[g00f]

So my car's in for repairs at the moment and it looks like I'll have some leftover cash from insurance is all said and done. Something I've been chewing on for some time is changing out my Performer 289 intake for something a bit more impressive.

Now, the internals of the motor are a bit of a mystery to me, previous owner put in aftermarket valve train components (looks to be all Comp Cams gear), I've had people say it sounds like it has a mild cam in it(for whatever that's worth) and has headers. I've tried to ID the heads with little luck, no idea if there was any machining done to them. At this time I assume theyre stock for the block (a '74). No idea if compression was ever adjusted from the smog era goodness.

I was looking at the Weiand Stealth. What I'm reading indicates it gives a bit more top-end gusto but doesn't adversely affect low-range rpm operation much. I've read other people saying they felt a bit more power through the butt-dyno all through the rpm band. I've read they're pretty good over stock motors and if there has been any more serious work done on my motor it'd provide a much greater benefit over the performer.

What I'm curious about is a.) Is there going to be any serious decline in my mpg? Might seem like an odd question but my car's my daily and I'm just trying not to lose much mileage,

b.) Is port matching on a new intake required or recommended? What I'm reading seems to imply pretty marginal gains.

Thanks in advance!

 

[mhuggler]

If you already have a performer intake you probably won't see much of a gain if any at all. They look better than a performer anyway. Lol

 

[g00f]

If you already have a performer intake you probably won't see much of a gain if any at all. They look better than a performer anyway. Lol

Really? I thought the performer was essentially an aluminum version of the stock intake. And the Stealth has a bit of height on it.

 

[mhuggler]

Really? I thought the performer was essentially an aluminum version of the stock intake. And the Stealth has a bit of height on it.

That depends on the application; they make a performer for just about everything. Typically though, they do have a little rise to them over the stock manifold and they definitely flow more. The only way you're going to see a significant gain by going to the stealth is if you have the performer maxed out which we won't really know without specs on the heads.

 

[Gt350HR]

Really? I thought the performer was essentially an aluminum version of the stock intake. And the Stealth has a bit of height on it.

The performer is a good bit different than the factory iron 4bbl intake. A switch to the Stealth "might" see 8-10 hp over a performer but WILL have a noticeable loss in low end power. There isn't a manifold ( for you at this point) that will give you more top without losing some bottom. My suggestion to you is try an "open" 1" spacer under the carb as my friend from the Edelbrock's dyno room recommended to me. Don't use the factory style four hole spacer it will not work in this case.
Randy

 

[g00f]

The performer is a good bit different than the factory iron 4bbl intake. A switch to the Stealth "might" see 8-10 hp over a performer but WILL have a noticeable loss in low end power. There isn't a manifold ( for you at this point) that will give you more top without losing some bottom. My suggestion to you is try an "open" 1" spacer under the carb as my friend from the Edelbrock's dyno room recommended to me. Don't use the factory style four hole spacer it will not work in this case.
Randy

Interesting. I do currently have a spacer on the carb, I believe a 1/2" with a four hole. I'll give the open spacer a try and see how it goes, pretty easy start point.

 

[Beechkid]

In addition to the above, I will throw this out......


If you swap to an Weiand Action Plus or an Edelbrock Performer, then you may as well keep the stock intake IMHO as there is really very little difference with regards to performance on a street vehicle. I would go futher and swap to any of the following intakes: Ford A321, Edelbrock F4B, Shelby "Cobra" (these are all basically the same intakes) or Weiand Stealth, Edelbrock Performer RPM, or Air Gap RPM (which might cause hood clearance issues)


With regards to manifolds, the Edelbrock Torker II (IIRR) manifold is a near duplication of the Shelby manifolds used in the 60's. RPM band is from 1500-6500 rpm (IIRR) and will easily handle up to 750 cfm. How they compare to the new air gaps, I don't know but the performer intake will not really provide as much benefit as what the article as say with the 289- but check with their Tech Dept. since things do change over time.
As you know, a dual plane intake is typically the best design for street use. The dual plane system allows for max atomization of fuel air at low & high CFM flows. Single planes are streetable, but typically are designed for track, high RPM use where max atomization is achieved at high CFM flows, most have very large runners and are more commonly called "open plenums", typically, low rpm drivability/tuning is difficult.

