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jwilcox · Posted: Tue Dec 30, 2014 20:34 Post subject: Gipsy Major

A new project for the new year. An old friend of mine owned, maintained and flew a DH82 Tiger Moth for over 40 years, sadly he passed a little over a year ago. I'm helping his son with the aircraft bits of the estate. The airplane was sold several years ago but the hanger is still a very interesting place to poke around. The Gipsy Major was found on a shelf with it's cylinder heads removed but pretty much complete otherwise. I suspect Roy was using it as spares if he needed them for the Tiger. We have found log books with the first entry in 1947 and removal from the Tiger in 1964 with 1200hrs. The engine will eventually be up for sale but we want to open it up and see what we have, maybe even run it if possible. It's been sitting since 64 in an unheated hanger and it's not seized or even corroded, won't be nearly as big a project as the 2600 but should be fun.
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100083.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100084.jpg

jwilcox · Posted: Tue Jan 06, 2015 18:15 Post subject: Gipsy Major

Just a few photos of the Gipsy Major, mostly apart now an getting cleaned up. Fairly crude old engine but interesting just the same. Almost every nut, bolt and bearing is marked for location, even the nuts on the main bearing caps are all numbered so they go back on the proper stud. Then you find there are no marks on the crank and cam gear they have to be timed on assembly with a timing disc, go figure. Had to make a fixture to hold the cylinders to give them a light honing and the engine stand is a copy from a picture in the manual, works great.
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100092.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100093.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100107.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100151.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100155.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100156.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100162.jpg

jwilcox · Posted: Sun Jan 18, 2015 18:21 Post subject: Gipsy Major

Already starting to put the Gipsy back together, the reason for taking it apart as far as we have was to determine if there were any major issues with it other than just being removed as time expired. From what I read these were one of the first aircraft engines to easily reach TBO limits and then be extended, going from only a few hundred hrs in the beginning to 1200 then 1500 hrs, not bad for a design from the late 1920s. This one is at 2400hrs TT, second 1200hr run, and shows minimal wear on the crank, cam and cylinders. Have already had a few expressions of interest in it as a core but we still hope to put it back together and do at least one run.
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100170.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100188.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100267.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100270.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100277.jpg

vbentley · Joined: 15 Sep 2014 Posts: 10 Location: Surrey, BC, Canada

Do you have the engine manual? I am across the country in Langley BC so could copy/loan you a manual. How about gaskets and lock washers? - rare items that you need to run the engine. You need to align the exhaust port faces with a straight edge before tightening the heads. Maybe you have all this info.

jwilcox · Posted: Thu Jan 22, 2015 16:47 Post subject:

Hi, Thanks for the offer of the manual but I do have one that the owner of the Tiger kept when he sold his plane. I did notice the bit about aligning the heads, must be just so the one piece intake fits up properly. I also noticed the cylinders can be shimmed for height but we aren't going to get that into it. We just want to hear it tick over for a few minutes then it's hopefully off to an overhaul shop and into an airworthy Tiger.
It was -16C here this morning and a poor time to be looking for parts in an unheated hangar but I needed 3 valve locks. Was about to give up when I found a dozen neatly wrapped and preserved. Photos of a couple of neat items from this morning to follow.
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100312.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100314.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100317.jpg

vbentley · Joined: 15 Sep 2014 Posts: 10 Location: Surrey, BC, Canada

Good to hear. Keep us posted on progress.

jwilcox · Posted: Tue Feb 10, 2015 19:51 Post subject: Gipsy Major

Getting a bit done on the Gipsy. The weather has been terrible with the daytime highs of around -15C and as low as -29C at night. Hard to get the shop comfortable. Heads, top (bottom end) cover and rear case are on. The valve gear reminds me of British motorcycle design, all the thrust washers and springs, way more parts than necessary but it works. There's no engine oil feed to the heads, each valve cover serves as an oil reservoir with a fill level to be checked each 25hrs. The engine has only one smallish oil pump for pressure, return to the tank is by gravity. We have some original mags but probably not complete enough to get running so plan is to adapt a set of Slicks for our run attempt, there's a pricy STC out there for mounting Slicks but we aren't going flying so will improvise. Going to paint it up a bit but not getting too fancy.
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100456.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100457.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100496.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100497.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100498.jpg

tfey · Joined: 13 Jul 2003 Posts: 104 Location: Arlington Hts., IL

Jerry, fascinating stuff. Thank you for the great photographs. So the rocker arms and valve stems are lubricated only by by splash? How is the oil scavenged from this inverted engine? Thanks and keep it coming. Tom

