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Posted by: agrump Jan 17 2005, 07:43 PM

Anyone know where I can get them?

Thanks

Posted by: URY914 Jan 17 2005, 08:34 PM

Can you cut the top (carb) flange off, cut a section out and weld the flange back on??
Just wondering? I've heard the short ones are hard to find and I need some too.

Paul

Posted by: Aaron Cox Jan 17 2005, 08:43 PM

whats great about the short ones?

taller = more torque right?

Posted by: r_towle Jan 17 2005, 08:45 PM

I have a few, what do you mean by short??

Rich

Posted by: scooter311 Jan 17 2005, 08:59 PM

Heya I just got rid of a set of shortys - I hated them, it was a nighmare trying to change plugs, wires, etc. I traded a dood for a tall set a short while ago. I would've paid you to take them, I hated them so much

Posted by: URY914 Jan 17 2005, 09:26 PM

QUOTE (Aaron Cox @ Jan 17 2005, 06:43 PM)

whats great about the short ones? taller = more torque right?

Well, Jake told me to get short ones soooooo, I'm looking for short ones
'neff said.

Posted by: cha914 Jan 17 2005, 09:54 PM

hmm...I like welding alum...just got a new bandsaw....sounds like fun

Posted by: r_towle Jan 17 2005, 09:56 PM

so, how short do you need them, I have a few sets here of differing lengths.

Rich

Posted by: Jake Raby Jan 17 2005, 10:04 PM

Its all dependant upon the combo!

Efficient engines like a shorter manifold to produce the best results in the upper RPM range. Intake length is just part of the overall runner length, combined with the velocity stack length as well..
The stacks and the manifolds must be chosen for the engine to make its most..

Thats why I have a dyno and every manifold and stack known to man. Every new combo gets tested with all them to see which ones give the best curves.

Posted by: r_towle Jan 17 2005, 10:40 PM

QUOTE (URY914 @ Jan 17 2005, 06:34 PM)

Can you cut the top (carb) flange off, cut a section out and weld the flange back on?? Just wondering? I've heard the short ones are hard to find and I need some too. Paul

Again, in response to YOUR question...
And the previous question, how short would you like to get.

I have, on my shelf several different length setups.

I am aware that each engine has differing needs, that was not the question here...

The question is where to get the manifolds.

I have some, what size are you needin?

Rich

Posted by: Racer Chris Jan 18 2005, 05:35 AM

QUOTE (URY914 @ Jan 17 2005, 09:34 PM)

Can you cut the top (carb) flange off, cut a section out and weld the flange back on?? Just wondering? I've heard the short ones are hard to find and I need some too. Paul

I built a fixture to do just that!
Specifically - I can shorten the standard IDF manifolds from 5 1/4" to 4 " runner length, which is the same as the standard Solex manifolds.

Posted by: DJsRepS Jan 18 2005, 05:59 AM

When I grow up Im getting me a motor by Jake! with one of his side shift 4speed. No need for 1st gear of a 5 speed with his dyno proven hp and rpm.

Posted by: Walter Jan 18 2005, 06:06 AM

I really don't have assets in that company, but Ahnendorp makes rather short manifolds, compared to the CB ones, both for 4-bolt and 3-bolt. Not one size fits all. And the 40IDF manifold has a 40mm opening, the 44IDF/45DLRA manifold has 45mm opening, not 48mm for all carbs as I've seen a lot.
Also, those manifolds let you mount your carb either way around

Regards,
Walter

Posted by: Joe Ricard Jan 18 2005, 07:18 AM

Wish I had a dyno

Posted by: agrump Jan 18 2005, 07:52 AM

Oh I hope I don't get lambasted for this. I need short manifolds so that I can use a pair of air cleaners from a 356/912. The purpose of it is to cut down on intake noise. I need at least an inch more clearance, 1-1/2” would be better. My current manifolds are the standard tall ones that come with your usual carb kits. 5 ¼” sounds about right so a 4” or less manifold would work for me.

I have not considered what effect this will have on performance. My engine is not that highly tuned from what I can tell from the paperwork I got when I bought the car. It’s a 2.0L euro pistons with a .03” spacer, FAT FC442 cam and 2.0L heads. I’m guessing the compression ratio is 7.5:1.

Posted by: maf914 Jan 18 2005, 07:53 AM

I bought a pair of short manifolds, shorter than the typical CB Performance manifold for 2-barrel IDF's, from PMO several years ago. They may still offer these.

