Installing A TCM IO360

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jamyat
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Re: Installing A TCM IO360

Post by jamyat »

My mechanic friend, Larry, installed the IO360 in my 170A. I spent a considerable amount of time working on it with Larry's supervision. The prop is a McCauley with a C67 hub used on the T41. The spinner is from an early model 182. I got the spinner from the guy in Artesia. Larry cut radial slits around the prop shaft opening in the lower cowl, made a backup doubler, pushed the nose bowl aft, and then flush riveted the doubler to the nose bowl. This flattened the nose bowl behind the spinner and provided more clearance. This mod to the cowl only changed the curvature behind the spinner and is not noticeable. The spinner is bigger than the original and spans the area between the two intakes. It reaches the edges of the intakes and does not block the intakes.

His installation sits high and close to the upper cowl. He made the engine droop 2.5 degrees from perpendicular to the firewall. The purpose was to alleviate the stick pressure needed during a go-around until the trim can be readjusted for climb. He said he did an engine swap on a duster and installed the engine perpendicular to the firewall. Stick pressure during a go-around was a real problem and he ended up redoing the mount.

Even though the engine is very close to the upper cowl I have not had any trouble with it rubbing the engine. I think since the cowl has been converted into a pressure cowl there is not a problem with the cowl flexing inward or downward. In fact, there is so much internal pressure that the forward rivets holding the left hinge to the center strip sheared after about 650 hours. We repaired it using twice as many rivets as were originally used. I got pretty nervous when I saw the left hinge start to lift upwards starting at the front. I slowed the airplane and landed at West Branson MO. Luckily I was only about 25 miles from the airport.
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Spinner detail
Spinner detail
Metal Master
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Re: Installing A TCM IO360

Post by Metal Master »

jamyat wrote:My mechanic friend, Larry, installed the IO360 in my 170A. I spent a considerable amount of time working on it with Larry's supervision. The prop is a McCauley with a C67 hub used on the T41. The spinner is from an early model 182. I got the spinner from the guy in Artesia. Larry cut radial slits around the prop shaft opening in the lower cowl, made a backup doubler, pushed the nose bowl aft, and then flush riveted the doubler to the nose bowl. This flattened the nose bowl behind the spinner and provided more clearance. This mod to the cowl only changed the curvature behind the spinner and is not noticeable. The spinner is bigger than the original and spans the area between the two intakes. It reaches the edges of the intakes and does not block the intakes.

His installation sits high and close to the upper cowl. He made the engine droop 2.5 degrees from perpendicular to the firewall. The purpose was to alleviate the stick pressure needed during a go-around until the trim can be readjusted for climb. He said he did an engine swap on a duster and installed the engine perpendicular to the firewall. Stick pressure during a go-around was a real problem and he ended up redoing the mount.

Even though the engine is very close to the upper cowl I have not had any trouble with it rubbing the engine. I think since the cowl has been converted into a pressure cowl there is not a problem with the cowl flexing inward or downward. In fact, there is so much internal pressure that the forward rivets holding the left hinge to the center strip sheared after about 650 hours. We repaired it using twice as many rivets as were originally used. I got pretty nervous when I saw the left hinge start to lift upwards starting at the front. I slowed the airplane and landed at West Branson MO. Luckily I was only about 25 miles from the airport.
Jamyat,
Did he build his own engine mount or who's STC did you use. I am wondering how he changed the engine angle to the center line. Mine could be adjusted with washers a 1/2 degree or so. Although I would not make any changes until after it is finished and see how she flies. Interesting what your mechanic did with the nose bowl. Looking at your picture it would still seem he would have had to cut the whole out larger to clear the propeller mount nuts on the back of the crankshaft flange. Do you have any other pictures of you overall installation or others you could share?
I have the undesired pointed spinner as well. I had a bullet spinner but it was too severely cracked for my taste. I almost had a trade worked out with a 182 owner but then he sold his airplane.
I am finding the baffling drawings in the STC to be only a starting point. I made some card board mock ups yesterday of the front Baffling pieces as drawn and could not make them fit as drawn at all. So I am using the drawings as a departure point.
Thanks for the picture.
Regards,
Jim
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
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jamyat
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Re: Installing A TCM IO360