jwilcox · Posted: Thu Feb 12, 2015 18:21 Post subject: Gipsy oil

Hi Tom, I think the rockers would actually be splashing in the oil in the valve covers so probably does a good job of lubrication and I suspect oil leaks. The pressure side of things is quite normal but the return is strictly gravity. The cylinders have a deep skirt that sticks into the crankcase same as most radials. The returning oil drains down to the bottom, in this case the cylinder side of the crankcase, and runs around the skirts to either a front or rear drain and back to the tank mounted low on the left side of the fuselage. Some photos to follow, one of a 2600 and Gipsy cylinders, the skirt is about the same on both. The others show the brass fitting on the rear, it's upside down in this photo, it would be pointing straight down in operation and the other of the drain at the front of the case. These two drains are connected with a T and on to the tank.
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100486.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100538.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100540.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100541.jpg

tfey · Joined: 13 Jul 2003 Posts: 104 Location: Arlington Hts., IL

Jerry, thanks. How do you fill the valve covers with oil? I guess the covers could get some passive (re)filling by crankcase splash running down the push rod tubes, and I guess it doesn't matter if the valve covers and push rod tubes overfill. Kind of interesting.

jwilcox · Posted: Thu Feb 12, 2015 18:48 Post subject:

Tom, I haven't done that yet, it sounds messy, the attachment bolt in the centre of the cover has a leather washer/seal, the bolt stays in the cover when off. You fill to a mark in the cover and then install on the head. I was looking at the push rod/lifter arrangement today, I do not think any oil could leak by and get to the heads, if it could it would be very little. Perhaps just enough to lube the top end of the push rod. The valve covers actually do have a stand pipe/vent tube that would just dump oil overboard if it did overfill. The lifters are not at all like modern aircraft or auto but look exactly the same, a bit bigger, as in my old BSA motorcycle. I have some in a drawer will post a photo.
Jerry
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100549.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100550.jpg

tfey · Joined: 13 Jul 2003 Posts: 104 Location: Arlington Hts., IL

Jerry, thanks, all quite interesting. I'd guess they'd have to jack the tail up to wings level to install the valve covers. Tom

jwilcox · Posted: Sat Feb 21, 2015 16:31 Post subject: Gipsy Major

The Gipsy is coming along nicely, have figured out the back end and the oil filters and lines are in place. There's an inlet screen and then a multi (hundreds) plate filter in line on the way to the main gallery. This filter has a T handle you can turn to clean the filter, I've never seen another quite like it. There's a quick coat of black on the engine, looks like it should.
I've been thinking I would need to adapt a set of Slick mags because I only had one original mag, partly assembled, but each trip to the hangar I find a few more bits. Today I started with the one partial and a couple of boxes of parts and now have two mags that make sparks. One even has an impulse coupling, I was surprised to know these had an impulse. It's a little bulkier than the modern Slicks and Bendix but it works exactly the same. Next to figure out how to time them to the engine, they bolt down solid and the coupling is used to do the initial setup on instillation. The mags weigh a little over 10 lb each.
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100607.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100611.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100704.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100717.jpg

jwilcox · Posted: Fri Mar 06, 2015 16:01 Post subject: mag timing

Here's an interesting part of the Gipsy Major. I had never worked on one and wondered what all the levers and rods on the back end were for. Obviously they were to operate the throttle and mixture but also an unexpected purpose. The two levers, one each side, by means of a cam arrangement retard and advance the timing during the first part of the throttle opening. Most general aviation engines start with the timing at TDC but immediately go to the run setting, usually 20 - 25 BTC. The Gipsy starts on the impulse mag and then the cam lever system which is on the throttle shaft advances the timing as the throttle is opened. A lot of extra parts to wear but a pretty neat system just the same.
The engine is ready to try a run, just need some warm weather.
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100795.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100797.jpg
http://www.enginehistory.org/BBimages/WilcoxJ/GipsyMajor/P1100807.jpg

jwilcox · Posted: Thu Mar 12, 2015 06:44 Post subject: Gipsy Run

With a lucky day of warm weather and a few sore muscles our Gipsy Major fired up. I didn't have a clue as to how much to prime (tickle) it, after a couple of short bursts we got the carb filled and away it went. The short video was taken by a fellow enthusiast who has helped a lot on the clean up and refurbishing of the Gipsy parts and also the R-2600 last year.
The engine ran well and sounds fine, had oil pressure from hand propping even before it started. We intended to only run it a few minutes but it shut down due to fuel starvation, the small tank has an AN fitting cap that I just loosened to act as a vent, the centre of the cap is floating and as the engine used fuel it pulled the cap in and closed the vent, vibration and angle probably assisting.
http://youtu.be/KRDeJtylAV4