Posted by: Racer Chris Jan 18 2005, 09:07 AM

QUOTE (maf914 @ Jan 18 2005, 08:53 AM)

I bought a pair of short manifolds, shorter than the typical CB Performance manifold for 2-barrel IDF's, from PMO several years ago. They may still offer these.

The PMO manifolds are 5 1/4" runner length. They are available properly sized for 40 or 44 IDF carbs.


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Posted by: Jake Raby Jan 18 2005, 09:22 AM

The intake noise probably won't drop much with the addition of the 356 air filters.... Many times the intake note is a by- product of the camshaft choice as well as the headwork. Alot of engines that have huge intake valves have this trait and it really can't be remedied.

The FAT cam you mention is notorious for this trait. Its almost as bad as the Web 494

Posted by: agrump Jan 18 2005, 11:01 AM

Ugh, that’s bad news; I was hoping that it would make a significant impact on the noise level. I don’t believe there has been any headwork besides a new set of stock valves/seats. I’ll still try it but when it doesn’t work I’ll consider splitting the block to change the cam and maybe bumping up the displacement. A cam change may be a good thing as I’m happy with the power but the mpg is lower then I would expect. I’m also planning on addressing the mpg problem by controlling timing with a megasquirt unit. I have all the pieces lying around so I might as well use them.


Racer Chris, how much would you charge to chop and weld a set of manifolds? Would it be more trouble to take out another ¼ inch? I have a spare set of Scat manifolds that look similar to the one shown except it has more webbing between the two ports.

Posted by: Walter Jan 18 2005, 11:54 AM

FYI, intake noise is greatly reduced with a central intake airfilter system. Not cheap tho..

Greetings,
Walter

Posted by: rhodyguy Jan 18 2005, 12:38 PM

when jake was doing forthcomings for trends, shortening a set of cb talls was written up. fat did the modification. jan 2003 issue.

kevin

Posted by: Racer Chris Jan 18 2005, 05:43 PM

QUOTE (agrump @ Jan 18 2005, 12:01 PM)

Racer Chris, how much would you charge to chop and weld a set of manifolds? Would it be more trouble to take out another ¼ inch? I have a spare set of Scat manifolds that look similar to the one shown except it has more webbing between the two ports.

I think it's about a 2 hour job including remachining the flange surfaces which won't be flat after welding inside and out.
Another 1/4" might be possible but it starts to get difficult to align the bore due to the taper.
Based on the time estimate my charge would be $132 plus shipping.

Posted by: DJsRepS Jan 19 2005, 06:34 AM

Build a dual ram air system into the front curve of a GT flare near the motor. That may change the sound. Connect that to my belt driven motorcycle blower on top the machined runner block concept and then you will have even more noise but no one will hear it too long you be gone. I know the MPS would not like it. Jake I have seen the plumbing nightmares with the turbo's but I have not seen any blower's. A blower would be childs play compaired to the turbo. There must be a reason.

Posted by: r_towle Jan 21 2005, 10:10 AM

Here is what I have


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Posted by: r_towle Jan 21 2005, 10:10 AM

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Posted by: r_towle Jan 21 2005, 10:11 AM

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Posted by: groot Jan 21 2005, 10:18 AM

If you're taking orders, I'd like to purchase the set on the upper right side (the ones with the adapters (don't need the adapters, but I'll take them if you don't want them).

Thanks, Rich. You've got quite a collection.

Posted by: groot Jan 21 2005, 10:23 AM

Or the ones on the bottom left.....

Are they 40mm openings on the carb mounting or 48mm openings?

Posted by: r_towle Jan 21 2005, 11:33 AM

Posted by: r_towle Jan 21 2005, 11:34 AM

The adapters seem to ensure that the bolt holes line up with the carbs. I would say bottom left are correct, top right are not quite right...not sure why.
Look in the classifieds.
Rich

Posted by: agrump Jan 21 2005, 12:17 PM

That is a nice collection. What I have now looks to be a standard Scat manifold measures about 6" from the bottom to the top when mounted. It is hard to tell how tall the maniflds are from the pictures bit I need a manifold that is at least an inch shorter then what I have. Also I have three bolt heads but I imagine converting one would just require drilling a hole.

