Engine Installation Thread

[spinningwrench]

There is an inner compression sleeve on the isolation mounts. I believe 25 ft-lbs is the desired torque although I would have to look that up again. -35 bolts worked for me.

[noema]

Thanks for the numbers, good to have refs.

[marcusofcotton]

... I have about 8 lbs still on the tail wheel. So even without the tail feathers on it does not tip over.

You might want to add some weight in the tail, a little bump or instant of leaning may result in it going over center and on its nose.

[noema]

Right, you never know when you get carried away with hangar flying Tail is tied to a wall bolt.

[noema]

Yes, these VIP dampers have an internal bushing but I am getting quite a bit of rubber deformation without running into the hard stop of this spacer. What is the generally consensus here, do I just clamp down until hitting the bushing. Do I add a washer to the bushing? Create a slightly longer bushing? How mush pressure/deformation should I have on the rubbers?

One thing I noticed is that the weld beads on both sides protrude a bit which may add just enough depth to the mount ring to make the bushing a bit too short. On the lower rings I actually had to trim the dampers a bit to prevent them from interfering with the corner weld joint. Still, if you look carefully, you can see that there is a small gap between the ring and the damper. This is caused by the edge weld joint of the ring.

To me this looks solid but I also do not want to have bad performance of the dampers by having too little or too much pressure on the dampers.

notched.jpgnotched2.jpg

[jaredyates]

I was hoping to find a picture of the mixture bracket but I didn't find one yet. I shortened the vans mount by cutting the corner to the new length, removing material on either the top or the side, bending the remaining side, and welding a new corner.

[noema]

I am figuring out the prop control. The gov I ordered is this one:

• Jihostroj P-920-032/A
• pressure to INCREASE
• Takeoff RPM 2700
• Takeoff power at 320deg (all in, low pitch)
• CCW (to increase pitch, pull prop control)
• 866:1 gear ratio

Supposedly -032 means it is setup for low pitch with the rod end bearing hitting the end stop at 320deg. I don't think this is what I got. Mine looks more like 220 deg according to this graphic from the Jihostroj order page.

gov.jpggov2.jpg

I think coming in with the control cable from the bottom left should actually work well. The end stops are adjustable but the bracket is limited by the resolution of the mounting screws. So 60deg up would be another option.

Bcone1381Brooks have you mounted yours already? I remember you getting the same gov.

[Bcone1381]

Noema, yes mine is mounted. Your arm needs to be reclocked. The manual tells you how to do this and it’s not diffacult.

I started using that same push-pull cable bracket from vans and ended up fabricating my own mount by securing the cable to the firewall. I’ll try to get photos in a day or two.

[Bcone1381]

EDIT: WARNING. I wont change any text in this post so the content remains original. My first photo is a bad example of how to attach a control cable. Do not use this method. The cable needs to be able to "dance" in concert with a vibrating engine. Use a bracket that is attached to the engine, not the firewall like my photo shows.
____________________
Here is the pdf version of installation manual for our Jihostroj P-920 type prop governor.

Here is the PDF of the manual.
Jihostroj P-920 installation manual.pdf

This is a 30p. manual. Page number is a bit goofy.
On p.502 find paragraph 5.5. titled calibration procedure. The clocking of the governor control arm is achieved by loosening the six small screws, rotating it to the desire position, then tightening screws them back down.

The big picture...
Screen Shot 2023-06-25 at 5.27.12 PM.png
This is how I ended up securing my the control cable. Others will see that this governor is close to the firewall, but requires no dishing out of the firewall. The Hartzell Prop Governor requires firewall modification because it penetrates the firewall.
Screen Shot 2023-06-25 at 5.27.22 PM.pngScreen Shot 2023-06-25 at 5.27.45 PM.png
This is a close up of the face of the governor. The safety wired slotted screws get loosened and the inner face of governor is rotated to adjust the clocking of the control arm.
Screen Shot 2023-06-25 at 5.27.54 PM.png

[noema]

Thanks Brooks for manual and pictures. I noticed you are coming thru with the control cables fairly close to the pedals. No worries that you might kick into them with your feet? You will probably also install inner side walls or something like that?

[Bcone1381]

I have sat in the seat with my feet on the pedals and I have zero recollection of any concern or conflict between my feet and the prop control

[Bcone1381]

I might seek out some criticism for that install of the prop cable. I wonder how it will behave with the engine moving around. Feedback?

