I'm in the planning stages of a rebuild on my stock silvertop. Due to some pitting in the cylinder walls it is going to require an overbore. Plans are pretty mild at this point, stock cams, already running megasquirt with edis. Future plans include cams and some port work. Must haves are a CR that is happy with pump gas (93 e-10 locally). The car is a second car that sees track days, autocross, and spirited street driving.

What do the minds of Club4ag have to recommend?

I have been working with Arias for the past six months to improve their designs and bring the absolute best possible designs to the table that we can.
While I can only match Paradise racings prices any support I can get for the hundreds of hours I have already put into this development process is greatly appreciated.

I also do fancy little things like calculate stock compression ratios to give you a more accurate info on the pistons range and also have a writeup on how to calculate your own compression ratios.

http://www.matrixgarage.com/products/ar ... n-20-valve

http://www.matrixgarage.com/content/4ag ... ormation-0


Now Arias doesn't currently have a high comp 20v piston but we have been discussing this and I should be able to get you something at the shelf price if we move on making a shelf piston that will suit your needs.
Otherwise I can always get custom pistons to suit your specific needs.

Now this is where it gets a little sticky.
Cam choice will dictate how much compression you can run and what piston will best suit your needs.
Doing pistons now and cams later will result in a very compromised setup.
To get a much more optimized setup you will want to start with picking a budget and power goal.
Next you will want to pick your cam and then your piston for the build.
If this is a truly optimized setup it will not work with a smaller cam as your compression will be too high.
I am currently working with TED and should have access to his full line very soon. If so I should be able to offer some tried and true badass cams. I am waiting on pricing right now but hope to be competitive with Kelford. I can also get Kelford cams who have some great 20v options as well.

Forgot about yoshi's site. Definitely support the people who support the 4ag platform

Forgot about yoshi's site. Definitely support the people who support the 4ag platform

Find out what the current Arias piston crowns look like. If they haven't updated them, if they look like the pics on the websites, then you don't want them. You can get better pistons from JE.

burdickjp wrote:Find out what the current Arias piston crowns look like. If they haven't updated them, if they look like the pics on the websites, then you don't want them. You can get better pistons from JE.

We will be spending more time on the shape if we do a high comp piston. For the 11:1 20v piston I really don't think that topography is going to have a big enough effect to warrant the additional 60% in cost.
I can get Arias, Wiseco, CP, JE, Supertech etc and can do custom designs but for someone looking for a little extra gain I don't think it's worth the $300 price difference. I can still get a fully custom Arias for less than the price of shelf CPs and definitely less than custom JEs.
Maybe at some point improving the shelf mid comp 20v design might take priority but I think it's pretty decent as it is. If you would care to share what you consider to be so bad about it I'd love to know.
I am going to see if we can do a high comp piston for ST and a separate one for BT so we can optimize squish and topography.

yoshimitsuspeed wrote:Maybe at some point improving the shelf mid comp 20v design might take priority but I think it's pretty decent as it is.

Just hand them a stock blacktop piston and have them do that dome on different bores. It's a beautiful design which provides decent squish on either head and makes for very economic use of material, so can be very light.