Replies to This Discussion

Permalink Reply by Ken Ryan on June 6, 2018 at 9:58am

Thanks for the detailed breakdown of expenses. How are you able to achieve 115 hp ?

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Permalink Reply by Don Morrisey on June 6, 2018 at 1:41pm

Hi Ken...raising the compression to 9.5:1...I believe stock compression is 8.5:1...increasing the compression ratio produces an increase in output throughout the rpm range

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Permalink Reply by Carl Orton on June 6, 2018 at 10:08am

Thanks for the callout, Don, but others should note that Don bird-dogged the core I purchased, so Thanks Again, Don!

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Permalink Reply by Carl Orton on June 6, 2018 at 10:42am

Here's my costs thus far:

10/30/2017 Purchased O-200 on  eBay / BAS Parts in Greely CO                 $4,376.00
11/6/2017 O-200 Assembly Video                                                                    $37.71
11/6/2017 O-200 Cylinder Wrenches (1/2 & 9/16)                                               $45.75
11/20/2017 Engine Overhaul Stand (Wag Aero) (36.75 ups)                               $245.65
1/10/2018 Magnaflux Crank @ Axxon Labs                                                       $85.00
1/17/2018 FedEx Charges for case to Divco                                                      $48.00
1/23/2018 UPS Shipping Charges to Aircraft Spclty Svcs (cam/gears/rods)         $69.65
2/13/2018 Magnaflux Cam; regrind & parkerize. Rebuild 4 conn rods w/new
               bushings. Magnaflux cam & crank gears. Aircraft Specialty
               Services Tulsa. Includes 45.92 return freight                                     $744.45
2/20/2018 Renovate Case; zyglo and repair. Reject accessory case
               (oil pump housing out of spec. Divco Inc; Includes $57 UPS               $977.81
4/24/2018 UPS Shipping Charges to Aircraft Spclty Svcs (tappets)                      $10.79
5/4/2018 Renovate 8 lifter bodies by Aircraft Specialty Services                         $298.44
                                                              Total thus far                                 $6,939.25

Note that I'm in DFW, so it's 1 day service to/from Tulsa.  I also forgot to list the O-200 overhaul manual I found on eBay for $12.  I used a local shop for the crank magnaflux as A/C Specialties told me they have a high failure rate; I wanted to avoid the shipping charges for a bad crank, so found a local Level 3 industrial / OSHA inspection facility.  All results were great. I gave them the Continental magnaflux criteria (certain amperages from certain aspects) which they followed.

Still have other major costs remaining:

Accessory case:   $1000 - $1400

Cylinders (superior):  $3900  (existing cylinders *could* be rebuilt for $500/ea, but I want Superiors)

Bearings / gaskets / rings / etc    $1000

I'd love new hi-comp pistons, but they're about $1200 with rings; New cyls from Superior have std pistons - I'd hate to waste them.

One slick mag:  $620 exchange  (other mag replaced 100 hrs before engine removal)

So, in total, I'm expecting somewhere around $14-15,000 for basically a full rebuild. And that cost includes shipping charges, unique tools, engine stand, etc.  I'm spreading-out the costs for cashflow reasons. Since I have at least another year on my airframe build, it's doable.

I'm comfortable with engines; was a professional tech in a previous life, so have the tools, experience, etc. I built the AeroVee (VW) engine for my prior plane.  There's a few oddities about the Continental that I still have questions about (like do I really need to re-install the vacuum pump bevel gear on the cam?), but they'll all get resolved.

Oh yeah; forgot to mention the starter / alt / carb:  The starter was new about 400 hrs ago; it weighs a ton, but works well; alternator & carb both overhauled 150 hrs ago.  Obtaining the logs along with the engine answered SO many questions that helped me plan a path forward.

Am I over-doing it?  Probably.  With any unknown engine, you have to do at least *some* teardown & inspection.  You *could* possibly do it for under $10k, but how comfortable would you be flying behind it?  As an example, when I first started tearing down the engine, I noticed a washer placed under the oil pressure relief spring. That is typically done as a bandaid to help raise oil pressure. (that was not the cause of engine removal). When I removed the accessory case, I noticed that there were grooves in the oil pump housing, so I kinda knew the case would be rejected. Big added expense, but at least I know *why* there were oil pressure issues and will take steps to correct it.

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Permalink Reply by Rob A on June 7, 2018 at 11:37am

Hi Carl,

Where did you read that you need to install the vacuum pump gear if not using the vacuum? Wondering this myself. Also I'd love to hear a few of the other oddities you've discovered.

thanks,

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Permalink Reply by Carl Orton on June 7, 2018 at 12:36pm

Hi Blue;

I haven't read it anywhere. Just over-analyzing!  I know I can leave-off the part where a vacuum pump would install; I've seen blockoff plates in several locations.  I'm just wondering about the bevel gear that rides on the end of the camshaft.

Since I need a new accessory case (and still looking for a yellow tagged one if you know of any...), I've noticed that there are at least 2 different part numbers. Can't remember the exact part number but the two variants are xxxxxA5 or xxxxxA19.  A good friend who is also an EAA national employee said that both should work; I'd really like to know for sure, though. 

