ISDT Qualifier

[bentrims]

PS Teddy,

Anza is not a certainty because of the rain that continues to belt the west coast. If we end up in Arkansas I hope you dont mind alot of question about the format and a general lack of enduro knowledge.
TB

[OUCWBOY]

Tom,
What's wrong with a little rain?? Back in my day, we raced in the rain, sleet or snow.

Donny Smith

[john durrill]

Tom.
   Here is a link with some pictures of a D set of cases. Doug was kind enough to supply the pictures. You can do the same thing in a different way to A/B cases. The D cases were prone to crank failures acording to Doug, if the throttle were held wide open for long periods of time.  Looks like they did not cool the bearings , were restrictive in oiling. The A/B cases did a better job. If the link does'nt work for you send me an e-mail and i will send you the pictures. They are in the Library.
http://autos.ph.groups.yahoo.com/group/PentonRestorationandTechGroup/photos/browse/253f

[bentrims]

Donny,
Personally it can rain at every race I go to. I always say Minnesota did not get those 10,000 lakes from our gorgeous weather.

One big AHRMA problem is they tend to cancel VERY easily. In 2002 I drove 1900 miles alone for a cancelled race. I dont remember motocross being like that. That was a long, lonely trip home feeling very stupid. I was so bummed out I nearly sold everything.
TB

[bentrims]

John,
I sent an e-mail your way. I could not get in. Thank you! Tom B

[bentrims]

Donny,
Is the Arkansas move still a go for you? Be sure to let me know if you need a place to store those trick bikes.
Tom B

[Knute]

Hey John,

Doug has told me of his experiences with the "stuffed" D engines as well and it makes sense to me.  Plus, I think the gains from "stuffing" the Sachs cases are fairly minimal anyway.

Also, aren't the D, D GS, and D GS Pro (and maybe some other versions?) all slightly different?  Something made me think that only the D GS Pro came with "stuffed" cases.  Maybe Doug can enlighten us.  In our case, we run a D GS without "stuffed" cases in our race bike and it has been very reliable.

Kent
 

[firstturn]

To everyone.  The GS and GS Pro engines are B engines...unless someone has a engine that is marked differently.  The D engine doesn't have the stuffed cases again unless someone tells me differently.  I have example of all these engines (some are NOS) and that is why I am putting this post up.  Also, there is an A GS engine that no one has discussed.
 
I agree with Doug Wilford (who wouldn't) about the stuffed cases being less desirable for Enduro and Cross-Country racing.  Please if anyone disagrees with me, please speak up, since I would like for us all to get the knowledge of the Great Sachs engines out to better understand the technological history of these engines.

Ron Carbaugh

[Dwight Rudder]

Here is some more information that I got from a Former Canadian PENTON KTM dealer and Leo Keller who is a world renown Sachs / Hercules Historian.
Dwight
===================================================
Leo,  when exactly did the Sachs D engine come into use.   I had a
mid year 1974 Penton Six Day 125with a GS ported cylinder but it was
a B engine with a 28mm Bing.   I have had several people say that
they had mid year Pentons with D engines from 1974 .  My bike had the
"Watermelon" gas tank as I know some of the early 1974 bikes still
had the flat sided tanks .   I thought the D engine didn't come into
use until 1975.  But I could be wrong.
Dwight
===================================================================

Dwight we brought 4 74 Pentons into our dealership in May 74 all marked KTM
special tuning but no D motors all B... 3 watermelon tanks and 1 toaster...
I still have the toaster tank bike and 1 of the watermelons  I would be
curious to know your frame serial number  the POG site lists 74 1/2 models
April 74 but I don't think so... Brian Taylor
==================================================================

Hello Dwight,

this is what I found:

29.10.1973: 454 1251/6B for KTM

12.12.1973: 133 1251/6BGS for Rossi Milano (Hercules Italy)

14.2.1974:  89 1251/6 BGS for SWM

That means that KTM did not get GS types

The last 5CMC were produced in Feb. 74 also.

In my list are only a few 6DGS motors for Italy in 76 (SWM and Sachs
Italia), I think that were spare motors.

Hercules came in GER with the D motor for the 75 models, so I think Sachs
produced the motors in late 74.
Leo Keller
==================================================================

The GS type had a special shifting - the difference between the B and D case
was the crankcase. The B type had only a slot for the connection rod, the D
type had an open case so you could see the crankshaft.

The same were the 5CMC and the 5 EMC motors.

7 fins for the B type cylinder, 6 and a rubber mount for the carb for the D
type.

I think KTM ordered standard motors because they had their own "KTM tuning"
for the gearboxes.

Leo

 =================================================================
Food for thought here.  I personally believe that some bikes were "UPGRADED" later with D engines.  But like you said there is not a clear advantage for the D engine over a GS tuned B.