 

[g00f]

In addition to the above, I will throw this out......


If you swap to an Weiand Action Plus or an Edelbrock Performer, then you may as well keep the stock intake IMHO as there is really very little difference with regards to performance on a street vehicle. I would go futher and swap to any of the following intakes: Ford A321, Edelbrock F4B, Shelby "Cobra" (these are all basically the same intakes) or Weiand Stealth, Edelbrock Performer RPM, or Air Gap RPM (which might cause hood clearance issues)


With regards to manifolds, the Edelbrock Torker II (IIRR) manifold is a near duplication of the Shelby manifolds used in the 60's. RPM band is from 1500-6500 rpm (IIRR) and will easily handle up to 750 cfm. How they compare to the new air gaps, I don't know but the performer intake will not really provide as much benefit as what the article as say with the 289- but check with their Tech Dept. since things do change over time.
As you know, a dual plane intake is typically the best design for street use. The dual plane system allows for max atomization of fuel air at low & high CFM flows. Single planes are streetable, but typically are designed for track, high RPM use where max atomization is achieved at high CFM flows, most have very large runners and are more commonly called "open plenums", typically, low rpm drivability/tuning is difficult.

Not sure if there was some confusion - the Weiand Stealth (8020) was the intake I was looking at, not the Action Plus.

I'm just kinda surprised from what I'm seeing here. My previous reading had indicated that the Performer 289 (not Performer RPM) was a moderate improvement over the stock 4 bbl, and the Stealth was a pretty solid upgrade(I'd seen a few people on various forums say its among best bang for buck) and they didn't suffer much in the low rpm bands and saw solid improvements from mid to high range. Specs for the performer vs stealth show almost an inch of extra height on the stealth, but if I'd see similar improvements bolting an open 1" spacer onto my current Performer I'd definitely be fine going that route since that would run me a tenth of the cost.

All that aside, I'm still curious what the answers to my original questions were. Would fuel economy be impacted one way or another and is porting highly recommended or just a small improvement?

 

[Gt350HR]

On a street engine I don't see porting /gasket matching as being worth the effort. It is very easy to do more harm than good.
Randy

 

[g00f]

On a street engine I don't see porting /gasket matching as being worth the effort. It is very easy to do more harm than good.
Randy

Thanks. That was kind of the impression I was getting, just wanted a double check.

 

[Beechkid]

Not sure if there was some confusion - the Weiand Stealth (8020) was the intake I was looking at, not the Action Plus.

I'm just kinda surprised from what I'm seeing here. My previous reading had indicated that the Performer 289 (not Performer RPM) was a moderate improvement over the stock 4 bbl, and the Stealth was a pretty solid upgrade(I'd seen a few people on various forums say its among best bang for buck) and they didn't suffer much in the low rpm bands and saw solid improvements from mid to high range. Specs for the performer vs stealth show almost an inch of extra height on the stealth, but if I'd see similar improvements bolting an open 1" spacer onto my current Performer I'd definitely be fine going that route since that would run me a tenth of the cost.


With regards to porting.....gasket matching, ok if it's fairly off, but most of the time, the fit is very good and porting, well, cleaning up is always a good thing.






All that aside, I'm still curious what the answers to my original questions were. Would fuel economy be impacted one way or another and is porting highly recommended or just a small improvement?

a little bit of my reply was more of a discussion point that I figured would come up anyway......in summary, keep what you have. The amount of $ you will spend are not going to get you much of any real world gain on a relatively mild street engine...as compared to what fine tuning will do.