LSx - Weber Intake Manifold

If the intake does not need to be a cast style. Then I would check with either Hogan or Wilson manifolds about a sheetmetal style. Most of hogans intakes listed on there price print out are under $2500 and you could get it built to you specs that you need. This way you could have injector bung put in on and pluged for later use once you go to FI.
For $400 I purchased the below intake. For another $2000 or so, I can put the Jenvey throttle bodies on it (after the planned modifications), and use the OEM LS2 injector configuration. Actually though, this manifold is pretty neat. The throttle body is up and away from the headers, and it could easily be modified for twin turbo forced induction...oops, now I'm thinking beyond my means again. If not for the configuration of the McLaren I'm trying to emulate, I'd go with this set-up just as it sits.

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Extrudabody lists an intake for the LS1, 6, and 7, but not for the 3. I'm not as knowledgable as I'd like to be, but I feel the LS7 intake should fit. If the O-ring groove is omitted, then the LS1 or 6 billet intake could be easily ported to match the retangular LS3 ports.
yes we will go ahead with our manifold as we believe it will represent a nice combination between the Weber classic look and the option to run either Carbs or injection throttle bodies at a reasonable price. We will design it for the LS3 as we run the CT 525 in our Can Am car. Will take still a few month though as we are busy in getting our Can Am car ready for production now.
Progress on a Poor Man's LS1 ITB set-up

Economy price for an LS1 ITB intake manifold; $1400
Economy price for a set of 8 ITBs for a V-8; $1800


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Re: Progress on a Poor Man's LS1 ITB set-up


Everything you have described looks perfectly viable to me. I do have a couple of questions and comments.

Randy V

Good work there Terry...

I had looked at doing something like this with my own manifold design some time back only I was looking at dual throat throttle bodies that are readily available in most wrecking yards from 351W Trucks / Vans.

Here's how the crummy ones look

But you get get nice shiny after market TBs like this as well

Your idea using the Chrysler parts is a good one..
I Apparently a single shaft per side - might be a bit of work to get all the throttle plates to seat properly, but I'm sure you're up to the task..
Great post Kelly...thank you! I've got 4 different types of couplers on the bench that I'm going to play with. They range from $5 to $50 a piece. The expansion/binding factor is well noted. The rod is for alignment purposes only. The OEM coupling mechanisms that were used on the connector tubes can be modified to work if I choose that route, but the best/simplest option so far is a spider coupler with zero back-lash.
Had a good weekend in that I was able to cut up the Edelbrock intake on the table saw, and welded yeasterday. The casting quality of the Edelbrock manifold was great. No porosity, and it welded as good as the billet I was welding on earlier:

I cut out wedges in each runner to angle the runner more vertically in order to space the banks apart from each other for linkage clearance.

Then I "just had to" place the ITBs onto the modified manifold

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Randy V

Nice work Terry...

Would you mind telling me/us - what was the alloy of the filler rod you used when you TIG welded the manifold back together?

Also - When you cut the wedges out, were they cut all the way through or were you able to heat/bend the inside walls of the manifold runners when you closed up the wedge gap (if that makes any sense at all)?

Don't know off the top of my head what filler I used (only that it was what was recommended by the welding shop - at work right now), but I did attempt to heat and bend the manilfold back together, but the backside snapped anyway (very brittle). It didn't make any difference anyway in that it all stayed aligned (since the plenum continued to hold all the runners in place).
I've not completed any plans on exactly how or where it will reside, but my plan is to create a vaccum box which ties together all eight vacuum ports (from each ITB ), and then use that box for a MAP signal.


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I've not completed any plans on exactly how or where it will reside, but my plan is to create a vaccum box which ties together all eight vacuum ports (from each ITB ), and then use that box for a MAP signal.

This was my next question. How to get an accurate MAP reading from the ITB's. Just as it was already stated, a common plenum would work, but I'm digging the vacuum box idea. Simplistic and also goes with the "look".

Great work, any updates?
My update,
In order of photos: the top of the plenum completely removed with the mounting plate adjacent to it. The next photo shows the mounting plate in its welding position to weld from inside rather than risk corner welding under the plate with it's typical warpage. The third photo shows the welded plate that was milled to remove the excess weld material, and tapped with 8 holes to mount the adapter plate. The last photo shows one plate welded onto the runner bank, and the other ready to be welded.

Unfortunately, I did get a little warpage even with the welding method I used, so both banks are at the machine shop getting a few thousandths (ok..a few 10 thousandths) of material removed from the upper and lower flanges to ensure all surfaces are true. They would have had to be faced anyway to knock of the excess weld material where I welded the plate to each runner. The adapter plate that I've shown in previous photos (with the ITBs directly mounted to it) have the holes cut and messaged to blend the round ITB port to the semi-rectangular runner shape. Its all very exciting, and I've spent less than $700 for everything so far.

Looking at the heads, my first assumption was a typical 45 degree face, but these hermaphrodite heads have a 35 degree face. Who woulda thunk it.


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Lubed those injectors up and the holes, and with some persuation, pushed those babies into the holes (used some white grease I had in the cabinet). So now I need to get a pump, filters, and a regulator, finish up tying all the TBs together with shaft clamps, and fab up a vacuum reservoir. In case anybody asks, those are blue fuel rails because they were originally purchased for the BlueOvalZ, and yes they are designed for a SBF, but the bore spacing and angle is so danged close, I thought I'd save some money and finally use them. Seems to fit very well. The Hilborn stacks are on their way, and will fit around the top of the TB perfectly. This will provide about 19" of intake runner length to the valve face.

It's amazing all the little stuff that slows one down. For example, cut a perfectly good and rigid intake in half, and then mount the individual halves on a smooth ramped surface relative to the bolt axis, a guess what, the individual bank want to slide down the surface of the head, inboard, so now the ports don't line up. So I had to shim the manifold to the center cam cover plate to keep each bank from sliding inward when I torqued them down.

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