CAV-Getting the Horsepower to the Ground

Bob Childress · 08-30-05, 10:25 AM

The number of new GT40 replica manufacturers is increasing and as a result all of the manufacturers seem to be making big improvements in their designs and quality to keep pace. (Good for everyone) Our cars are already way out there on the 99 percentile but every day GT40s seem to get bigger engines, better brakes, stronger suspensions, and improved safety features like roll cages, fire suppression systems, and fuel cells. Those of us who already have cars, and like making those sorts of improvements, can pick and choose from a growing list of upgrades from our original manufacturers and aftermarket dealers.

Over the past year I have posted to the forum, asked a lot of questions, and now finally think I have finally collected a group of compatible parts from four sources, all of which seem carefully engineered and are within the capability of most home garages.

So like it says in the Army Jeep Repair Manual, first remove the frame…….

Bob Childress · 08-30-05, 02:46 PM

I will start by saying that my car was one of the last stainless steel monocoque cars made by Cape Advanced Vehicles (hense CAV). Some of the upgrades I will describe here have already been done on the new CAV factory cars now coming from John and Jean at Autofutura.

Everyone seems to think it is a good idea for performance and handling to lower the center of gravity of the car by lowering the engine when possible. Me too.

Here is a picture of the original CAV motor mount assembly and a set of new upgraded motor mounts. I am always amazed at the number of really talented replica owners who go about designing things for their own cars without much publicity or fan fare. These mounts came from one such person who just finished makeing a set of motor mounts for himself and graciously agreed to make a set for me also.

I like the design of the new mounts as they are obviously stronger and will spread the weight of the engine more evenly on to the side pods. They are made out of stainless and match well with the monocoque. And, while not identical to the original GT40 mounts, they are similar. The mounts are fully adjustable up and down; forward and back; and left to right. These mounts will let me move my motor down and forward.

Bob Childress · 08-31-05, 08:46 AM

The original motor mount assembly was unbolted and ss button head allens screws used to fill the stock mounting holes.

One thing you quickly learn when working on a CAV is that stainless steel is really tough to drill or cut. I used carbide tipped drill bits and, on a suggestion, a little anti-freeze as a cutting lubricant. As crazy as it may sound, the anti-freeze worked much better than the real cutting fluids that I had tried in the past.

The upper part of the new mount sits directly over a diagonal reinforcing strut inside the pods. I attached the mounts with 3/8 inch bolts and heavy oversize machine washers on the back side. The notched bracket at the bottom of the mount holds the stock emergency brake cable.

Bob Childress · 08-31-05, 08:49 AM

The mount could have been welded in place but since this is a newly designed part it seems prudent to just bolt-in the first set.

Canuk40 · 08-31-05, 11:46 PM

Hi Bob,

Great stuff, thanks for posting the pics. Beautiful work

Cheers

Bob Childress · 09-01-05, 08:21 AM

There are bolt slots in the brackets for fore & aft and left & right adjustments. This picture is a detail of the support bushings and spacers used for up & down adjustments. The cup for the lower bushing is recessed and 2/3 of the length of the bushing is down inside the lower cup. The same is true for the cap on the upper bushing. The bushings are shown uncompressed. In this case they are dense rubber but they could be polyurethane. When the brackets are bolted to the engine block, they become a rigid structural extension of the block itself and hold the motor mount bolts vertical to minimize any tip or pivot.

Bob Childress · 09-02-05, 08:19 AM

And, ta da.....both motor mounts as finally installed on my car. In this view you can see that the brackets bolted to the pods are symmetrical but the brackets that attach to the engine block are asymmetrical to match the offset on the engine block itself. Cosmetically the new mounts definitely add to the look of the engine compartment but I have to admit that I also did a bit of cosmetic surgery on the parts before they were installed.

Gary Gibbs · 09-02-05, 10:50 AM

Hi Bob. Nice work and photos. It appears that you have a modified crossmember connecting the two shock towers in the back. Could you post a few photos of that?
Thanks

Tim Kay · 09-02-05, 11:12 AM

Very, very nice. Gr8 job [img]/ubbthreads/images/graemlins/wink.gif[/img]

Bob Childress · 09-02-05, 07:33 PM

The person who made these mounts has a philosophy that making parts more like those on a real GT40 is always better. On his car the motor mounts have two big holes on the upper bracket like the originals. In this picture you can see his two hole bracket (and also note the really cool looking heads on the bolts that were used).

Two big holes make the top of the bracket wider. It is not that I did not like this look, but the wide brackets interfered with the remote battery terminals that I previously added at great expense to my knuckles. So, before installing on my car, I did a little surgery and shortened the upper part of the brackets down to only one big hole and reattached all the mounting flanges. (Note: For anyone adding a vent or brake duct, I have two large holes left over from this job that I will sell really cheap.)

So, here ends the tale of the motor mounts. I hope you guys liked this post which had a little more detail than typical. Tomorrow I will start posting Part II - a saga of the most beautiful crossmember in the world that should be displayed on a desk and not hidden between two shocks.

Bob