Rear Clip - Engine Opening

[Lance]

Hello there,

I know it’s not the “standard”, but does anyone have images of a GT40 which has had the flat area of the engine cover under the rear window opened right up to showcase the engine? I’m thinking of doing this to mine.

A bit more like the MkIV(?) I believe. Bit of a shame to cover it all up.

Thanks for any help.

Cheers,

Lance

 

[Bill Musarra]

Lance,
I think you should be able to do it. I personally wouldn't. You will have to pay attention to the rear sections underneath the vent. May have to give it a lip so that these pieces maintain their rigidity causing the side pieces to flex. One problem you will run into is going to be the heat from the exhaust. It will be rising up and will be more of that in the intake and stress to the rear plexi(if that is what you have). I think you will wind up with a big open space that won't look right. The visual appeal of the car is the webbers or 8 stack sitting there. You will lose the visual focus of it.

Bill

 

[Geert-Jan]

I have seen a transparent version somewhere on this forum.

 

[Bill Musarra]

Believe it is Mike Trusty's brown 40. Sounds O K, but you better have something to see in that space!!

Bill

 

[Lance]

I think that will be OK.

 

[Dr. Bob Woods]

The main purpose for the smaller cut out is to block the intake air from coming from the hot engine area and letting it all come through the air inlet vents on the sides of the body. Some cars build a box around the carburetors to seal the intakes from the engine heat. That smaller opening helps with the stiffness of the rear body section as well.

Here is a photo of my buddy's P1083.

-Bob Woods

 

[Lance]

Hello there,

Thanks for the comments.

Yes, I can stiffen up the clip as required. In my case (not typical, I think?), my clip retains a cross brace at the front, so will be quite strong anyway (refer image), even with the larger opening.

Yes, air in and engine heat out. I’ve given a lot of thought to that. Initially, I was planning to shroud around the T-shaped opening to separate the intakes from the engine bay. If I open this area up, I will still provide shrouding for this purpose. Some cars go to great lengths in this regard.

I’m also looking at doing something with the rear window in this context. Cosi has an F40 type rear window in his, which looks great. I’m considering having a window moulded with a scoop built into it (refer image). Hopefully, this will pull cold air in and allow heat loss while standing, but still retain what rear visibility exists.

These rooftop scoops are the flavour of the month at the moment, however, many cars, including the MkIIs, seem to go to a lot of trouble to draw in cold air, even to the point of not bothering about rear vision sometimes. It’s actually a look I like (that Porsche speedster must be one of the best looking cars of all time), but I don’t see it working on a GT40 myself.

By the way, I couldn’t find Mike Trusty’s car by searching. Can someone provide as link or search clue please?

Bye for now. Have a good weekend everybody. Cheers,

Lance

 

[Jimmy P]

Lance, sorry I can't offer assistance to your question but I will say +1 on that old skool Porsche. That car is stunning!

 

[Bill Musarra]

One thing you might give a thought to is to add engine bay cooling fans. I have two 5" fans on either side of the bay that for now are manually operated and help keep the temps down by keeping the air flow to the rear. They are controlled with a "run on" relay timer(after shut down) that allows them to run from a few seconds to 10 minutes(I have mine set at 3 minutes) from Wayteck. I will eventually hook it to a thermostat.

 

[Lance]

I decided to cut out this area. I've built in a return edge to stiffen it. I like the look. A lot of interesting things to see. Don't worry, I'll be ditching these filters and arranging some cool air for the engine.

Cheers,

Lance