I wouldn't say that a 600 cfm carb is too big.........tune it, adjust it so it works......4bbl 318 Cop cars used 800 cfm Thermoquads, I've done 3310 Holly's with no problems......if you have the 600 on hand, use it.......find a cheap Performer and move forward
318 alminum intake?
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I wouldn't say that a 600 cfm carb is too big.........tune it, adjust it so it works......4bbl 318 Cop cars used 800 cfm Thermoquads, I've done 3310 Holly's with no problems......if you have the 600 on hand, use it.......find a cheap Performer and move forward
pishta
I know I'm right....
Curious to find out how far the 800 TQ secondary doors ever opened on a WOT 318. They had great part throttle response with their quarter sized primaries.
PRH
Well-Known Member
It’s interesting how much variation there is in this thread on preferred manifold choices for a build like this.
I look at the SBM Performer as an easy 1hp/ci intake for mild 318’s/340’s/360’s.
I did a low Cr 318 about 30 years ago......
Mild ported 318 heads, Performer, 600vs Holley and a carter 625, 340 cam, headers.
Made 280+hp, depending on carb, spacers, timing, etc.
I think the best run was like 293hp.
Here’s a 340 with a Comp 268H cam, Performer, 650dp Holley, headers......
Went in a Lil Red Express.
I look at the SBM Performer as an easy 1hp/ci intake for mild 318’s/340’s/360’s.
I did a low Cr 318 about 30 years ago......
Mild ported 318 heads, Performer, 600vs Holley and a carter 625, 340 cam, headers.
Made 280+hp, depending on carb, spacers, timing, etc.
I think the best run was like 293hp.
Here’s a 340 with a Comp 268H cam, Performer, 650dp Holley, headers......
Went in a Lil Red Express.
Anything is better than the factory iron dual plane 2 barrel 318 smog intake. Replacing that boat anchor with any dual plane four barrel intake is a night and day improvement. I understand all too well about hefting a cast iron intake.
The grills in the F body are fragile as an eggshell! But the grill in this F body is already broke in half and missing a chunk!!! Not easy leaning over and doing any intake there! ha
Any decent 4 bbl will be a great improvement even in this smogger.
I agree with the other post about the 600 cfm carb. The larger primary over the 500 isn’t a gas waster but a throttle response and power improvement over the 500. In other words, it just simply feels better when you press the go pedal.
I have a dead on its heels no HP making smog era ‘78-B 400 (that was running excellent but crap for HP) that I tried a small primary TQ on top first. Figuring the low power smog engine probably wouldn’t need that much carb. Then I made the switch to the larger primary TQ. Gas mile didn’t change but the throttle response picked up SO much I knew that was the right size primary for that engine. Judges gavel slams down, the bigger primary stays! BLAM!
I should have asked if there where any future plans for the build such as headers and cam and gearing or if you are still having to use your smog equipment and EGR. There was a used street dominator on here for sale a while back, they are a good choice too. A performer with the 600 carb you mentioned properly tuned would well be worth the effort. Most of the ones I have messed with we used the hated and maligned quadrajets with a little extra air door tension, they have very good street manners.
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I doubt seriously I will build this 318, just a driver car, yes I would like to find a better gear! NO smg stuf here in Tx. No headers just stock exh. man. I just like to cruise here in the country a little, put my foot in it and feel a little response! and heae the secondaries jump in! I like thermoquards but never have been smart enough to tune one.! ha
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I know a car here in OZ that had to be slowed down as it was running in the 11.00 bracket and was right on the edge so they decided to change from an Air Gap to a Performer in the hope it would slow the car down. The car only lost a 10th.
I have a 600 Ed. on my 273 and it works perfect.
LD4B. And headers with 2.5 inch exhaust. Took a 71 Charger with a 318 from an absolute dog to something that would burn one tire. LOL. And at 17 that's all I cared about. Wait a minute........
Glad you wrote that! The Performer is about a dead equal to the factory iron 4bbl. Both intakes are rated to 5500. They will still make power with more rpm. A tenth is an easy 50 hp at that level.
I wish someone would make a copy of an LD4B, at least people would stop charging new airgap prices for them. If performance work is planned, I really like the regular performer rpm non air gap manifold. I come across them used for reasonable prices. With the exhaust heat blocked, it's virtually the same manifold.
That’s true. The benefit of the heat cross over is great for the true dual purpose daily driver. Perhaps, a fully heated up engine, there maybe a small difference. Very small.
Hello All, have been reading through this post of the hunt for an Aluminum 318 4bbl manifold. Thought this would be a good place to jump in here on Post Page #24. Think I know kind of what barbee6043 would like for his simple 318 low compression driver.
