3D Printed and Carbon Fibre Engine Mounts fit

I’ve created the front engine mount in CAD (another post to follow) and now I need to test the engine height with the mount and the bonnet fitting – it’s no good having a beautiful mount if the engine then doesn’t clear the bonnet. I’ve gone for a trial fit of the mount (several hours of CAD and printing) to be sure it works before I go through the process of moulding and making the CF part. What I wanted to do was put the mount in place (it cradles under the front of the sump and bolts on to the front of the dry-sump). It also needs to curve around the awkward external dry-sump pump which seems to get in the way of everything.

Having fitted it, here are a set of photos that attempt to show the bonnet in place, and the engine having about 30mm of clearance between the top of the engine and the bonnet. One of the other interesting things about doing this is it’s the first time in a couple of years that the car has had any bodywork attached. It’s gone (in my head) from an abstract chassis concept back to something that relates to being a car again.

From a reference point of view, the sump will sit between 115 and 125 mm from the floor, and my suspension is height adjustable so on a track I can lower it a bit more. Right now, I’m safe to go over a house-brick without writing off the engine.

Here you can see the bonnet resting on a clamped large table-mat as a reference line. (Clamped to the top chassis rail). The mat and clamps weren’t strong enough to handle the weight of the bonnet, so I needed another idea. So, what you can see sticking down is a piece of (cut to size) wood that represents the chassis rail height to the floor as a relative position. The table mat is now just sat there without any vertical load – it works well as a reference point.


With the bonnet properly propped, this a bit of a scrappy shot down the bonnet. There’s loads of clearance here, and you can see the CF footwell and gearbox.





More of the same here and you can make out the 3d printed blanking plates I made.





And again – hopefully you can see the oil filler cap at the front a good 30mm below the bonnet.





Here it is from the top down. It looks a tiny bit like a car again.

Soda Blasting

So, nothing is going back into the engine if it’s scruffy. There are various ways of making it clean, but the varnished on oil from the engine front cover I very much doubt would clean up in a parts-washer.

So, to the soda blaster again.

Here is the before-and-almost-after picture.


Prep for the Dry-Sump


So, there are a couple of things that need to change if you’re running ARP crank cradle bolts on the titan dry-sump. The bolts are 2mm too long. I wizzed them down to Simon and Cornering Force, and we span them in the lathe and took 2mm off them. The results are below.


imageThen they go into the block again and the nuts spin on. They needed a little finishing off after the lathing. Firstly the sides needed a 60 degree chamfer and Simon has a lot of experience here – he puts the chamfer on so it just meets the thread, and then the nut should start straight away. You can just see a tiny lip at the remainder of the hex head in the middle (there’s about 2mm of recess left). This was filed off with a needle file to remove any overhang and a dremmel (slowest gentlest setting) to remove any protrusion. The top is now perfect.

The bolts spin in to only 4Nm torque (which just so happens to be the torque on my electric screwdriver) so they’re back in the block. There isn’t enough recess left in the top of the bolt to get any more torque in than that anyway.

And yes, the nuts fitted beautifully on the threads. Simon did a great job.