Well after MUCH searching for a cheap Weber cross-ram and realizing that I'd probably be better off finding a FI manifold instead, I ran across what I feel has got to be the sweetest looking intake for my built-up rocket block project.

Check out these pics....

















The size of the openings are 57mm, and the rectangle ports are 32.4mm x 50.8mm, which I'm guessing should flow somewhere around 340CFM. Runner length is about 9.5 inches, about 11.5 inches to the ends of the horns.

Now I'm sure this will mate well with a planned 650+HP buildup, but I'm curious to know if anyone thinks I can run this on a stock 350? The only reason I'd consider putting this on the stock engine would be so that I could go ahead and redo the fuel system so that it'll be much easier to drop in the built motor once that's done (still a long way off! :smash: ).

My guess is that it's going to seriously bog the motor, but I'm not really sure. Any comments?

I'm also thinking of getting rid of the horns and having custom air boxes made for each side so I can run cone filters up front with the turbo hood. :D

Cheers,

Tony

 

:eek: Will want to hear the result of that critter! :cheers:

 

Looks neat. Are you planning to run it as constant flow or have it converted to EFI?

I have a splayed stack Hilborn that I had converted to EFI for my car. It's not running yet so I can't say "done that" yet, but I'm not expecting any drivability problems with mine which has 2 3/16" throttle bores (about 55 mm). I've talked to several people about dialing in the EFI. The "good" ones say it can be done but takes carefull tailoring of the map with regards to throttle position. The "others" just say they tried it once and had all kinds of problems. I'm pretty much decided on Fonz performance in NJ to dial mine in as they have done a lot of 8-stack EFI jobs before.

Let me know if you want any info on my conversion, and keep us informed how yours goes.

-Greg

 

Hi Greg,

I will most likely convert it to EFI. No idea on what mfg or type to go with just yet. Which one did you choose?

I've been keeping an eye on your project since I found out you had bought a Hilborn. I was very close to buying one myself, but it would have meant a lot of custom work to keep it under the hood.

Cheers,

Tony

 

I had the conversion done by Rance Baxter (www.racnefi.com) and it is setup with the Accell Gen 7 DFI and matching ignition with the dual sync signals so I can run true sequential with it. It's being used with the mock-up motor at present, but I hope to detail it and install it on the real motor and get it dyno tuned in the spring.

I had Hilborn make a special set of short stacks to keep the total height under my hood scoop. I had talked with Kinsler about one of their cross ram setups, but when the injectors and fuel rails are added to the cross ram (to the top like on your current constant flow nozzles) the total height was actually more than I've been able to achieve with the spalyed vertical stacks.

If I get my duff in gear and get the AFR heads bolted to the mock-up motor (so I can start fabbing the exhaust) I'll get some pictures of the motor/heads/injection to post.

-Greg

 

Greg,

Sounds like a nice setup! Can't wait to see pictures of it!

Curious about the height of the Kinsler, although from the pictures it does look taller than mine. Do you remember what the measurement was on that? I'm fairly sure I won't have any problems, but safer to know what problems I might encounter now rather than later!

Cheers,

Tony

 

That is one clean looking set-up...is it going to have a surge tank installed in the engine bay?
:cheers:

 

Hopefully it won't be necessary, but at this point I don't really have any idea. I already have to deal with finding a home for the oil tank and remote filters for the dry sump system! I don't relish the thought of having to locate another tank in the engine bay, even if it isn't that big!

Thanks for bringing that up though, it's definately something I'll have to keep in mind.

Cheers,

Tony

 

Tony, You really need the stacks to get them to flow right. You might be able to get 4 sprint car type K&N's to fit those stacks or maybe buy theirs.

Out of all the 8 stack intakes yours is the least common. I've owned several hillborns and I've been trying to think of what might have kept the cross ram out of main stream sprint car racing.

It's only a guess but weber injection nozzles are really far from the intake valve. where hillborn mechanical is very near the port and the nozzles have a splash plate to diffuse the squirt 90 degrees right at the valve. Or maybe the Weber 9-11 inch length has a lower rpm tuned length. MY SBC hillborn had 3 sets of stacks and tuned for different rpm

 

GKull -

You're right about these being uncommon! It's taken me well over a year to track down something like this! Who knows why they aren't popular...weight may be a factor, perhaps its cost. It's definately cheaper to find a Hilborn as opposed to a cross-ram of ANY type!

