D model barrel on a 6b lower end

[Bryson Williams]

Having my D model barrel, "GS ported" using the port spec's on the VINTAGEMONARK page. Will the barrel be an exact fit or do I need to mill the bottom of the barrel?.

Dirk Williams

[Doug Wilford]

I personally would not mill the bottom of a "D" cyl, (barrel) as the "D" cylinder is already 1 mm shorter than any "B" or "A" cylinders.   Hope this helps, I am not sure I completely understand what you want to accomplish.   Some porting only widens the ports and some raise them.  If they have been raised then milling the barrel would lower the ports??

[Frenfroe]

I think Dirk's asking, do the transfers line up between the cylinder and the cases or is matching needed? I think he used "milled" instead of "matched".

Frank

[Bryson Williams]

Doug and Frank, I'm doing another Monark,when I received the motor,I was surprised that it had a "D" model barrel on it.  I'm certain that it's a "B" lower end.

 I was thinking that I had read somewhere on the POG page that the D barrel needed slight modification to work properly. The "GS" spec's I'm using are the wider and "Chordal, yes that word again".  The spec's are on the VINTAGEMONARK.com page under the MOD's/TIS section.

The cases according to the TIS publication need to be matched. I noticed that the motor did not have a base gasket, I thought this was an oversite, could it be that the last owner was making that MM up by not putting a base gasket on.  Sounds kinda odd to me.  

[Doug Wilford]

Matching the transfers from the cases to the cylinder is not a bad idea.   As far as the base gasket, I would check the piston (deck)height at the top of the stroke.   The Sachs doesn't set deck height with gaskets like PUCH and a lot of others.   It may have been the previous owners way to lower the cyl as you said.

[bildough]

Doug;

Im glad you are giving Dirk all this input. He definitely needs it. In Klamath Falls he has been frozen in this winter and his mind is playing tricks on him. He is trying to invent new and better ways to get his sachs engines to run with mine. When he sees how the engine you just did for me performs he will be very despondent. With him being a police officer I might have to LET him win occasionally. After all he is a PGRT member also.

Bill Cappel

[gooddirt]

I have a 1974 six day with a D motor it is not stuffed case model, are the center cases different from the B cases?  They look very much the same.  I also have run a B top end on my stuffed case race bike with stock base gasket.

[gooddirt]

Passed said, the porting specs on the vintage monark was on a B barrel by looks of the pictures. ( seven finned barrel)

[Doug Wilford]

Good Dirt;
If your Penton is original.    What you have is a "B" lower unit and a "D" cylinder.  The "D" cases are easily identified with the cylinder off.   The rod has only a small rectangle to work through.  Because the Penton was used mainly for cross-country (enduros) etc. we found that the "D" rod bearing was not getting enough lubrication to hold up during long (miles) wide open.    There were no production Pentons with the "D" lower unit.   There has been many people, lets' say alittle disappointed thinking they had bought a true "D" enngine with their "Penton".   In reality they did get the best deal in my opinion.  Personally I will sacrifice one or two horse power for reliability.    Having Fun is the most important.

[Bryson Williams]

The engine I have is certainly a B lower.  I guess my next question is do the porting spec's apply to both the B and the D model barrels.  The B barrel is 7 finned and the D is 6 finned, with a bolt on intake manifold.

 Dirk

[Doug Wilford]

Yep it can be done. but much easier if you have a "D" sleeve put in the B cylinder, then at least you won't be grinding on the sleeve, just matching cylinder to liner.

[Bryson Williams]

Thank you Doug.

 I was just going thru my Sachs stuff and came across a porkchop style crank. It looks odd, the rod on the crank is the bronze Sachs rod so I'm thinking this is some sort of Sachs Crank.  I've never seen one like this. Has anyone ever seen one, if so are they ok to use and what advantge would they provide.

 Dirk Williams

[Doug Wilford]

I personally would not mill the bottom of a "D" cyl, (barrel) as the "D" cylinder is already 1 mm shorter than any "B" or "A" cylinders.   Hope this helps, I am not sure I completely understand what you want to accomplish.   Some porting only widens the ports and some raise them.  If they have been raised then milling the barrel would lower the ports??

[Frenfroe]

I think Dirk's asking, do the transfers line up between the cylinder and the cases or is matching needed? I think he used "milled" instead of "matched".

Frank

[Bryson Williams]

Doug and Frank, I'm doing another Monark,when I received the motor,I was surprised that it had a "D" model barrel on it.  I'm certain that it's a "B" lower end.

 I was thinking that I had read somewhere on the POG page that the D barrel needed slight modification to work properly. The "GS" spec's I'm using are the wider and "Chordal, yes that word again".  The spec's are on the VINTAGEMONARK.com page under the MOD's/TIS section.

The cases according to the TIS publication need to be matched. I noticed that the motor did not have a base gasket, I thought this was an oversite, could it be that the last owner was making that MM up by not putting a base gasket on.  Sounds kinda odd to me.