cutting front bumper for intake air..tips, ideas??, like to preserve the chrome finish.... Options

[Mueller]

well, I broke down today and ordered the Renegade Hybrids radiator and hose kit, so now I'll have to cut a hole in my front '74 chrome bumper to get some air into the front trunk.....

sawzall seems like it would be too ragged and I don't think my air nibbler would be able to cut the metal due to it being too think

[skline]

I would pick up a black bumper and cut that one instead of the chrome one. Or pick up a fiberglass bumper, maybe the GT one with the front lower valance also. Save the chrome one since they are so hard to find.

[Trekkor]

Drill 4 corner starter holes. Mark your cut out with blue tape.
Use a jigsaw or even the 'Zall with a high quality blade. (IMG:style_emoticons/default/sawzall-smiley.gif)
10 minutes max.
File it out. You win (IMG:style_emoticons/default/smilie_pokal.gif)

KT

[SirAndy]

Save the chrome one since they are so hard to find.

(IMG:style_emoticons/default/agree.gif)

[bondo]

Pound some big dents in the part that you're planning to cut out, then it won't be such a loss (IMG:style_emoticons/default/smile.gif) Have you considered a plasma cutter? They cut without heating up too far from the edgs, dunno what it would do to the chrome tho, maybe you could try it on some chromed scrap. Besides that, my only other thought would be an air body saw. (with lots of tape on the part you're keeping so the foot of the saw doesn't scratch the finish)

[boxstr]

The fiberglass bumpers on the market today take alot of work to try and fit. I would cut my opening in the wall area behind the bumper a little larger and then just cut the front lower valance, leaving the bumper as is.
I have done alot of research on this and this is the way I will go with JLO.
CCLINGOWITHTHEFLOW

[Mueller]

chrome bumper is staying, had the 'glass (carbon fiber actually) bumper before...no thanks (IMG:style_emoticons/default/smile.gif)

I had not looked at the valance area too much, I like that idea...besides with my smaller motor, I won't need the cooling like I would with a HiPo V8 motor

[boxstr]

The fans are going to do all of the work. What about the times you are sitting at a stop. No airflow. Fans will kick on when needed. I have a thermostatic control and a flip switch if needed.
CCLINKEWLDADDYO

[Mueller]

I need to call Scott and ask him about the ducting for the hot air....i currently have a big @ss hole in the front trunk for the dealer installed A/C, I have a new (used) trunk floor to use if it would be worth the effort to do so....

[BIGKAT_83]

Here is a picture of a car I found on the internet. The opening in the bumper is smaller than most you see,but if you look you can see that the area around the valance is opened up.

On a good hot day this summer I took my V8 car and covered up my air intake on the bumper and ran in traffic and at highway speeds to see just how small of a hole was really needed.
With a intake opening of about 50 sq inches I could cool fine. I would stop the car and turn the fans off and let the engine get in the 220 degree range and then drive at 55 mph with no fans. It would start to cool down as soon as I started moving and in less than a mile would be at 180. (thermostat)

On my new LS1 914 project I'm going to start with a opening no bigger than a 914 GT oil cooler valance and bumper. Its always alot easier to go bigger than it is to go smaller

Bob

[John2kx]

I faced the same challenge with a freshly rechromed bumper. The results turned out well using the method mentioned (drill a hole at each corner, tape the outline to prevent scratching..........I used a air powered jig saw to cut out the remaining material........no scratches).

John

[GWN7]

I think someone will have a painted one for you to cut up...wasn't there a pile of them sitting outside HPH in one of the pics from there?

Cutoff wheel, tape the outline.

[Rusty]

This would be my plan, if I wanted to cut a chrome bumper.

Tape down the surface you want to cut. Draw your lines on the tape.

Cut the lines with a dremel. Just cut through the chrome surface and into the steel a bit. That should save the chrome from major flaking or chipping.

Then, cut over the same lines with a larger cut-off wheel to actually make the hole.

If you're not comfortable with this idea... do you have a shop in your area that specializes in repairing chrome bumpers? Maybe if you call them, they have a favorite method for custom fabbing stuff.

Hope this helps,
-Rusty (IMG:style_emoticons/default/smoke.gif)

[serge914]

I had the same concern and decided not to cut the bumper. Just the GT fiberglass valence seem to get me enough air flow.

[Slowpoke]

water jet (IMG:style_emoticons/default/wink.gif)

[seanery]

I'd try Serge's method and if that's not enough then I'd cut a matching hole in the bumper. If you scratch it just send it out to get rechromed.

[Mueller]

I'd try Serge's method and if that's not enough then I'd cut a matching hole in the bumper. If you scratch it just send it out to get rechromed

...wow, very clean look, I like it....I'll try that one first !!!!

[andys]

I'm in the selection process as well, to determine what exactly to do with the front bumper/valence/spoiler on my V8 conversion. That said, I would like to ask anyone that has a good picture of the 916GT front bumper WITH the oil cooler cut out on a completed and painted car (4, 6, or V8). Since I'm converting a '75, I can go any direction.........maybe some posts of all the various front treatments would be nice. I would greatly appreciate it.

Andy

[andys]

ttt

[Mueller]

for a bunch of pictures of GT front openings, try here:

Jon Lowes 914/6 GT Resource Page