I haven't been able to ID the exact model I have. If you go to the Continental online parts catalog, you enter the serial number, but then have to select the version - of which there are at least 20.  I *think* mine is an O200A48B, but not really sure. To complicate matters further, in a previous life, the case was replaced with a rebuilt case - and they just riveted the old serial number plate to the replacement case.  Again, no idea if these little issues matter.

I have the flanged thrust washer, so dunno if I'm still supposed to check the fit for end play. I've never seen multiple part numbers indicating different thicknesses like you do for the non-flanged thrust washers.

I intend to install a light-weight starter. I have no idea if I need to keep the old starter pinion needle bearing in the back of the main case; I'm concerned about needles dropping into the case. I *thought* new starters bypassed the pinion shaft, but I've never seen one in person to know for sure; sales guys haven't been able to help.  Maybe the shaft is still there.  If I remove the bearing support block though, that just  opens up the rear of the main case to the accessory case.

When the main case was reworked, the shop shaved the mating surfaces just a hair to ensure parallel. I'm wondering if that's going to affect the pushrod length geometry. Same thing with the cam - it was reground.  One pushrod is shorter than the others. I've "heard" that there are only 2 sizes of pushrods - std & .030.

I could just really use a homebuilder who's done this and has experienced the same areas.

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Permalink Reply by Don Morrisey on June 7, 2018 at 2:02pm

Hi Carl,

FYI

My engine builder did leave the vacuum pump gear in place, thinking I might add a vacuum pump at some point and a plate was added.

Also..the accessory case was one of the hardest items I had to find and I could not find a "yellow tagged accessory case".  I did manage to find one on ebay that was in spectacular condition...after having gone through one,  that like yours,  was scored beyond reach in the oil pump gear area. I spent more time hunting the accessory case than any other item.

It's good that you have those worms going in the back of your head...when you're done, you'll have an engine you're very comfortable with:)

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Permalink Reply by Charles T. Valade on June 7, 2018 at 9:08pm

Don ;

           You can leave the vacuum pump gear off but be careful on most of the cam's some of the taped holes go through to the oil groove. So to get oil pressure screws will have to be in there.

            The other thing is the standard o-200 has 7 to 1 compression ratio and for each ratio you raise the compression you will get about 5 o/o increase in horse power. The 2.5 increase should give about 12.5 to 13 HP.

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Permalink Reply by Don Morrisey on June 8, 2018 at 9:01am

Charles, thanks for that good info!

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Permalink Reply by Rob A on June 8, 2018 at 8:08am

I was wondering too if you needed to install the vacuum gear if you plan to never install a pump. I see below in Don's reply that some bolt holes may need a screw for the oil. I'll need to check my cam. I'm also wondering where to buy the cover plate for the vacuum since I'm not installing one.

I will also be in the market for a new accessory case and light weight starter and alternator. If you find out about the part numbers for the case let me know please.

I too have a O200A48? case. I sent it in to Crankcase Services to have it overhauled. Came back really nice. I think (not an expert) that some cases can accommodate different types of bearings. I removed a flange bearing (A2 if i remember) and bought an A6 which comes with a separate thrust washer as I understand my case can accommodate it too. The advantage to having separate thrust washers vs. one piece is the separate are available in .020 under. The one piece are only available in std and .010. If you need to regrind the crankshaft for some reason you can go to .020 without changing the case (so I'm told). I think the flange one is more $ too but can't remember for sure.

I'm not sure either about the needle bearing. Would rather not install it. I will wait until I can afford a starter and see what my options are. Maybe it's not needed with some models...

My case was shaved a bit too. I've talked to Aircraft Specialties about the push-rod length and was told to just try different rods in different positions until you get a good fit. I have my old rods but may need to buy new ones when the time comes.

I found my O200 on Kijiji for really cheap but unfortunately the crank was cracked. I have new Superior cylinders, overhauled cam and a new crank. I've also pushed in new bushings in my rocker arms and the small end of the connecting rods but need to find a shop to hone them for me. 

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Permalink Reply by Don Morrisey on June 10, 2018 at 7:00pm

Carl,  I checked with my engine builder regarding your question on the old style needle bearings...you need a special tool to extract the old style needle bearing, another bearing w/o the needles gets installed in its place and it is a press fit.  B&C will rent you the tool for $20

In regard to the pushrods after having the case shaved he says...the lifters need to be installed DRY and valve lash then measured between 30 to 110 thousands, using pushrod lengths that get you between those measurements.  When the lifters fill up, there is actually zero valve lash

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Permalink Reply by Carl Orton on June 11, 2018 at 9:04am

Thanks for checking, Don; I have the pinion bearing out already since I sent the case for rehab, but just didn't know if I needed to reinstall or not. I'll check on that bearing replacement, regardless.

I knew about installing the lifters dry, but since I'm a LONG way off from reassembly I hadn't checked the allowable lash.  Also knew about hydraulic lifters, but was concerned that shaving the case might have made even the shortest pushrod too tight. Sounds like I have .080 to play with, so hopefully all will fit well.

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