GT40 - Grillwork - need opinions plz

[Randy V]

Hi Guys,

I'm starting to make some progress on the Forty - albeit slow..

GT40 MK1's have grillwork above the exhaust system (to allow heat to escape) and at the rear of the car. There are basically two different styles of grill-work for the MK1 cars. The Original "Louvered" design and the "Lemans Oval" design.
I've chosen the Lemans Oval as that is the style that I like the best.

The manufacturer of my car made some very nice grills that are waterjet cut from 1/8" thick aluminum. They are very strong but the edges are sharp (very sharp).
The originals are actually stamped from aluminum that is far thinner (around .060" thick). Being that they are stamped, the oval holes are chamfered with a radius that strengthens the thin alloy grill.

I asked a friend of mine with access to some very nice CNC equipment if he could assist me by doing a back-cut on the top grill (over exhaust) so that it would fit down in the molded relief in the body.
He asked me to send all three grills as he had an idea on how to take care of the chamfer issue as well..

Shown here on the first post are pictures of the two different styles of grills and the .062" deep relief cut in the rear body clip for the exhaust heat grill (pay no attention to the box/model laying in the "soon to be" hole for the grill)

These pics will show what the grills looked like before and after my friend CNC cut the .0005" steps to form the chamfers and the .0625 step that he cut in the top grill to fit in the relief of the body so the grill did not sit proud of the body.

Note that he left .010" at the bottom of the chamfers so that it did not produce another knife edge ((great work and a nice touch!))

Before Chamfer;

After Chamfer;

All three pieces

Nice relief cut!

This is really the meat of the issue.

While I would like to present a more traditional look in my car, I also really like the look of polished aluminum.

Given the look of painted -vs- satin -vs- polished -vs- SUPER polished (not shown)
- which would you choose for the look of the grillwork?

Painted - Mark Reid's car ((thanks Mark))

Satin

Polished

Super Polished would look very close to Chrome..

So - In that I am somewhat undecided on this issue, I thought I would post it out here for some of you guys to take a shot at it...

What do you think?

Thanks!!!!

 

[Chuck]

Very nice work. So nice, would hate to cover it with paint. The multidimensional affect really adds some class. Would opt for the shine, not the super shine. The chrome look does not really fit a race car. The shine rather than paint would add a bit of contrast to the painted car. With paint it would tend to disappear.

Just my two cents worth . . . .

 

[Brett James-McCall]

Personally Randy, I like the Satin Look like the pic on the Red car.

Next Question... will you be doing a run of them at all?

Brett

 

[RichardH]

Just a quick (dumb) Q - does the design affect downforce at the rear? I appreciate that it is (relatively) a small surface are, but I would think the first style is less likely to reduce downforce? Maybe even increase it?

 

[Jack]

I would prefer the satin. Elegant, yet unobtrusive. It will look as though it belongs to the car. Super polish would not be fitting for the GT-40.

 

[Chris Kouba]

Chris,

You've gone through great lengths to accurately reproduce an authentic livery. My recommendation would be to do what Essex did.

If you're not interested in that, I'd then say what many others have posted on here- it's YOUR car, make it what YOU want!

Not a lot of help for you there but you're so close to finished with the outside, it'd be a shame to deviate now.

 

[Chris Kouba]

Whoops, sorry Randy. I saw Chris Martino's car and never even looked at who wrote the post.

I hand-chamfered my holes as well. If you're keen on polished, do it! I bet there are some originals out there which had them shiny.

 

[Dutton]

Randy,

That's some very nice work done with the radius as well as the back cut on the panel. Your solution cures one of the few details I'd like to see improved on my car as well. I'd sure appreciate it if you'd inquire with your CNC-equipped friend as to his willingness to perform the same process to another set of aluminum panels. Coincidentally, my panels came from the same batch as yours so his initial set-up should be able to be used once again with little additional trouble. Please advise at a convenient moment.

As for the finish if these panels, whatever direction you decide to go I'm certain will look great!

Best,

T.

 

[Rob]

Hi Randy,
I struggled with this same decision quite a bit. I reworked my exhaust cover no fewer than 8 times with different finishes until settling on one that is most similar to your "polish". I tried brushed.. to high polish and everything in between with different methods of creating the finish. Ultimately liked wet sanding with a final quick buff with 3M compound and polish.

So...... I guess my vote is for the polish (not to point of chrome). It will then match the fuel fillers too.

I love the machine work. I hand radiused my exh cover holes, but no where near to the same degree. Looks fabulous. See if your buddy wants to do mine with Duttons... :thumbsup:

 

[andy loveday]

Hi Randy

like the look, polished works for me, the chamfer would also help us uk boys get through the SVA test, no sharp edges, keep up the good work, Andy :thumbsup:

 

[Randy V]

Thanks for all the feedback and PM guys...

My friend did this for me as a favor on equipment owned by his employer.. I've sent him an email to see if he would be interested in doing more as I've rec'd many PMs asking about it.. I do know that he had to set it up for each hole independently.. The holes are basically two different sizes and he needed to set it up for each hole. The back cutting was probably more simple but I don't want to speak for him...

I'll check to see if he could/would be interested in doing more..

So right now - I think I'm leaning towards paint on the top grill and polished for the rears... I just may have to fabricate another top/center so I can have it both ways...

 

[Peter Delaney]

Have you thought about ceramic coating the panel - it ends up somewhere between polished & satin, will never need polishing & will withstand the heat for ever.

 

[egoman/ Shawn Wedge]

Paint and only paint will do the trick. The body lines will look cut up if these stand out. The other people only want them shiny so they will stand out but they are only a piece of the package. Another more sinister thought is they dont want your car to look better than theirs. Paint them and have your revenge.

 

[Simon]

I really like the satin black look on any colour car. Like Brett says...you doing a run of them?
Simon

 

[Dutton]

...I'll check to see if he could/would be interested in doing more...

So Randy - any word back from your skilled (and benevolent) friend? I have to believe there's a good market out here for just his kind of magic should he have a little free time and be inclined...

T.

 

[Randy V]

I've not heard back from him... I'll ping him again..

 

[bob peckham]

Hi, i might be able to help out with the cnc work , i found out that i have a customer that has a machine shop at his house with a cnc machine should know by the end of Nov. will keep you posted thanks Bob future rcr owner

 

[Brett James-McCall]

Hey Randy,
Any news from your friend? Obviously I am keeping my fingers crossed

Brett

 

[Randy V]

Brett - Guys,

Actually I did hear back from him last week but have been working so many hours I just forgot to update you all. His employer will not allow him to do any more work on their machines - however - he did say that he was going to try and get the programs to me in case anyone else could use them. Also the steps were not in .0005 increments, they were in .0001 increments..
I'll try to stay on top of it this time.