If there's any performance advantages or disadvantages, I have no clue. I was hoping someone knowledgeable in that area would speak up...maybe I should start another thread...

Regardless, I didn't pick this intake for pure performance reasons, I wanted something unique and eyecatching. I think this does the trick. :D Now I just need to make it work.

Tony

 

Regarding your question about using this set up on a 350. A well design/tuned efi is pretty forgiving. I don't know what size Rocket block engine you are building, but I would presume it will be much bigger than a 350. You will probably need to have a set of smaller injectors for the 350. You might also need to go with smaller throttle bodies. In comparison with a carb., in a carb you change jets. With efi, you can do only so much with chip tuning, and then you have to change throttle bodies, rail pressure, and injector sizes to make it work. To make that set up work on a street 350, and then put it on a built up Rocket block with significantly more displacement, I think you would have to change a lot of expensive parts.

 

I came across a company a while back (it was a BMW fuel injection site) that specifically did EFI conversions and sold already converted Weber manifolds. If I can find the link, I'll send it to you. (It's on my work computer so I won't be able to check until Monday.)

 

Using measurements from the manifold to block valley surface:

My Hilborn is 6" to the top of the cast manifold, and I have 3" stacks.
The Kinsler vertical manifold is 8" to the top of the cast manifold, and they said they could make aluminum radius plate inlets for it to keep the total height to 10".
The Kinsler cross-ram they said needed about 12-14" (can't find the exact number scribbled anywhere), with the fuel rails feeding the injectors being the highest point.

-Greg

 

GregP -

Thanks for the info. I haven't measure the height on mine just yet, but I should be under 10 inches with fuel rails, so that is good news...

Russ -

My plan is to build the rocket block up as a 427ci, so that's a significant difference from the stock L-48 motor! I'm very skeptical about putting this large of an intake on the stocker...I suspect it would take more than just proper sized injectors and good programming! However I'd love to hear otherwise!

Six-T-Six -

Kinsler is nearby, so if I decide I need help, I'll probably send the manifold to them for conversion.

Cheers,

Tony

 

Actually, proper sized injectors and tuning will probably make it work ok. Efi doesn't depend on air velocity to atomise fuel, so if you aren't getting big puddles of raw gas laying in the bottom of the manifold you should be ok. To get the maximum out of an engine, you need the intake optimised to the engine size. You have probably got too much intake volumn for a street 350 to get the max out of the set up, but if you don't mind getting an extra set of injectors and doing some tuning, I think it would work ok on the street.

 

I finally got some potos of the intake up on the site. Click on my signature link and then the Jan 2003 update.

-Greg

 

GregP -

Very nice! That is going to look fantastic when you have it nicely finished. Have you yet decided on polishing or powder coating? Perhaps even colored anodizing would look slick!

Russ -

Thanks for the extra words of encouragement! I knew that the EFI systems didn't rely on air velocity in the way a carbed system does, but still wasn't convinced. But what you've said makes sense and I may just try to get it working with the 350 after all.

Much thanks to everyone for the input!

Tony

 

Greg - What are you going to need vacuum for? I just can't see 8 stack plumbing working with your cam. I would think that a belt driven is the way to go. I like your web pages!:)

 

Gkull -

There are actually two sets of "vacuum" plumbing installed on my manifold, one feeds the IAC and the other is for the MAP sensor and the fuel pressure regulator.

I found a second cam profile that I am considering, same duration and lift as the original but with 110* centerline instead of 106*. I think it would work a little better running a full (although all 3 1/2" pipe) exhaust system.

-Greg

 

I wasn't thinking there!:) I forgot all about your MAP and EFI. At anyrate the milder 110 cam with less overlap might make A/F ratio tuning much easier.

Have either of you ever looked down a stack on a runnning mechanical fuel injected motor? Because of the constant squirt and the pump and barrel valve being non linear in fuel delivery. You have a fuel fog that rises above the throttle blades at idle because of intake reversion. as you slowly open the throttles and rpm rises the fog goes farther down towards the point where the constant injection is happening. That's why in the Sprint car classes that don't yet allow DFI the high tech heads used are called down port injection.
The injector is right next to the spark plug and sprays the fuel on the back of the intake valve and into the cylinder when the valve is open. Manifold intake tracks have entirely different dry and wet flow cfm values