Dwight Rudder
7 time ISDT / E medalist
8 time National Enduro Class Champion.

[firstturn]

Dwight,
  Thank you for your leg work.  One question....what is Leo refering to when he uses the initials CMC...chrome moly chassis??  Thanks again.  It is time that we nail down some of the myths and give people as exact answers as we can.  We will never be 100%, but we will get high marks for great information and trying to do it right.  I hope you are healing fast.

Ron Carbaugh

[Knute]

Hey Dwight,

Thanks for checking with Leo.  That's great info.  Does he have any info on the GS Pro versions?  As far as the Penton goes, the earliest D I've seen is 4 06.  Also, Donny has an original 4 07 with a D engine, and I have a very original, unrestored 4 09 enduro with a D engine.  Again, I call this 74 1/2 or late '74 but others may call it 1975.  Here's a picture of my 4 09 that shows the uniqueness of the D cylinder for everyone who wants to see what we're talking about. http://gallery.pentonusa.org/gallery/album06/DSC09461

Ron,  That's great info about the B engines.  So which engines came with the "stuffed" bottom end?  The B GS and B GS Pro or just the B GS Pro?  Did any D engines come with "stuffed" cases?  When are you Sachs guru's going to put together a database with the specs for each model and version of Sachs engine so the rest of us guys can get this all straight?  

Regarding the D GS engine, I use a completely original, unmodified D GS engine in our race bike.  It came out of a Hercules enduro that I purchased from the original dealer. http://gallery.pentonusa.org/gallery/album06/DSC09489

Thanks again guys,
Kent

[Paul Danik]

I question what Leo said about the difference between the "B" and "D" crankcase below.  I have found that the "D" crankcase is the one with the slot and is referred to as being "stuffed", the "B" cases offer a view of the crankshaft.

Below is what Leo stated in Dwight's post.
Paul

The GS type had a special shifting - the difference between the B and D case
was the crankcase. The B type had only a slot for the connection rod, the D
type had an open case so you could see the crankshaft.

[firstturn]

Kent and All,
  All of the B GS engines I have seen torn down had the stuffed cases or the small opening that allows the rod to just clear the cases.  The main idea is to keep all the area down inside where the crank is as "dead air"....no volume so to say.  I really don't call these cases stuffed cases as I relate to the first time I heard the term stuffed cases which was back in 1959 and it refered to Go Kart engines.
  With that said, I have never torn down a D GS engine so I we have to wait till you tear your engine down to and send us pictures??

Tom B,
  Your question of stuffed cases goes to the situation of what I call stuffed cases and you put cork or what ever to make a small tight crank case area.  I can tell we are going to have to do a show and tell on this subject.

  I guess I should have never ask what was legal and just set up and run what I wanted.[][B)]  But we are having fun.

Ron Carbaugh

[Paul Danik]

I have a set of "A" cases that Ted Penton had stuffed a number of years back.  He had machined a notch in the center of the cases, in the area between where the flywheels would rotate, he then machined a horseshoe shaped aluminum insert that fits perfectly in the notch and extends into the crank area between the flywheels. The insert reduces the volume within the crankcases, this process was also referred to as "stuffing" the cases by engine builders.

     To be able to identify these cases he put an "X" on the oil fill plug and marked the cases with " S 10 " in the area behind the fill plug.  Since these cases are " S 10 ", there might be 9 other sets of these cases around, check your oil filler plugs for the stamped "X".

Paul

[OUCWBOY]

Kent,
My 74 looks just like your enduro, except my cases say Sachs, and not Penton, and mine has the cable strps and not the leather strap.
By the way, Great looking bike.

Paul,
I remember some talk awhile back about the use of the D engine in the Penton's. As I recall, they olny used the regular D and not the D GS. I don't remember everything that was said about it, But I worked in the parts Dept at a dealer the spring of 74 while I attended school and remember reading a Sachs bulletin about the new Sachs D engine. It was before I left California in May, so I think it was in March or April. So I am sure the D engine was available by mid 1974.

Ron,
The MX bike I sold about a year ago, had the D GS engine in it. I was told that it came out of a Monark. It did have the cases with just the slot in it. Also, it had a 5 speed gearbox with the shift lock unit installed. It also had an internal flywheel Motoplat and a 32 mm carb. It was actually faster than my 2002 KTM SX 125 in a straight line race.

Dwight,
There was no mention by Leo of Sachs engines being set to Monark during that time frame. I do know that they had bikes with the B GS abd D GS engines. The GS Pro Series as I know it, were modifications done by Monark as indicated in their parts manual. The GS parts all have Sachs part numbers and the GS Pro parts all have Monark/MCB part numbers.

Donny Smith