While I wait to get my 360 short block sorted Ive had plenty of time to research this particular Weiand intake and some of the plenum and runner work that can be done to it. I've gasket matched and blended the roofs about 3" in, enough so that the roof of all runners have a nice smooth curve out to the exit. The insides of the sharper turning runners were blended better. The floors only had a light pass with the sanding rolls. On the plenum I radiused all the sharp machining edges, and radiused the plenum to roof transitions as best possible. I've left the divider untouched for now as I haven't decided on carbs or what spacer, if any, I will use. Right now I'm thinking an Autoline reman 71 340 TQ (they bush throttle shaft bores if needed, unlike many other box stores) or the Demon Street Demon 750. Been reading a lot on cutting the divider down, can't find any pics of it done to these intakes. With the picture shown, about how deep and wide would you go, as a baseline start? Plenum work look good to go?
Weiand Action Plus Porting
- Thread starter 12many
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Specs: 3300lb A-100 van, 360 .030", 10:1, 275adv/[email protected]/.501"/108lsa/59overlap, (1.6 roller rockers) EQ ported magnum heads, step headers, 727 w/suitable TC, 3.73 gears. Street with some strip fun.
xLURKxDOGx
"An angel fat, at satan's feast"
I did the exact same thing to my action plus last week for my 360. My ports were so far off from the gasket it was stupid, i had a lot of work to fix them and i got to say yours turned out way better than mine did. I also took a couple of reference pics of an LD340 as well as an old Offenhauser manifold and cut a divider into it, it was around 1/2 deep and 1 or 1 1/8 across from the back of the manifold.
Jake
C130 Chief
Mechanical Genius
Nice clean up on the intake. Try cutting a 4-hole spacer into a 3-hole before you modify the plenum divider to see how your engine responds. I suspect with a 750 carb, either the Demon or the TQ, you'll lose more throttle response than you'll gain at high RPM. If you were running a 600, it might be a different story. Weren't 71 ThermoQuads an oddball? And unless your experience with parts store rebuilt carbs is a whole lot better than mine has been (120% bad), I would skip the TQ.
Autoline is out of Canada, they actually have a good track record of remanufactured carbs, like I said, they actually bush the throttle shaft bores, and ensure correct parts go back in, not like a shagged rebuilt 20 times carb from AutoZone with mismatched jets and rods and ovaled shaft bores (been there before) The various 2-bbl carbs I've used from them in the past look like restoration pieces, I'd only get a rebuilt TQ from them, highly likely the same carbs offered by Summit, but they wouldn't reveal where they get them from. Probably want one from 72-74 I'm told. I like the three hole spacer idea. I'm just limited on doghouse lid to carb/air leaner space with the van so we'll see what spacer and air cleaner setup I end up with.
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And here's a couple pics of the final round of porting on a Weiand Action Plus, when you haven't got the parts needed to actually start assembling, you have plenty of time to buy air angle die grinders (and up things to a 408 stroker!) and really go deep..... Radiused all the corners, (the 90° angle grinder was the ticket )and removed the carb stud lumps that hang down into the upper plane. Damn I wish I could have it flowed just for kicks
yellow rose
Overnight Sensation
The plenum looks like you knew what you were doing. Looks pretty dang nice.
mischiefdart
Well-Known Member
Nice work. Amazing how much time you can spend porting. I did a garden variety performer 318-360 and mostly concentrated on the port openings and maching them with heads. It went on a 318 that I had seriously reworked the ports on. I must have raised the roof on the intake ports close to the size of a J head. I was surprised at how much it woke the motor up. Good luck with your van. A100s are cool!
I've done grinding and sand rolls where I've said "it's good, I'm done", only to pull it back out and find areas to do more about 4 times now. Better stop before I **** it up!! I've got my EQ heads all assembled that I did mild porting, and am fighting the urge to work on the pushrod pinch that a few here said I should open up some more, gotta say I enjoy it, just wish I had the extra cash to put on a bench to see what the results are.
