Oil cooler install using Nutserts

[jdoug]

I want to install an oil cooler on my 63 SA Ghia using 3 nutserts (rivet nuts or whatever you want to call them).

It was suggested to me to install (2) 1/4-20 (though I'll probably go metric) rivnuts in the bottom of the torsion bar housing and one on the frame horn.

This should allow a nice install but I've no experience with installing rivnuts. I have a friend that has a Nutsert tool (is that a specific brand of rivnut?) and said he would help me install them.

I suspect that torsion housing is pretty thick. Are rivnuts sold for for specific widths of material to go through? If so, any idea what size I might need for torsion bar housing? Also, do I need to buy Nutsert specific rivnuts?

Thanks

[Ol'fogasaurus]

jdoug I wouldn't feel comfortable advising the nutserts in the torsion housing for several reasons. The material of the housing for one, drilling holes in it second and expanding the nutserts in the torsion housing for another. I am not too sure how much clearance you would have to the torsion bar itself but it you scratch the torsion bar's surface you put a stress riser in its surface and it could fail there.

Now if you properly installed a pair of mounts on the housing, that is another thing.

[helowrench]

Alright, lets see if I can answer these.

Nutsert is a brand name, as is Rivnut
As far as the tools go, and long as it is the correct thread and pitch to match the insert, you are good.

Yes, the inserts are made with a specific material thickness (grip) range. Coding for this depends upon the manufacturer of the insert.

Torsion housing?
Where are you planning to mount this?

[helowrench]

After a bit of a think, I would recommend welding a nut onto the torsion housing before I would the nutsert/rivnut

To me a clamp would be even better

[Bruce.m]

A 'U' bolt exhaust clamp would be the simplest solution & very robust.

[ProctorSilex]

I am a couple months late, but I have used these multiple times and thought I should put my experience here for future reference.
I got mine years ago to install a front lip on a plastic bumper cover because I did not want to pay a couple thousand for some shop to seamlessly integrate it. The lip just came with a few sheet metal style screws and no directions. Rivet nuts with finishing screws on the sides seemed like the cheapest option so I bought a tool with a set of inserts. I drilled holes into the lip then holes slightly larger than the insert into the plastic bumper cover. It went well and I thought it looked good.
The inserts that I used were steel and they started to rust within a few years, probably from the winters.
Recently, I wanted to install a lip on my Miata. Same issue with weak looking sheet metal type screws holding it to a plastic bumper cover. I got stainless inserts this time to avoid rust. Stainless are a PAIN to install. They take far more effort. For most of the locations, I could not squeeze hard enough and had to use a C clamp to compress the tool. I ruined one insert because I had to let go of the tool to try the clamp idea for the first time. The inserts distorted the plastic which made getting the bolts started in very difficult for some. Over all, it worked well and I think it should hold the lip on at the high track speeds this car experiences (first event with the lip went well).

Notes:

• Steel inserts are much easier to work with, but will probably rust on a car.
  Stainless inserts require increased installation effort. M6 are barely possible with the C clamp trick and I doubt you can use anything higher without a powered tool or a tool with much better leverage.
  Aluminum might be a good option but I have never used one. You are probably not needing much strength if you are using rivet nuts. I probably should have gotten aluminum instead of SS.
  You can get these on Fleabay and Scamazon. I found it hard to get them from domestic fastener companies as they only seem to deal with high volume business. All the ones that I could get have come straight from China.
  You might have trouble getting range specs from these Chinese sellers. I did not have any and just guessed.
  It can take a while for shipping from China.
  Buy a set to save money.
  Get extra in case you ruin some.
  The tool has a depth limiter. This is hard to gauge. I made a guess then adjusted afterwards based on the plastic distortion. Instertion into a stronger material probably won't require the depth limiter. You would have to know the depth specs on the insert and the thickness of the material (and include any allowable material compression).
  Remember that the inserts are grabbing onto the material like an aluminum can that was put half way through a hole then crushed. I would not expect it to handle a lot of torque. Mine have not spun given my low expectations.
  If you just want to do a couple, there are DIY possibilities including using a nut and bolt.

Alternatives:

• Rubber rivet nuts that do not require a special tool and insulate electricity.
  U-nut is a similar toolless alternative for the edge of a material.
  Weld nut is a nut specifically made for welding that might be a better choice for metal mounting.
  Welding a a regular nut can distort the threads, but I and many others have had success welding a nut to metal too thin to tap.
  T-nut is for mounting in soft material like wood. These could also be a quick alternative to weld nut as they are available at the local HW store.

Nut inserts are a great tool to make a neat installation with bolts on a thin surface where other fasteners are not the best option.