O-200 in BC12D; Motor Mount

[Robert Lees]

I have purchased an O-200 to fit into my BC12D, and the last remaining structural question for UK approval is the motor mount: is the BC12D motor mount made of the same tubing thickness and diameter tubing as the F19?

(I know the F19 has a longer mount...but if the tubing is the same outside diameter and wall thickness, then I can get approval for a short mount.)

Anyone have a drawing of the F19 motor mount?

Any other things I should consider?

Thanks.

Rob
Robert *dot* Lees *at* Taylorcraft *dot* org *dot* uk

[captjon]

Re: O-200 in BC12D; Motor Mount

Rob:

How about your cowlings.........will they be long enough (even with a short mount) with the lord mounts that the O-200 uses. I think they extend the engine a little further from the mount than the standard cone bushings.

Cheers,

[crispy critter]

Re: O-200 in BC12D; Motor Mount

It adds an inch(1 inch) to the length. Rob,the are made of the same tubing, in fact the 0200 long mount has the same size tubing and less bracing over a longer distance.

[barnstmr]

Re: O-200 in BC12D; Motor Mount

Are you planning to install without some of the accessories? I have a friend "structurel" DER. He would consider providing you with a DER approval of the mount. Contact me offline if you need help. He is reasonable.

[Robert Lees]

Re: O-200 in BC12D; Motor Mount

Thanks for your offer, Terry...In the UK (on the G reg) the approval process is different and is outside the DER and FAA requirements. I wish to install without the starter & dynamo, so some blanking of accessory access holes will be required.

Kevin: it is the documented evidence of the same tubing that I seek.

On a practical note: with the additional thickness of the accessory case, would I need extensions to the mount? Or does your 1" allow for that? And will the whole thing shoe-horn into a BC12D cowl (albeit with new baffles)?

Photos would be wonderful.

Rob

[VictorBravo]

Re: O-200 in BC12D; Motor Mount

I dunno, Rob... I'd take some measurements for sure...
you may even have to build a SHORTER mount for an O-200 to fit in the stock cowl. My A-65 doesn'thardly have an inch to spare on the front left corner. OR, I'd guess you may have to move the nose bowl further forward where it attaches to the main cowlings. I'd buy a fiberglass replacement nose bowl and extend the mounting flange joggle another two or three inches aft, then put in a short propeller extension to keep the prop a few inches more forward of the nose bowl. I have long suspected that the proximity to the cowl is killing some bit of propulsive efficiency. But of course that puts you into a slightly off-white color (sorry, colour) of paper...

[crispy critter]

Re: O-200 in BC12D; Motor Mount

Rob,
I called the Taylorcraft factory about 2 years ago when I first started trying to get approval for Crispy and was conserned about the original short mount also. In fact I called looking for a BC12D-85 mount and they told me they used the exact same mount as the BC12D(65) and the model 19 and F-19 used the same size steel tubing,same thinkness too,stretched a little longer with one less brace(don't know the brace they were talking about).
As for the stock cowling....I have had my 0200 mounted on the firewall with the cowling in place(no baffles on the front of the engine)and it did fit but just barely. The only tight spot is around the number 4 cylinder(front left looking from the pilots seat),it is a very close fit and I'm not sure if I can make a baffle that will fit unless I use a solid engine mount bolt to eliminate the extra inch that is added with the stock 0200 rubber mounts & spacers.

Thanks for your offer, Terry...In the UK (on the G reg) the approval process is different and is outside the DER and FAA requirements. I wish to install without the starter & dynamo, so some blanking of accessory access holes will be required.

Kevin: it is the documented evidence of the same tubing that I seek.

On a practical note: with the additional thickness of the accessory case, would I need extensions to the mount? Or does your 1" allow for that? And will the whole thing shoe-horn into a BC12D cowl (albeit with new baffles)?

Photos would be wonderful.

Rob

[Robert Lees]

Re: O-200 in BC12D; Motor Mount

Kevin: The extra brace (I'm not too sure either) seems to get in the way of the starter or dynamo.

Bill: I've done a bunch of measurements between my A-65 and the new O-200. The main external dimensional difference appears to be the deeper accessory case...this means that the magneto cap (and hence leads) will be 1" closer to the firewall with the O-200 on the A-65 mount, excluding the Lord mount extension.

