side draft manifold lengths?

[nobody]

I'm looking for the lengths of dual sidedraft manifolds. The distance from the head side flange to the carb flange. I'd really like to have a few different types to compare. I have an idea I'd like to look into a bit more but need some more info to find out if it's cost effective or not. Any info on Cannon, Irmscher or Magnoletsi types would be helpful.

[GTJIM]

Have Irmscher 'long'; 'short' and Manglotesi here and will measure them for the record.
One point: The GT manifolds have the flange cut at an angle to compensate for the tilt of the motor so the bottom of the runner is longer than the top - will get both measurements.

[kiekmer]

Hello,

I have some side-draft manafolds at home. Don`t know the brandname but they have the initials C/T.

The length is 9.5 cm (3.74 inch). I`ve tried to install them with DOHC`s but dont fit with the heater box....

DSC00098.jpg

[nobody]

The reason I want the dimensions is because I found a local steel supplier that has a new water jet and a high end plasma cutter. They are looking for work for them both and the prices are very good.

In a nutshell I like the linkage mounts on the Cannons. The depth of the short Irmschers and the cross link on the Magnoletsi. I don't particularly like the vacuum setup on any of them. I was thinking about fixing all of these things into a single manifold to go with a new style header.

Jim I was going to check a stock intake for the angle. I keep thinking it was 14 degrees but I could easily be wrong.

[GTJIM]

Dave, I have an idea it was 7 degrees - but will check when I measure them.
Have not made it tothe workshop yet due to a gouty big toe which is preventing me from walking at the moment .... hurts too much ...

With the price of Irmscher it should be possible to fabricate something better for the same cost or less!

[nobody]

This company was supplying me with seamless tubing at a rate of 41.00 per 20 feet. I imagine a total would be reasonable for all the parts. They do it off templates and the weber side is done already. When I get the intake side done I'll get a price.

Before anybody asks. They would not be for sale. However if your on my Christmas list already you can never tell what might show up at your door.

Jim, hope you get to feeling better soon.

[nobody]

First to bump this back up in hopes of some more dimensions.

Second, a bit of an update to the design idea. I brought out a stock intake and made the template for the head side flange. Now I can start resizing them a bit to fit the 1 1/4 inch tube, since this is the perfect size for both carb and head sides. I can have them cut to fit the tube internally and make the fabrication process painless. Then once the tubes are bent for the width changes I can simply roll them a bit to get the angle right. Since this will go with a custom exhaust on a RallyBob flange I can use standard size plate for the flange and forget about the washers or using metric plate. Since this will be all new and never around oil I can have it powdercoated easier too. Bright yellow would be cool.

[GTJIM]

Should get over to my workshop on Monday and have this on top of my list of stuff too doo!

[opelgtworld]

Take a look at ebay for the following dual sidedraft manifolds:


Mattig



Bilas

[GTJIM]

Back on my feet again .. and not limping anymore .. so went over to my workshop to do a bit.

The angle on ALL the manifolds here is 14 degrees

Here are the Intake manifold measurements:

1) Irmscher Short - low side 75mm/high side 93mm (middle 84mm)

2) Irmscher Long - low side 98.5mm/high side 116.5mm (middle 107.5mm)

3) Manglotesi - low side 101mm/high side 119mm (middle 110mm)

In each case the measurement is perpendicular to the head/manifold interface. (ie:chipboard!)

[GT01]

Originally Posted by kiekmer Hello, I have some side-draft manafolds at home. Don`t know the brandname but they have the initials C/T. The length is 9.5 cm (3.74 inch). I`ve tried to install them with DOHC`s but dont fit with the heater box.... Attachment 11471

Do you still have these, and would you like to sell them?

[nobody]

I was thinking about this a bit and realized that for the GT the length is critical. However for the other models it's just the opposite. The best flowing of the bunch are the longest ones. Since this is a going to be a very short production run. I should look at it from how long can I fit in vs what has been done before. I could go to maybe 120 or more in a wagon or a Manta. Just thinking out loud a bit.

[davegt27]

TWM's are 3.5" long




Davegt27

[davegt27]

the FI TB is an OER item

the linkage on the Manifold is a Mikuni item the linkage on the TB is an OER part


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HTH
Davegt27

[nobody]

Dave, I like that linkage point on that one. It beats what was offered with the cannons by a long ways. are there bearings or bushings in the pivot point for the main shaft on that setup? I'm liking that idea alot. Thanks for the input, that is what will make the difference between a great idea and a so so idea. I really like all the curvature pics and with some idea of the flow ideas this may be a good one.

It's kinda funny, in my spare time at work I do the finish work on some lost sand castings out of a company in Longmont. Ah to be back in my world of machine tools is a blessing. Ok I'll be quiet about this till it's ready to be seen but please keep the ideas coming.

[davegt27]

bushings on the TWM setup --heim joints on the OER linkage

HTH
Davegt27

[yellaopelgt]

bump.... How goes the battle on this??
Joe

[opelbits]

I have a pair of DSD manifolds that seem to be from Greece.

They measure 82mm on the top, 94 on the bottom.

[yellaopelgt]

If I may ask... Did you get those off e-bay? motorman 253? (not an e-bay ad plug)I was seriously considering getting a set of those.... he has a great feedback score and was waiting for someone here on this site to post the results of fitment before I took the plunge. They really look identical to shorty Irmschers..... but pics can be decieving. I was considering them for a GT so if you could post what type of car you have and fitment on the car it would be helpful for all of us if we need them, Thanks,
Joe

[nobody]

Ive finished off the templates and they are at the steel shop and I should have a quote to run with shortly. I wanted to crunch all the numbers and then double check it all. I can put them together at around 65mm in length but will go with the dimension for the short Irmschers instead. there were a couple of things that made me wonder a bit. Some of the more critical dimensions came up perfect compared to some of the other pieces. Such as the carb spacing being completely centered and fit a standard linkage perfectly. The tube bends came out exact on centers with no trimming needed and spot on size for the carbs and intake sides.

