SACHS DOLMAR

[flatspinjim]

I'm thinking Ralph knows a little bit about these engines!

[Tired Old Man]

Prolly no more than one or two....hundred.

[Superrmario]

	Quote: Originally Posted by rcign
	Many companies have used Sachs 49ZN cylinders...There is no way to tell the date... Look at the con rod...A copper colored rod is a Sachs, a silver color is A&M...Both work, the A&M is not so good... If the bottom case bolts are parallel to the top it's a Walker engine, it WILL have a Sachs crank... A Sachs 4.2 cylinder engine is stronger than any 50 class engine... The original color was orange...If the case is anodized red it's a Precision Eagle....All Sachs parts... A Sachs crank will have the production date etched into the crank web...All Sachs crank engines are older, Sachs was sold to Makita years ago...An old Sachs crank in good shape is as good or better than any modern crank.....

Thanks for the info. I assume you have much knowlege on this. The crankcase is just standard unpainted / colored aluminum, not orange or Anodized red.

I was told by the previous owner that it was run on the standard 30-1 mix with 87 octane. Curious if I should bump it up to 93 with a 35-40:1 mix.

How about HP ratings? As you can see, its on a 96" heavy old Carden from the Mid 90's. This plane is in the 25lb range, but yet it flies very nicely spinning the 24*8 prop.

Once the engine is cleaned up, I will snap some pictures if interested.

[rcign]

You don't need 93 octane, the chainsaw (Sachs Dolmar 120 or 120 SI) made to run with 87...And any old oil the lumberjacks had...

[Superrmario]

	Quote: Originally Posted by rcign
	You don't need 93 octane, the chainsaw (Sachs Dolmar 120 or 120 SI) made to run with 87...And any old oil the lumberjacks had...

LOL.... Gotcha, I was just curious if I should add more oil if I up the Octane rating because it will obviously be more of a snappy motor with a high Octane rating.

Thanks for the information! Lets say that I am happy with this motor, and want another one. Who do i contact?

[rcign]

I seriously doubt you will see any difference with 93 octane...Except to the wallet..

[yakpilot]

A higher octane rating simply means that it burns slower to prevent detonation. It could even give you slightly less power unless your motor was specially tuned for its use. ie.higher comp.ratio,advanced timing,or tuned pipe.

[Superrmario]

	Quote: Originally Posted by yakpilot
	A higher octane rating simply means that it burns slower to prevent detonation. It could even give you slightly less power unless your motor was specially tuned for its use. ie.higher comp.ratio,advanced timing,or tuned pipe.

I am coming from the world of Boosted 4 cylinder neons that punch out over 400hp at the wheels. LOL

Not that its "much" related but In my experience with my car, 93 Octane always made a diffrence. But again, thats a PCM controlled engine with tons of advanced timing thrown in and 23lbs of boost, more fuel, yadda yadda, i wont go into the specifics. This is a 1 cylinder 2 stroke

[n0ms4]

	Quote: Originally Posted by yakpilot
	A higher octane rating simply means that it burns slower to prevent detonation. It could even give you slightly less power unless your motor was specially tuned for its use. ie.higher comp.ratio,advanced timing,or tuned pipe.

Any ideas on a good 3D prop for the Sachs 3.2? I was thinking of a Vess 22A or B.

[Edgeman 540]

	Quote: Originally Posted by n0ms4
	Any ideas on a good 3D prop for the Sachs 3.2? I was thinking of a Vess 22A or B.

I have a Fox 3.2 in a 30% PAU Edge and it has unlimited vertical.The prop that I'm using for 3D is a Bolly 22 X 8 wood prop.

[rbarnett]

Does anybody have a picture of the back of a Sachs Dolmar 5.8 engine with a mount on it. I have one of these, and am going to install it on a scratch built Extra 330, 106" wingspan. There doesn't look like much to attach a mounting plate to on the back of the crankcase. Can I drill and tap the crankcase, and if so , what locations. Also, should I hard mount this engine, or soft mount it? Is it a terrible vibrator, as some have said? Does anybody make a aluminum prop hub for the 5.8, single bolt preferably. Mine has the Sachs Dolmar crank.
Thanks,
Bob

[rbarnett]

Anybody got that picture? rcign, Tired Old Man, anybody have a picture of the mounting plate bolted to the back of a Sachs Dolmar 5.8? I guess I am going to drill and tap mounting holes into the back of the crankcase. Can I also use longer crankcase thru-bolts, that protrude through a mounting plate. They seem small in diameter for this purpose, but with the added mounting holes I am going to make, will that work?

Also, can anybody that is still flying with one of these comment on the vibration issue.
Thanks,
Bob

[rcign]

vibration is not too bad, most 5.8s are solid mounted..
I have used a 1/4 inch flat plate...Drilled the case bolts all the way through with a 1/4 inch drill, and used 4 long 1/4 inch allen bolts threaded into the mount plate and cut flush....
Some of the 5.8s used 5mm flatheads through the plate into the rear crankcase about 3/8"...The holes are long enough so that the 5mm case bolts don't quite touch the plate bolts...
If the case is CNC the mounting holes are already there, 5mm flatheads are adequate...

[rbarnett]

	Quote: Originally Posted by rcign
	vibration is not too bad, most 5.8s are solid mounted.. I have used a 1/4 inch flat plate...Drilled the case bolts all the way through with a 1/4 inch drill, and used 4 long 1/4 inch allen bolts threaded into the mount plate and cut flush.... Some of the 5.8s used 5mm flatheads through the plate into the rear crankcase about 3/8"...The holes are long enough so that the 5mm case bolts don't quite touch the plate bolts... If the case is CNC the mounting holes are already there, 5mm flatheads are adequate...

Thanks Ralph,
I like the idea of using the long allen bolts, wtih the drilled out crankcase holes. I think that is the way I'll attach the mounting plate. Any idea of the RPM with a 26-10 Bolly?
Thanks again Ralph,
Bob

[Tired Old Man]

I agree with Ralph.