Unfortunately, that makes it very tight!

I am prepared to manufacture a new mount to take the Lord mount on the O-200, but I am not convinced that it will resolve the 1" shortfall.

Still investigating! And still seeking photos of an existing non-electric O-200 in a B model cowl.

If it all goes to a ball of chalk, I will have the engine re-certified and sell it for a profit. Or put it in a clip wing.

This engine is new, unused, with only the 1 hour 35 minutes factory test cell schedule from 1968 on the factory paperwork and that's all. The original owner dismantled it...long story.

Even came with the original "Board of Trade" Log Book, nothing in it! Comes with fuel pump, carb, mags, dynamo & starter. Only things missing appear to be the spark plugs and the Rolls Royce cowl logos. Talk about zero timed...this one is zero time!

Loads of AD's to resolve, however.

[Dano"T"]

Re: O-200 in BC12D; Motor Mount

Rob,

For what it's worth, I have a C-90-12F on the short mount...and a 337 approval for its installation on the existing mount....Isn't C90-12F the same basic setup. Anyways...here is a picture. I can take more...I owe Crispy some pictures of the exhaust.

[Dick Smith]

Re: O-200 in BC12D; Motor Mount

Rob, I copied these dimensions from the 1970 Continental overhaul manual:
Dash #(C75,C85,C90)
overall length:
-8 : 30-1/2"
-8F : 29-13/32"
-12 : 32-23/64"
-12F : 31-11/32"
-14F : 31-11/32"
-16F : 31-11/32"
0-200 : xx27-17/32"

The statement was made in the manual..."Features common to all models:
Overall width of engine: 31-1/2 inches"
Dick

xx= To front of crankshaft flange.

[Robert Lees]

Re: O-200 in BC12D; Motor Mount

Isn't C90-12F the same basic setup?

I don't know, Dan...is the 90 like an 85 or the 200? The long oil filler neck and kidney tank and what seems to be a short accessory case makes me think it's more like a C85 than an O-200.

Did I mention I want to use a single-stack exhaust, made from my A-65 exhaust instead of the double stack? What is the diameter of your exhaust stacks?
And what's your clearance between the firewall and the magneto leads (looks like you have Slicks)

Nice to see you using unshielded plugs too...I hate cowl bumps.

Rob

[Edit: thanks, Dick...I will investigate further in the morning]

[mulwyk]

Re: O-200 in BC12D; Motor Mount

Dan:
Yes! unshielded plugs on top with Slick mags. I want it! How did you do the harness for the unshielded side? Did you make it, or buy it somewhere?

Bob Gustafson

[dedrekon]

Re: O-200 in BC12D; Motor Mount

There's a motor mount listed on Ebay right now......it says it the long mount "perfect for a Harer conversion."

There's also a left elevator that looks nice for $250, minus the trim tab though.

http://cgi.ebay.com/taylorcraft-cont...QQcmdZViewItem

http://cgi.ebay.com/Taylorcraft-BC12...QQcmdZViewItem

[Dano"T"]

Re: O-200 in BC12D; Motor Mount

I don't know, Dan...is the 90 like an 85 or the 200? The long oil filler neck and kidney tank and what seems to be a short accessory case makes me think it's more like a C85 than an O-200

.

Heck, I don't know...I just thought that since the O-200 and C-90 were on the same data sheet they were basically the same. I have a C-85-8 in the other plane and I do not have an O-200 to compare to.....the case on the C85-8 is obviously different and cannot be compared. I'll measure the distance to the firewall tonight from the back of the mags. The dual exhaust gives the illusion of more room back there and the cans are small enough to keep from having to put bumps in the side of the cowl....I have measurements for Crispy....I'll check again when I get home. Oh, and also whether it means anything or not the oil filler neck is on the opposite side on the C90 vs the C85. I know that you were looking for an O-200 install....but I thought this might help.

[dedrekon]

Re: O-200 in BC12D; Motor Mount

I have an 0-200 that's been installed on my airplane. We're recovering the plane so it's not ion the plane right now, but it's still on the mount. It was installed without an electrical system, starter or gen/alt.
I'm not sure which mount was used. If you need any pictures or measurements, let me know.

Vincent