Weiand 8311 carb intake with EGR

[Saturn V]

I've been looking for one of these for the last couple of years. I've never been able to find any factory documentation for this intake, and have only found a few anecdotal comments about them on the web. Occasionally I search for these on Google and last week I found this one on some obscure forum. I found that the part was also posted on Craigslist so I contacted the seller, made the deal, and it was delivered to my house today. Below is a photo of the 8311 next to the original intake from my car (I installed an Edelbrock Performer 302 earlier this year).






The reason that I wanted to find an 8311 is because other than the Performer 302, it's the only aftermarket intake that I know of that includes the EGR port on the carb flange. I intend to retain the EGR system, along with all other emissions controls. I want to eventually upgrade to a roller short block and aluminum heads, but believe that the Performer 302 intake will be a bottleneck.

For comparison, I took measurements of the stock intake and the 8311 as best I could. The dimensions for the Performer 302 are from Edelbrock's website. I don't recall the Performer 302 looking any taller than the stock intake, but maybe it is. It's clear from the photo above that the 8311 could easily be about 3/4" taller than the stock intake.

	Front H	Rear H	Port W	Port H
83-85 Stock	3.0	4.25	0.8	1.56
Edelbrock Performer 302 (3721)	3.4	4.75	1.1	1.8
Weiand 8311	3.75	5.13	1.06	1.9

One thing I noted is that there's not a lot of difference in port dimensions for aftermarket intakes. See the thread below, which provides dimensions of other intakes.

http://vb.foureyedpride.com/showthre...d-Dual-Snorkel

Since I intend to eventually install the 8311 with the factory EGR spacer plate, I may have hood clearance problems. I'd rather not install a scoop for clearance. The Performer 302 fits fine now, so if the dimensions above are correct, I only need to clear about another 3/8" to make the 8311 fit. I've thought about milling the 8311 carb flange down about 3/16", maybe milling the EGR plate a little, and taking out the hood insulation. I've read different things about convertible engine mounts, but am starting to believe that these won't offer any more clearance over the original worn mounts that are in there now.

[Saturn V]

The intake plenum of the 8311 is cavernous compared to the stocker. Also note that the path to ports 6 and 7 is almost a straight shot, more like a single plane intake.




I'm glad to see that the 8311 includes water passage ports for the two vacuum switches. I think that all factory accessories will bolt up fine.




There's a little corrosion around the water passages, but I hope that cleans up when I have the intake blasted and maybe powder coated.

[Saturn V]

I welcome any comments or additional information about the 8311 intake. Here are some other pics for comparison.

[84GT350CONV]

Not hard to see why you bought that intake. I have zero clearance on my factory setup to the hood. Looks like the factory carb spacer won't work without hood clearance problems. I'm interested to see what will work for you or if another member has a solution.

[burntorange84]

Saturn,

Nice find, I didn't know that one existed. One thing you might be able to do is two fold. Buy the Edelbrock replacement EGR plate which is aluminum (#8053, I believe) and mill it down on both sides to the workable limits. You might have to plug the front port and tap a smaller barbed fitting in there. Also, you could shave the top of the manifold maybe .125 to get a little more room.

Also, I have put the vert motor mounts (Ford 93 mounts) on and noticed no height difference. I believe that is a web myth because to keep the same drivetrain angle, the tranny would have lower also, which still changes the drive shaft angle.... they look stronger for sure but I doubt Ford lowered it.

If you wanna sell that 3721, let me know! I still haven't down loaded photos from the show...hope to catch my breath in a few days. BTW: I started a bumpsteer thread and I suppose you might have the same issue since you lowered your car too.

-j

[JACook]

The runner arrangement on this intake is like the old Edelbrock F4B, and most other aftermarket dual-plane
intakes from the '60s. The theory was, you have four longer runners that aid low-RPM torque, and four short
runners that would work better at higher RPM, not unlike the log intake Ford used on the small sixes. This
was supposed to widen the overall curve.

In practice, like the log intake, fuel mixture distribution is not as good as it is with more equal runner lengths,
and those short runners allow more disruption at low RPM from reversion pulses. I don't know of any company
making a dual-plane intake with that runner arrangement anymore.

