Harer (Barber) STC update

[Ragwing nut]

Re: Harer (Barber) STC update

Hey All,

Very interesting discussion on engines. A couple of minor points...

The lucombe 8c had a C-75-12 in it which was identical to the C-85-12 EXCEPT it had the smaller 65 spider on it. 10 hp loss just from the restricted spider

For the record, the Luscombe 8C had an A-75-8J (fuel injected) not the C-75. To convert a C-75 to a C-85 requires only a carburetor change. The spiders are the same.

There is at least one existing field approval for converting an A-65 to use C-85 cylinders and pistons. Here's a link to a copy of that field approval:

http://www.popav.com/337/8.pdf

It's a very straight forward mod. The engine legally stays an A-65 but the slightly larger bore gives you a larger displacement. One great advantage to this mod is the availability of new manufacture C-85 cylinders and pistons.

Dan

Then it was the 8D then. Also the Ercoupe used the c75-12 alot. My mistake, carb was a 65 carb then with 1-1/4" venturi instead of the larger 1-3/8" venturi on the 85's

[dmcneil]

Re: Harer (Barber) STC update

Hey All,

Very interesting discussion on engines. A couple of minor points...

The lucombe 8c had a C-75-12 in it which was identical to the C-85-12 EXCEPT it had the smaller 65 spider on it. 10 hp loss just from the restricted spider

For the record, the Luscombe 8C had an A-75-8J (fuel injected) not the C-75. To convert a C-75 to a C-85 requires only a carburetor change. The spiders are the same.

There is at least one existing field approval for converting an A-65 to use C-85 cylinders and pistons. Here's a link to a copy of that field approval:

http://www.popav.com/337/8.pdf

It's a very straight forward mod. The engine legally stays an A-65 but the slightly larger bore gives you a larger displacement. One great advantage to this mod is the availability of new manufacture C-85 cylinders and pistons.

Dan

[Ragwing nut]

Re: Harer (Barber) STC update

Bowers Fly Baby - Harry Fenton on Continental Engines

Modifying A-65 Engines to Accept O-200 cylinders
A list participant writes:
> I have a chance to pickup some decent o200 jugs and was wondering if a guy can bore the A65
> case and make the Cylinders and pistons work with the A65 crank. My research indicates that
> this should work with perhaps a custom piston pin bushing. I would balance the
> engine and operate at reasonable rpm's, say 2450 max 2200 cruise to keep torsion and vibration
> from twisting the smaller case. I would use standard pistons and CR. My purpose is to build a
> custom motor and utilize the engine I have to build a custom -8 configuration. I am an old
> hotrodder and Diesel mechanic by trade and would love to tackle this
[RJW Note - Harry has amended his answer since his original posting. I have changed the following based on his comments.]

1. Although I've never done it, the A-65 case could probably be bored to accept the O-200 jugs. The C-85/O-200 cylinders have a bigger bore than the A-65, the bolt pattern is the same. The cylinder holes in the A-65 case would have to be opened up to accept larger bore cylinders, but that could be done with little trouble.

2. Next, the C-85 crank and rods will drop right in and is the same throw as the A-65 crank. So with the C-85 jugs and C-85 crank, the A-65 could deliver basically C-85 performance.

3. The jury is still out on using O-200 lifters with the A-65 or C-85 cam, but I'm in the process of sorting this out.

4. However, before everyone runs out and starts hacking up their A-65, keep in mind that the C-85 case (until I'm proven wrong!) is a bit more robust. My best recommendation is that if one has a mixture of A-65 and C-85 parts lying around, then it would be possible to build an engine. However, I still wouldn't recommend purposely building a hybrid as there are plenty of C-85 or O-200 engines to be found that could accomplish the same end to the means in a more reliable manner.

5. As a point of interest, the Formula One air racers have used C-85 pistons in the O-200 for years for extra power. The C-85 piston pin bore is a bit lower in the piston, so with the longer O-200 crank throw the net result is a bit more compression which yields 15-20 more hp. Further to the Formula One mods, they are required to modify C-85-8 case with an extra case through stud and welded reinforcements to the case. The O-200 case is much beefier, has larger diameter through studs and more of them.

