Lust for POWER!

[jCandlish]

Re: Lust for POWER!

You mean bore and stroke? I don't have any more detail than that, except the C85 crank/rods/pistons results in roughly the same combustion chamber volume at TDC as the C90 crank/rods/pistons.

Thanks !

I was hoping to know: Rod length, Piston height & skirt depth from the wrist pin, and the internal cylinder height from c/l.

The lowest I operate is 1700msl, (taxi). In the lowlands I usually cruise at ~3500msl & that keeps me in G airspace. But to the West there are some altitude challenges! A little more compression may just compensate for the altitude.

That and I feel like I'm entitled to get all the value out of the 3SFr/l = $12/gallon 100LL I'm buying.

Once again thanks for the infos. Getting clearer now.

Cheers
jCandlish
.

[astjp2]

Re: Lust for POWER!

http://www.bowersflybaby.com/tech/fenton.htm

http://www.bowersflybaby.com/tech/engines.htm#a-series

These are a great articles on the little continental engines. You can do the 85 piston swap (not legally), it yields about 8.5 CR, but you have to machine a recess for the plugs or you may contact. I know of several guys that have done it and they seem to run the best on 100LL, if you use a -14 case, you get the lord mounts and reduced vibration It does move the engine foreward 5/8" on the short mount. The long mount is about 5 inches longer which will allow for a 90kg baggage area.....

Aircraft Specialties can legally dynamically balance the crank and static balance the rods/pins/rings/pistons. Its well worth the money. If you install an Ercoupe spinner, you can then get the whole shebang dynamically balanced and will probably have the smoothest running 4 cylinder aircraft engine in Europe....

[NY86]

Re: Lust for POWER!

Excellent information. Is there some technical documentation to be found showing the swept-area geometries for these engines?

You mean bore and stroke? I don't have any more detail than that, except the C85 crank/rods/pistons results in roughly the same combustion chamber volume at TDC as the C90 crank/rods/pistons.

Bore is 4.062". Stroke is 3.625" for the 188 cid engines and 3.875" for the 201 CID engines

Also, is it the 90-8 case that has the same mounts as the a-series?

All A-series, C75, C85, and all C90 except C90-14. C90-14 and O-200 have "Lord" mounts.

And what are the pros/cons between Millenium and TCM cylinder assemblies?

Hmmm, a religous question....

Continental has had valve guide issues in the past and went through the "combo of the month" for a while. Until someone convinces me they've got it together, I'd not use them. Superior was bought by Thielert (sp?) and they filed for bankrupcy in a foreign country (Germany) so I'd not use them for now. That leaves ECI who is wading through some sort of production issue, except I'm not sure it affects the small Continental product. That leaves no one...

I have a parts catalog that calls out 6.3 and 7.0 compression ratio pistons for the o-200.

I've not seen that. The 6.3 CR pistons are for the C75 and C85. The 7.0 CR pistons are for the C90 and O200.

What is the CR with the -85 pistons on the -90/0-200 crank?

Roughly 10:1 You need C-90 rods too.

Do the -85 pistons carry an oil ring on the skirt?

No. Moving the wrist pin up for the C90 necessitated moving the oil ring down.

Jeeze, I could go on forever! Where does one find this information?

A lot is in the overhaul manual.

When I get around to inserting tab-A into slot-B I want it to fit.

One thing to watch is the clearance between the rod bolts and the cam shaft if you mix the C90 crank and C85 cam. Also, the oil slinger on the C90 crank requires a mod to early cases.

Oh, yeah, don't mix C85 pistons, a C90 crank and REM37BY plugs...

[jCandlish]

Re: Lust for POWER!

The mounts on the O200 (and C90-14) line up with the A- and C- series but they are thicker fore and aft. An O200 will sit about 1/2" farther forward. Don Swords has an STC'd bushing to convert it to the conical mounts that corrects this.



There are 2 basic cases, pre-O200 and post O200. Pre-O200 cases have studs on the center main bearing. Post-O200 cases use through bolts and are a lot stronger, The A-series and C75 and C85 share one crank and one stroke. The C-90 and O200 share a different crank and longer stroke.

If you put C85 pistons on a C90 crank and rods the compression ratio goes [way] up because there is more piston above the wrist pin. With the C85 crank the compression is less because the piston top comes to the same point in the bore [as the C90] but the stroke is shorter.

Thanks John

Excellent information. Is there some technical documentation to be found showing the swept-area geometries for these engines? Also, is it the 90-8 case that has the same mounts as the a-series? And what are the pros/cons between Millenium and TCM cylinder assemblies? I have a parts catalog that calls out 6.3 and 7.0 compression ratio pistons for the o-200. What is the CR with the -85 pistons on the -90/0-200 crank? Do the -85 pistons carry an oil ring on the skirt?

Jeeze, I could go on forever! Where does one find this information? When I get around to inserting tab-A into slot-B I want it to fit.

Thanks again
jCandlish
.

[NY86]

Re: Lust for POWER!

I've heard that the most substantial difference between to c- series cases and the o-200 is the mount. Is this just rubber?

The mounts on the O200 (and C90-14) line up with the A- and C- series but they are thicker fore and aft. An O200 will sit about 1/2" farther forward. Don Swords has an STC'd bushing to convert it to the conical mounts that corrects this.

I've also heard that the webbing strength, from weakest to strongest case is -85 -> -90 -> -200. Is this so?

There are 2 basic cases, pre-O200 and post O200. Pre-O200 cases have studs on the center main bearing. Post-O200 cases use through bolts and are a lot stronger, especially if you make a habit of hitting hard objects with your metal prop. The studs will rip chunks of the main bearing saddle loose.

I've been lead to believe that the -85 piston has more crown, or has a deeper wrist-pin, so that it develops more compression than the -200 piston in the same bore. True/False?