Post by jamyat »

Larry designed the engine mount. He used a mount from a Piper Seneca and modified it to fit the 170. So the 2.5 degree droop was built into the mount. He did widen the crank hole so the nuts on the prop would clear. It's interesting how much clearance he was able to get since he also moved the engine closer to the firewall. TCM says that 2 inches is required between the alternator and the firewall, but he ended up with 1.5 and the alternator is easy to remove. The reason he did that was to get more clearance between the front cross-tie of the mount with the nose bowl. The baffling is from the front engine of a Cessna Skymaster. We had to trim it down, but it just took a few minutes to do that.

Larry had done one other IO360 swap into a 170 using a T41 mount. That mount gave him a lot of trouble because the front cross-tie bowed out so far that he had to put a skirt on the rear of the cowl so the cowl would clear the cross-tie. That gave more trouble since he had to reverse the back plate on the spinner to clear the nose bowl. It also made the exhaust installation difficult.

The airplane flies great. We didn't have to do any tweaking to get it to fly straight. It takes a lot of down trim when in cruise.

I will post some more photos in a day or two.
Metal Master
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Re: Installing A TCM IO360

Post by Metal Master »

jamyat wrote:Larry designed the engine mount. He used a mount from a Piper Seneca and modified it to fit the 170. So the 2.5 degree droop was built into the mount. He did widen the crank hole so the nuts on the prop would clear. It's interesting how much clearance he was able to get since he also moved the engine closer to the firewall. TCM says that 2 inches is required between the alternator and the firewall, but he ended up with 1.5 and the alternator is easy to remove. The reason he did that was to get more clearance between the front cross-tie of the mount with the nose bowl. The baffling is from the front engine of a Cessna Skymaster. We had to trim it down, but it just took a few minutes to do that.

Larry had done one other IO360 swap into a 170 using a T41 mount. That mount gave him a lot of trouble because the front cross-tie bowed out so far that he had to put a skirt on the rear of the cowl so the cowl would clear the cross-tie. That gave more trouble since he had to reverse the back plate on the spinner to clear the nose bowl. It also made the exhaust installation difficult.

The airplane flies great. We didn't have to do any tweaking to get it to fly straight. It takes a lot of down trim when in cruise.

I will post some more photos in a day or two.
Thanks! Jaymat. That is useful Info
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
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jamyat
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Re: Installing A TCM IO360

Post by jamyat »

Left full view with top cowl on.
Left full view with top cowl on.
Left front view with top cowl on.
Left front view with top cowl on.
Left full side view.
Left full side view.
Here are some photos. Number 1 and 2 show the clearance with the top cowl from the left side. They were taken just a few days ago. The W end of the intake manifold is at the front. You can see that we had to carve out some clearance for the manifold. We tried it with the W end at the rear, but air filter did not clear the cowl. We would have had to tilt the air filter downward so it seemed easier to put the W end at the front. Photo 3 shows the left side of the installation. It was taken shortly after approval. The muffler/heat exchanger is from a Bonanza. The tail pipes are from a Bonanza, but shortened to fit the 170. The exhaust manifold is from the front engine of a Skymaster. It was too long so Larry shortened it by cutting out a section between the collector and the egt probe. The right side is similar except he used a resonator from a Cessna (I don't recall which model). Both the muffler and resonator were rebuilt with new interior baffles. If you look closely you can see some changes to the baffling from the old photo and the new ones. For one thing the duct tape is gone.
Metal Master
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Re: Installing A TCM IO360

Post by Metal Master »