6. The best way to hop up the A-65 is to balance the internal engine parts and drop in high compression NFS pistons manufactured by Lycon Rebuilding. The pistons are expensive, but way less expensive and more reliable than extensive case mods. In terms of RPM, the A-65 turns a measly 2300 rpm, so spinning up to 2500-2700 will yield more hp with the high compression pistons.

7. Be aware, though, that the A-65 connecting rods are much less robust than the C-85 and O-200 connecting rods, so I would not run much past 2700 rpm if you want to maintain reliability. If you compare the A-65 and O-200 connecting rods you will see that the neck and crank end of the A-65 connecting rod is about 20% less beefy than the O-200. Any cylinder and compression mods will be limited by the strength of the connecting rod.

8. Having said that, I have an A-65 built which is hopped up and should produce around 100-105 hp. I beefed up the A-65 case by welding in some reinforcement plates around the cylinder base studs, welded a weak joint at the #3 bearing web, installed an extra through stud, re-indexed the cam to optimize the lift from 2300 rpm to provide more power at 2700 to 3000 rpm, ported and flowed the heads, installed 10.5:1 compression ratio pistons, align bored and dynamically balanced all of the reciprocating parts, and installed an Ellison throttle body.

I have not run this engine yet as the airplane it is destined for is still under construction, so I can't report if my work is best way to do things. If you simply drop in high compression pistons, balance the internals and run a couple hundred more rpm, you would probably achieve 90% of the same results and maintain an acceptable level of mechanical reliability.

August 2002

1. many years ago crop dusters flying cubs installed 85 cylinders on 65 cases for more power flying in the restricted category. Cases were bored and 85 parts installed.

2. It will not deliver identical performance without changing to the 85 camshaft as well. profile is different. Also you would need to change to an 85 spider. it has a larger bore than the 65. The lucombe 8c had a C-75-12 in it which was identical to the C-85-12 EXCEPT it had the smaller 65 spider on it. 10 hp loss just from the restricted spider

3. Cannot use the O-200 lifter bodies with a cast iron cam, wrong metalurgy. Also the cases will have to be machined to clear the enlarged lifter body at each web location.

4. C85 cases are lighter than A65 cases in that the webs are solid on a 65, an hollow on 85's. The 85/90/200 cases vary in casting thicknesses as well and also hollow

5. do not know formula 1 regs so i can't comment

6. two problems with turning up a 65. First is cam profile. It has a sharp lobe that when turned at higher rpms can cause valve float. bigger problem is the small exhaust valve stems. A80's were notorious for popping valve stems and they turned 2800 at takeoff. If I was ever to build a true a80 for someone, they would have to have the superior 65 cylinders that had the o200 heads on them

7. The 65 rods and 85 rods are the same, with one exception, piston oil squirt in the top of the rod cap. A75 alos has the oil squirt. Even the same casting. Early 90/200 rods are even the same cating as the 65 rods, but had the tops of the rod caps machined to clear the case and camshaft due to longer stroke. They did change the rod forging at a later date when they started making IO-360's. Later O-200's share the same rod, but the wrist pin bushings are different sizes.

8. Sounds like an engine with potential. I hope when you welded the cases they were done at temperature and then relieved in an oven after welding. if not, case will crack right where it was welded within a short time period, seen it happen. Watch for valve float if you used a 4546 cam. Many hotrod continental guys like the obsolete c90 cam. Makes gobs of torque.

[Larry Lyons]

Re: Harer (Barber) STC update

A humble suggestion: I like where this thread has gone and would love to see everything about the engine mods, hp delivered, case differences, etc., all put in to a new thread that could have a life of its own. Larry

[VictorBravo]

Re: Harer (Barber) STC update

Like I said, there are far more talented/credible engine experts than myself. Harry Fenton is known far and wide as one of them.

Harry wrote that the 85 case is stronger than the 65 case, which may be true... what I had heard (from another source) is that the 65 case is as strong as the O-200 case. That would mean that Continental figured there were places where they could save weight when they designed the O-200. If this is not the truth than please accept my apology for passing on bad info.

What I do know for certain is that there are several A-65 cases with O-200 crankshafts (and other parts) that are operating reliably (at reasonable RPM's - no screamers).

The point of my previous post on this subject was that there is an alternative for those who are mechanically capable, and who are running out of patience waiting for an STC solution.

