Toyota 4A-GE phenolic intake spacers?: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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May 6, 2009 9:08 p.m. ae86andkp61 Reader

Is anyone aware of a source of phenolic intake gaskets for the "bigport" 16-valve Toyota 4A-GE? (As fitted to Mk1 MR2, Corolla GT-S, Corolla FX-16, etc.)

It seems you can buy them off the shelf for 22R and several generations of 3S-GE, but I am having a hard time finding one for the 4A-GE. I emailed ATS Racing, Outlaw Engineering, and Gizzmo Electronics....does anyone know of someone else I can contact or any other place to look? Google searches turn up very little.

If all else fails, I guess I will buy a sheet of the raw material (expensive!!) and try to make one myself, but I am not confident that it will be either quick or of decent quality. :p Is it any different from machining soft metal, or is attempting this a bad idea?
May 6, 2009 9:30 p.m. erohslc New Reader

I used to work in a machine shop that did Bakelite (phenolic) parts. It's kinda like working dense plywood. You can work it pretty easily with hand tools, but mind the dust and fumes, they are 'not good'. I'd use a jigsaw to cut the outline, and maybe the ports too, else a holesaw. Keep the speed kinda slow, else it may sieze and crack, and use compressed air to blow away the swarf. If you can beg/borrow/steal a drum sander, then the edges will clean up really nicely, but hand sanding will do. You can probably knock it out in a couple of hours that way. Not sure where you are, but surplus places sometimes have the material pretty cheap (Skycraft !!!).

Carter
May 7, 2009 11:48 a.m. Dr. Hess SuperDork

Did you try the dealer?
May 7, 2009 6:39 p.m. ae86andkp61 Reader

Hess, the dealer has intake gaskets (in fact, I already have a Toyota intake gasket) but it doesn't offer any particular thermal advantage. I'm after an aftermarket part which will take the place of the stock gasket, insulate the ITBs from the heat of the head, and also space out the manifold a little bit, lengthening the intake runners for a torque boost.

Carter, thanks for the advice. I have access to a drill press, mill, bandsaw, and belt sander, but no jigsaw or drum sander at the moment. I have read that G10 or G11 Garolite is the best type for withstanding with the heat of the engine, but that it is tough to cut and that the dust can be real nasty for you, so I am currently leaning towards having one cut by a local machine shop with a waterjet cutter...just trying to explore and evaluate my DIY options before paying to have a custom one-off made.
May 7, 2009 8:04 p.m. Dr. Hess SuperDork

Oh, I thought it was an OEM part. You gotta remember that I've never driven a 16v motor. Pulled a couple and set them aside, but that's it. I think I was remembering the TVIS plate thingie.

You might look at some DCOE or DHLA spacer thingies. They may be very close to what you want for your ITBs. Personally, I just get the CAD stuff out, come up with what I wanted and bring it down to the chicken plant manufacturer to cut out with their waterjet.
May 7, 2009 8:30 p.m. ae86andkp61 Reader

Good thought...taking a quick peek on Google images it is hard to tell how close the Weber spacers are, so I will have to do some more poking around.

I still may end up just having a manifold->head gasket duplicated with a waterjet.
May 7, 2009 8:48 p.m. erohslc New Reader

Yah, if you can get them waterjet cut at good $$$, that's the way to go. Once you have the *.dxf file for the pattern, you could sell a few extra ones to recoup your investment.

What thickness?

Maybe the WJ can double or triple stack them, they usually charge by the linear inch of cut (because time == money).

Carter
May 7, 2009 8:59 p.m. Stealthtercel New Reader

You might want to check out a guy named daox at tercelreference.com. I believe he makes and sells something similar to what you're looking for, except for the 3E and 5E engines found in Tercels and Paseos. He's a knowledgeable and approachable guy in my experience, and if his stuff won't directly meet your needs I expect he will at the very least have useful advice for you.
May 7, 2009 9:07 p.m. Dr. Hess SuperDork

My waterjet place charges by the hour/fraction of an hour. The computer will guestimate how long it will take for the material and the tolerance you need. For example, cutting a flange pattern out of 040 aluminum takes a couple minutes. Cutting the same pattern out of half inch 304 plate takes an hour or more. They will cut me a test piece out of the aluminum before I go for the final run so I can make sure my CAD work is OK and make any adjustments to it. TurboCAD is my choice. I hate AutoCAD.

I'll bet that the Weber spacers will be real close. Get ones for whatever ID your ITBs are. It seems to me that the ITB makers tended to use the Weber spacing/holes as a starting point. When I was contemplating DHLAs on a 20 valve, I measured it all up and it looked like the DHLAs/DCOEs would just about fit exactly on the 20v ports. You might have to elongate the mounting holes, but if you start out with the right center size, it should be pretty easy. It still might be cheaper to have your own piece waterjet cut. For some reason, people think anything that has anything to do with a DCOE is gold plated.
May 8, 2009 11:52 a.m. Jensenman SuperDork

You might also look at motorcycle phenolic spacers. Lots of 4 stroke bikes had them to insulate the carb from engine heat.
Sept. 14, 2009 3:53 a.m. ae86andkp61 Reader

So, time to drag this thread back from the dead for an update. Apparently phenolic resin isn't recommend for cutting on a waterjet because they can start to delaminate or come apart or something.

After months of looking and asking around with no luck on phenolic spacer or any easy way to make one myself, I took a different route and picked up a nice sheet of fancy aircraft-grade Baltic Birch plywood:

Rather than trace the outline I needed, I just used an old intake manifold gasket as a template and dusted it with a light coat of spray paint. Sharp eyes will notice that this particular one is a smallport, and I am running a largeport, but the first one will probably end up going to a friend, and I will make another for myself.

I started with a guide hole in the center of each hole and from here slowly worked up to size.

I then used a hole saw for the ports and a coping saw to rough out the outside shape.

Further filing and sanding with a drum sander got it nice and flat and smoother in shape. The inside of the ports is still fairly rough because I want to get it on the head for a port match, so I am leaving extra material to work with for now.