Porsche G935 - 010 - Intercoolers-Sills


Co-Hog Porsche 935 builds - next steps

The parts in blue are those being worked on this time around. Piece by piece, the Porsche G935 group of four is taking shape. It’s taking longer than expected as so many other projects are coming to a head at the same time. I have to stay nimble to keep them all moving.

Co-Hog Porsche 935 builds - next steps

The sills were carefully fitted both in length and in matching the double angle needed to join the rear fender.

The vertical side surfaces will actually have a subtle compound surface from the front wheel well to the rear. I needed to leave some extra meat to match up the rear fender lines later.

You’ll see them mounted in place in a later pic.

Co-Hog Porsche 935 builds - next steps

Intercooler boxes were rough cut from butterfly cut and glued jelutong stock. CAD-generated paper templates and maintaining squareness were quite helpful. Precise curves were needed to match the roof lines.

Co-Hog Porsche 935 builds - next steps

Each intercooler was double-face taped to the master square block and the roof line mating surface was drum sanded to the template line using the drill press. Hand-sanding then matched each intercooler to a particular body.

Taking my time and thinking smooth thoughts helped.

Co-Hog Porsche 935 builds - next steps

The same process was followed for shaping the top surface. The double-face tape is aggressive enough to hold it in position even with only tiny lines of contact.

The front edge gets quite thin, but enough thickness must still be left for the final hand sanding to blend the surfaces together. The templates start to shift away at the tip due to drum rotation, so it comes down to careful eye-balling to get it close.

Co-Hog Porsche 935 builds - next steps

You can see the delicacy of the piece ready for plan view side curves to be added before fitting to the body. The greenhouse drip rail chamfer has not been added yet.

The vertical line on the bottom rear of the intercooler indicates an additional mating surface that must also be fitted before it can be glued in place.

Co-Hog Porsche 935 builds - next steps

The plan view curves for each greenhouse varies slightly, so the outlines are traced onto the bottom of the matching intercooler box. The straight arrows show how subtle the curves are in each plane that need to be followed.

Slow removal of material on the 5” disc sander let me sneak up on just the right line for each side while still being centered on the body. The one on the sander has already been shaped.

Co-Hog Porsche 935 builds - next steps

Here you can see the sills in place with that little bit of extra thickness as it joins the rear fender. The now vertical surface will be blended front to back with a compound surface.

Now the intercooler boxes have been glued in place and hand sanded to blend into the roof line. Filling and sanding along the feathered joint leaves a smooth roof surface. The greenhouse chamfer surface can also be clearly seen, running from the windshield base to the tail end.

I use a great wood filler called Timber Mate which is made in Australia. It's very stable, water-based and easy to work with. The hardness is just a bit less than the jelutong so it's easy to remove excess filler without taking the wood too. Takes finishes like a champ and doesn’t swell.

It's meant for use as a grain filler, but I find that by building with thin layers, it's strong enough to beef up corners and edges as well.

Co-Hog Porsche 935 builds - next steps

All four G935s now have their sills and intercooler boxes. Filling has barely been started on all of the joints. Oh the joy of filling and sanding! It makes things right, but takes all night…and day.

Upper door curves are also moving along. The crease where the door curve meets the rear fender has to be dealt with very carefully.

What the deuce? (Meant in the old Pennsylvania Dutch way that my grandfather used it - "What the devil?") Every now and then I do something besides cars (quite a lot of things, actually). Recently had a great night out at the ballpark with my wife courtesy of a wonderful friend's generous sharing of his season tickets.

His fantastic seats are on the first base line close to home plate. People have gotten a lot bigger since the original seats were built in 1912. I'm well over 6' tall and it took three seats to have enough room to be semi-comfortable.

I was out wandering around to stretch my legs when I took this shot.

Now, back to cars!

Next up - 010 – Intercoolers-Sills – The side and plan view profiles are closer to final with the addition of two more key components: the intercooler boxes and sills.