Another issue that I have personally seen is that the 65 and 85 and O-200 crankcases are different, which causes some issues:

When I tried to re-install the original 65 HP exhaust system, it was 3/8" too narrow. We had to cut it in half, and weld a small "extension" in the cross tube behind the engine.

As soon as we did that, I had to cut the heat muff apart and rivet similar extenders into that so it would fit on the wider exhaust.

Then the cooling baffles had to be adjusted and re-fit so they fit inside the nose bowl, at the front left corner.

Then you might find that the magnetos turn the other way, and either had to be modified or replaced.

Then (if you're using an actual O-200 engine) you need adapters for the rubber engine mounts to go from a Lord mount to a cone mount.

Then it is my understanding that the O-200 rear accessory case a just a bit longer, meaning that your magnetos are pushing against the firewall. Even with the 85 HP engine installation, we had to tap a slight depression into the firewall to get the original mags back in. The best way is (once again) to use a smaller magneto to overcome this problem... but no matter which magneto you use it will be difficult or impossible to remove or replace the mags once the engine is bolted in place.

With the Harer STC, there are several additional airframe mods, which I have complained loudly about already in previous posts. Those have to be done in order to have a 100% legal installation.

The very best way to get the engine in would be to have a slightly modified nose cowling, short 1" or 1.5" spacers between the engine and engine mount, and a 2 or 3 inch propeller extension. That would give you some more room to have a cleaner and easier engine installation, without the problematic full 4 inch longer engine mount that was used for the Model 19.

So all things considered, keeping that 65 HP crankcase, keeping your exhaust, mags, carburetor, and baffles... then keeping your original fuel system and only having to do the core common sense stuff... has a lot of merit in my book.

[Pearson]

Re: Harer (Barber) STC update

Bill,

I completely agree with you about the C90 engine being preferable in many ways to the O200. In fact I prefer the C90 engine. But my reasoning behind going with the O200 is availability. Both C85s and C90s are getting very hard to find. And when you do find one, they are expensive.

As far as modifying an A65 into something like a C85, I think that would be fine if all you are doing is making left turns around pylons for a few hours. As far as an engine in a get in and go somewhere airplane, I want the most reliable thing I can hang on the front end. That is not to say that modifying an A65 wouldn't be a lot of fun. I love that sort of stuff. I am just saying for my tastes, if I were trying to get a C85, I would just go find a C85 case, crank, etc, or a whole engine.

I think there are three different cranks. I think I read on Harry Fentons website where he says;

If the lightening holes are 1" the crank can only be used in an A65.

If the holes are 7/8" the crank can be used in either an A65 or a C85.

If the crank has no lightening holes it IS a C85 crank.

[Dano"T"]

Re: Harer (Barber) STC update

Bowers Fly Baby - Harry Fenton on Continental Engines

Modifying A-65 Engines to Accept O-200 cylinders
A list participant writes:
> I have a chance to pickup some decent o200 jugs and was wondering if a guy can bore the A65
> case and make the Cylinders and pistons work with the A65 crank. My research indicates that
> this should work with perhaps a custom piston pin bushing. I would balance the
> engine and operate at reasonable rpm's, say 2450 max 2200 cruise to keep torsion and vibration
> from twisting the smaller case. I would use standard pistons and CR. My purpose is to build a
> custom motor and utilize the engine I have to build a custom -8 configuration. I am an old
> hotrodder and Diesel mechanic by trade and would love to tackle this
[RJW Note - Harry has amended his answer since his original posting. I have changed the following based on his comments.]

Although I've never done it, the A-65 case could probably be bored to accept the O-200 jugs. The C-85/O-200 cylinders have a bigger bore than the A-65, the bolt pattern is the same. The cylinder holes in the A-65 case would have to be opened up to accept larger bore cylinders, but that could be done with little trouble.

Next, the C-85 crank and rods will drop right in and is the same throw as the A-65 crank. So with the C-85 jugs and C-85 crank, the A-65 could deliver basically C-85 performance.

The jury is still out on using O-200 lifters with the A-65 or C-85 cam, but I'm in the process of sorting this out.

However, before everyone runs out and starts hacking up their A-65, keep in mind that the C-85 case (until I'm proven wrong!) is a bit more robust. My best recommendation is that if one has a mixture of A-65 and C-85 parts lying around, then it would be possible to build an engine. However, I still wouldn't recommend purposely building a hybrid as there are plenty of C-85 or O-200 engines to be found that could accomplish the same end to the means in a more reliable manner.

