Anyone mention "D" engines?

[Bryson Williams]

Hmmmm, so I guess I'm not looking for a 175 Sachs.  I do have one  running jackpiner," Has lights on it" and two 175 motors some guys in Washington state gave me in trade for 2 125 Penton frames.  " They made Penda's" What Engine # would I need, to do the 175 Penton  top end swap, to the 125 Sachs.

 How much bigger is the header pipe on the 175 then the 125.  

I have two Sachs pistons that are forged, and have a machined hole above the wrist pin holes, Somehow they got put into my Cr Honda 125m piston drawer.  Are these perhaps the GS piston I was bugging you guys about?

 Dirk

[john durrill]

Dirk,
 You can do the 175 swap with either an A or B engine. I would use the A motor for a smoother power delivery. Its easier on the clutch and gears.  You can use the old , long piston 175 cylinder and head or the 76/77 new short piston cylinder and head. Both have their advantages and dis-advantages.
 The pipe header diameter depends on which cylinder you would use.
The old long piston cylinder uses a larger head pipe diameter than the short piston cylinder.
What year frame would you want to put the engine in? The 76/77 and up pipe is not a good fit in the 72-75 Six-Day frame. We used a 72-75 Jackpiner pipe and modified it to fit after trying to install the 77 175 pipe first.
 We went with the new short piston cylinder because at the time the long pistons were very hard to get and the 77 cylinder used a liner that could be removed when modifying the cylinder. We then had to open up the exhaust port diameter between the where it exits the cylinder and meets the pipe. Blending it back towards the piston from the exhaust flange about 3/4 of an inch to let us use the old style Piner pipe.
 How serious are you in doing this? The reason We went with the swap is the 125/175/5 or 6 speed is about 30 lbs lighter than a stock Piner. BUT big BUT here, you give up strength in doing the conversion. Haveing said that Monark use the 175 KTM top end bikes to win medals in the ISDT so they can do the job. The 5/6 speed Sachs engine is an old friend to me. I'm not hard on gearboxes , have never had one fail on me. We use the bike for the Reunion Ride and some fast trail rides 25 to 60 miles long 5 or 6 times a year with Rick G.
 The engine cases need to be opend up to recieve the 175 cylinder. The bottom of the cylinder liner would need to be shortened probly and reshaped. If you use the tall cylinder you would need the cases machined down where the base gasket sits to get a base gasket seal and set the piston in the right place in relation to the rod length and piston crown height.
 Ill be glad to go over step by step what we had to do if you would like.
John D.

[Bryson Williams]

I just returned from Medford Oregon, where I picked up a Pention/KTM.  Has a blue tank, layed down rear marazocci shocks, leading axle marzocci front shocks has six fins on the barrel and a bing 54 carb.  

 This bike is stuck, I paid 185.00 for it. The tank is a smaller version of the green tanks and the blue tank on my Jackpiner.  was looking for the engine,"75210145"  Did I do good what the heck is it?

I was told it's a 175 is it the right barrel for this project.

 Dirk

[john durrill]

Dirk,
 Here is a shortcut to some pictures of my engine.
Are you thinking about building a Sachs/ KTM 175 6A or 6 B? Whats the engine #?
http://pg.photos.yahoo.com/ph/sachs175/album?.dir=/1a95
John D.

[Bryson Williams]

I thought a 175 engine in a Sachs would be cool.  A 175 in one of my Monarks would be even cooler.  So yes, I am really thinking about building one.  While I was over the hill I checked out the 1974 Penton 125 "D" model motor.  Not a GS still a very clean bike. I offered 1200.00 for the bike.


 The Penton/KTM I just purchased would be a cool bike to rebuild.    I need to check the engine #'s I have on the two 175 motors I have in my shed. I would hate to rob the top end off of this KTM, if the other motors top ends will work.  I do remember that the two motors are Black in color.  Can't do that until tomorrow.


Dirk

[john durrill]

Dirk,
 The older black engine cylinder is what Monark first used. Use the base gasket off one of them and lay it on the 125 cases. That will give you an idea how you need to  go.
 We will try and get some digital pictures of my engine cases apart so you can se what will need to be done. You need to find a machinist that can do this work. Everything needs to be cut on the same plane as the stock 125 . The cases will have to be opened up with out messing up the center case gasket sealing area where the cylinder goes in. Same with the base gasket area. It will need to be machined down some. The A cases and crank would be a better choice I believe. Did the pictures help any?

 John D.

[Bryson Williams]

John I do have two 125 early Penton Fan head motors aswell.  Are you recommending that I use that lower end rather then a Monark B motor?


