Edelbrock Performer or iron 340 intake?

[plumbcrazy69]

I've heard great things about both of these manifolds, but for use on a stock 318, which is better? This isn't a race car, just a fair weather cruiser. However, I also wouldn't want to turn down a quick run off the traffic lights around town either!

Whaddaya think guys?

[1972roadrunner]

hmm...what size cam are you running?? what kind of carb are you planning on using? what heads?

(i'm sure some of these questions are what the experts are gonna ask, i'm just curious )

personally i'd go with the performer, but it also depends on what cam you have, so you can match the intake with the cam...

good luck!

[plumbcrazy69]

OK, I'll try not to sound too dumb here. I'm merely a Mopar fan, not a mechanic....

When I bought the car, it had the original 318 w/2bbl. I bought a cast iron intake from someone at a swap meet for $50 to put on an Edelbrock 600 carb. The cam I assume was swapped by the previous owner, because it didn't look to have any junk in there. It was nice and clean. I dont know about it's lift/duration. Heads are original. I will also be adding headers in the near future.

The reason I asked this was because I read somewhere around here about the ports not matching up on the intake/heads of the 318 and loosing compression with the iron intake. I've also read that it was one of the best intakes around, so I'm left confused.

[1972roadrunner]

hmm...only thing i can think of is go ahead and get the performer and try it...see what it does...if you don't like it, put the iron intake back on. more than likely (guessing here ....i just wrench on the motor...dad orders the parts ) the you'll like the performer performance wise... if you don't like it, sell it at a swap meet or on ebay or sumthin...

good luck!

BTW: ya might wanna wait for an expert like rumblefish360, cuda67233, MoparDad, Doug Wilson, 5th Ave Sleeper and others out there before making any decisions i've got a lot to learn about matching cam/intake etc...(i'm only 16...i'll be 17 in Jan. )

[Doug Wilson]

I'd use the factory 340 intake. The port mis-match is a good thing for it gives lots of turbulence, which is good for a relatively low RPM street car. The 340 intake will work better than the performer, but it weighs maybe 30 pounds more. Another consideration is cost - if you already have one or the other - use it. There won't be any noticable performance gains by switching.

[72Challenger]

On the issue of lost compression, that happens when you use the 340 (or 360) heads, not the intake manifold. I agree with Doug, run what you got. If you do decide to do the head swap later (and mill them to get back your lost compression) you'd just have to get rid of the Performer anyway, it's too small for the bigger port heads.

[plumbcrazy69]

Awesome, gang. Thanx for the advice!

[mtrv8n]

um..you should check whether the 340 intake is square or spread bore. HP 340 intakes used the spreadbore to match the tq carb, a spreadbore (small primaries/large secondaries). you can put a spreadbore carb on a square intake, but not a squarebore carb (modern holley) on a spreadbore old 340 intake. Well, maybe you can, but you shouldnt.

the performer will give you more top end, and probably not affect bottom end noticeably. It is taller though, and you may not be able to fit the stock air cleaner over it.

[RogerH]

I wouldn't reccommend putting a 340 or 360 on a 318 with 318 heads. Its not so much the port mismatch, but you want to get good velocity in the runners to fill the cylinders with as much air/fuel as possible. A 340 intake on a stock engine will slow the velocity down and most likely kill power sicne the cylinders wont fill with as much air/fuel.

A 340/360 head/intake combination works great when you raise the compression and put a big cam in the 318.

I have heard good results from the performer intake on mild performance vehicles. When the engine gets built larger, where a 340/360 intake can be used, the RPM dual plane is an excellent choice!

Roger

[Doug Wilson]

Roger - Wouldn't the velocity be largely controlled by the carb, before the stuff (air-fuel) reaches the manifold, and also, by the heads' ports after it goes through the manifold??

Is the Performer taller than the Hi-Po 340 manifold??

Spread-bore/square-bore issues are pretty easily solved with a 4 hole adapter/spacer - no??

