Mr Charles

Mr Charles

Well Known Member
I purchased a 4 built in 93 and am trying to convert from FP to a CS...someone mentioned older 4's didn't have a firewall recess for the govenor...can someone provide info on this for me? Pics of the recess...how to retrofit...ideas? I have a PCU 5000 located, which I understand is a fairly small govenor...will it work without firewall modification? Also, I am concerned because I have a Christianson inverted oil system, and think I may have a lot of stuff "in the way" for govenor installlation...anyone have this combination on a completed 4 ?
Thanks!
Charles
 
I don't know about the -4 but if I had to do this on my -9 (assuming the recess wasn't installed during the initial build), you would have to remove the engine and engine mount to get access to the firewall.

You will need to cut a hole and then rivet the recess in place. One advantage to doing all this is it will give you the opportunity to inspect the engine mount and firewall.
 
Ditto on the SS bowl, seen it done, and it looks nice. Minimal air gap seams compared to building a box from a SS sheet.
 
Recess followup

Great idea on dog bowl! But however I build or install recess, what about rudder pedal travel interference on the inside? Won't any recess protrude into my rudder pedal area?
Charles
 
That 'someone' was me :rolleyes:. When I read your earlier post about wanting to convert to C/S I kinda' thought that you may have overlooked this since you weren't the builder.

Adding the recess is not difficult. As mentioned, best to remove the engine but that doesn't take long either. If you are going to use the dog food bowl you may as well just fab up the recess per the plans...either way works fine. I've never seen an issue with the rudder pedals so I wouldn't expect any with your installation.

Instead of asking for pics may I suggest you post a pic of your install, this might speed up your responses....the future recess area would be a good place to start.

Good Luck!

Mr Charles said:
I purchased a 4 built in 93 and am trying to convert from FP to a CS...someone mentioned older 4's didn't have a firewall recess for the govenor...can someone provide info on this for me? Pics of the recess...how to retrofit...ideas? I have a PCU 5000 located, which I understand is a fairly small govenor...will it work without firewall modification? Also, I am concerned because I have a Christianson inverted oil system, and think I may have a lot of stuff "in the way" for govenor installlation...anyone have this combination on a completed 4 ?
Thanks!
Charles
Click to expand...
 
Just wondering how familiar you are with your engine and install. Some engines have the governor mounted on the front of the engine. Obviously if that were the case no recess would be required.
Ryan
 
Dog food bowl will not work on the -4. If you look at the firewal you will see it has a step where your feet go. The middle of the step is where the cutout needs to be......
 
that's how our firewall recess looks like

Charles,
That's how our firewall recess looks like. The previous builder planned to install a O-320 with a constant speed prop and governor. Presently we do not use it, because we go the fixed pitch route. Notice that it's not completely symmetrical.

6962709130_e1de527447_z.jpg
 
Clouddancer said:
Charles,
That's how our firewall recess looks like. The previous builder planned to install a O-320 with a constant speed prop and governor. Presently we do not use it, because we go the fixed pitch route. Notice that it's not completely symmetrical.

6962709130_e1de527447_z.jpg
Click to expand...

Thanks everyone...yes, I am somewhat familiar with engine/govenor setup...I have the pad on rear accessory case...right side, opposite fuel pump. The govenor I have is a PCU 5000, from an O -540 where it was mounted upper left front of cylinders...my understanding is same govenor for either location. The PCU is smaller than most other govenor choices...but assume by comments that I will still need to build the recess? This may all be a moot point as I am questioning whether I have a hollow crank (posted questions other threads)...but if I do have, will go ahead with swap!
Charles
 
Not all need a recess

I used one of the chech governors, starts with a Z that whirl wind sells and it fit a 6a without the recess. Most said it could not be done. A 4 is certainly a different animal but the moral of the story is to measure.
 
Watch the governor speed ratio

The prop governor for a 540 runs at a different ratio than one for a 4 cylinder. Make sure you talk to a governor shop to determine if yours will work on a 4 cylinder without modification. The shop I talked to said most could be modified to get the gearing correct but be aware you will incur cost to have this work done.
 
Vans sells the materials and plans to make this cut-out - no need to re-invent the wheel.

Nigel Marshall
RV-4


Mr Charles said:
I purchased a 4 built in 93 and am trying to convert from FP to a CS...someone mentioned older 4's didn't have a firewall recess for the govenor...can someone provide info on this for me? Pics of the recess...how to retrofit...ideas? I have a PCU 5000 located, which I understand is a fairly small govenor...will it work without firewall modification? Also, I am concerned because I have a Christianson inverted oil system, and think I may have a lot of stuff "in the way" for govenor installlation...anyone have this combination on a completed 4 ?
Thanks!
Charles
Click to expand...
 
You must log in or register to reply here.