[svyolo]

+1 I am with brooks. A simple bracket (store bought or home made) off of the governor, or engine will prevent prop actuation with throttle actuation. Several companies sell them. I think 30-50 bucks. I made mine.

Reclocking is easy. I reclocked mine.

[noema]

This might cause inadvertent control input on the gov. Hard to tell how much of a problem it really is. I leave this slowmo of an engine startup here for consideration: https://www.youtube.com/shorts/DJFriVB3cNU

[Bcone1381]

I will reinstall the same Governor Bracket that you use in Post #20 so the cable is secured to the engine not the firewall.

[noema]

I test-fitted the prop and spinner today. I noticed a few things:

- the hub is indexed with a "0"
- the prop can go on there in only two positions
- the spinner front/aft position can be adjusted with spacers but comes with quite some instructions in the Hartzell manual
- the crankshaft has a plug in it

Obviously the constant-speed prop won't work with this plug. Lycoming has some info in Service Instructions 1435 what the configuration should look like. Unfortunately it does not say how to remove it. Do I just drill a small hole into it and then pull the plug?

1435.jpgcrankshaft plu.jpgprop.jpg

[spinningwrench]

When you adjust your spinner washer stack up make sure you only loosen the four related bolts. I confirmed this is OK with Hartzell as there are dire warnings about loosening hub bolts in the Hartzell manual. Hartzell has superb tech support.

Regarding the front plug the normal technique to remove the front plug is to use a very dull tool like the head of a cap screw and to tap, tap, tap with a hammer to make the plug concave at which point you can remove it with a magnetic tool when it releases from the bore. The goal is to produce no chips. Verify that the rear plug is in place.

[noema]

I see, the plug starts convex. Then, you tap it to expand and jam it in place. Afterward, you can keep tapping it to make it concave. Does this make it fall out again? I will try that before creating any chips.

The Hartzell manual is really useful (once you disregard all information that does not concern your prop model). It goes into minute detail, all the way to where to place spacer tape in the spinner cone to prevent any play.

[noema]

The other day, I jiggled up the nose bowl. This was not as easy as expected. First of all, there is a lot of measuring to figure out the correct offset from the spinner. The whole process really starts with adjusting the spacer of the spinner to achieve an equal gap around the prop blade. Then I measured the distance of the aft spinner edge to the prop flange and looked for something that would bring the front of the nose bowl up to the spinner with a 1/4-1/2" gap. After considering a lot of different options, it was a 3/4" (19mm) plywood board that did the job. A planer would be really useful here.

I used the flywheel as a template on the piece of plywood. This allowed me to cut it out in a way that attaches it to the prop flange without play. Since I do not have the appropriate AN8 bolts (they are hard to remove from the prop, and my hardware stores don't really deal in UNF), I simply used cable binders and Clecos for now. It works well because the board can't slide around and only needs to be held flush on the flange.


nose1.jpgnose2.jpg

I am still wondering where the cowl doors should start and end. This determines where the four angle brackets between the nose bowl and firewall go. Probably will be a matter of finding a good gap between the boot cowl mounting screws on the firewall flange.

cowl.jpg

Feedback welcome!

[spinningwrench]

I probably ran my lower cowling up a bit higher than most, it is even with the bottom of the screws on the valve cover. I figure the entire cowl will come off at annual to inspect the engine and remove plugs so I went with the somewhat smaller size as it should make fitting the hinged covers a bit easier.

[Pbruce]

How wide is the centre top section Bruce? What is the hieight of the doors?

[Bcone1381]

Here is another view point on the size of the cowl door. Most Super Cubs engine cowls I see (btw, a very limited number) have a door that travels down low to help ease maintenance and lower plug removal.
Screen Shot 2023-07-05 at 10.41.04 AM.png

[noema]

Seems like no wrong way doing this, just different tradeoffs.

[spinningwrench]

You’ll find that the lower cowl is essentially the stiffener for the nose bowl which is another reason I kept the lower cowl as much of a “cone” as possible. Quite happy with the result as the nosebowl doesn’t budge.

[noema]

I finally got the heat box on the engine, if only with cable ties. Does anybody know what bolts work for mounting it. The carburetor seems to have threaded holes that are more coarse than typical AN bolts. I guess they should also be head drilled for running some safety wire through them. Mark Goldberg


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