Prophet7000

During my rebuild I purchased most of the standard things (ie Banzai oil pan brace, IRP SS OMP lines etc), but I refused to shell out the money for poly motor mounts.

The choices:

Banzai Racing - $250 for the mounts for the 1 aluminum/1 steel arm setup or $130 if you already have 2 steel arms (I had a stock aluminum one). My worry was that I've heard reports of people having vibration issues, but I don't know if that's actually true as I've had no direct interaction with their product.

IRP - I was quoted $200 for mounts made to work with 2 steel arms. I thought these were an attractive option since they have a poly puck under the subframe to cut down on vibration.

Garfinkle? - I've seen some pictures of blue nylon ones that I believe are made by Garfinkle but they weren't out when I was ready.

DIY - I could make my own with a puck for a lower price with an order to McMaster and the purchase of a steel motor mount arm.

What you need

McMaster:
Amber poly rod, 3" diameter, 6" long, 80A durometer (you can buy softer or harder) - $55.40 (8784K983)
Amber poly rod, 1.5" diameter, 6" long, 80A durometer - $21.18 (8784K923)
Jumbo washer, 3/8" screw size, 3" OD - $5.32 (98264A275)
Large washer, 3/8" screw size, 1.5" OD - $8.53 (91525A140)
2 3/8" bolts approximately 4" long plus 2 nylock 3/8" nuts (local hardware)

Optional: Steel motor mount arm (I got mine from Japan2LA)

Tools: Drill press and bandsaw

Walkthrough

You first need to decide how thick you want your mounts. My measurements put the stockers at 2.25" thick. To offset the rise caused by my 3/8" thick Banzai oil pan brace, I cut the 3" poly rod to a depth of 2". Word to the wise, this is easier said than done than on a bandsaw. My suggestion would be to practice cutting in the middle of the rod then when you're ready, cut your mounts off of the ends of the original rod (since the ends are already clean cuts from McMaster). Mark all the way around the rod with a marker and take your time. Next, cut pucks out of the 1.5" poly rod for placement under the subframe. I cut them to .75" thick. Then, drill 3/8" holes down the center of the 3" and 1.5" poly rod pieces with a drillpress. After assembly it should look like this:



During installation you should put a dab of sealant between the large poly and its lower washer to stop the washer from simply falling off the bolt. I torqued the nylock nut so everything was in contact, but I didn't follow torque specs due to the fact that it would crush the poly and increase the chance of transmitting vibration.

Final total: $90.43 + shipping and optional steel motor mount arm

Ride quality

When everything was assembled, I was actually quite worried due to the fact that the engine was rock solid (I guess I was used to the movement with my blown OEM motor mount). Thankfully, after putting 200 miles on the mounts they have been completely vibration free from mile 1. Very happy with the results.

Dudemaaanownsanrx7

iTrader: (23)

Awesome job. I did something similar for differential mounts. Worked out really well.

IRPerformance

iTrader: (41)

Good try for a DIY job. You won't be able to get a good cut on a band saw. I tried many times and it is very difficult to get a straight cut without deforming or melting the material. I machine the poly to the size I need.

t-von

iTrader: (8)

Hmm I think a miter saw and multi purpose cutoff wheel should cut this stuff pretty good. The disk will also sand while cutting. This is actually what I used for most of my cutting on my 20b project.

BluRR

iTrader: (1)

What about solid aluminum mounts. See them on ebay for fb and fcs for like $40-$70. How come now one has one for the FD there and cant the ones from the FC be used anyway providing it the right height?

MR_Rick

iTrader: (7)

Solid mounts are just that, SOLID MOUNTS. They don't reduce engine vibrations. I don't like my filling shaking off my mouth or have to yell at my passenger because it is loud inside the cabin.

I did this about 6 years ago and I still think it is the way to go.

BluRR

iTrader: (1)

Yeah I know they are SOILD mounts..I never been in a car with solid mounts, so I wanted if the vibration is too much for street use

MR_Rick

iTrader: (7)

Trust me, it is annoying. I was only able to put up with it for less than a day. I put them on, started the car and I couldn't stand it. Drove the car to the end of the street to go back and put the stock ones back on.