The key benefit of this intake over the Eddy 3721 is the rise, and larger plenum volume, but the higher rise is
also it's biggest liability under the hood of a Fox, if you're wanting to use it's EGR capability. Also keep in mind
the factory EGR plate will require the spacer between the plate and the intake, like you have with the 3721.

The factory EGR plates I have here range from .720" - .760" thick, and you could probably go as thin as .700"
without issue, but I don't know that I would go much thinner than that. While Ford did make low-profile PCV
spacers back in the '60s/'70s, I do not know of any lower-profile EGR plates. I don't have the Edelbrock 8053
plate here, but Edelbrock says it's 1" tall, so if true, that's starting off in the wrong direction.

I would take Edelbrock's published measurement of the intake heights with a large grain of salt though. Having
swapped out the stock intake on my '85 hatch for the 3721, I don't believe the 3721 is anywhere near .5" taller
at the carb pad than the factory intake. For the purposes of discussion, I wouldn't count on your existing 3721
being any taller than factory, apart from having the 8017 adapter plate under the EGR spacer.

[Saturn V]

Not hard to see why you bought that intake. I have zero clearance on my factory setup to the hood. Looks like the factory carb spacer won't work without hood clearance problems. I'm interested to see what will work for you or if another member has a solution.

I think you're right about hood clearance problems.

Saturn,

Nice find, I didn't know that one existed. One thing you might be able to do is two fold. Buy the Edelbrock replacement EGR plate which is aluminum (#8053, I believe) and mill it down on both sides to the workable limits. You might have to plug the front port and tap a smaller barbed fitting in there. Also, you could shave the top of the manifold maybe .125 to get a little more room.

Also, I have put the vert motor mounts (Ford 93 mounts) on and noticed no height difference. I believe that is a web myth because to keep the same drivetrain angle, the tranny would have lower also, which still changes the drive shaft angle.... they look stronger for sure but I doubt Ford lowered it.

If you wanna sell that 3721, let me know! I still haven't down loaded photos from the show...hope to catch my breath in a few days. BTW: I started a bumpsteer thread and I suppose you might have the same issue since you lowered your car too.

-j

Yes, I thought about milling the intake carb flange a little. That's a good idea about the Edelbrock EGR spacer, but Jeff says it may be even taller than the original part. I even thought about a custom-made EGR spacer that's about 0.5" tall. I think you're right about the vert engine mounts.

I put on the Steeda bumpsteer tie rod ends along with all of the other mods and haven't noticed any problem.

The runner arrangement on this intake is like the old Edelbrock F4B, and most other aftermarket dual-plane
intakes from the '60s. The theory was, you have four longer runners that aid low-RPM torque, and four short
runners that would work better at higher RPM, not unlike the log intake Ford used on the small sixes. This
was supposed to widen the overall curve.

In practice, like the log intake, fuel mixture distribution is not as good as it is with more equal runner lengths,
and those short runners allow more disruption at low RPM from reversion pulses. I don't know of any company
making a dual-plane intake with that runner arrangement anymore.

The key benefit of this intake over the Eddy 3721 is the rise, and larger plenum volume, but the higher rise is
also it's biggest liability under the hood of a Fox, if you're wanting to use it's EGR capability. Also keep in mind
the factory EGR plate will require the spacer between the plate and the intake, like you have with the 3721.

The factory EGR plates I have here range from .720" - .760" thick, and you could probably go as thin as .700"
without issue, but I don't know that I would go much thinner than that. While Ford did make low-profile PCV
spacers back in the '60s/'70s, I do not know of any lower-profile EGR plates. I don't have the Edelbrock 8053
plate here, but Edelbrock says it's 1" tall, so if true, that's starting off in the wrong direction.

I would take Edelbrock's published measurement of the intake heights with a large grain of salt though. Having
swapped out the stock intake on my '85 hatch for the 3721, I don't believe the 3721 is anywhere near .5" taller
at the carb pad than the factory intake. For the purposes of discussion, I wouldn't count on your existing 3721
being any taller than factory, apart from having the 8017 adapter plate under the EGR spacer.

