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Dynafocal Bushings Misaligned

acam37

acam37

Well Known Member
I've been rebuilding a -4 for nearly a year now. It came time to re-mount the engine using new Lord Mounts with the same part # as the old ones. No matter what we do they will not align properly. I didn't pay much attention to the old mounts when removed but by looking at them it appears they were also mis-aligned. This engine is an older 0-320-E2G. It appears the engine mount might not be the right one for this engine, but not being the original builder I have no idea what was ordered with the kit. Comments or advise would be greatly appreciated.
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Notice there is a spacer between the engine and bushing. We thought of removing it, but that would place the fuel pump right against the firewall and the engine mount itself would hit the engine, so that is no longer an option.
 
The spacers shouldn't be there.

Given the angles involved they would make the bushings push outwards from the center of the mount - which is what seems to be happening.
 
FYI.....Mine doesn't have the spacers. Relocate the fuel pump?? I wonder if the cowl fits with the spacers installed?
 
Looks like it could possibly be a Dynafocal 2 mount that somebody "made" work?
The angles are different on that mount.
 
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Spacers

If you remove the spacers (3/4") as mentioned, then it looks like the fuel pump will hit the firewall. Also there would be interference with the cabin heater bracket. It looks like we may have to do some major surgery to make this work. I need to look at another RV-4 to compare the position of the engine components to see if there is anything that can be done to remove the spacers. I would most definitely have to re-work the cowl, but because it's not yet gone to paint it shouldn't be a problem.
 
Mel said:
Looks like it could possibly be a Dynafocal 2 mount that somebody "made" work?
The angles are different on that mount.
Click to expand...

Can you check to see if there is a 12 degree difference from the plane of the engine mount "sockets" and the "ears" on the engine?

EngineMountTypes.jpg
 
As others have suggested, the first step is to determine whether the engine and the mount are Dyna 1 or 2 and possibly mis-matched.

It will be interesting to see what the problem turns out to be. But, the spacers definitely don't belong. At most, there might be a washer on the engine side of the bottom mounts - but nothing like those spacers.

If they were there before you started, and you remove them (assuming you solve the interference problems you mention), you'll probably also have to deal with some changes to the cowl.

Dan
 
The fuel pump over flow fitting is usually what would rub on -4's unless the firewall is pinged/dented in a bit to clear it and/or the installation of the vans fitting they make and sell. This was the case on mine with a conical mount and the same when I switched to the dynafocal mount.The heater box was probably placed where it is when the engine was mounted with those spacers and may have cleared then but when you correct the spacer. Issue you will most likely need to relocate it. It's very tight in there as you know. I used The Lord dampeners too and they call out for a washer (for eventual sag) on the lower to donuts only. No spacers. I'd put money on having miss matched mount to motor as mentioned.

Your -e2g appears to be a Type 1 dynafocal mount from what I read on Wikipedia

Type 1 (30°) dynafocal mount attachment and Type 2 (18°) mount attachment (angle to crank)
 
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Your last picture shows both of the bushing havles are pushing in an outward condition relatively equally. This would indicate that the bolt angle is on the same plane as the mount and it is consistent with extending the angled fittings away from each other (in this case the spacers). If you were dealing with different angles on the engine and mount, you would expect the two bushings halves to be bulging in opposite directions or one in one direction and the other appearing normal.

Larry
 
Spacers

I did check and it appears the engine mount is the same angle as the engine, so we are good there. So the next step is to take out the spacers and see what happens. I've never had to install an engine so I figured since the spacers were there when it came off, then that's how it was supposed to go back together. I looked at the plans and nowhere does it show spacers installed. I wonder why the builder put them there in the first place?
 
acam37 said:
If you remove the spacers (3/4") as mentioned, then it looks like the fuel pump will hit the firewall. Also there would be interference with the cabin heater bracket. It looks like we may have to do some major surgery to make this work. I need to look at another RV-4 to compare the position of the engine components to see if there is anything that can be done to remove the spacers. I would most definitely have to re-work the cowl, but because it's not yet gone to paint it shouldn't be a problem.
Click to expand...

I know where you could look at a bunch of RV-4s this week. :)
 
aerhed said:
Also, if you remove the spacers your spinner will hit your cowl for sure.
Click to expand...

This will clearly take some work or thinking to address. I would give Sabre Mfg. a call and see about getting a different sized prop extension. He may have other ideas, such as possibly using a crush plate as a spacer.
 
The stock 'overflow' fitting on the fuel pump will hit the firewall. Vans sells a modified one or you can make your own. The -3 and -4 are tight but it will fit.

Have fun.
 
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