582 engine mount questions

A few questions about the 582 side rail engine mount please.

- Are the firewall attach stations for the 582 side rail engine mount the same on a Model III and IV?

- Can the 582 side mount for a Model IV be used on a Model III?

- Did the 582 side rail engine mount for Model III come in two different configurations, to fit one of two (early and later) ring cowl options?

- Can anyone confirm that the 582 side mount for a Model IV is a direct replacement for either of the two different Model III cowl configurations?

Can you see where I'm going here? Assuming it all works out...

Service Bulletin #17 says: " The Side Rail Mount must be used only with the Rotax 582LC engine with the Type C gearbox with the 3 to 1 ratio. It must not be used on engines equipped with gearboxes with ratios of 3.47 or 4.0 to 1. To date Denney Aerocraft has only supplied the type C in 3 to 1 ratio."

- Will a 2.62:1 ration C-box work with the side rail 582 engine mount?

- Where to source new engine brackets and bushings?

Thanks for your help.

Anyone? Surely not everyone has given up on the oil burners.

OK, since pics are worth 1000 words, one last try. Attached are pics of the 'old' style bed mount on my M-III. Note the integral supports and camloc receptacles for the lower ring cowl. Next is a pic of one of the 'new' style side rail engine mounts I found online (BUT, I don't know which one of the supposed two side rail mount models this is).

Q.) Does anyone know if there was another 'new' style side rail 582 engine mount that incorporated integral supports for the M-III ring cowl?

TIA

Don't know if this will help you, Doug, but both of my model IVs the ring cowl does not mount to anything but the boot cowl halves. No interface with the engine mount at all.

I bought a 582 from Jim S, it came with the complete side engine mount set up, you might ask him but I remember him telling me it will only work on the model 4 Kitfox,but I may be wrong. Randy

Doug,

My Model III is the newer mount with support for the cowl ring. See the pics.

-- Paul S

Hi Paul-

YES, that's it! Thank you very much for the pics, you have confirmed what I have always suspected.

Man, there is precious little info about this particular engine mount online. I don't think too many were made. I never did find a picture or any detailed description other than one reference to a part number. Sure wish I had saved that info. :(

Now (and I am completely speculating here) my guess is that these were produced and offered as a retrofit for the M-III's that already left the factory with the old bed mount and cowl support design, but most M-III's incorporated the new side rail mount without cowl supports from the get go. Or, I suppose, it could be that a handful of new M-III kits were supplied with the mount you have before the factory changed the cowl support method and the side rail mounts (without cowl supports) became standard. Do you know if your mount came with your kit or was added after-the-fact?

In any event, I have to suspect you have an early to mid-range s/n M-III like me. For reference, my kit was ordered 5/14/90 and delivered 10/19/90, and the Service Bulletin announcing the new side rail mount (see below) was dated June 10, 1991. Based on all this I think it is safe to assume, even if the firewall attach stations for the M-III and M-IV are identical, that the 582 side rail mounts for the M-IV were never produced with the cowl supports.

So... now that it's existence is confirmed, if anyone has a M-III 582 side rail engine mount with cowl supports available for sale, I would be quite happy to put it back into service. Please give me a ring.

Thanks to all.

Quote:

---

June 10, 1991

SERVICE BULLETIN #17
SUBJECT: Side Rail Engine Mount
TO: Kitfox™ Model III Builders with Rotax 582LC engine
FROM: Denney Aerocraft Company

Recently an engineer for Bombardier-Rotax GMBH approved the new style Side Rail Engine Mount we designed for the Rotax 582LC. He recommended that we emphasize the following points:

1) The Side Rail Mount must be used only with the Rotax 582LC engine with the Type C gearbox with the 3 to 1 ratio. It must not be used on engines equipped with gearboxes with ratios of 3.47 or 4.0 to 1. To date Denney Aerocraft has only supplied the type C in 3 to 1 ratio. (Any problems using the side rail mount with a 2.62:1 ratio C-box?)

2) One hexagonal screw M8 x 90, Rotax part # 440 366 must be shortened about 5mm or replaced by a screw of 85mm length.

3) This shorter screw must be used only in the position shown by sketch #1. (Does anyone have a copy of this?)

4) All other attachment screws part # 440 366 must remain the original 90mm length.

5) You must thread the attachment point on the P.T.O. - rotary valve side of the upper crankcase to 8mm and a maximum length of 17mm. See sketch #2. (Does anyone have a copy of this?)

6) Use one of the 8mm x 16mm screws supplied by Denney Aerocraft at this attachment point. You must use a screw with an active working length inside the upper aluminum crankcase housing of 16mm.

---

Doug,

You're right about the chronology. My Model III is SN 910 and it arrived late in '89 or early in '90. The engine mount came about in '91 and it seemed like a very good idea.

Maybe there's tooling or a jig left over from the Denny days?

Good luck on your search.

-- Paul

Hey Paul,

After taking another long look at our engine mount pics, it appears that your engine sits higher than mine relative to the side cowl supports (ie. your supports seem to come away from the engine at 90* degrees while mine are angled upwards). With your ring cowl in place, is your prop centered in the opening or is it oriented off-center towards the top of the opening?

Doug,

It's set up with the prop hub centered. Sorry I can't send a picture as I'm still working through the electrical system and final assembly.

-- Paul