1975 Plastic fantastic aka Corvette

[Bob Holmes]

That vehicle was beat on a bit.

[SuperBuickGuy]

That vehicle was beat on a bit.

it will look fondly back to those days when I'm done with it....

but the frame isn't cracked, it hasn't been wrecked, and there's no rust in the frame...

next up is poly bushings and figure out why this thing is wandering (beside the nose-high springs)

[Bob Holmes]

If you're really going to beat on it, I'd suggest Delrin (really, you should go with rod ends). We squished a set of polies in 12 track weekends. In a Miata!!!

[SuperBuickGuy]

delrin isn't cheap - how much would I hate aluminum bushings?

[Bob Holmes]

If its only track driven, you'll probably really like them. If you intend to drive it on the street, not so much.

[Beagle]

http://www.ebay.com/itm/ACETRON-ACET...item4cef051c22

acetal / delrin is pretty cheap this way, so is aluminum. Del/Alum ala Global West I believe? They're both soft and easily machined.

[SuperBuickGuy]

knowing its derivative term "acetal" helped me find a supplier in Seattle.... thanks

The supplier charges $8.00 a foot....

[Bob Holmes]

I am told, by a guy that should know, that UHMW would make the best bushing material. I just can't find anyone that has bushings made out of it. Of course, I should just make my own.

[SuperBuickGuy]

I am told, by a guy that should know, that UHMW would make the best bushing material. I just can't find anyone that has bushings made out of it. Of course, I should just make my own.

sounds like a challenge and test.... I'll buy some and post up what happens.

[milner351]

Do you have a lathe to build your own bushings? That would be flippin sweet.

[SuperBuickGuy]

Do you have a lathe to build your own bushings? That would be flippin sweet.

I do... 12x36 grizzly (see prior posts about buying this beastie)

and I found this.... interesting stuff
from USPlastics.com

What is the difference between the Acetron GP and Delrin?
The Acetron GP is a copolymer acetal. This general purpose acetal is the only porosity free acetal product available. This allows it to provide the performance and machinability of acetal without the center core porosity.
The DuPont Delrin is a homopolymer acetal. It has slightly better mechanical properties then the Acetron GP acetal but may contain a low-density center, especially in larger cross sections.

So that means that Delrin is for Miatas?

[milner351]

Sounds to me like I need to get you the dimensions of the spring eye bushings and some $ for material and shipping ;-)

[SuperBuickGuy]

Sounds to me like I need to get you the dimensions of the spring eye bushings and some $ for material and shipping ;-)

I ordered the UHMW, so I should have plenty

One thing to keep in mind, the Corvette has no suspension parts that move in 2 planes, so using solid bushings isn't a problem - that could be a real problem for the Falcon because, beside vertical compliance, the spring has to twist too. Since you have such short springs, putting solid or relatively solid bushings may not be optimal.

Interstateplastics.com was cheaper by a bunch for UHMW

[Bob Holmes]

Delrin is a trade name.

It'll be interesting to see if you can machine the UHMW. My understanding is that it is a bit gummy.

[SuperBuickGuy]

Delrin is a trade name.

It'll be interesting to see if you can machine the UHMW. My understanding is that it is a bit gummy.

as is acetal

I asked my dad about using UHMW for bushings, he thinks its a good idea - and he's been machining it for ages. The only issue he brought up is the 180 degree temperature limit - the underside of the car does get pretty warm, and many bushings are near exhaust.... it melts at 273. What he said is it gets gummy at 180 then eventually cracks.... but it takes years to get there (he uses it for a myriad of things, but in this case it was on a commercial dishwasher as a door guide - they cycle to 180*). Also, on one of the sites it said to be sure a keep your material at less then 73* to avoid problems with machining - I wonder if what you said is the problem they're implying?

Also, there are different types of UHMW, one is more brittle then the other - and you can get specialty mixes like oil impregnated