Jamyat,
Great pictures. Thanks for Posting.
I have decided to use the front part of the Skymaster baffling that came with my engine it fits so much better around the fuel pump and prop governor. I have already fitted it and installed the cowl and it looks like it will work great. I built the baffling pieces for the front of the engine as drawn on the STC. I could make the front right fit with a few changes but could not make the front left fit with any changes that did not incorporate a complete re-design. I worked on baffling most of last weekend and a few evenings this week. I am hoping to have the baffling mostly completed by the end of this weekend. All of the large sheet pieces are completed and I am attaching the seal to them now. I will post pictures when I have a more complete installation.
I see the changes in your baffling going from stapled to pop rivets and changing the configuration around the oil cooler. I am curious why the changes as it is not very significant? My Skymaster baffling looks entirely different than yours on the side pieces and I do not want to use them at all.
It is encouraging to see the intake manifold fit in the normal orientation on the early style cowl. How many hours of operation do you have on you Installation now?
I did get my reconditioned lifters back last week and have been able to complete the engine assembly and do the dry tappet clearance. All is looking good.
Regards,
Jim
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
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johneeb
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Re: Installing A TCM IO360

Post by johneeb »

Jamyat,
Thanks for posting your pictures. Very beneficial to study different ideas on how do things. When you put in the GAMI injectors how much difference is there between each injector?

I wish I could see more of your motor mount as the pictures make it look like the mount does not reach the forward motor mounts.
John E. Barrett
aka. Johneb

Sent from my "Cray Super Computer"
bagarre
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Re: Installing A TCM IO360

Post by bagarre »

I was trying to figure out the mount and exhaust too.

Were you able to measure a difference with the injectors?
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blueldr
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Re: Installing A TCM IO360

Post by blueldr »

I used to wonder if the installation position of "Gamijectors" would have to be adjusted for the reversal of the "Intake Manifold" as I did on my conversion.
BL
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jamyat
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Re: Installing A TCM IO360

Post by jamyat »

I made the baffling changes to seal the baffling tighter. I didn't like the way the oil cooler was sealed so I made the metal insert and extended the left side seal across the oil cooler baffle. It didn't make much difference, but was worth a try. The engine doesn't run hot (oil temp) in cruise, but it heats pretty rapidly in a climb. On a hot day I climb about 2000 feet at 100 mph indicated and then put it in a cruise climb. This keeps the temp below 200 and it still climbs 400-500 fpm and still have 120 mph tas. I have an engine analyzer now and the cylinder head temps are toward the low end of the acceptable range.

With the Gamijectors, the engine runs smoothly lean of peak. I could sometimes run lean of peak with the continental injectors, but often (who knows why) it would run too rough. I run it between 60 and 65 percent and it will burn 7.5. The airplane has a better range than it had with the C145. I sometimes fly to Galveston from my strip just north of Edmond OK. With the C145 I always made a fuel stop, but now can go non-stop if the headwinds aren't too strong.

The engine mount does extend just below the forward baffles. The photo as posted is darker than I see on my computer. I also have to crop the photo so it will upload. I am uploading a photo of the right side. You can see the mount better in this one. You can see, barely, the front cross tie. It looks like a little bump sticking down at a 45 degree angle at the front end, but it is a tube that ties the two sides of the mount together at the front. The engine was situated with only 1.5 inches between the Ford alternator and the firewall so there would be adequate clearance between the front cross tie and the nose bowl.

I have about 790 hours on the engine.
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Metal Master
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Re: Installing A TCM IO360

Post by Metal Master »

