Welding nuts in place & solid mounting of engines

[v8rfun]

This is my first question here:

Can I weld the two nuts at the bottom of the transmission crossmember to the crossmember so I can just bolt it up without having to reach both sides of the floor at the same time (instead of spring washers)

At the moment the crossmember is only held by two m14 bolts, but also im going to add an extra steel plate to reach the four factor bolt holes (one each side of the m14 bolt), meaning there will be a total of 6 bolts holding the cross member in place

(im using solid mount engine and transmission, in a "souped-up" 360 cubic inch V8)

[Justin]

Hi there

Yes, you can weld the nuts in place.

Just make sure that you don't apply too much heat during the welding process - this will damage the threads. Two tack welds, one on each side of the nut should suffice.

Here's an example - it's a seatbelt anchorage 'doubler-plate'.


Re solid mounting;

There are a few things to remember with solid-mounted engines and gearboxes. Firstly, whilst it’s
not a safety issue, you’ll get a lot more NVH (noise/vibration/harshness) coming through the car with
a solid-mounted engine.
Secondly, the most common view on this subject is that if you are solid-mounting the engine at its
factory mounting points, the gearbox could be solid-mounted or rubber-mounted. If however you are
solid-mounting the engine with a front and mid plate, the gearbox should always be supported by a
rubber mount.
Thirdly, opinions differ on this one, but some say that you shouldn’t rely on solid mounts where
they’re only at the front of the engine and rear of the gearbox. In some cases there won’t be
enough support at the back of the engine/front of the gearbox. Some experts believe that it’s a
good insurance policy to use a mid-plate as well in this case.

[v8rfun]

Thank you for your very detailed response.

The engine is solid mounted from the factory sub frame to the factory engine mounting points.

I replaced the bottom of the subframe with 6mm steel as I felt the orginal was to thin.

The engine mounts are gusseted and braced and triangulated made from 22 pieces of steel. (bullet proof ) the 22 pieces where professionally welded and crack tested by phenox welding.

The Transmission is solid mounted onto box section steel, with a piece of solid 10mm thick steel welded on top at the bolt area. (its short and very strong)