 Dirk

[john durrill]

Dirk,
 I wouldnt use the D GS cases. They are easy to tell apart from a B or A set. Doug told me last year that the reason Pentons didnt come with the stuffed cases is the crank ( I think it was the Rod) didnt give the relability  at sustained high RPM,s . Long straights , desert races , ISDT, that was needed.
  I would use a set of 6A cases. The B crank is lighter and would pick revs up quicker but that would put more load on the crank, clutch and gears. As a 175 the engine will put out a  lot more torque than as a 125. I think the A crank is 1 and 1/2 lbs heavier than the B. That will smooth out the power delivery and give the drive train some relief.
  Look at the pictures in the folder. The transfer port area of the cases will need to be matched to the cylinder. The cases you use should have the metal already cast for you to make them as large as mine are. Then you will have to make the cylinder match the cases.
 We had to find someone to weld up the back transfers  for things to fit ( look at the pictures).
 My cylinder is 3.575 from head gasket surface to base gasket surface. I did not have to mill down my cases   with the 6 fin cylinder just use a 1/64 inch base gasket to get my deck height right.
once you get the cases opened up and the cylinder spigot trimmed to fit you can slide it on and see how much will need to be milled off the base gasket area of the cases.
 The tall cylinder transfer ports line up a lot better with my cases than the short cylinder. With Al now haveing tall pistons in different sizes in stock and someone to reline worn cyliders I would use the tall , 72-75 cylinder. I dont think i can go much over 64.25 mm on bore size so i will reline the cylinder after 2nd over is worn out. The 72-75 pipe fits the Six-Day frame with just a little modification also  so the 72-75 cylinder and head would be my first choice on a set of 6A cases and A crank and a 72 or 73 175 pipe.
John D.

[john durrill]

Dirk,
Here is a short cut to my photo album. it has 2 folders with pictures of the engine cases, cylinder base and how we did a 12 spring clutch to handle the added torque of the 175.
http://pg.photos.yahoo.com/ph/sachs175/my_photos
 Let me know if you can view them and if they help any please.
 I have the files in the photo section of the library also folks.
John D.

[Bryson Williams]

John after giving this project very careful consideration I'm wondering if I have the skills to get it done.  I do have a set of Sachs cases with a Crank in them.  I will take them to a machinist friend and see if he is capable of doing the work.  

I'm not having any luck in locating the sites your posting.  I read that it would also be best to upgrade the clutch as well.  Hmmmmmmmm.  I am chasing a Sachs 175 lower end in Reno Nevada.  

Dirk

[Bryson Williams]

John, I was able to access the photos. WOW that bike is fantastic.  I'm going to give it a go as my winter project.  I'll contact Charlie Brown to see what a new sleeve will cost.  Is that an Letron carb on your bike.  I have what I believe is a 36 or 38mm letron carb in a box.  The carb came with some pumper carbs I was given several years back.

 I think I'll ask Charlie Brown do the machine work on the cases as well.

Thank you.  Dirk

[john durrill]

Dirk,
 If you have a long piston 175 cylinder that is Std or 1st over with a good bore you wouldnt need a sleeve. Al has cylinders with sleeves installed on an exchange bases now in stock. The cylinder in the pictures is a KTM 76/77 175 cylinder not a Sachs 125 with a big bore kit.
 Use the pictures as a guide. Everything you guys do will be a little different than mine. The cutout for the cylinder spigot is max on my cases dont go any larger than mine. Take a stock 125 case half with the crank, piston and cylinder installed on it. Rotate the whole thing through a complete cycle. The piston will come out of the cylinder at the bottom of the stroke a good bit. I would keep that to a min. on the 175 cylinder. I think you will have to shorten the liner at the bottom some to have it fit . The piston may then come out at the bottom of the stroke  on the long piston 175 cylinder . We had to cut the short piston cylinder about .120 inches at the bottom and then tapered the od to fit the cases.
 Yes the carb is a Lectron but a 30 mm. 30 mm Bings or an Amal is what came stock on the early Jackpiner. You dont need more power than what came stock on the Piner . You could have hand grenade on you hands if you are not prudent.[V]  chuckle chuckle!!!!!
 A 30 mm Bing or Mikuni would be my choice for a carb. If anything comes up e-mail me or post it on the board. Measure every thing twice and think about any changes you make long and hard. Its easy to remove metal but very hard to put it back on []
John D.

[OUCWBOY]

Note to all.
The D motor was a 1974 engine and Monark was around thru 1976. On the Monark I mentionrd a couple years ago, there are at least 6 listed with D motors.

Now a new question, what is a 1251/E motor?

Donny Smith
Paragould, AR

[Guenther68]

Hi Donny,

the 1251/5 E MC was the last version of the MC engine until 1975.

Best regards
Guenther Vogt,
Hercules Club, Germany



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