As a point of interest, the Formula One air racers have used C-85 pistons in the O-200 for years for extra power. The C-85 piston pin bore is a bit lower in the piston, so with the longer O-200 crank throw the net result is a bit more compression which yields 15-20 more hp. Further to the Formula One mods, they are required to modify C-85-8 case with an extra case through stud and welded reinforcements to the case. The O-200 case is much beefier, has larger diameter through studs and more of them.

The best way to hop up the A-65 is to balance the internal engine parts and drop in high compression NFS pistons manufactured by Lycon Rebuilding. The pistons are expensive, but way less expensive and more reliable than extensive case mods. In terms of RPM, the A-65 turns a measly 2300 rpm, so spinning up to 2500-2700 will yield more hp with the high compression pistons.

Be aware, though, that the A-65 connecting rods are much less robust than the C-85 and O-200 connecting rods, so I would not run much past 2700 rpm if you want to maintain reliability. If you compare the A-65 and O-200 connecting rods you will see that the neck and crank end of the A-65 connecting rod is about 20% less beefy than the O-200. Any cylinder and compression mods will be limited by the strength of the connecting rod.

Having said that, I have an A-65 built which is hopped up and should produce around 100-105 hp. I beefed up the A-65 case by welding in some reinforcement plates around the cylinder base studs, welded a weak joint at the #3 bearing web, installed an extra through stud, re-indexed the cam to optimize the lift from 2300 rpm to provide more power at 2700 to 3000 rpm, ported and flowed the heads, installed 10.5:1 compression ratio pistons, align bored and dynamically balanced all of the reciprocating parts, and installed an Ellison throttle body.

I have not run this engine yet as the airplane it is destined for is still under construction, so I can't report if my work is best way to do things. If you simply drop in high compression pistons, balance the internals and run a couple hundred more rpm, you would probably achieve 90% of the same results and maintain an acceptable level of mechanical reliability.

August 2002

[VictorBravo]

Re: Harer (Barber) STC update

There is an advantage to using some models of the Continental over others. If I recall, one experienced engine expert let me know that the 90HP engine has more torque and will use less gas than the O-200 at the majority of usable power settings, because of the cam profile and compression ratio, etc. So the "one hundred horsepower" catch-phrase sounds great but it may not be the best choice. when you put torque and fuel consumption into the picture.

I am NOT one of the big engine experts, but they are here on this Forum. Perhaps one of them could explain this better than I.

I understand the ultimate engine for a B model T-craft, where the BALANCE between economy and power is important, would be certain versions of the C-90.

On a separate note, if someone is really interested in making the best overall T-craft engine upgrade... you are ALL missing something important:

1) There are several airplanes at my local airport that have Continental A-65 engines. Some of these engines appear to be quite a bit healthier than others. There are rumors (un-substantiated of course) that there may be C-90 or O-200 guts inside those 65 cases. I have it on good authority that there are relatively few changes or adjustments that need to be made in order to do this. There are reportedly a few, like the rods clearing the piston skirts, but not many.

2) When I asked one engine expert about this, he told me that the A-65 has a heavier, stronger crankcase than the O-200. As such, there would be far less reason to worry about the extra power damaging the A-65 case on a structural level.

3) It would be very very difficult for anyone to look inside the A-65 crankcase and see whether the crankshaft and camshaft are 65, 90, or O-200 style. Matter of fact, the entire engine installation would be completely identical on the outside.

4) The newer modern COM radios, smaller GPS units,a nd even LED lights are far far far more efficient than previous stuff. A small battery would provide a very significant capacity.

5) A properly adjusted Bendix carburetor and good impulse couplings make it very easy and reliable to hand start any of the small Continentals. A good friend of mine has very successfully experimented with a slightly different propeller "clocking" position, that allows you to start the engine by walking sideways (away from the prop) and just holding the prop tip at waist, high level. This is far easier and less physically demanding than the old method.

6) An imaginary Taylorcraft, that just happens to have such a really healthy A-65 engine on it, but that was still operated within the same weight, speed, and maneuvering limits as it always was, would NOT require any extra modifications to the fuel system, would NOT require any structural modifications to the wings, would NOT require a huge paperwork battle, would NOT require new magnetos, and would NOT have any appreciable effect on balance or flight handling.

