1/2 VW bed mount and Mosler mount questions

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

FritzW

Well-Known Member
Log Member
Joined
Jan 30, 2011
Messages
3,776
Location
Las Cruces, NM
On a bed mounted, cut case, 1/2 VW: I assume you use the two front lugs at the bottom of the case. But with the back of the case cut off, is there a preferred way to handle the rear mounts?

Also, are people really happy using the front two lugs on the case for the front two bed mounting locations? It seems like the fatigue life of those lugs would be pretty short.


On the Hummel website he mentions "Mosler mounting" as an option for the cut case engine. Does anyone know the dimensions for Mosler mounting? I found an old PDF Mosler manual online but the resolution is too low to do any good.

I asked Scott Casler these questions on his website but it's already been 30 seconds and he hasn't gotten back with me :gig:
 

Hot Wings

Well-Known Member
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
6,736
Location
Rocky Mountains
Also, are people really happy using the front two lugs on the case for the front two bed mounting locations? It seems like the fatigue life of those lugs would be pretty short.
IMHO using those little lugs, even if they are still intact (they corrode away pretty fast on ground bound where salt is common) is a bad idea. Using the mounts found on a 'universal' case, or one from a bus or Tp III, is much better. After all that is what they were designed for.

I don't know if they are still available but at one time we could buy bolt on adapters that used the 4 oil pump cover studs to simulate the pulley end engine mounts. With modern CNC duplicating something similar might be a good option.
 

Daleandee

Well-Known Member
Joined
Sep 11, 2015
Messages
935
Location
SC
Also, are people really happy using the front two lugs on the case for the front two bed mounting locations? It seems like the fatigue life of those lugs would be pretty short.
My reply don't directly address the particular question you asked. In fact I'm guessing you may already know this but I thought I'd pass it along ...

Leonard Milholland made a statement that should be considered by 1/2 VW engine builders:

What ever you do DON’T cut the case. You will get in to more work and no good benefit from cutting the case. The part one cuts weighs 4 pounds and 1 pound can be removed by cutting the transmission flange off it. This only covered the clutch on the car. The first thing you cut off is your engine mount, then you have to put it back on it (adding angle to the bottom of the case) which results in more weight and lots of extra work. Then you will have to have some sort of a oil cooler which equates to more weight and more work. Then you will have a lot more crank case pressure and will need to add a set of reed valves to take care of that which again results in more weight and more work. There is NO benefit to cutting the case and I don’t see why others keep cutting it.
Above quote was edited by DA for grammatical errors

Found that reference here:

http://ereksonfamily.org/ragwing/engine/12-vw-info/

FWIW,

Dale
N319WF
 

Pops

Well-Known Member
Log Member
Joined
Jan 1, 2013
Messages
7,655
Location
USA.
I built one cut case 1/2 VW engine and would never do it again. A full case 1/2 VW is the way to go for far less problems. Of all the 1/2 VW's that I have seen with a bed mount, an aluminum angle was bolted to the side of the case below the pushrod tubes and the bottom on the flat side the full length. The bare case half was drilled for the bolts and the extruded angle is bolted on the outside case before starting to assemble the engine.

Joe, say something.
 

FritzW

Well-Known Member
Log Member
Joined
Jan 30, 2011
Messages
3,776
Location
Las Cruces, NM
With guys like Leonard Milholland on one side of the argument and Scott Casler on the other, it's hard to decide. But I do know that if I want a 1/2 VW that I'm willing to fly behind, I'm not going to be the guy doing the engine work. And if I want it in my life time I'm going to do like Joe and write a check.

>>>

Thanks Dana, that's the exact drawing I was looking for.
 

radfordc

Well-Known Member
Joined
Feb 5, 2008
Messages
1,283
Scott Casler knows how to make a good cut case engine. But, I built a cut case VW once and I would not do it again! Too much work for no gain and probably less performance/reliability in the long run.
 

Hot Wings

Well-Known Member
HBA Supporter
Log Member
Joined
Nov 14, 2009
Messages
6,736
Location
Rocky Mountains
I've done a cut case as well. Lots of work, but I'd do it again if it was the best option for that particular project. I'd also try very hard to find a different option.

The only real advantage of the cut case over the full is that the result is more compact and lets the center of gravity of the engine be closer to the firewall. That cold be very important when dealing with an existing design. If it is a clean sheet project allowances for the longer arm of the full case can be worked around. Then the builder can choose either the full case and a short engine mount or the cut case and a longer mount. Could even use the same cowl.

Given the cost of a new VW engine case, that is just going to be cut up adding further to the cost, what we need is a modern version of the Global/Mosler case. Such an engine would be a nice fit between the O-100 and the 1L industrial engines.
 
Group Builder
Top