I see your point about the compromises of the 8311 intake. I guess it's not as good as a modern dual plane, but it's the only one other than the 3721 that I could find with EGR. I even thought about seeing if I could modify one of the new dual plane intakes to add an EGR passage. That would likely require more work that just drilling, since it seems the carb base plates aren't wide enough on the passenger side to accommodate the passage. Also, most don't seem to have the two ports on the rear water passage for vacuum switches. I'm not planning anything immediately with the 8311, but if I ever do the roller short block and aluminum head combo I'll try it.

Yes, I'd need to re-use the EGR adapter plate from Edelbrock to seal the bottom of the stock EGR plate. I think you're right that I won't be able to mill too much off of an OEM EGR spacer without compromising the integrity of the passages. Of course, I wouldn't try that on the original part ... I've got a spare OEM part for that (with 3 vacuum connections in front ... wonder what it came from?).

I tend to think that you're right about the 3721 measurements ... I don't think it's really 0.4" taller than the stocker. Of course, I could have measured the stocker incorrectly ... maybe it's a little taller than 3.0" at the front?

[8ballEinstein]

My recommendation is to grind open the ports on the Edelbrock and be done with it. I did this with mine - hand porting 1 mm in each dimension. Could've gone a bit more, especially on the height. Real easy to do.

[JACook]

I've actually given some thought to an extrude-honed 3721. But I'm not quite sure how that would work,
given the runner layout. I've also thought about crafting an integral-EGR Performer RPM, using the later
Explorer-style EGR valve, since that intake would rule out the spacer plate. But so far it hasn't progressed
past the thinking about it stage...

[Saturn V]

My recommendation is to grind open the ports on the Edelbrock and be done with it. I did this with mine - hand porting 1 mm in each dimension. Could've gone a bit more, especially on the height. Real easy to do.

Per the Edelbrock website, there's not a lot of difference in port size between the Performer 302 (1.1 x 1.8) and Performer RPM (1.05 x 1.86). I'm not sure that porting the Performer 302 would make much difference. I think the real difference is in plenum volume and runner size throughout the intake.

I've actually given some thought to an extrude-honed 3721. But I'm not quite sure how that would work,
given the runner layout. I've also thought about crafting an integral-EGR Performer RPM, using the later
Explorer-style EGR valve, since that intake would rule out the spacer plate. But so far it hasn't progressed
past the thinking about it stage...

I've read about extrude-honing a carb intake. I've not been serious enough about that to call a vendor, but have read that it costs a few hundred dollars. If I knew how much the process would actually benefit the 3721 intake, versus the 8311, I'd consider it.

Do you mean using an EGR valve like the one below? Where were you thinking about tapping into the exhaust and then into the air path?

[8ballEinstein]

Per the Edelbrock website, there's not a lot of difference in port size between the Performer 302 (1.1 x 1. and Performer RPM (1.05 x 1.86). I'm not sure that porting the Performer 302 would make much difference. I think the real difference is in plenum volume and runner size throughout the intake.



I've read about extrude-honing a carb intake. I've not been serious enough about that to call a vendor, but have read that it costs a few hundred dollars. If I knew how much the process would actually benefit the 3721 intake, versus the 8311, I'd consider it.

I'm dead-set against Extrude Honing a 3721. It's an expensive process and it removes the casting flash - which sounds good but carbed intakes need that flash for turbulence to help atomize the air-fuel mixture.

The Edelbrock design has tapered runners going out to the exits. Hand porting the exits to remove some of that taper makes the job real easy. Cost will be minimal.

Just my humble recommendation ...

[Saturn V]

I'm dead-set against Extrude Honing a 3721. It's an expensive process and it removes the casting flash - which sounds good but carbed intakes need that flash for turbulence to help atomize the air-fuel mixture.

The Edelbrock design has tapered runners going out to the exits. Hand porting the exits to remove some of that taper makes the job real easy. Cost will be minimal.

Just my humble recommendation ...