Thanks, Roger

[moparman318]

I would invest my money into something better than an Edelbrock. The performer intake on my 318 really was a peice of work. The thermostat housing was all pitted and a different size than my old one. What a surprise. If I could do it all over again I would have got a matching MP cam and intake instead of the performer package. Course the intake was free. Still edelbrock has done nothing to impress me. My advise would be to use what ever you have lying around unless you really want to burn that money. In that case "Get real, Get Mopar".

[Doug Wilson]

Congratulations on joining the Corps! I've got 4 sons in the military. Everyone on this forum respects and admires those of you who sacrifice for our Country.

Disagree with your Edelbrock thoughts, though.

[moparman318]

Thanks Doug. What branches are they in?
Anyways I just don't think its worth the money to buy another intake. Right now my truck is running Edelbrock performer cam, intake and carb. Carb came with the truck. Intake was stolen off of my friends truck (not litterally, more like a redneck-swap trade parts for beer). I have owned the truck for a year and the carb just doesn't feel right. I know it needs a tuning but with an out of the box performance claim I would have though they could have done better. The stock Cater TQ probably performed just as good, if not better. The manifold still doesn't impress me and the cam has not caused a noticible difference. That only happened with the intake. Given that the stocker was all clogged up and leaking. But thats just my opinion

[Doug Wilson]

1 - 82nd Airborne - a Ranger, 2 - Special Operations Command - formerly 101st Airborne, 3 - F-18 Hornet Troubleshooter, 4 - Sapper/Combat Engineer - 1st Armored in Germany.

When do you go on active duty, and for how long??

I think you need some tuning. If your car is not performing nicely maybe you need your distributor curved, cam indexed, carb jetted and tuned. All of this stuff can be done cheap or free. Added to your new headers, you should get a snappy 318 out of it. If you need to know, we can tell you how to derive your cam specs - you'd need a magnetic base dial indicator, but they can be borrowed, andd they are easy to use.

By the way, 1972RoadRunner - thanks for the nice words - I appreciate them.

[George G. Leverette]

I am running a performer on a 318 1974 Duster because of emissions, the Edelbrock came with provisions for the egr valve. The 340 intake thru 72 did not have the egr valve or I would have used it. The performer is a direct replacement for the 340 and will mount the square or spread bore carbs, the 340 will only mount the spread bore. The Mopar dual plane M-1 is an alumnium replacement for the 340 intake with mounts for the square only and the choke well interfers with some carbs, the 340 intake is the best choice if emissions is not a factor.

[Doug Wilson]

Thank you, George... I feel validated.

[plumbcrazy69]

If you need to know, we can tell you how to derive your cam specs - you'd need a magnetic base dial indicator, but they can be borrowed, andd they are easy to use.

Do tell, but keep it simple - My only engine work experience is chrome valve covers!

I am of course, eager to learn. My car has sat idle for a while and I'm dying to get her up and going strong!

[RogerH]

Doug...

Actually, you need to look at it in reverse. The signal is coming from the piston, and if you are using a carb that can't flow enough air to feed the engine, you need to upgrade to a larger carb.

The most important feature of a manifold, for selecting which one works best for an engine combo, is runner length and area. Length is tuned for rpm, and area for desired horsepower output. On lower speed engines, a longer runner is better, and they get shorter for a higher reving engine. The runner area is determined by the type of typical cam and horsepower level for the engine. From there it is sized to give the desired average velocity in the runner. The plenum acts as a buffer between the carb and the runners, and they are typically too small on a carberated intake, which is why we usually see better performance when a 2 inch spacer is put under the carb.

The main target is to optimize the airflow throught the runner, of both the intake and head.

It is also amazing how bore and stroke combinations for the same target horsepower output can vary the runner area. In general, for the same horsepower, a chrylser intake will have a smaller runner area than a chevy....yet make the same power.

I don't know which manifold is taller, I have not seen a 340 Hi-Po.

Yes, a carb spacer can be used to adapt a spread-bore to a square-bore manifold, and there are some in our catalog!

Roger

[Doug Wilson]

Thank you, Roger.

[George G. Leverette]

Doug, I have too much respect for your opinion to violate you, am I confusing the spelling? sorry Doug just had to do it.

[Doug Wilson]

You broke me up with that. The spelling is VALIDATED, not VIOLATED!!!

Been both - like validated better.