I am considering to use a 1.60 IFS in my next pattern plane. I would appreciate more info on the engine. What is the difference between the W and SP versions ? Can one use methanol with this engine? What lubrication must be used with engine?

Piet,


The IFS is the spark-ignition engine and it uses gasoline with 30-40:1 synthetic oil; not methanol fuel.

It has needle bearings on both con-rod ends.

I don't know enough about the new SP version, but it appears to have a different head (canted plug), a 'horn' on the Walbro carburettor and even a different crankcase...

MVVS has beefed up the 160 bottom end. To do this, the crankcase has been redesigned along with crankshaft and big end. These parts are not interchangable with older engines

The SP (side plug) engine has some extra features like Dar already said. The head and carb horn (very short carb stack) are offered as update set. All versions are still IFS engines (Ignition, Front intake, Side exhaust)

Pe,

When did they change the case and crank? Do all the engines with the newer plug cap 7.4v ignition have the newer crank? How can you tell the difference? I think I can see an increased thickenss band aroung the bottom of the crankcase. Did they make the crank to cylinder angle 90 degrees on the redesign? I remember they had the cylider laying back at a slight angle.

Below is a photo of the SP.

The engines factory delivered from feb. 2008 are all modified, and can be recognised by the added bulge on the crankcase.
The included angle in a cantilever crank design never is 90° for it must compensate for crank flex under load. That is so with your humble glow plug, and it also is so in the MVVS and DA.
I still have some stock of old types for the old price. The new types are more expensive and are therefore listed as a separate item.

What's the weight on the new engine compared to the old one?

Brian,


According to the MVVS web site, it is the same weight (940 grams).

The quoted performance is also exactly the same.

We'll see.