Fwd LH Baffle issue inside cowlRS.jpg
I have been working on the baffling for the IO-360 install:
The first picture is of the STC fwd left baffling as designed and installed on top of the prop governor. This is how Tom has it installed on a Cessna 172 he has at his facility. It will not work in the 170, 170A and early 170B cowls with the grill. As you can see in the picture the plate comes out in the middle of the cowl opening. I took all of this baffling down to Toms weekend before last and showed him some of the issues and other items that are in error on his drawings. The drawing actually shows this baffling piece installed on the bottom of the prop governor and that will not work as the vertical parts come no where near the cylinder fins in that position.
Engine W baffles overall view II RS.jpg
Baffles as built JAS installed LH View IIRS.jpg
The next two pictures are the baffles as I have installed them. Tom took pictures, traced my baffling and made notes with plans to change his drawings. The instructions for the STC are generic in some respects and are not detailed specifically in every instance for a specific model aircraft. This leads to fitment issues.
In the two attached pictures I elected to use the forward two parts from the Cessna 337 Skymaster. They had to have nearly 5 or so inches trimmed off of the forward edge to fit inside the 170A cowl. I manufactured angled flanges for the Red Silicon baffle seal and the doubler for each of them. I also made similar angles for the rest of the baffling as required for better fit.The doublers are called off on Toms drawing but this is a part of the STC instructions are ambiguous and allow local fitting for the particular application in each installation. The angles I have created allow the cowl doors to close with a nice interface with the baffle seals and at the same time make closing the cowl door easier. I will be fitting the cowl back on this week for some additional fit checks and pictures.
I have had the exhaust bolted to the engine but have not made any permanent mods to it yet so that I may keep the 170 flying while I build this up.
Engine W baffles Lw LH side View II Btr RS.jpg
And the beauty shot.
Regards,
Jim
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
flyboy122
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Re: Installing A TCM IO360

Post by flyboy122 »

Refresh my memory, what's the change in weight and cg vs. a stock 170 for this conversion?

Thanks,
DEM
Metal Master
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Re: Installing A TCM IO360

Post by Metal Master »

flyboy122 wrote:Refresh my memory, what's the change in weight and cg vs. a stock 170 for this conversion?

Thanks,
DEM
I have not installed the engine on the airplane yet so have not weighed the AP yet. Probably in about two months
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
Metal Master
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Re: Installing A TCM IO360

Post by Metal Master »

Aryana wrote:The way you built up that engine on a faux firewall is genius. Does your firewall stand allow you to test fit the cowl on too?
To answer that question check these two pictures out.
Engine Cowl & Ignition harness RS.jpg
Engine Cowl & Ignition Harness LS RS.jpg
I have arranged with my flying buddy Steve who has a 1956 172 Tail Dragger with a Lycoming 180 HP engine to get current in his airplane tomorrow rather than fly mine. That way we can go ahead and stand my airplane down and start installing the engine on the 170A airframe. He has been begging me to let him help install it anyway. so I am heading to the airport next week with the engine. I stopped by the prop shop last week and my McCauley 80 inch constant speed prop is finished. I checked today to see how the spinner will fit with the cowl and prop. It is going to fit without any major issues. More pictures will follow in a couple of weeks. I want to get this done before the begining of sport flying season.
Jim
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
Metal Master
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Re: Installing A TCM IO360

Post by Metal Master »

Finished up the ignition harness installation Saturday afternoon and early Sunday morning on the 170 IO 360.
Sunday was a Beautiful day to go flying. Drive to the airport was in light traffic. Steve and I reset the low pitch stop on his Hartzell prop as he is only getting 2680 rpm on take off. I got to do the run up and first take off. It has been awhile since I flew Steve's airplane and have become accustom to the 170A's simpler operation and no constant speed prop. Take off performance with the prop set at full RPM without hauling back on the yoke was about 900 ft a minute. It took off from a nose down wheeli position after the tail came up only having to adjust trim Fwd slightly. After that it was great flight playing with cruise trim, steep turns approach & departure stalls and then back to the pattern for some pattern work. I did the first landing - the trim adjustment when the throttle is pulled with the constant speed at full RPM stop is aggressive compared to the Stock 170A although it is similar to when I had the 8042 prop installed on the 170 as far as the slight pitch over when the Throttle is retarded. My short approach and round out to a three point was less than pretty, I called it the jack rabbit approach, the subsequent landings were much improved. Steve,s airplane flies with two in the front on the forward end of the CG envelope. And stalls and short field work take some practice with the later Cessna fowler flaps. I only used 40 degrees of flaps on the very last of the approach. The deck angle with forty degrees of flaps is impressive. I think all in all this was great opportunity to see how my airplane might fly after the mod.
Steves 179(sic in the hangar).jpg
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
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