The more I look into it the more I'm shocked that it hasn't been done before. This is going to be easy.

[GTJIM]

Originally Posted by yellaopelgt They really look identical to shorty Irmschers..... but pics can be decieving. I was considering them for a GT so if you could post what type of car you have and fitment on the car it would be helpful for all of us if we need them, Thanks,Joe

Those Greek intakes look very much like the Irmscher "Shorties" but if you look at the respective measurements it appears that the Greek ones do not have the same angle on the carb mounting flange - it is considerably less than the Irmschers for the GT and I would guess they are for Manta motors.

Sounds like you are making viable alternatives, Dave!

[opelbits]

Originally Posted by yellaopelgt If I may ask... Did you get those off e-bay? motorman 253? (not an e-bay ad plug)I was seriously considering getting a set of those.... he has a great feedback score and was waiting for someone here on this site to post the results of fitment before I took the plunge. They really look identical to shorty Irmschers..... but pics can be decieving. I was considering them for a GT so if you could post what type of car you have and fitment on the car it would be helpful for all of us if we need them, Thanks, Joe

I don't recall at the moment. I bought them from a private party on ebay, not the guy in Greece. These manifolds may be the ones that were on ebay a year or two ago and the guy I bought them from had originally bought them way back then.

I haven't put them in a GT yet, but when it gets a little warmer I have a second car I can test fit and take measurements and pics. I bought them with the possible idea of using them in a Manta I have.

I am not too convinced they will be very good. The turn close to the head flange is really tight and can't be too good for flow. I would imagine they will be most suited for a stock or mild motor with 40 Webers, a balance between decent low and medium rpm power and the coolness of being able to say you have dual Webers.

If you find a set cheap enough, you could try to extend them into a longer runner manifold. Basically, you make your own DSD manifolds using these as a source for carb and head flanges.

There is something I have been pondering...but it takes someone who knows something to answer it...

If the problem with short runner manifolds is the reduction of flow from the tightness of the turns and the inability to get a nice straight shot at the intake port, what effect might there be by trimming the divider on the head side of the manifolds? Would the disruption of flow offset the potential of gains by each cylinder being able to draw from both barrels at higher rpm?

[GTJIM]

Originally Posted by opelbits There is something I have been pondering...but it takes someone who knows something to answer it... If the problem with short runner manifolds is the reduction of flow from the tightness of the turns and the inability to get a nice straight shot at the intake port, what effect might there be by trimming the divider on the head side of the manifolds? Would the disruption of flow offset the potential of gains by each cylinder being able to draw from both barrels at higher rpm?

The twists and turns in the short manifolds may be slightly restrictive but have the advantage of creating swirl in the mixture to keep the fuel/air mix more homogeneous at lower flows in the lower rev range. It is usually thought that bends can drop fuel out of the air flow stream but the turbulence crated off-sets this, allowing the fuel droplets to re-enter the flow stream - particularly if the wall finish is not smooth.

One of the major advantages of individual porting to each cylinder from each barrel of the carb is tunability of each cylinder separately. Though the Single Side Draft manifold does double up and use on barrel for two cylinders.
I doubt that removing the dividing wall on a Double side draft set-up would make things any easier to tune though!

Never let to many doubts stop you trying something though - "Your mission, should you choose to accept it, ....... " Then report back to us !!

Just remembering ... the old 'Stovebolt' Chevy six-cylinder motors had siamesed intake ports and Side Draft Webers were used on them with both barrels feeding through an intake manifold into the one dual intake opening ...

[opelbits]

I keep in mind the siamesed ports (like the Stovebolt...are you familiar with the HWM Stovebolt Special?) and also the current v8 intakes with that cutout below the carb.
I was thinking of something like a 1/4" to 1/2" cut back to allow a little flow from one manifold runner to be drawn into the other, ideally at higher rpm. Kind of a crutch to make the engine think it has either a longer intake runner or a bigger carb.

[nobody]

Still no word on pricing for all the assorted little bits to be cut. I was planning to give out a phone number and details with pics to allow anybody else to utilize the opportunity for an intake flange. Direct only, I won't touch it.

After dealing with and using several DSD manifold types I did find with some info here what was good and bad. The Magnoletsi flows the best of the ones tested, the angles and longer run after that are the differences. The Cannon has poor castings and bad angles were the Irmscher has more severe angles with better castings but both have bad flow rates.

If this pans out the next step after weld up is out for powder coat. It seems that for a good powder coat the part is first sand blasted to an extreme. I spoke with them about a few minutes of flow blasting the runners and it was no problem. Not smooth but all edges gone and optimized. Then it will get a color but the main reason is the bead blasting.

The biggest problem I saw was the reduction from 90mm centers at the carbs down to 37.5 at the intake ports all in 70mm or less. Oh and don't forget the 14 degrees if it's meant for a GT. An old pipefitters trick will be used for that one. I'll write it up when it all goes into reality.


here is the reasoning for it all. First is an intake for a beastly motor about to make an appearance. Second is for an EFI intake for another project of mine. Lastly is to have on hand a better twins manifold than I could buy just in case I want one.

Dave, I added the points for that style linkage and mounting system. Base angle for perpindicular at that point is plus 20 degrees on one side and minus on the other.