You need the answer to the next question first.

I'm lead to believe that the crank is the same between the -85, -90 and -200, and indeed the stroke is the same as the a- series. True/False?

False. The A-series and C75 and C85 share one crank and one stroke. The C-90 and O200 share a different crank and longer stroke.

If you put C85 pistons on a C90 crank and rods the compression ratio goes [way] up because there is more piston above the wrist pin. With the C85 crank the compression is less because the piston top comes to the same point in the bore [as the C90] but the stroke is shorter.

What cams and cam+ingition timings are available. I've heard that you can advance the cam timing gear for a performance boost, at the cost of hard starting. True/False?

You're on your own here, AFAIK.

[N95193]

Re: Lust for POWER!

Friday is my day off, so I'm looking forward to going out to the airport and playing with my new toy.

I will heed your advice and see if it helps.

I'm just looking forward to having fun flying in the T-craft. It is such a pleasure to fly it.

Mike

[jCandlish]

Re: Lust for POWER!

The problem with this engine isn't the first start, it's the next one after taxiing to the fuel pump, putting gas in, and then trying to start the engine again.
Mike

Hi Mike.

I always shut my engine down with the fuel shut-off valve, never with the mag switch. That way every start is from a relatively empty throttle body. The imperial valve (shutoff) and float/needle assemblies will leak enough to keep the fuel bowl full.

You can also open the throttle and carb-heat between starts, but watch that throttle setting mags hot!

Cheers
jCandlish
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[N95193]

Re: Lust for POWER!

The problem with this engine isn't the first start, it's the next one after taxiing to the fuel pump, putting gas in, and then trying to start the engine again. It's terrible. The engine just floods, even with the fuel turned off.

I'm new to this airplane, so I hope after getting more time with it, perhaps I will have the same experience as you all. I'm still a little nervous about the hand starting. Don't want to get hurt, and don't want to lose all my flying buddies after they get sick of helping with a hand crank.

Sounds like it needs some work.

Thanks for the information.

Mike

[jCandlish]

Re: Lust for POWER!

I want to add a starter to make life easier.
Mike

Hi Mike

Life may be easier without the starter. My engine almost always catches on the first hot blade. The key is to be systematic.

Cheers
jCandlish.

[VictorBravo]

Re: Lust for POWER!

I just bought N95193 - '46 BC-12D with an A-65-8 for the powerplant. I want to add a starter to make life easier.

A properly adjusted carburetor and impulse coupling magnetos on an A-65 allows the engine to start on the first hand pull each and every time.

IMHO, putting a starter on an A-65, including the battery installation, wiring, and other modifications, would be making your life a lot more difficult. The extra weight and complexity, having to charge the battery, modifying the instrument panel, etc. also favors the simpler way.

I think the vast majority of people on this group will agree that we can personally guarantee you will have less hours in your logbooks and less money for avgas if you decide to put a starter on than if you decided to make your airplane hand start reliably.

Having your carburetor even fully overhauled is a lot less time and money than adapting the starter to your engine. Tens of thousands of T-crafts, Champs, Cubs, Porterfields, Luscombes, and many more have been starting easily and reliably for... oh, about seventy years now... without starters.

[N95193]

Re: Lust for POWER!

I just bought N95193 - '46 BC-12D with an A-65-8 for the powerplant. I want to add a starter to make life easier. I've got a line on an accessory case for the A-65 with the bracket for the starter. Will I be able to convert the A-65-8 to accept the accessory case and add the starter, or should I save my money? Should I look for an engine that already is adapted for the starter?
Mike

[jCandlish]

Re: Lust for POWER!

Buy the 85, you can bolt it to the short mount without any modifications...the 90 is great but not worth the extra wait or cost.

Hi Tim

I'll be buying with money that can only be spent once, so I'm looking to make the best informed decision. Unless someone would like to donate an engine to a good cause!?

This is for next winter, as my airplane is flying now, or it was last week, and will be again and in annual this months end.

I'm of the impression that there are more c-90 cores here in Europe because of the WWII liaison aircraft, and most of those seem to be rolls-royce.

So now to the question section.

I've heard that the most substantial difference between to c- series cases and the o-200 is the mount. Is this just rubber?

I've also heard that the webbing strength, from weakest to strongest case is -85 -> -90 -> -200. Is this so?

I've been lead to believe that the -85 piston has more crown, or has a deeper wrist-pin, so that it develops more compression than the -200 piston in the same bore. True/False?

I'm lead to believe that the crank is the same between the -85, -90 and -200, and indeed the stroke is the same as the a- series. True/False?

What cams and cam+ingition timings are available. I've heard that you can advance the cam timing gear for a performance boost, at the cost of hard starting. True/False?

Thanks
jCandlish
.

[astjp2]

Re: Lust for POWER!

Buy the 85, you can bolt it to the short mount without any modifications...the 90 is great but not worth the extra wait or cost. Don's Dream Machine can get you the STC for the O-200 rotating assembly in the -85. You would get the O-200 size but in the 85 case. Its the best all around option and you can use the same motor mount rubbers as the 65 and the baffling will interchange. If you really want to fool someone, have Don's modify it to a -8 and use the O-300 intake elbows and it looks like a 65 but perfroms like a 90. Tim

[jCandlish]

Re: Lust for POWER!

Hi Brie

I've found 2 high time running engines over here. an o-200 and a c-85. I'm still on the lookout for a c-90.

I'll be keeping the original engine as the serial # matches the original factory logbook.

Stock engine? Thats funny.

Cheers
jCandlish
.

[taylorcraftbc65]

Re: Lust for POWER!

If you decide to make the engine swap in the U.S., will you be willing to let the Taylorcraft owners members have first crack at your stock engine? ( it never hurts to have a spare). Brie