the EGR holes, the rear "t" fitting hole for the vacuum line, and the 8 mount stud holes. I have decided to go ahead and test this thing running on the 2.8 to see what the heck it will do if anything. If it works and shows improvement, I'll then send it out to be Ceramic-coated to match my headers and Fiero valvecovers. That will help keep the intake cool as well as make its appearance better.

 

do you have a vacuum guage in your car or one that you can hook to it? i'm curious what the big plenum will do to vacuum. i think you got the mounting all figured out! i hope it shows improvement! i know how you don't like to drag race that car but, i'm curious what times it would do with and without that intake! maybe just once???

 

I dont recall hearing how thick that material is. Just dont recess to much causing a weak spot.

Other then that, I think you got a good idea.

 

That drawing is exactly what i was thinking.

Instead of leak checking with water, if you can blockoff the bottom and TB mount you can use compressed air and soapy water, makes the welding go a lot quicker than drying out the whole plenum

 

I use 3/16" thick top and bottom, and 5/16" thick on sides.
I'll only recess the "o"ring holes about 1/16- 3/32" based on the thickness of the "o"rings I find to use

 

I am glad to see someone try something like this.

I know the MPFI V6 in the Camaro has got to have one of the most restrictive intake systems that I have ever seen. Especially when I can remove the four deflectors below the air filters and instantly tell a difference in throttle response. I would love to replace my intake; but, Eldebrock only makes one for the carbed variety. Does anyone know if the 3.4 intake will work?

Great job on the intake! Sealing is extremely important, but dont forget ported vacuum ports.

Brakes, PCV, EGR, FPR, etc.

 

I found a better method. Earls performance sells Aluminum washers called Stat-O-Seals. They consist of a synthetic rubber "O"ring mechanically locked into the inside dia of an aluminum washer and seal a positive force around the bolt shank when compressed. They are also designed to take the heat. Part # 178005ERL(2 per pkg.)
http://www.earls.co.uk/car/6_compone...ies/index.html

I'm getting closer on this. Amazing how long it takes me to get things done anymore. 10 years ago I had so much more free time. I am actually having to replace my entire steering column in my truck this weekend because it is worn beyond repair and the tilt assembly actually broke.And the starter when out on me last night, AND the u-joint is giving an occational cracking noise and ready to cut loose. always something.

 

looks good

 

what kinda gains are you hoping from this?

 

that looks really good! i'm not doin anymore with my plenum until i get to use my friend's work's plasma cutter!

 

ANYTHING better than what its currently running.

If this does work, I will worry about the beautification later. I will have it ceramic coated at that point- No Alan, I am not sending it to you to do for free so you can try it But guys, he was nice enough to offer a while back.

 

lol...i wasn't going to ask/offer again. you turned it down once so... but, i'm not quite as anxious to try your anyways since i'm making my own now. i know that they are very different setups anyways.

 

Please take no offence with this when I say I am not about to send a one of a kind part I made completely across the US to a stranger to try, and neither I think you would or should do to me either. If you lived close by were I could find you, then yes. Its not in my best interest and I have spent too much time on this.

But again, I do want everyone to know that you are a hell of a nice guy to offer- that was generous.

 

i know exactly what you mean. no offense taken. its hard to put faith in somebody that you've never met...sometimes its hard to put faith in somebody you have met! but, no, i do know exactly what you mean.

 

Dean, that looks badass! My thought was going to be to cut a gasket out of black gasket material, it would be a hell of a thin "outer edge" gasket- but the o-ring idea is Much better. (And much easier to replace then having to cut a damn gasket all the time!)

 

Reminds me of the plenum used in the Firehawk. It Should up the low end power quite a bit.

 

actually, he is looking for top end power gains. shortening the runners like he did will raise the rpm range of the powerband.