atb

I talked to an M5 owner about it and he said the Dinan Stacks were serious $$$. I don't remember the amount, but it was over $1K. I've looked on the Dinan website but didn't see them listed.

And I think your are right Sterling, they should be 50mm. I'll know soon enough.

Lizard928

Thank you for that Louie, it did help.

However what I am seeing from the factory intake with the standalone is that there is alot to be gained by freeing up the restrictions, and equalizing the flow between all the cyl.

With my 86 engine that I have standalone on I could run two plenums with no issues and pretty much guarentee that I had equal flow.
But I am also thinking about an intake for an S4 engine that I could use the stock MAF on (requiring a single plenum) to see how much could be gained just by an intake change.

In the attached pic this is something like I am thinking, and may play about with it once I get home. But this would be looking from the FOE, and the runners (red and green) would point to the airbox (green) on the passenger side of the engine.


The only thing about this is that the area under the hood may require too tight of a bend in the passenger side runners and cause a serious imbalance in flow between banks. The throttlebody would then go on the end of the airbox right at the front of the engine, but in front of the crossmember, or behind for a SC car.

The fuel rails could be either left in facotry locations with proper location of the runners, or could move the injectors further up the runners in hope of abit better atomization. The airbox would be attached the same way the factory attaches the 85/86 boxes.

Louie928

What you have looks to me a lot like the intakes on some Ford V8s. They have a single plenum and rather longish runners that feed both banks from almost the center. You have the runners entering the cyl heads vertical, but in reality they are more aligned with the ports and valves if they enter at about 17 to 20 degrees toward the center of the engine. That makes it easier to fit in. Other obstacles to overcome, but probably workable. It also resembles the '85/'86 intake which isn't a bad design. The runners on those are actually larger than the S4 runners. You could put a throttle on the front of each of the side plenums and plug the vertical leg of the big "T" that comes up in the center, but leave the crossover. I've always wanted to try that, but haven't yet.

hans14914

Yep, that drawing above looks exactly like a 5.0 HO intake from a mustang.

Lizard928

Interesting on that, maybe it is worth a go then.

Louie, it was a rough drawing but yes making it as much in line with the current opening would be the plan. I as well have thought long and hard about putting a throttlebody on either of the two end tanks. However the issue that I see with doing that is #1 you will still have imbalance in flow between ports with the long runners and the short. The other thing which has prevented me from doing this is that I dont think that simply bolting a throttlebody on the end of it is such a good idea, I think that putting a slot all the way along the outter parts and welding a pipe to the outside so that it gets even airflow at the rear cyl as much as the fronts, and then have the TB off that runner.
The main reason that I scrapped that idea is that the end caps are a mag compound and welding aluminum to magnesium can be tricky esp when one is cast material which will be fairly soaked in oil.

I also dont have a tig yet, and I really dont think that mig is upto the job, esp seeing as I doubt I can get the appropriate wire to mate the two.

hacker-pschorr

FWIW, the picture below is one of the preferred Ford SB intakes to replace the stock unit:

BC

All these intakes seem like a compromise. And thats what the S4 intake is. And the S4 intake is cheaper, since I already have one.

Louie928

Your concern about the throttles on the very ends of the side plenums is valid I think. If you take the '85/'86 manifold as a whole, it isn't bad. Ken Lauridsen has shown that his '86.5 auto with )( pipe, and some timing improvement can better an otherwise equal S4. The bottleneck of the '85/'86 (S3 I guess) style intake, as I see it, is the smaller throttle and the abrupt 90 deg bend downstream of the throttle where it goes up to the horizontal cross pipe. The throttle size apparently isn't much of an issue on the TS SC installations, but I think would be on a NA engine. A lot of fabrication of aluminum/magnesium can be accomplished by use of the proper adhesive rather than welding.

Louie928

Nice. Wish we had about 4 more inches of height above the engine.

Lizard928

I had thought about using adhesives as supposed to welding as well, but with high heat, and boost am concerned about the adhesive leaking or fully seperating, as well as taking a fair amount of surface prep time to ensure a perfect seal. I personally find welding to be a much much more acceptable solution.

