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New Slant EFI intake....
https://slantsix.org/forum/viewtopic.php?t=53276		 Page 5 of 11
Author:  pishta [ Thu Oct 03, 2013 8:44 am ]
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Yeah, that FLAT rear mount I was designing may not work as planned. The oil seal on the cover is almost 3.5 wide and the bolt circle for the mount is 3.075 so the bolts will hit the coverl if they are flush with the rear of the balancer whos plane is behind the oil seal. well, back to the drawing board......
Author:  Dart270 [ Sun Oct 06, 2013 2:13 pm ]
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Let me think about it. I would not go too long, assuming a fixed runner is involved. Probably something like the middle runner length on a Clifford 4bbl intake. Tapered runner cross section sounds like a good idea too.

We have a lot of possible different applications here (racing, street, low RPM, high RPM, turbo....), so it will be tough.

Lou
Author:  CNC-Dude [ Sun Oct 06, 2013 2:35 pm ]
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Ok, I was thinking between 8"-10". I have material on order to make a working sheetmetal prototype to send to you to kinda' work out the kinks of runner length and plenum design before going into the cast version.
Author:  Reed [ Sun Oct 06, 2013 2:41 pm ]
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Quote:
Let me think about it. I would not go too long, assuming a fixed runner is involved. Probably something like the middle runner length on a Clifford 4bbl intake. Tapered runner cross section sounds like a good idea too.

We have a lot of possible different applications here (racing, street, low RPM, high RPM, turbo....), so it will be tough.

Lou
It would also be nice to allow for the use of AC.
Author:  Tim Keith [ Sun Oct 06, 2013 4:45 pm ]
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Quote:
It would also be nice to allow for the use of AC.
Even here in Texas I don't often use AC. I'd like to mount the compressor down low where power steering pump usually is. I don't need power steering, but I could find an use for a manifold like that. I can't have it all, but some things are too cool to pass up.
Author:  Reed [ Sun Oct 06, 2013 6:45 pm ]
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I live in western Washington state and I use the AC year round. :shrug:
Author:  pishta [ Sun Oct 06, 2013 8:29 pm ]
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http://www.chrysler300club.com/uniq/all ... theory.htm

also there are a number of intake runner length calculators on the net that ask some interesting questions. I answered all in the Wallaceracing calculator
and got like 30 inch runners!

But check out this page http://www.wallaceracing.com/runnertorquecalc.php
and they have some more localized formulas. I like the 4000 RPM peak torque 225 motor that has a runner length (back of valve to plenum) of 8.15 (doable) and has a runner cross sectional area of 1.7 inches, thats a 1.5 inch diameter runner, pretty close to ideal!

numbers guys will appreciate this site for turbo piping diameters. I played with it for about an hour. break out the metric convertor! http://dairally.net/daihard/chas/MiscCa ... iPipes.htm

lot of info, I used cam specs from a stock slant cam: events-
int 10/50 240
exh 50/6 236
lobe sep 111
centerlines of 111/112
16 overlap

8 CR
6.7 (170mm)rod
3.4 (86.36mm) bore 4.125 (104mm)stroke
mult by 25.4mm/inch for conversion
Author:  CNC-Dude [ Sun Oct 06, 2013 10:12 pm ]
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I posted a link to a recent Hot Rod magazine article where they were trying to prove the the theory of calculating the optimum runner length of an injected engine using the original Ramchargers formulas and calculations. They started out with the ram tube length at 19-1/2", and ended up shortening it down to 9", a reduction of 10-1/2", and it only made 10 HP difference.
So, I think my goal of starting at between 8"-10" is pretty close to being a good length for a street intake, the race version I think can benefit from and adjustable length runner. But its all subject to testing, as this provides the best analysis, not formulas.
Author:  pishta [ Mon Oct 07, 2013 8:30 am ]
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Quote:
So, I think my goal of starting at between 8"-10" is pretty close to being a good length for a street intake... But its all subject to testing, as this provides the best analysis, not formulas.
that is true. Even the Ramchargers used a telescoping intake to get the final version down, rumor has it was the 5th trial. 8-10 sounds good to me. That is what mine are. Im thinking 1.5 diameter runner might be a more productive size but we are talking dry, not wet.

There was a cool youtube video of an active variable intake system that used a stepper motor to slide the ram tubes in and out like a trombone slide. It was on a GSXR 600 race motor and even at RPM, the slider was moving with various inputs controlling the stepper, ie track location, G forces, etc. crazy stuff.

I want to drive this car to work...
http://www.youtube.com/watch?feature=pl ... xW0OVX-he4

trombone intake
http://www.youtube.com/watch?feature=pl ... MVioC2XGO0

I think anything made by CNC Dude is going to be exciting for the slant community and commend his passion and support for this platform.
Author:  CNC-Dude [ Mon Oct 07, 2013 10:13 am ]
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Cool videos, thanks for sharing. Thanks for the kind words also, just trying to provide more options for the slant world, hopefully they will also be better options as well.
Author:  aspen76 [ Fri Oct 25, 2013 7:27 am ]
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Hey guys,

I just wanted to throw in here that I will be very interested in any FI manifold you guys come up with.

I'm looking forward to see what comes out of this!


Brandon
Author:  CNC-Dude [ Fri Oct 25, 2013 11:02 am ]
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Thanks for your interest Brandon, will do!
Author:  ntsqd [ Fri Mar 14, 2014 11:04 am ]
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Boy! Talk about a rabbit hole!!! Next thing I knew after starting to read this thread is that I've got some intake/exhaust books on order.

The topic is one that I've given passing thought to, and even went as far as a simple SW model just to look over the design & fab options.
Image
After reading this thread and some of the links I'm more inclined to build it with 'J' shaped runners like Toyota did with the 22RE intake. For me not so much, but for this project I could see emulating, as has been discussed, the Toyota two-piece intake. Further, I can see where several different bend sections might eventually be offered to tune the runner length as appropriate to any particular engine.
(Ignore the red marks, someone in a thread didn't know about that thru-bolt.)
Image

So my question is, any progress on this project?
Author:  pishta [ Fri Mar 14, 2014 3:53 pm ]
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it is what you make...go for it. J tubes off the flange and bend it up, down, back, front..wherever itll fit but the upswept toyota design is going to be tight going right up into the hood unsulation. I thought up and over the valve cover would be cool if you were going after a Looong runer. Some of those plastic intakes look like a labynth inside.
Author:  CNC-Dude [ Mon Mar 17, 2014 2:47 pm ]
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The reason that some engines use a J-shaped runner is so they can make the runners long enough to suit the engines peak rpm needs. The longer the runner, the lower in the rpm it brings its power band. Most engine compartments can't accomodate a runner length of 15"-16" inches straight out from the head. So creating a U-turn upward is the only likely alternative. But it is the length of the runner that is really the reason behind that concept and design.
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