In an emergency (such as an unexpected in-flight weight gain due to menstrual cycle activity, or in-flight weight gain caused by water retention from high salt intake at lunch), it would be very nice to know that the engine has the reserve power capacity to provide a positive climb rate. Even if the aircraft's takeoff weight accidentally exceeded 1200 pounds and approached the LSA weight limit.

[jim cooper]

Re: Harer (Barber) STC update

Its all too complex for my feeble mind but.......if I were going to do an 85hp. update, I too would go for the 0200. Its alot of work so why not just do it ALL? An 0200, especially a new one would be a dream come true on a BC12D! It would really get off, climb fast, cruise at about 100(?) electric start (big plus) and on and on. I personally think ALL these small planes were underpowered, champ cub, etc. I always wanted a 180 horse supercub but never could afford it! JC

[Pearson]

Re: Harer (Barber) STC update

Although I totally agree that the new lightweight O-200 would make a great engine for a Taylorcraft. I would hope that anyone going to the trouble and expense of seeking an STC would try to get approval for the more common older versions and include the new lighter weight engine as an option.

My dream has always been to have an O-200 on the short mount. I don't care about a starter or generator. I would mount a lawnmower battery in the back and utilize a solar panel to supplement it. It could be easily removed for recharging overnight.

If someone doesn't get an STC for an O-200 by the time I am ready, I plan to file a 337 to use a C-90 with the Harer STC.

[Forrest Barber]

Re: Harer (Barber) STC update

Agreed , we need to revise the whole thing and do a new STC for the 0-200 inclusion. No call yet from Robbie Harer.

[RoN43220]

Re: Harer (Barber) STC update

For the future I'd wish to see an STC for the new lightweight 0-200. Seems that would be a sweet match.

Ron
#6879

Re: Harer (Barber) STC update

This has been explained many times;Jack Gilberti was the Chief Engineer, he applied to the CAA to take the BC12D-4-85 up to the 1500 Gross, all the testing had been done by the factory. The CAA said they wanted to go to a new TC ( 1A9 was assigned) . since there had been so many changes to the original 696 . Soooo that was done .
The Gilberti, now Harer STC , takes a 1946 BC12D up to the "equivalent" of a Model 19 at 1500 Gross. The FACTORY BUILT BC12D-4-85's ALL had the changes made to make them 1500 Gross when built. The approval ahd not been done yet . That is why the ser#'s apply as on the TC data sheet. BUT you can use any ser# above 6400 to apply the mods indicated as differences from the BC12D up to the BC12D-4-85 . "equivalent" is a term that should be easily understood by any IA. I really have to go and do family things. I will pick up on this Tues....
get on the holder of the TC's to DO something.... read the first Taylorcrafter , it spells it out.

Can this be documented along with the Taylorcrafter on the foundation page as part of the history?

[freightpilot27]

Re: Harer (Barber) STC update

BUT you can use any ser# above 6400 to apply the mods indicated as differences from the BC12D up to the BC12D-4-85

Great! What documentation can I show my PMI to prove I can do this with my serial number airframe?
Hearsay and word of mouth don't fly with the Federalies. I need written documentation.

[Forrest Barber]

Re: Harer (Barber) STC update

This has been explained many times;Jack Gilberti was the Chief Engineer, he applied to the CAA to take the BC12D-4-85 up to the 1500 Gross, all the testing had been done by the factory. The CAA said they wanted to go to a new TC ( 1A9 was assigned) . since there had been so many changes to the original 696 . Soooo that was done .
The Gilberti, now Harer STC , takes a 1946 BC12D up to the "equivalent" of a Model 19 at 1500 Gross. The FACTORY BUILT BC12D-4-85's ALL had the changes made to make them 1500 Gross when built. The approval ahd not been done yet . That is why the ser#'s apply as on the TC data sheet. BUT you can use any ser# above 6400 to apply the mods indicated as differences from the BC12D up to the BC12D-4-85 . "equivalent" is a term that should be easily understood by any IA. I really have to go and do family things. I will pick up on this Tues....
get on the holder of the TC's to DO something.... read the first Taylorcrafter , it spells it out.