Posted by: groot Jan 21 2005, 12:29 PM

I'm guessing that the top right set is for Solex carbs, but has an adapter for Webers.

I can machine/weld them up to make them work, but it's easier to start with the bottom left set. I responded to your classified. Thanks, again!!!!

Posted by: maf914 Jan 21 2005, 02:42 PM

QUOTE (r_towle @ Jan 21 2005, 09:34 AM)

The adapters seem to ensure that the bolt holes line up with the carbs. I would say bottom left are correct, top right are not quite right...not sure why. Look in the classifieds. Rich

I thought the adapters were there to allow a switch from Solex bolt pattern carbs to Weber/Dellorto pattern? I recall seeing those on Weber kits for early 356 Porsches. I thought one used the original Solex manifolds and added the adapters.

Posted by: Racer Chris Jan 21 2005, 05:54 PM

Rich,
Imagine a line (with a curve) running through the exact center of the runner on each of those manifolds from the surface of the top flange to the surface of the bottom flange.
What are the lengths of the manifolds measured that way?
The runner length of the original supervee manifolds that the E and F prod rules are based on is approximately 4", which appears to be significantly shorter than all those pictured.

Posted by: carambola Jan 21 2005, 06:20 PM

ok, super dumb question here, but how is an efficent defined. more oversquare, more overbore or is it all in the headwork?

Posted by: r_towle Jan 21 2005, 06:41 PM

QUOTE (Racer Chris @ Jan 21 2005, 03:54 PM)

Rich, Imagine a line (with a curve) running through the exact center of the runner on each of those manifolds from the surface of the top flange to the surface of the bottom flange. What are the lengths of the manifolds measured that way? The runner length of the original supervee manifolds that the E and F prod rules are based on is approximately 4", which appears to be significantly shorter than all those pictured.

I will check tommorow

Are you telling me that the SCCA has made a ruling on manifolds that arent even available for purchase??? Only to be custom made?? If so, that is just plain stupid.

Rich

Posted by: davep Jan 26 2005, 03:56 PM

What are these manifolds? 48mm carb dia and 33mm intake dia. about 4.6" compared to about 5.5" in the previous photos.


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Posted by: davep Jan 26 2005, 03:57 PM

used with Solex 40PII I seem to remember


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Posted by: agrump Feb 9 2005, 07:59 AM

I'm not sure anyone will care but I did find a set of shorter manifolds and did install a pair of 356 knecht air cleaners. The amount of noise at idle did not change but at WOT there is a world of difference. Instead of the "look at me, I'm accelerating" drone coming from the carbs all I hear is the exhaust. To me this sound is far more sporting as it tends to increase in volume as RPM's go up instead of just droning all through the RPM range. Also the cabin noise is not nearly as loud with the top off as it was. Don't get me wrong, it's still noisy but most of the noise is coming from the back instead of the top of the engine.

If anyone is interested in doing this mod, here is what you will need. Buy a pair of air cleaners from EBay, search for "KNECHT PORSCHE". The air cleaners came on 356's and older 912's. They are the fully enclosed ones with snorkels. You will need to mod the base plates by drilling new mounting holes and center holes for the idf/dell vents. The ventura holes are in the right spot. The base plates have tiny velocity stacks on them. I cut these off to mount standard stacks. I believe the carb openings are around 40mm so I had to add a small spacer to keep the passageway smooth bacause I'm running 36mm dells. I welding a couple pieces of 1" angle iron to the base plates which I used to mount a crossbar linkage from them.

Oh I almost forgot, the manifolds I used are standard bugpack type iv's. They are about 1" shorter then my old ones. My old ones are the ones that have drilled webbing in between the ports. Air filer elements are hard to find but the NAPA 2299 will work but they are about 1/4 too high.

Posted by: spunone Feb 9 2005, 09:49 AM

Do you have one.Im a visual kind of guy

Posted by: agrump Feb 12 2005, 07:18 AM

I only had time to repaint one of them but you get the idea


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Posted by: agrump Feb 12 2005, 07:19 AM

Linkage is attached to a peice of angle iron welded to the bottom of the air cleaner.


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Posted by: agrump Feb 12 2005, 07:22 AM

With the engine cover closed the air fillter closest to the battery is the nearest one to the lid. There as about an inch of clearance. This is without the rain guard. I left the snokels unmodified. They both fit with plenty of clearance to the sides although the battery cables are in the way.


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