keep us updated, port projects are always fun regardless of outcome....Bet your curve is about the same just more of what you got.

If you carb'd it a good dual plane would be better all around on the street. Just donated an LT1 intake with the lid cut off to a neighbor who was turning in scrap lol

 

Well I’m looking forward to this.

 

Give me a little while. This thing was laying around if you know what I mean.
Again, a friend was looking into using the heads I have on his build but as it turns out pretty much no dual plane will cover the port. I was surprised the stocker did (just barely at that but it did) he was going very very similar to me and it would have been a good comparison but now with different heads I can't compare apples to apples so I scrapped that idea. I suppose if I was very careful I could make a 1206 seal on a performer but just laying on the gasket there was very little holding it there... I would think an rpm air gap would work but he had a regular performer so...
Awesome

 

So here is what I got:


Interestingly, this one has the balance ports between the runners (casting 017) mine does not if I recall correctly. Now it may look dirty but I have a hot pressure washer. Not an issue.

This is a photo I found of the port cutaway. Not a lot to work with...


so here is what I'm thinking based on work I've seen others do... anything in red is the removal zone lol

Swirl plates, gone. Easy enough.

I'm going to clean up and square the end of the runners like so. Make the port ends similar to a renegade.

So this is generally the area I've seen people port match to. Kind of gives a crappy entry angle to the head port...portI think I will try this.

The blue area I will braze in extra aluminum. Then I will grind to that angle giving a better turn radius and less of a sudden expansion so more fuel stays in suspension. Instead I will work the top half of the runner as best I can and not worry about punching through the runner to the water jacket. That should again allow for a straighter shot at the head and valve and should help.

There really doesn't seem to be a ton to be gained here. Less than I originally thought but it will be an improvement none the less... any thoughts on this plan of attack? I'm new to porting but have a basic understanding of fluid flow and why things do certain things so I am ears to improvements and opinions.

Also, anything I break through up top can be easily repaired so it seems a better approach...

 

I am not a CFI guy, so I haven't looked at these parts a lot. Funny to see the fins in there to stir the mixture.

I am guessing these are in there to help mixture at low engine speed. Curious if anyone has ever noticed a difference when removing them?

 

Te side walls are pretty thick. Get after them, too.

Also, radius the under side of the lid, @ the TB "outlet". You don't want the a/f mix coming out of the bottom of the lid at high velocity, and slamming into the plenum floor....IMO. So you can slow ans spread the mix, I feel, but tapering the bottom of the TB bore below the throttle blade's closed location, blend that into the lid hole where you can radius it out. When done, and with the TB's bolted to the lid, flip the lid over and the holes should look like a "reverse" velocity stack.


.

 

They are a joke. You'd think that any engineer who looked at that "solution" back in the day might say to themselves...."Something has gone awry with our plans here."...and try to fix it. But they didn't...they put it into production, propeller blades and all!
IMO, they hurt distribution as much as they help it, by tapering smaller at their outlets. DUMB. They're accelerating the A/F mix into the floor of the plenum. Yeah they're trying to "spin" it outward, too, but they should have flaired out the bore around the "propeller" blades.
I don't think they're for low speed; the throttle plate is already a barrier in the path of flow, that would do that somewhat. I think they're for when the throttle is far open. I couldn't look at those things and agree with myself that they should be there...so I got rid of them and did as I described above. The detriments? Zero. Anyway, whatever criteria they were put in there to help meet, is criteria that we don't care about.


.

 

So taper in the underside of the plate like a lip on a pot?
They are basically a simple static mixer. All they introduce is turbulence and a pressure drop across them and I don't believe they help in anything other than cold weather when the plenum is cold to help dispersion. Once its warm the whole underside of the intake is heated anyway. Not seeing a real benefit.

 

This is what I did:




-NOTE, that the smallest part of the opening is larger than even the 53mm bored TB's I had, so I started that outward taper IN the TB, below the throttle blades.


I agree but would add that they didn't do squat (in a meaningful way that WE care about) when cold either. My car had them gone, heat stove disabled and warm air blocked with cowl valve tied open, water passage removed under plenum, ....and it would still fire right up and run fine in 10* weather.

 

I can do that for sure. Renegade was flat cut on the bottom iirc but the plenum height was greater as well so it didn't fall out as bad.

That should help with dispersion for sure provided the flow is great enough.

