Engine mounts are us has been at it again. This time another fwd. The original mount is a lousy bit of engineering. Axial load taken by squishing and extending a soft rubber cone and the shear plane is not only outside the frame but again just in the rubber section.
Screwed back together just to make the jig but you get the idea. There is an aluminium section on the flat side of the bracket but it stops under the sheared part. On the otherside just rubber.
First thought was to get the shear force in the encapsulated area so I machined the aluminium part and extended it about 35mm with some aluminium hollow bar. Tapped inside and ran an M8 10.9 bolt through its guts. Then ground the inside of the block out to a cone and fitted a 50x50 square plate under the head of the bolt to push on the urethane and force it into the smaller diameter of the cone to take axial loads. That aluminium cone is inside the rubber in the top pic.
On the other side I drilled and tapped the block and fitted a coverplate to support the urethane which supports the engine weight. Left a hole in the centre so if any urethane is forced out it is easy to the mount has failed. It also made it easier to turn...
No idea if this will work or not, the engine in question has had a lot of work done to it and chews the factory mounts to pieces in about 4 weeks. Took about 5 hours all up including getting my head around the changes.
And there will be some work on the race XR4 today, new springs and shocks, the inlet manifold with extra bling to go on and the cage going in next week.
Stay tuned with bated breasts!