Prophet7000

Well I did get a good cut as my picture shows. First off, I ran the bandsaw as slow as possible. Then I started with a very shallow cut around the circumference as a guide. Finally, I cut in one direction until I felt like it was starting to bind and turn at which point I backed out and started from another direction.

I did say "easier said than done" and I'm sure there are better ways, but this method did work for me with the tools I had on hand.

Force13B

iTrader: (19)

How long did it take you to make these?

Prophet7000

The actual cutting, drilling, and assembly only took about an hour. Getting the right parts and having a working engine to bolt them up to is the hard part.

tom94RX-7

iTrader: (5)

i just ordered the himni-racing poly mounts made to fit the stock steel and aluminum mounts so I dont have to get another steel mount, saved $45, I dont have to bother making them, and they only $105 shipped. It seems like a great deal. I cant imagine them being much different than the others, but I will be sure to post some feedback on them after I get my rebuilt motor back in the car. I bought them on ebay and they had all good feedback on ebay from the other buyers who bought these for their FD.

Prophet7000

When I was shopping around I actually seriously considered them. The only reason I didn't was the lack of feedback I could find for the FD ones (there were only a couple of guys running them that I was aware of) and I felt a design utilizing a puck under the subframe would best match my needs.

I also kind of wondered why Mazda stopped using the aluminum one and basically all of the other companies modify them for use (if they'll even use them at all).

tom94RX-7

iTrader: (5)

ya i know I was suprised there has not been any talk about them on here. It seems like a good cheap option, hopefully I am happy with them. Their communication has been good, they emailed me back and said I just have to get all the rubber off the aluminum mount bracket and drill a hole, they are made to fit perfect after that.

Prophet7000

Well when you get them installed come back and give us your impressions after a few miles.

tom94RX-7

iTrader: (5)

ya I will. Good job on the writeup.

Dudemaaanownsanrx7

iTrader: (23)

The Polypropylene rod can be found quite a bit cheaper if you search around. I've seen it for around $10 ft for 3" diameter. When i purchased mine i got an assortment of different sizes for like $25, probably close to 4ft worth in different diameters. It turns down real nice on a lathe, itls actually kinda fun to turn it down.

hwnd

iTrader: (4)

Ever tried with high tooth count blade for softer metals?

Prophet7000

Well if you've got a cheaper source, link it up man! If we could get poly rod for significantly less than what I paid then people could save some serious bucks.

flaco

iTrader: (7)

i got the solid ones for 45 bux shipped

Prophet7000

But the big question is what is the ride like? Do you still have your fillings?

tom94RX-7

iTrader: (5)

Here is some pictures of the Himni Racing motor mounts and the drivers side aluminum motor mount bracket with a hole drilled and the rubber taken off so the Himni racing mount fits good on it, all this was easy to do, a drill press makes drilling the hole easy.

Banham

Just got the Himny ones myself.

To me they seem very hard, and I fear they will transmit alot of nois and vibration.

I made a set of poly engine mounts earlier this year from durameter 90 poly. and this worked quite well with only a small amount of vibration.

A while afterwards however my diff started making horrible noises, and it turned out that the drive axle was out of balance. After replacing all bearings in the diff and not wanting to repete it soon again I decided not to trust the home made engine mounts. Measuring the Himny mounts they are same hight left and right, while my left one was 1/5" longer.

This might have contributed, but probably I also had the drivetrain misaligned.
Anyone experienced similar problem?

Only hope Himny got the hight right

tom94RX-7

iTrader: (5)

Ya they are very hard, like solid. Are the other poly mounts this hard? Was the 90 poly alot softer? Mines not a daily driver so it won't be that big of a deal if there is a bunch of vibration, but I hope it's not bad. I will know in a couple weeks when I get the rebuilt motor in.

Dudemaaanownsanrx7

iTrader: (23)

I don't think it was your mounts. Many people have one or both of the stock mounts fail and don't fix them right away. Some of the aftermarket mounts cause the engine to sit a little higher. Ppf's fail, differential mounts fail and rarely do i hear anyone with differential problems. Maybe your bearings got too hot, the oil was low or contaminated, metal fragments, or maybe just high miles/hard life.