SACHS 175 engine

[joe novak]

I have seen the Sachs bottom end blended to the KTM 175 top end to build a hybrid Sachs/KTM 175.   I believe Tom Penton said that he thought this hybrid gave him the best handling and performance in a Penton CMF frame for woods riding.  Both the Sachs and the 175 KTM use a 54mm stroke engine.  I have heard that the 175 KTM cylinder will align with the four Sachs cylinder studs.   Seems like an interesting engine build.  What more is needed to assemble the engine?  Is a modification needed to assemble a KTM 175 piston and wrist pin on a Sachs rod (top end).

[t20sl]

Check with John Durrill.  He has vast knowledge on this subject.
Should also be able to look up this topic in the POG search engine for more help. Ted

[Kip Kern]

Personally, if you want a 175, I would stick with the 74 175 KTM engine.  Has the later shift drum set up and no shimming in the transmission;)

[Ernie Phillips]

Kip,  The KTM motors have their advantages, but light weight aint one of them.  I'd love to ride a converted Sachs 6B -175 in a '72 CMF and see how it works.  I know in the 100-125 displacements, the early CMF bikes are fantastic woods machines.  I don't know if the reliability would be there running 175cc displacement, but the added torque would make shifting less critical.  Nimble, light weight and less shifting -- maybe that is why it was as one of Tom Penton's favorite. -EP

Ernie P.
Chattanooga, TN

[Kip Kern]

Now you have me curoius Ernie, I have 4 NOS Sachs bottoms, several 175 cylinders and heads, Heck, I may have to make one of these critters!  5 speed "A" only though;)  Look out Forest and John, here I come with another welding project!!!!!!!! I am getting dizzy, I can hear the "On any Sunday" tune[]  Harvey, is that you???

[john durrill]

Kip,
 I looked through my files on the puter tonight and added some labeling to some pictures we took back in 2002.
Here is what we did. I know there have to be better ways to do this job chuckle chuckle!!!!
 If we would have had access to the tall 175 pistons back in 2002 we would have use the 7 fin cylinder to build the engine. The base gasket area is a much better match over the 6 fin.
 Included is some info from a 7 fin cylinder we had on the shelf so maybe the pictures with comments will help.
 It would have been a lot easier if i had someone like Forest within driving distance
Joe , maybe this will answer some of the questions you posted.
I think you would need 6 / 5 A cases Kip. A 6B engine would be a hoot to ride but may not last as long as the A.
 











































Kip,
The difference in cylinder heights between the 6 and 7 fin is made up for by the pistons. The B rod is the right length but the big end pin is a little wide for the A crank slabs , so the  big end pin needs to be shortened 1 mm ? each side. It been a few years chuckle chuckle!
I dont know how big in over sizes this setup will take. Std.  63.5 , 63.75 and 64 mm for sure. Don,t know if a 64.5 would clear the cases.
With my liner shortened .10 inches the piston skirt  at BDC is about .060 below the liner.
 I have a new NOS liner on the shelf so next time we need a bore i think we will have it coated so i can just run STD pistons from then on out.
 With differences in engine cases over time its possible you would need to deck the base gasket area on the engine cases a little. If we pull my engine down this spring we will try fitting a 7 fin just to see whats what if that would help.
Joe did this answer any of the questions you had? Best i can do for now guys. I'm no typist and you need a time Lapps  camera just to see me move from one place to another. []
 john d.


 

[Kip Kern]

John, Appreciate the help and photos, will be scratching my head and talking to Forest and John Cooper(the best welder on this planet)  Forest, Kaleb and I are heading to Kevin grimes for our annual spring break "Husky/Penton craziness" trip.  Going to meet up with Ron Carbaugh, swap some bikes and talk Penton/Husky projects.  Kevin and Forest just built some "top secret" Husky Pro Fab stuff.  We do a bunch of lying, BS'ing and all around good fun stuff!!!!!!!!!! BBQ here we come[]  "On the road again, just can't wait to get on that road again"

[Larry Perkins]

The 175 KTM topend would take the bike out of Classic Class and it would go to Sportsman if that is a consideration.

Larry P

[Kip Kern]

Just something to play with in the local woods and trails;)

[john durrill]

Larry,
 The Lectron put's me in Historic . BUT that carb makes it easy to ride  with the  76 cylinder and helps the drive train with the extra torque.......... i think.
   For us , the class it put us in didn't matter much . Having an easy to control , light 175 with great handling lets me ride a few more years even in the mountains. Now that was the real reason for the changes.
   You were a big part in helping me get the engine done. You had all the top end parts i needed the day i called. You know now that i think about it , its been 9 years since we ordered the top end from you. Time is slipping by way too fast. You were a BIG help my friend, many thanks.
  Ron C. , he helped  with  mods we had to do to make it more reliable.
    Leo , Speedy , Gunther , Martin , Al B. , A bunch of the POG guys.
 All those folks had answers , information or parts for me at just the right time
The Lord had His hand in that project for sure.
john d.

[joe novak]

Thank you to everyone who responded.  John, great photos and description of all the detail work needed to pursue this project.   Also, I did do a POG "search" which lead to a lot of interesting information.  Joe

[VICTOR MONZ]

I ask, why not a trick Sachs 125 cylinder on a KTM bottom end to improve the shifting ?

Or am I off base.

Beautiful exhibits, they are exceptional.

Victor

[john durrill]

Victor,
 That would be my choice for a KTM first generation 125. ( But i'm prejudice for sure on this one [] )
It should not be a hard fit. The key would be to get the cylinder/ engine case ,  base gasket area to fit and flow smooth . Get the deck height right on the cylinder so the piston is where it should be at TDC in the cylinder. Adapt a 72-76 Sachs Six-Day pipe and fit an air boot to the 27 mm Bing and the air box.
 It would give you an engine that will make plenty of power , and last a very long time on top end rebuilds.
 Only down side is it will be 20 or so Lbs heavier than a Sachs engine.
 Barry Higgins put 175 top ends on some of the first 125 KTM's for his customers back when . That's another good option if you are not fond of the 125 KTM engine.
The KTM 125 primary gears are a different ratio and one of the gears , 6th on the  main shaft, is a different size .
 You know i have always wondered if that gearing would  have been a better setup for the 175 engine..............
It would be a fun project Victor for sure.
john d.

[joe novak]

Victor,   You have a great idea of putting the Sachs top end on a KTM bottom end.  It has been done.  If memory serves me correct, there was an article (which I still have in archives) in the old Keeping Track magazine about Carle Cranke cranking out one of these.  It was a 100cc set-up.   Some young racer from Iowa raced one of these at the Joshua McCoy Nashnal Hair Scrambles at Amherst Meadowlarks.   Joe

[Kip Kern]

That's it John, I am building a Tom Penton replica!  I just checked my shop and I think I have enough junk to do it.  Have her ready for 2011 Mid Ohio I hope.  Have 2 Husky's and 2 Steel Tankers for this year to finish.  Looks like another fun project, if I can make the Puch/Penton by golly I can make this thing!!!!!!!!!!!!!