 

@Tom400CFI Did you bore your own TBs, or have a machine shop do it?
I have a machine shop (small 1 or 2 man shop) that's willing, however i learned his "hourly rate" also includes him being super slow.
(I had him make Delrin bushings for my steering rack, he did a great job but holly F he was expensive, he blew his own quote out of the water... lol)

I also got the feeling that he priced it right at what he needed...
Right as i was paying he called the city to let them know he had the money to pay a fine...
Nice that i could help him out and all, but he lost a customer over that one.

 

I bored my own but had access to a boring bar (for motorcycle cylinders). The "you can go 53mm" claim was BS. I holed the **** out of my TB's. I repaired them w/epoxy, then hand sanded the epoxy and finished with a brake hone.


Try H&S Machine on ~3300s and 1400w...right behind Plaza Cycle. Excuse me....Karl Malone Motorsports. They are awesome, do good work and listen to you. Price is fair.

 

@Tom400CFI
Nice, I'll check them out.
Plaza cycle, i remember that name.

And i have a set of Holly 2in butterfly's and a spare set of throttle bodies for the project,
I believe they were off of an 82. Not sure if there is any difference there.

@84 4+3
My original 84 intake also has the balance ports

 

 

Nope I don’t think they do a thing, well not in my climate anyway.

 

You guys might be surprised what they are there for. Why I assumed for low speed: My 2005 3V 4.6 Mustang () had "Charge Motion Plates" that I deleted. Yes, you buy a casting without the machining for the plates and it is an upgrade. They were there for low speed engine operation to create turbulence and improve mixture. I believe they were fully open at 1500 RPM, but that is going off 15 year old memory. Once I went to a 4.11 in the back, I never operated the car below 1500 RPM except to leave form a dead stop. Didn't notice any change in vehicle operation there either.

I get the idea of a reverse velocity stack to not slam the mixture into the floor. Possibly below the TB openings, the floor should have a low cone shape to spread out the flow that hits it, or a "fin" that will push it toward the correct intake openings. Just an off the cuff thought.

 

i saw a post once from one of the engineers that worked on the crossfire. Obviously they had lots of competing priorities that we don’t care about ie emissions, fuel economy, and being able to function correctly the a wide range of climatic conditions. Anyway apparently they had problems with fuel pooling in the intake. My Renegade doesn’t have a heated floor like the factory intake and doesn’t have swirl plates and I don’t have any problems with fuel pooling. I live in a pretty warm climate so that may help. I’ve also heard that the GM engineers were rushing to get it ready for the 82 and were too busy with other stuff on the 84. I’ve also read that the casings came back wrong and the front and back TB should have been reversed ie left at the front and right at the back, but that would mean everything would need to be reversed and I can’t see why it would make any difference. Anyway that’s one of the many things I’ve read, I don’t necessarily believe them all.

 

It's NOT BS! If done properly you can go farther than that. Mine are bored 2.13" and 53mm is only 2.08661". Mine are NOT sleeved at all and done professionally by my machinist locally. Ben73 in Australia has his TBs bored to 2.20" without issue. The Renegade will except up to 2.25" TBs.

Good luck with your project and waiting to see how it does. We did some comparisons many years ago, but I don't know where that data is anymore and Jim may still have it somewhere. We did a lot of flow tests on a bench with both the stock manifold and ours. To our astonishment, the company doing the flow tests found an issue with the stock manifold. The issue is there is a dead spot for flow and almost siphons the charge out of the runner. We thought they were kidding, they weren't. We saw what they saw and I had to scratch my head on why would GM engineering make that manifold like that? The Renegade was designed differently on the floor of the manifold and the runners themselves...Do a comparison side by side and you can see the difference in a BIG way. Also, the Bell lips on the runners were done purposely, it specifically super charges the A/F charge into the runners and rams the charge into the heads. This was confirmed on the flow bench and watched it work with smoke introduced into the manifold with a clear top plate. Pretty impressive to say the least to watch it in action. There was a lot of design built into that manifold that you will not see by just looking at it.

This testing cost a great deal of money with 3D modeling, flow testing, design changes etc... That is why EddyMS pissed me off with their non-ability to machine the manifold correctly after all this cash spent to create a good manifold for CFI. In the beginning, Jim and I were going to be the ONLY two Renegade manifolds produced. Jim still has the original prototype manifold on his 84 which is a piece of art. When done correctly, the manifold works like a champ and has been proven time and time again on a dyno.

Me...

 

Yep I can confirm Ben’s throttle bodies are to 2.20”. That thing is a monster.

 

OK Tom. You'll have to show me how to keep machining out a wall that isn't there any more. Tell us what "properly", is?