However could you recommend an adhesive that you think would do the job? If you can and I can locate another set of sideboxes to be able to use I will open them up and give them a try before I take the engine all apart. I may even do a before and after dyno to see how much of a gain there is to be had from that, and to see if there is any restriction in the rest of the manifold.

Lizard928

Agreed with Louie, wish we had more height under there. However if we were to build one like I showed above it could be done with correct size pipes and less restriction than a factory mustang intake. Sure it wouldnt be as prime as what you have pictured, but we are working with what we have, and I cannot stand the look of huge holes in the hood.

I would consider having a slight raise in the middle, or remake the cross brace so it sat low, and run the intake lines above it, this would possibly require two little ridges like the cayenne turbo though, imo that would also be liveable.

hacker-pschorr

The one I pictured above does not sit any higher then the stock Ford unit. The SB Ford is a very narrow engine compared to a 928 block, so how much would you lose from the runner length by making the base wider, stretching it out while at the same time making it lower?

Take a look at the 16V intake, what about making a 32V version? IIRC the runners are about 7" long.
Maybe push the plenum down quite a bit, mount the TB on top so you could have the intake go up and over the radiator bridge. The V is sure deep enough, DR puts an intercooler down there!

Sorry if I missed this data, what runner length are you guys shooting for?

Lizard928

Eric, for myself I am less worried about runner length, as supposed to equal lengths and more importantly equal flow.

as we hear from other people the S4 intake has upto a 25% variance in flow between cylinders, this means some will run lean and be more detonation prone, and others will run overly rich and rob power.

This would bring in the necessity of doing what tod did with 8 WB O2 sensors, I would rather get away from all that complexity, and equalize the flow as much as is possible between all the runners so the need for trying to tune each cylinder is reduced as much as is possible and each cyl perfoms to its fullest. By going to a single plenum and throttle body I could run the factory EFI and see just how much could be gained just from swapping the intake out.

As said previously I believe there is a fair amount to be gained on these engines from intake work. NA as well as boosted.

hacker-pschorr

Then a center mounted plenum should be possible with equal runners. Every 16V has a setup like this.
Todd has mentioned cutting up a stock 16V intake to see if he could make it fit a 32V. Since bore spacing is the same (fuel rail's are interchangeable) it's not that far off.
Unless you are going with an aftermarket engine management, the eight WB's will not do you any good.

I agree a new equal length runner intake would be an excellent upgrade with very few downsides. We should be looking at what's available for the Chevy's versus Fords (especially the big blocks) since the overall engine size is closer.

This would be ideal, but hard to do with sheet metal:

Louie928

I was thinking of the adhesive solution more of getting a prototype configuration working to test. Once you had the layout you want, then think about a more permanent method. However, welding to magnesium will take some research I think. I have never tried it. I've seen magnesium burn and want no part of it.

I don't have a specific adhesive recommendation. Check 3M Scotch-Weld products. I use an epoxy resin with a temp rating up to 450F for underhood composite layups . I has to be oven cured over about 6 hours to get it to withstand that temp. I only cure it to about 250F as I figure that's good enough. So far, no problems with it. I also use 3M Scotch-Weld 1838. It can be force cured at up to 200F. It works for underhood apps. There is plain old JB Weld. that stuff is amazing and shouldn't be discounted just because you can get it almost anywhere and relatively cheap. My pressure washer motor had a connecting rod fail and it went out through the side of the block. Big hole. I cleaned up around the hole, got a piece of glass cloth and slathered it with JB Weld and put it over the hole. I replaced the rod and have used the engine a lot for over 5 years. There is no oil leakage, or other evidence of the JB Weld patch. Other good product is "The Right Stuff". It remains flexible and seals against oil at underhood temps. If you ever had to take apart something sealed with it you know how well it bonds.

I don't have any '85/'86 side plenums, or other parts for those manifolds. One possible source for TBs is from junk yard Fords. Many have plastic TBs that work ok, and have round stub tube ends so can be adapted to hose connectors easily. The V8s and V6s have different sizes.