Been through a lot of this already on the hunt for a manifold on my buddy's performance build 318 with 318 heads. We settled on the LD4B and are extreamly happy with it. One of the biggest deciding factors was the port size of the specifc 318 manifold and the ease of port matching to the 318 heads.
Mostly everything else we looked at turned out being too large of ports for the 318 heads, like large port to small port. Anyhow everyone knows where I am going with this. We love the LD4B but now they are getting super rare and anyone that has them gets a premium for them.
Here is a simple cost effective way to get a 4bbl on his 318 and get some more fuel into that engine and have the secondaries to play with. Worked for me on this low mile original 69 318 that I did not want to open up and loose the originality on, but I knew i wanted the 4bbl and knew that 318 was just begging for more fuel just from the sound of it. Nice having the secondaries to play with now too. Edelbrock 1406 bolted right on, no rejetting and just runs great, and to my amazement good performance and 20 mpg pushing the car around with the 2.94 gears. That is a dual plane stock 318 2bble intake that does not need to be port matched because the ports match from the factory. Here we go:
This for starters:
To this:
Then to This:
Using This:
We have these LD4Bs but are saving them for our performance build 318s:
This setup above with the air cleaner on the Edlebrock on the red 318 was the first day rough draft setup. The next day I did a little machining on the Mr Gasket 4 to 2 bbl adapter where the mount bolts go to the manifold and used the below grade bolts with the kit to keep them out of the way of the butter flys opening up, then I was able to get rid of that carb spacer, drop it down, and make a nice clean install out of it.
Very happy with this 4bbl adapter setup on the 69 318, runs, drives, performs just fine. Popping on the the LD4B would wake it up even more, but it is a stock original and runs just fine now. Even the tone of the engine deepened up with the added fuel available, but yet still great mileage.
Kind of Unreal.
That is what is fun about this stuff, finding things that work out. Thanks
MopaR&D
Nerd Member
Did they switch to the Performer or the Performer RPM? Pretty big difference between the 2, regular Performer is basically an aluminum copy of the factory iron 4-bbl 360 intake but with the dual-pattern carb flange. Performer RPM is a "modern" dual-plane designed in the 1990s using Computational Fluid Dynamics (my avatar is an image of a CFD simulation of air flow through a 5.7 Hemi intake port). The RPM better damn well make more power lol.
CFD didn't exist until the 1980s or so btw, when computers started to have some actual useful power. It's literally solving hundreds of differential equations at the same time, by hand it would take years.
Edelbrock performers are all over the place, I have one on my 318.
Since you are changing the intake out, may as well put in a new cam and timing chain while you have the hood up.
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Dont forget the advil with leaning over the damn fenders.
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Picked up these Factory cast 1970 340 manifolds at the Super Swap here in Melbourne FL this year. No egr, no smog, factory square bore so the Edelbrocks drop right on, yes heavy, but they are mopar good.
Mopar Nationals in Davie FL tomorrow Sunday 3.3.19
Down by Fort Lauderdale, Good Show for anyone in the area.
Mopar Nationals in Davie FL tomorrow Sunday 3.3.19
Down by Fort Lauderdale, Good Show for anyone in the area.
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I thought they meant an RPM at first too but no it was definitely a Performer manifold.
MopaR&D
Nerd Member
Well... dang! That's all I can say lol
Go Mango
Never enough beer...
I looked at intakes all afternoon yesterday at the swap meet in Indy. Found a real nice performer 318/360 for $110, and several LD4Bs for around $275.
Yep, that Preformer was a nice one and worth the money.
The Weiand stealth or action plus is nearly an identical copy of an LD4B, flow testing by Hughes on hotrod network with dulcich shows a performance advantage over the base performer. The flow is marginally higher but the CFM spread from port to port is closer, which is worth a lot more than bigger numbers by itself. The flow numbers aren't that far behind and LD 340 with an action plus. Am presently putting a big block BBD (365 CFM) in place of the small block BBD (285 CFM) with a 1/2 inch adapter plenum matched to the ‘71 iron single plane. Probably not going to be a huge difference but doing it to improve part throttle cruise response and help clean up the idle tuning a little.
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Go Mango
Never enough beer...
Only problem was that I was looking for an intake with the larger ports for a 340. Found a total of 3.
Torker 340, Torker ll 340, and an LD340 that was overpriced.
I saw a LD340 for $150 on Friday but it got snapped up fast. I went back for it and it was gone. Probably to someone elses vendor spot. LOL
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