The old MP engines book suggests the below modifications to the LD340 (pictur ed) for increased power/RPM for there kit car program and other race venues that demand a dual plane intake to be used. The stated cam sizes best for use were listed only as over .600 lift. No duration numbers given. But! Given the time it was written, any cam with .600 lift or better was a very healthy cam for sure!
I have used this on much smaller cams with OK results and would caution on its use. Once the metal is gone, it's pretty much gone. I would certainly try a spacer. But a TQ spacer is unobtainium. A TQ adapter, which is spreadbore down to a squarebore metal spacer could be hogged out for best results in matching the entrance of the intake. Blend as needed.
P.S. You cam is a tiny one! IMO, I would not cut down the divider. But use a spacer instead.
famous bob
mopar misfit
A guy in broken arrow, ok. does intakes for $10 a port . I had him check my torquer 2 when I started opening it up to make sure I was doing the right thing.I've done grinding and sand rolls where I've said "it's good, I'm done", only to pull it back out and find areas to do more about 4 times now. Better stop before I **** it up!! I've got my EQ heads all assembled that I did mild porting, and am fighting the urge to work on the pushrod pinch that a few here said I should open up some more, gotta say I enjoy it, just wish I had the extra cash to put on a bench to see what the results are.
Well, along with all the time passing as I tried to source a 360 short block (which ultimately fell through) reading a bunch by Vizard and elsewhere, and then a few visits to the drag strip, I ended up with an assembled 9.8:1 408 short block and decided on upping the cam a little to an Isky 280 Mega on a 106°LSA - 280°/232° @.050"/.517"lift, 68° overlap, rest of setup the same. This is what happens when I make a plan and start buying **** in reverse order, only to have it go off track.
That ought to be a nice power plant.
Just an addendum to this thread about porting and divider mods, for the most part its generally accepted (by those without access to aluminum welding skills or services) that once you cut the divider out in any amount it pretty much permanent. I've done stages of divider removal and strip runs, among other mods, lots of test and tunes, and haven't been able to get back to the 60' times I had prior to complete divider removal. So I've been doing some piddling around in the shop, and came up with a work around to be able to run the intake with any size of divider via a removable insert. Restore it back to original, or any size of cutout. My setup with this intake seemed to do best with about a 1/2" cutout. Will make one at that spec, and any other spec cutout insert is just spending a little more time in the shop "piddling". This might keep resale value up! Keeping in mind that for my setup I have no room at all for various sized spacers to tune with, so cutting the divider is my only option with dual planes. Mainly just an example of options to revert to unmodded condition or anywhere in between full divider removal per Mopar bulletins. The pics show how the insert fits into the manifold. Nothing new, I've read elsewhere of others mentioning doing something along this line, but pictures not readily available that I could find
Very slick!
Looking forward to your work!
FWIW, I can’t remember if it was Mr. Gasket or someone else, but.... they have a 1/2 spacer that has this very thing. But it does raise the carb a 1/2 up.
Good to see some noddles being used around here.
Not to Hy-Jack, but I’m getting ready to port match a Victor SBM intake. Some pictures I’d like to share. The rest of this thread back to you!
Looking forward to your work!
FWIW, I can’t remember if it was Mr. Gasket or someone else, but.... they have a 1/2 spacer that has this very thing. But it does raise the carb a 1/2 up.
Good to see some noddles being used around here.
Not to Hy-Jack, but I’m getting ready to port match a Victor SBM intake. Some pictures I’d like to share. The rest of this thread back to you!
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yellow rose
Overnight Sensation
As a general rule, if removing the divider loses 60' times, the carb is too big, you can use a bit more initial timing, your converter is a bit tight or a combination of any or all of those things.
Now that you mention all that, I think I need to go over all my notes on stuff I've done in stages, rethink things, might be something else causing my slight loss of 60' times. (ever so slight but definitely lost somewhere) I have improved in mph each outing up to now with all the tuning,
Nice work!
yellow rose
Overnight Sensation
Cool. If the MPH is going up you are making more power. That means it can also be a chassis I issue. I look at MPH first before making any tuning changes and if MPH is going up you made more power.
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