WANTED 6 x 7.5 x 16" machinable plastic block!!!

[BlownV6]

Help!! Im trying to build a set of billet stage 2 heads for my dragster. We are making a lot of changes to the original version and should have a program ready here in a few weeks. Im looking for a chunk of plastic or something machinable that we can easily machine and check everything out before final attack on my billet chunks of aluminum. I have been checking various places around here and either having no luck or getting prices that I really dont want to spend.

Anyone have access to anything or any info that might help me out would be appreciated greatly!!! Thanks Mike

 

[87 Pete]

My company cnc-machines plastic prototypes and it is difficult to find any plastic stock thicker than 2-3" thick.

You can either laminate a plastic like ABS, or try machining it out of round stock, i.e. 8" diameter and you order it by the foot.

McMaster-Carr has a good variety of plastic but it looks like ABS and delrin round stock maxes out at 6" diameter, so you would have to use 8" dia. acrylic.

You also might try machinable wax, but again, it's tough to find that thick.

Pete

 

[Phatman]

Check around with you friendly marine supplier...
I've used a product called starboard, but I don't know if you'll find the thickness your looking for. You may have to bond pieces together. They make numerous types of it.

Custom Creative Plastics - design and fabrication of Acrylic Store Displays - Shoe Stands

What ya got in mind Mike, starting with a clean slate?
Maybe raising the ports a little....

 

[BlownV6]

My company cnc-machines plastic prototypes and it is difficult to find any plastic stock thicker than 2-3" thick.

You can either laminate a plastic like ABS, or try machining it out of round stock, i.e. 8" diameter and you order it by the foot.

McMaster-Carr has a good variety of plastic but it looks like ABS and delrin round stock maxes out at 6" diameter, so you would have to use 8" dia. acrylic.

You also might try machinable wax, but again, it's tough to find that thick.

Pete

I have located plastic in this size at Alro steel. Problem is its in giant sheets that they would have to cut. Price is about $385.00 I dont think I paid that much for the billet blocks a couple yers ago!! I also found machinable wax that I can get for $175.00 which I could live with but were not sure exactly what the final product would feel like and how it would hold up! Maybe you have some experience with it. If we machine a head will we be able to handle it and bolt it on a block and bolt valve train to it to see how it all looks??? *" round will not work , the block side of head is 7.5" and the intake side is going to be about 5" , you cant get there with a 8" dia. bar.
Mike

 

[BlownV6]

Check around with you friendly marine supplier...
I've used a product called starboard, but I don't know if you'll find the thickness your looking for. You may have to bond pieces together. They make numerous types of it.

Custom Creative Plastics - design and fabrication of Acrylic Store Displays - Shoe Stands

What ya got in mind Mike, starting with a clean slate?
Maybe raising the ports a little....

How would you laminate this together?? Yes we are moving a number of things!! Goal is to achieve a 400cfm intake port , most stage 2 are about 310 to 315cfm. Gotta do something to catch Duttweiler Mike

 

[Mike E]

What about a big chunk of hardwood? I've heard the leftover fibers are bad for the ways and coolant system, but the price is right.

 

[87 Pete]

I also found machinable wax that I can get for $175.00 which I could live with but were not sure exactly what the final product would feel like and how it would hold up! Maybe you have some experience with it. If we machine a head will we be able to handle it and bolt it on a block and bolt valve train to it to see how it all looks??? *" round will not work , the block side of head is 7.5" and the intake side is going to be about 5" , you cant get there with a 8" dia. bar.
Mike

Yeah, you are in a tough spot... wax and most plastics won't hold up too well if you start bolting valve train parts to it, especially if you plan on moving them.

 

[BlownV6]

Yeah, you are in a tough spot... wax and most plastics won't hold up too well if you start bolting valve train parts to it, especially if you plan on moving them.

Really would just like to be able to bolt it to a block (so it doesnt move or fall off) and just bolt the valve train to it with very light checking springs , just to confirm valve train geometry and pushrod location/clearance. Nothing would be even tightend up very much , defenetly not even torqued 10#.
Mike

 

[injdinjn]

Couldn't you make a mold and pour your own plastic block using resins?

 

[steve hughes]

Mike did you check for drops or cutoffs at Alro. It changes daily. If you can't find a piece big enough you could glue them together and maybe drill through the layers and dowl them together with plastic rod. You might also check Mendelson's if you have a few hours to waste looking.

 

[BlownV6]

Mike did you check for drops or cutoffs at Alro. It changes daily. If you can't find a piece big enough you could glue them together and maybe drill through the layers and dowl them together with plastic rod. You might also check Mendelson's if you have a few hours to waste looking.

Steve, Were on the same page. First place I checked was alro for a drop but they had nothing even close. Im planning on hitting Mendelsons today but you know how that usually goes. Alro gave me a price on cutting a new piece of $385 so Im holding that as a backup plan. How would you go about glueing the plates together?? I may hit alro again and find out that answer. Mike

 

[Phatman]

How would you laminate this together??

They make adhesive/glue that I have used, worked damn good, but then I wasn't chucking it up in a cnc machine. It may be worth a phone call to talk with someone better suited to answer your question in regard to densities and bond-ability.

Good Luck....

 

[steve hughes]

Mike you might also browse ebay. I have also heard of a place called Laird Plastics. I'll talk to some of the drivers at work tonight and see if i can find any other places for you to check.
Different types of plastic will require different bonding agents. Can't help with recomendations there. I don't know much about plastics.

 

[BlownV6]

Mike you might also browse ebay. I have also heard of a place called Laird Plastics. I'll talk to some of the drivers at work tonight and see if i can find any other places for you to check.
Different types of plastic will require different bonding agents. Can't help with recomendations there. I don't know much about plastics.

Went to Alro again , Mendelsons and Laird today. I have been checking various ebay items but nothing that will work yet. Im patient!! Mike

 

[BlownV6]

After 3-4 days of searching for some kind of plastic block with little luck , I decided to check on aluminum for the heck of it. I ended up buying an aluminum block for nearly half of what the plastic would have cost!!
So I guess if the program is spot on I will pretty much have an extra head for a usable spare. Thanks for all who tried to help!!! Mike

 

[The_Six]

I was watching OC choopers last night and they laminated a block using plywood and then made a prototype.

 

[chopped39]

check out usplastic.com

 

[DR BOOST]

you can make your own block out of two part acrylic.