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$20 Delrin Plenum Spacers 3.0 V6

3981 Views 4 Replies 2 Participants Last post by  MC#4
I've seen a fair amount of interest in plenum spacers lately but at this point they are pretty hard to come by. kmperformance only does them in batches and its hard to organize even a few people to get them in a timely manner. I didn't want to wait so I bought a $20 piece of Delrin off ebay. Yes that piece cost $20 shipped. 1/2" thick.

I just layed it out by tracing the gasket. A very fine sharpie works great. (The piece in the picture is 2 5/8" x 24")

Then I drilled the holes out with a 1 1/4" hole saw. The actual hole is 1 1/2" but I didn't want to make them too big. I just made them the right size by "porting" them with a die grinder with a carbide cutter. Here you can see How I started to get the rough shape with a 90 degree cut off wheel.

After getting the rough shape down, I just went around it with the die grinder and smoothed it out. If you really want to make it nice, a dremel with sanding bands would do the trick.

I'm very happy with the results for the price. It does take some time if you want them to look nice. I've got about 3 hours in each start to finish but they could use some dremel work to make them look really nice.

If you decide to do this I would recommend Delrin or something that can withstand engine bay temps. There was a picture floating around on the Stealth/3000gt forums of a spacer made out of ABS plastic and it was completely melted! Delrin is a proven winner, Certain types of Nylon have been used as well as Wood. Steel and Aluminum could be used but you don't gain the insulating properites of the other materials which help keep the upper plenum cooler. Also it has been said many times that P-bodies can only take a 1/2" spacer due to hood clearance. Even with 1/2" you may have to remove some the the underhood "skeleton". Keep that in mind!
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General note, you want to make the port holes smaller than the gasket holes. They should also be smaller the the lower runners, but larger than the port in the upper intake.
If delrin is close to nylon (what I have used), you can get away without gaskets.
Sorry for the late response redrocks. I'm in snyder county pa. About an hour north of harrisburg. I lost my internet for two weeks right after I made this thread and missed all the notifications.

Anyway, I have since installed my spacers and am happy to report no hood clearance issues on my 94 shadow. I did however remove some of the underhood bracing because they were hitting my poorly mounted nitrous solenoids so it may not have cleared with all that crap in there. I ended up not putting any gaskets or sealer on the spacers and have not had any issues with it. I also noticed that no matter how long or hard I drive the car, if I pop the hood right after and touch the plenum it is DEAD cold. It will heat soak after a while with the hood closed however.
greetings hello brother .. I am very interested your work, but would like to know if you sell that material. or spacer over, or just show your work thanks
Thank you. Unfortunately I do not sell the material or the spacers. It was just a little project I did and then displayed here so others could see. The material is still available on ebay. Just search for delrin sheet and there will be many size pieces available.

Update: I've been running these on my car for about 5 months and have zero issues. I ended up not putting any gaskets on either side and no problems.
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