Datsun Roadster Forum-311s.org

Nothing wrong with an H20 - I like mine!

spl310 wrote:Not evil at all to use an H20 block. Of course, that would mean it is not a stroker...

Just bored?

Edit:
Steve, there was a posting of a full size template to tape on the piston and cut clearance in the R16 piston skirt, As Sid mentions below, it's in the Bob Sharp manual.

Not the wiki, the Bob Sharp Manual that is available on datsun.org

Thanks for the info. I read Bob Sharp's Competion Manual and the use of R-16 pistons. I am concerned about 12+ to 1 compression. I would like to end up with a driver, not necessarily a full blown racing engine. My current R16 has been punched .30 over and was rebuilt in 1998. Prior to my purchase, it was last registered by a dead guy in 2001. So there is probably very little wear on the internals. I'm just thinking that 12+ to 1 compression ratio is too much for the crappy gas I buy at the SAFEWAY.
What is the volume of an r16 Aluminum head?
What is the volume of the U20 flat top piston?
What is the volume of the H20 dished piston?
What is the Volume of the R16 domed pistion?

Thanks

Steve

What is the volume of an r16 Aluminum head?
Combustion chamber volume on 2 heads I measured ranged from 47 to 50 cc on each of them.
1) 46.7, 49.5, 50.0, 48.9
2) 47.0, 49.0, 49.7, 47.3

What is the volume of the U20 flat top piston?
Flat top piston. Volume is 0.00 cc.

What is the volume of the H20 dished piston?
????

What is the Volume of the R16 domed pistion?
Working backwards with all other info an online calculator, I remember it being somewhere near 6cc.

To accurately calculate what your compression ratio will be you ned to know what your deck clearance will be. Stock parts and block will likely leave you below deck height by a significant amount. Taking .010" - .040" off the block deck can significanly raise your compression.

I think the 12:1 compression is for the U20, I didn't see any mention in the comp prep manual using a stroker crank and stock 1600 pistons in the R16. If it was otherwise stock what do you get.......

Using a piston volume of 10cc (probably closer than 6... ), below deck of .020"(?), and a gasket thickness of .050", cylinder head volume of 49cc, gasket bore of 3.49", with standard bore and stroke (3.433" x 2.63"), I get a compression ratio of 9:1. Increasing the stroke to 3.2678 brings it to....10.95:1... Don't know what I did the other day that only made it 10:1......?????

Easy enough using the flat top pistons to get it into the 9.5 - 10:1 compression ratios, skim the head and or deck the block.........

Thanks Millions for the info. I think I will be using flat top U20 pistons. Depending on the cost of course.

Steve

I seem to remember reading that the dished H20s are 5.6 cc.

tim

Poobah wrote:Thanks Millions for the info. I think I will be using flat top U20 pistons. Depending on the cost of course.

Steve

Yeah, it may be worth it to have custom pistons made using modern materials and ring technology. That's what my machine shop guy and several others are saying.

Due to ongoing problems over problems, I have to tear down my own engine (thats the short story) and have another engien relatively local that I can get my hands on. I am debating what to do next. On one hand, I would just like to drop another 1600 in and get the car running. On the other, if I have to tear down an engine, maybe its worth building a stroker??? I have a local friend that would help with the tear down and re-build. Plus, I got a lead on a brand new NISMO crank

Why not both? Drop the running engine in the car and rebuild the other at you leisure.

shifty wrote:Why not both? Drop the running engine in the car and rebuild the other at you leisure.

Im not sure of the cost of the build.

And, the one that has to come out may have head and/or block damage.

Time to do the R16 turbo! Was talking to my friend Steve the other day, giving him the stroke of the U20 so we could add that to our cam selection data. He got very excited when I told him the stroke of the R motors. He said with a bore and stroke like that you could build a very high reving, fast responding motor. Short stroke motors have some real advantages I gather.

BTW, custom pistons costs are going through the roof per Steve, so keep that in mind.

Gregs672000 wrote:Time to do the R16 turbo! Was talking to my friend Steve the other day, giving him the stroke of the U20 so we could add that to our cam selection data. He got very excited when I told him the stroke of the R motors. He said with a bore and stroke like that you could build a very high reving, fast responding motor. Short stroke motors have some real advantages I gather.

BTW, custom pistons costs are going through the roof per Steve, so keep that in mind.

I was going to go NISMO stroker crank, and H20 pistons and rods.

If you need a 5 main block to play with, I have two in the garage...