Oil cooler nutplate hitting cylinder fin

[LettersFromFlyoverCountry]

I finally got the oil cooler bracket doubler and such finished. I got it as high as it could go and, because it's a slightly larger cooler than standard, couldn't go inboard too far because of the interference from the engine mount (I -- or rather Pete Howell -- cut the flange away).

Everything fit great until I noticed this...



The lower nutplate hitting the cylinder fin in this lovely IO-360 from Mattituck. I tried grinding bit of it away but it's still not going to be good. Building buddy Brad Benson suggests getting rid of the nutplate and finding a low profile nut, but I'm not sure that's not going to interfere either.

Anyone else ever had a problem with this location?

[Bruce]

Bob,

I think I would lose the whole nutplate.

Two screws on the inboard and 3 or 4 on the outboard is plenty,
just so you put a doubler on the outboard corner.

My .02

[Walt]

Yep same here 4 bolts total.... top 2 bolts on the I/B side and top and bottom bolts on the O/B side (I used large diameter washers and nuts rather than nut plates)

[Vlad]

I don't even have this one on my plans.

[LettersFromFlyoverCountry]

//just so you put a doubler on the outboard corner.

Yes, I put a .125 hunk of aluminum as well as the .063 (I think it was .063) spacer. on the outside corner.

The only problem with losing the bolt entirely is that it's the center of the the flange that's cut away to clear the engine mount, so there would only be one long bolt and one short one here.

[LettersFromFlyoverCountry]

Originally Posted by Vlad

I don't even have this one on my plans.

OP-27, I believe.

[Vlad]

Originally Posted by Bob Collins

OP-27, I believe.

Double checked, not found

[Walt]

Plenty of room on mine, no trimming the oil cooler flange required.

[Bob Axsom]

How about relocating the lower inboard mounting hole. The inboard and outboard mounting flanges of the oil cooler are just two parallel flanges on the oil coolers I have had and I assume the same is true for yours. If there is room above the current inboard lower mounting location and the flange cutout I would carefully relocate that mounting location upward. This would require drilling new holes in the oil cooler flanges and the baffle and relocating the platenut installation. That is the easy fix. Beyond that you have to get more creative and I am reluctant to make suggestions at a distance for someone else's airplane. I will say there are options that you can come up with to anchor the inboard side of the oil cooler with at least two fasteners if you think about the requirements and the constraints. These kinds of awkward situations are where we builders earn our spurs.

Bob Axsom

[LettersFromFlyoverCountry]

It might be possible to move that hole higher but just looking at the picture, it looks like it'll have to come up a fair amount to clear the fins, looks like there's only about 3/4" before the nutplates would collide. I'll get the tape measure out.