Older engine needs N/V Assembly

[Andrew Saunders]

I have an OS Max 3 .35 that needs a N/V Assembly. What ST N/V would work in it? It has great compression still. Looking to put it on a Profile classical plane.

[Gene Martine]

 Check with Randy Smith at Aero Products.
 Gene
 

[qaz049]

I have an OS Max 3 .35 that needs a N/V Assembly. What ST N/V would work in it? It has great compression still. Looking to put it on a Profile classical plane.

I don't know which ST NVA would fit but I have an Enya 29/35 one in my OS .35 Max 111. It works beautifully, is almost the same as the original, and they're relatively inexpensive at $12 each.

You can get them from Ken Enya at Enya Direct or from Shtterman on ebay at:

http://www.ebay.com/itm/290909411484?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Ray

[Hoss Cain]

I have an OS Max 3 .35 that needs a N/V Assembly. What ST N/V would work in it? It has great compression still. Looking to put it on a Profile classical plane.

I think that either OS or Enya needle valve assembly will work fine in your OS engine. Way back before dirt, when I was an active CL Stunter, that is all I used in any engine, OS, Fox, Johnson, and/or my G. Aldrich ST 40.  Placing the spray bar with the hole straight back, just out of sight made for great engine runs.
Now there was that pre-production Testors-McCoy Gray-case, simply a K&B innards in an ugly case, well nothing made that engine into a stunter. OTOH with a decent carb it was A-OK in a RC machine.  OOPS not concerning the question!! 

[EddyR]

 Back in the late 50's and early 60's we used  that version of the Max for FF and Combat. Be sure the restrictor in in the venture or it will not pull fuel.
Ed

[Chris Wilson]

Honestly, save yourself the pain.

Get Randy Smith onto this one, he KNOWS what will work, goes to great lengths obtaining items and postal and payment options are a breeze!

[Steve Helmick]

The OS Max III .35 was my first combat engine. Without the restrictor, on 9-7 prop and Missle Mist, it was a haulin' azz engine. I find it hard to believe that it could ever be used for stunt, but might work for sport. They're pretty heavy. I have one (NIB), for some reason or other.  Steve

[Chris Wilson]

Hi Steve,
             here in Oz many years ago that engine was routinely used in both combat and stunt, and I have heard of fliers simply swapping venturis, props and fuel thus using the same engine between disciplines.

[Andrew Saunders]

Unfortunately the Veturi on this one is fixed. It cant be switched.

[qaz049]

Unfortunately the Veturi on this one is fixed. It cant be switched.

Then you're missing the venturi insert. There were two that came with the engine, a smaller "stunt" and a larger holed "combat" insert.

The one shown in the pic of mine is the stunt version IIRC. They certainly were routinely used in both stunt (10 x 5" wooden prop) and combat (on a 9 x 7" Tornado).,

the latter on crankcase pressure mostly via a pressure nipple in the backplate but occasionally one sited under the venturi like on an Enya 29/35.

I ran my example a few weeks ago and was impressed by the instant cold starts and the power on an APC 9 x 7.

The dimension across the venturi bosses is 0.6". The Enya 29/35 NVA is shown fitted.

Ray

[Steve Helmick]

I only remember one insert, which didn't want to come out until I screwed a tap (about 5/16"?) into it and yanked it out. I ran mine with no insert, on pressure. It went like he!! on a Super Swoop, and was very loud!  Steve

[qaz049]

I only remember one insert, which didn't want to come out until I screwed a tap (about 5/16"?) into it and yanked it out. I ran mine with no insert, on pressure. It went like he!! on a Super Swoop, and was very loud!   Steve

It's possible that the two inserts were supplied to the Australian market only then. While the US was well supplied with choices for big engines ours was far more restricted.

Not that the OS Max 3 engines were inferior in anyway. I remember when we first saw an example of a Fox 35 and were completely unimpressed with it c/w the OS equivalent.

I ran my OS's on pressure without a restrictor with a home made pressure nipple made out of a threaded piece of 1/8" copper pipe.

The hole was reduced to about .012" using the solder and c/l wire trick.

The one I recently acquired from a clubmate may very well be the same that I sold in late 1964 when I moved on to Fox 35x's.

It has a blanking screw the same odd thread as we used in the pressure nipple hole and the head has the scars of many sudden arrivals. :-)

Ray

[EddyR]

For you really old FF guys I had mine in a Ramrod 750 and a Sandy Hogan . I had two of them and they were better than the K&B 35 green head that most people were using. The build quality was much better than the K&B and the K&B got slop in the crank bearing easily.
Ed

[jim ivey]

venturi hole needs to be at least 5/16Th's dia I.D use 5/16Th's O.D. thinwall tubing copper or aluminum engine don't care slip it into venturi and mark spraybar hole. drill make sire spraybar slides thru easy. mark the length you want. cut off and deburr.                                              PS after 50 years got my very old number back 15452     Jim