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.
 

Terry Oxandale

Skinny Man
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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Is there any current Weber style intakes for Ls3 chevy available.

LMP-Wolf Are you going ahead with your intake? Will it work with LS3

thanks
 

Terry Oxandale

Skinny Man
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.
 
Adrian,
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.
 

Terry Oxandale

Skinny Man
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<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com
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The ITBs. The Chrysler LHS 3.5L motor has a unique set-up for their throttle bodies. This engine uses two Holley 48mm throttle bodies in which one is attached to the throttle cable, and the other (on the opposite side of the intake connected by a torque tube) houses the TP sensor. For a factory TB, these pieces are surprisingly simple, and is lacking the usual crap that is attached to a factory part. So I purchased a bunch of these to experiment with to see what could be done with them.
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The adapter plate will make the transition between a round ITB exit, and the semi-rectangular intake runner. I placed a rigid .390” rod (10 mm was too large) through all the bearings to align the TBs perfectly, spaced them to match the runner centerlines, clamped them down, and then used the TB mounting holes as a guide to drill the mounting holes into the adapter plate.
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Then I drilled and tapped the holes for M8 studs (used the Chrysler studs because they’ve got a neat pilot shoulder to index the TB.
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Then mount the ITBs, scribe out a circle on the plate for the exit hole

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Rinse and repeat for the other side. Don’t know if this will really work, but cannot find a reason why it shouldn’t, and I’m having a ball so far! Once I get it all together, I'll clean up the plate to remove excess bulk, lighten it up, and make 'er pretty!

PS, sorry for all the spaces. The preview shows none at all, but the post shows otherwise.

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Mirage photo-documentation<o:p></o:p>
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Kelly

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

Terry,

Everything you have described looks perfectly viable to me. I do have a couple of questions and comments.
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What will you be using for ECU? Apologies if already mentioned in this thread but I didn’t see mention of it with a quick scan. I’m mostly just interested in what control scheme and a sensors you are planning to incorporate.
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I noticed the single shaft through the bank of ITBs in one picture. Was this just an alignment tool for drilling mounting holes and do you plan to use the individual throttle shafts for each ITB? If so, what are you going to use as a shaft coupling? For safety reasons, I would strongly advise you put some thought into your coupling method. If the throttle plates fit the bores closely (and they must) the difference between the thermal (axial) expansion of a single steel shaft, aluminum manifold, and ITBs can cause binding of the throttle plates. Garry at TWM actually has incorporated <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com
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Oldham</st1:place> couplings in his IDA throttle bodies to address this issue because he thinks it’s necessary even on 120mm IDA bore centers. The old Enderle, and like single shaft mechanical injection systems had a reputation for sticking.

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Kinsler makes a billet spring/screw connector that allows for angular misalignment and axial displacement while still providing zero lash. They are quite proud of them and incorporating six of them might increase your cost 30-50%. I would highly recommend at least one such coupling between your center ITBs on each bank. As a low cost alternative, you can find similar hardware on Mikuni carb set ups for inline four motorcycles as the issues of coupling inline carbs has been well known to cycle engine builders for a very long time. They are typically stamped steel but equally as effective.
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You may want to have a read through the Kinsler catalogue. –<st1:place w:st="on">Lot</st1:place>’s of useful information in their catalogue and tech sections. It’s available online as a pdf free for download. Kinsler even goes so far as to recommend a toe strap (to manually close throttle plates) for their systems even though the incorporate safeguards.
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If you set your induction system up off your engine and then bolt it down, it’s not uncommon to find that the intake deflects enough to cause bind or alter you linkage settings. Best to do your set up when mounted on your engine and spring/screw connectors help in this regard too.
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You are well on your way but just for the consideration of others who are interested in low cost approaches to IR, if a tunnel ram is available for your combo, make an adapter and that connects two four barrel carbs in IR fashion to the tunnel ram base. You can by aftermarket billet 4-barrel TBs or just use carb bodies as ITBs. You’ll have to hunt a little bit for sufficient bore are in a symmetric pattern for the latter but there are plenty out there. Add injector bungs and your pretty much there.
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Keep us posted on your progress.
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Best,
Kelly
 

Randy V

Moderator-Admin
Staff member
Admin
Lifetime Supporter
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
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But you get get nice shiny after market TBs like this as well
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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..
 

Terry Oxandale

Skinny Man
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.
 

Terry Oxandale

Skinny Man
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:

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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.

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

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Randy V

Moderator-Admin
Staff member
Admin
Lifetime Supporter
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)?
 

Terry Oxandale

Skinny Man
Randy,

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).
 

Terry Oxandale

Skinny Man
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.
 
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?
 

Terry Oxandale

Skinny Man
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.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com<img src=" /><o:p></o:p>
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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.<o:p></o:p>
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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.<o:p></o:p>
 

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Terry Oxandale

Skinny Man
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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Randy V

Moderator-Admin
Staff member
Admin
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Nice work! How did you calculate the optimum runner length?
 
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