8ball, I hear what you're saying about the casting flash and had similar thoughts. I called Kennametal today and talked to a guy in their Pittsburgh facility where they work on automotive intakes. He said that the price to extrude hone a SBF carb intake is $535, plus shipping each way. He said that they've seen gains of 10-15 HP on carb intakes. I asked if this was on race engines and he said they've also seen similar gains on street engines. My skeptical extrapolate-o-meter tells me that on a mild street engine, the gains would be more like 5 HP, maybe 10 HP, tops. I asked about fuel puddling and he said with all of their testing they had not seen that as a problem due to typical high flow velocities. He also said that the work does not effect emissions legality of the part and I think I read that somewhere else, too.


$600 sounds spendy for 5-10 HP. I wouldn't do it for a near-stock engine, but maybe with a cam and aluminum heads if I couldn't make another intake work with EGR and clear the stock hood.

[burntorange84]

.....My skeptical extrapolate-o-meter

I got one of those too. Not worth the cost for those gains in my opinion!

BTW: I agree with Cook on the 3721 that it is the better manifold. I think if you upgrade your exhaust you'll finally feel and see the power gains of the 3721, on your current stocker. I want to dyno my car before I swap to the 3721...

-j

[Sinister]

that too much, I would say, hang that intake on the wall for antique, and get a eldelbrock rpm intake and call it day.

[8ballEinstein]

... My skeptical extrapolate-o-meter tells me that on a mild street engine, the gains would be more like 5 HP, maybe 10 HP, tops. I asked about fuel puddling and he said with all of their testing they had not seen that as a problem due to typical high flow velocities. He also said that the work does not effect emissions legality of the part and I think I read that somewhere else, too.


$600 sounds spendy for 5-10 HP. I wouldn't do it for a near-stock engine, but maybe with a cam and aluminum heads if I couldn't make another intake work with EGR and clear the stock hood.

I think picking up 10 - 15 HP is entirely possible with some port work ... if the bottleneck is at the intake. Spending $600 to pick up 10 HP is a little pricy when compared with other ways you can get those 10 horses - 1.7 RR's or underdrive pulleys, for example.

Keep us up to date with your progress, whichever way you go.

[JACook]

Do you mean using an EGR valve like the one below? Where were you thinking about tapping into the exhaust and then into the air path?

Not necessarily that specific valve, but yeah, that's more or less what I had in mind. I haven't really fleshed out
how I would connect it all up, but I figure I could tap into the exhaust crossover underneath the intake. The more
difficult part is the delivery tube. Best would be to bore into the rear, splitting the plenum divider just below the
carb pad, but there's not much height available there. I also thought about going into the divider at the floor of
the upper plane, but that seems pretty sketchy.

An alternative version has me cutting the tray out of an airgap intake, to run the tubing in the gap, with a vertical
delivery tube right up the center of the plenum from the bottom. Then weld the tray back in.

Being there's no ECU, I would have to use a backpressure compensating style EGR valve, so possibly something
like the valve for a carbureted 2.3L would be the general idea. I could more or less position it in the same location
as the original, and it wouldn't attract much attention. A non-compensating valve might could be used along with
an external backpressure compensator controlling the vacuum to the valve. Lotta Japanese engines used those.

I'm not sure what I would do about the TVS bungs, but one possibility would be to weld in bungs on each flange,
like the RPM 351 has, or a complete rear crossover from another intake. I could also fab a crossover from tubing,
and connect it to nipples at each flange, with short pieces of hose. The earlier version of the 7121 has a crossover
with a single bung, as did the Ford Racing version. Those would only need a single bung added.

I'm really not sure if/how well any of this would actually work, or whether it would just be a lot of work to turn a
perfectly good intake into scrap metal. This was a lot easier back when I added EGR capability to

[Dean_T]

I have an Edelbrock Performer 302 on my '78 Wagon's 302 with the Holley replacement 2bbl. It all fit under the stock hood and felt like an improvement over the heavy cast iron 2bbl intake it replaced. I seem to recall the port size was a little smaller than the Performer 289 intake.