Sachs "D" motor intake manifold

[metalkfab]

As I await for answer from Larry,I thought I better check elsewhere.Does anybody have a intake manifold for a "D" cylinder that isn't cracked and they are willing to sell? Mine cracked from oldness and is sucking massive air.So much for racing this weekend!

[john durrill]

Metal. is it a rubber tube or a rubber flange like on a Mikuni?
 If its a tube you can use fuel filler hose  from and auto parts store till you can find something else. Its used for inlets hoses for gas tanks, that and two good stainless steel clamps should work.
John

 

[metalkfab]

I have the rubber style and it's cracked right at the flat flange area and I don't think that the hose and clamp will hold.Thanks

[Larry Perkins]

John,

The D ones are a rubber set-up like a Mikuni.  I don't have one, Karl.  There may be a Mikuni one that could be made to work.  Al might have one but you may have tried there already.  Sorry.

 

[john durrill]

Metal,
 I have the sudco book with all the dimensions for the flange type  mounts they offer.
Get me on Yahoo or send me an e -mail with the stud width and the diameter of the hole the carb fits in. will see if we can match something up.
 does the flange press on the stock spigot
 of an aluminum cylinder? that's what the pictures I have show. if so you can remove it and use a hose that will handle gas.
John

 

[OUCWBOY]

Karl,
I have a D motor complete, but, not for sale. Do you think anyone could remake this part?
Donny

[rob w]

I just got my hands on my "D" motor for the first time, here's what I found. Someone had used a Suzuki part for the intake manifold. The dimension between mounting holes was smaller (less) than that on the cylinder, so they enlongated the holes until they broke out the outsides of the manifold flange. The bolts were holding it on pretty well, but the set-up did not look good enough for me to want to use it again. The carb to manifold fit was excellent, the diameter of the intake to cylinder was right on, just the bolt spacing was off. Maybe if we made a stainless plate to slide over and down on top of the Suzuki flange, it would have better holding pressure. Or find Sudco part.

Here are the dimensions I've taken for the flange needed.

Distance between mounting bolts= 68.25mm
Mounting bolts= 8mm
Dia. of intake into cylinder= 30mm
Dia. of carb mounting hole= 38mm
Depth of carb inside flange= 17mm
Over-all length of flange= 36.5mm

I hope this could be of some help to us all. Later can we talk about who's doing what mods to these "D" motors, I've got to tear into this in a couple of months. Thanks, Bob W.

 

[john durrill]

rob,
 look at the addy below and plug in what you measured. see if anything their will work.
Larry does the flange mount press on a standard aluminum cylinder or is it perm. attached?
 i have never seen one except in pictures.
 Metal hope this helps,   best i can do for now.
 Our library addy for the file is in the photo section
http://groups.yahoo.com/group/PentonRestorationandTechGroup/
 John D.

 

[Larry Perkins]

John,

It is machined into cylinder.

 

[john durrill]

rob
 look at the page in our library and see if one will fit. i used one for a snowmobile on my Lectron.
 all the sizes Sudco carries buy Mikuni are listed on that page with dimentions. worst case you could weld up a plate with a spigot on it that would bolt to the cylinder and use a hose  to connect it to the carb .
John

 

[Gavin Housh]

I recently put a six fin monark "D" cylinder on my "B" motor with a high compression head from an "A" motor. This setup allows the use of a 30mm Mikuni carb. I also was unable to find the correct manifold so I puchased a Mikuni manifold from Pro-Flo with a smaller hole center than the center of the two studs that stick out of the cylinder. Then I used a round file to widen the exsiting holes in the manifold. With some careful file work and stopping to check your work against the cylinder you'll be in business. If anyone wants to try this on a Penton you end up haveing trouble fitting everything in between the cylinder and the air box. I also used allen bolts in place of the studs to give myself the ability to move the carb out the side when I need to remove it. If I was to do this again I'd have bought the 28mm Mikuni and hade it bored out to 30mm. The reason for this is that the 30mm carb has a bigger body than the 28mm carb, and the float bowl on the 30mm I am now using comes into contact with the top of the engine case. I also couldn't get my air boot to fit over the 2 1/4in. end of the carb so I had to fabricate a metal adapter that I use hardwear store bought plumbing connectors to fit it all togeather. It all barely fits and I'm dreading the first time I need to make jetting changes. I also bought the carb from Pro-Flo and the jetting was spot on. Just for your information you should know that the six fin Monark "D" cylinder has the same porting as the "B" cylinder the only advantage is that there is alot of metal that can be bored away in the intake area to increase the size of the carb. The "B" cylinder has a spigot that can be widdened but the metal gets mighty thin. If you want to get more perfomance you'll need to get out your right angle dental grinder and start removing metal from the exhaust and transfer ports. Gavin