Datsun Roadster Forum-311s.org

Which pistons are used to build motors, and which brand(s)/what specs are desirable? I know this will normally depends on what the build is, but some general info would help.

As a store/shop, we are doing a bulk purchase with CP pistons, and I wouldn't mind picking up a set or two for the R16.

Thoughts and discussion are much appreciated.

I am putting H20 forklift pistons in my stroker.
tim

Garm,

What's the aim of your game? If it's full race, speak to Nick Diblasi at JE Pistons. That's what I run.

Bill

The aim of my game is to keep my shop open. I'm considering a purchase with CP pistons, because I can sell several sets to my other customers. And I might want to have a set on hand for any rebuild (or race build) I do.

So my question was, what are people using and is it worth it to stock a couple of sets for Roadster owners?

Seems that each build is so unique, it may not be possible to pre-stock pistons. But worth a discussion, I think.

Seems that each build is so unique, it may not be possible to pre-stock pistons. But worth a discussion, I think.

I think you have this part right. Pistons for a roadster are going to be a custom order so you have them made to what you need for your specific application. If your having pistons made to set block, head and cam specifications then you can build engines to fit the pistons. Race engines have modified heads, blocks and cams so pistons will be specific for those builds. I've used both J&E and CP with good results. I've also had them make me pistons where I do the final machining. One word of caution is that the manufacturers like to move the ring package up on modern pistons. You need to specify where this should be on you roadster pistons especially if you need eyebrows for a high lift cam and use a decked block. Otherwise, the ring package may be too high if you don't warn them. I hope this helps.

Mike

Are the H20 pistons dished? I would think this would lower compression quite a bit.

Ross
sports imports

Don't remember, I would have to look when I get home.

Can the compression lost to dished pistons be compensated for by removing block or head material? Clueless minds want to know. (sorry to hijack the thread!)

tim

H20 Pistons are dished for sure... Not sure how much though.

Datsun.David wrote:H20 Pistons are dished for sure... Not sure how much though.

Mine were flat topped.
I decked the block and it was smmmmoooooth across!

Hmmm... I stand corrected. I think that they come both ways. I'm sure that that was why I didn't buy them when I rebuilt my old 69...

dw

Garm,

Mike's got it right....when building a race motor, you're talking hand built and precise clearances. Final machining is a prerequisite; there is no one size fits all.

That said, you've got to start somewhere and JE and CP have 1600 and 2000 designs. Similarly, I have old race pistons from Arias, Venolia and Cosworth.

I can only speak to the 1600. The issue with that design is the rather tall compression height. Manufacturers have wanted to raise everything up for lightness. The only way to do that and run in the 1600 is to lengthen the rod (already 6.0") and changing rod length is illegal in SCCA so that is a non starter. When I talked with Wiseco, their blanks weren't long enough to even work with.

But to build a 1600 race engine, start with the Sharp 1600 manual. [Likewise, to build a 2L, start with the Sharp 2L manual.] You will learn what it takes in terms of machining the head to accept the piston pop-up and fly-cutting valve pockets in the pistons for the valves and such. The JE design has the compression height that Sharp achieved by decking the block. When you think about it, Datsun designed the spherical head and dome piston pretty well and the Sharp manual tells you how to pump it up, while staying basically stock. To go beyond that does get unique and pricey, but also purpose built to race.

Hope this helps,

Bill

That helps a ton. Sharp 1600 and 2L manuals can be found where? ...seems, like a good reference, should be posted into the thread.

I've got a link to the 1600 version somewhere. Not sure where but do have it. If nothing else, I have a hard copy I can copy and mail if no one gives a link.
tim

1600 and 2000 Comp manual can be accessed through
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..................................................................you guessed it
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........ The WIKI.....................LOL


Search Manuals...go to the bottom of the page.
click on Comp Manuals.....
Go to the bottom of the page and download them...


easy pizzy

The wiki has everything!