Datsun Roadster Forum-311s.org

I’ll probably do that this weekend, but still the simplest way to avoid a serious mistake is buy the right sprockets and use correct SAE sprockets on the SAE cam, and metric sprockets on the metric cam.

Is there also a difference in chains with the two marks on it?
I tried to work according to the manual and it didn't work.
When the timing marks are opposite along in line, I would think cilinder 1 is in TDC.
If the mark on the gears are different between SAE and metric, how to use the marks on the chain?

3 vendors list the same chain for 1500, 1600 and 2000 lower chain. The online parts manual has one chain listed for 1600. Different part number for 2000.

Make that 5 vendors.

Curtis, Mechanically all the lower chains are the same. It was the use of shiny links on the chains that made for the difference in part numbers. I don't remember what the 1600 chain looked like, but the 2000 has shiny links to help with the "assembled position" to the dimples on the gears. The upper chain has them as well if it is a Nissan chain.

D-

My ones I bought before had the "bright and shiny captain" links on them. My new one I have now does not. I just looked at the photo in the service book and counted 8 and 1/2 links.

Curtis wrote: Fri Mar 11, 2022 11:24 pm My ones I bought before had the "bright and shiny captain" links on them. My new one I have now does not. I just looked at the photo in the service book and counted 8 and 1/2 links.

Yes 8 and 1/2 links works the best one both SAE and metric, cams look the same (lift and duration) except for the bolt thread.

All this time I thought the cams were different grinds but it appears from what I've found so far they are not, just the bolt. All the timing difference is apparently in the gears only. And the distributor.

Contact Delta cam in Tacoma and they can run them both through their equipment and tell you. They have always been cool, reasonable and helpful with me.

Gregs672000 wrote: Sun Mar 13, 2022 12:39 am Contact Delta cam in Tacoma and they can run them both through their equipment and tell you. They have always been cool, reasonable and helpful with me.

Richard has already provided me the info. SAE and metric cam grinds are almost identical. Only need to look at them side by side now to look at the lobe to key way position. If the lobe position is the same then all the change in timing is done via the gears and distributor it seems.

I have also been given much more info from people that know about the timing. I also learned about crevice volume gases and why timing was changed to clean up the exhaust. Explains one of the reasons why the top rings are much closer to the top now.

Here are the data sheets provided by Richard. He ask me to post them for him.

http://www.kendo-usa.org/datsun/datashe ... metric.pdf

http://www.kendo-usa.org/datsun/datashe ... 55_sae.pdf

That is cool data. Dave and I were just discussing if Nissan might have modified the grind slightly for emissions.
(Of course that is largely irrelevant unless you are running the full emission kit).

I did a quick measurement and it appears the cam key indexing is very similar for metric and SAE (within about 1 degree) using
a degree wheel. I’ll try to verify that this week using a DRO and completely different measurement methods. That will definitely
confirm/reject the quick measurement results since we’ll have fractional degree resolution.

There is still no question the sprockets are different, so I’m positive you would not want to mix metric and SAE sprockets.
J

JT68 wrote: Sun Mar 13, 2022 5:30 pm [snip]

I did a quick measurement and it appears the cam key indexing is very similar for metric and SAE (within about 1 degree) using
a degree wheel. I’ll try to verify that this week using a DRO and completely different measurement methods. That will definitely confirm/reject the quick measurement results since we’ll have fractional degree resolution.

There is still no question the sprockets are different, so I’m positive you would not want to mix metric and SAE sprockets.
J

Did you ever get a chance to do this JT? If yes, did it provide a different/better/etc. results?

Thanks,

For reference, I have a 3-main SAE R16 w/ SAE Performance #1 camshaft from DatsunParts.com, and the metric H20 forklift timing gears from Motive Power. Cam is installed, but not the timing components.

I've read this entire thread and the TechWiki articles multiple times. Unfortunately, it sounds like the only recommendation is all SAE or all metric. That means I need to purchase a metric cam as SAE timing gears are unobtanium at this time

Is it really not possible that the camshaft doesn't matter as long as both timing gears (crank and cam) are both SAE or both metric?

Yes? No? Maybe?

Pete: From what I remember, you HAVE to match the cam & sprockets (whether they’re sae or metric, doesn’t really matter).

ppeters914 wrote: Thu May 12, 2022 8:45 pm For reference, I have a 3-main SAE R16 w/ SAE Performance #1 camshaft from DatsunParts.com, and the metric H20 forklift timing gears from Motive Power. Cam is installed, but not the timing components.

I've read this entire thread and the TechWiki articles multiple times. Unfortunately, it sounds like the only recommendation is all SAE or all metric. That means I need to purchase a metric cam as SAE timing gears are unobtanium at this time

Is it really not possible that the camshaft doesn't matter as long as both timing gears (crank and cam) are both SAE or both metric?

Yes? No? Maybe?

Ross rebuilt my SAE R-16 with a Metric cam. Not sure about the gears, but he would know for sure. JT would also know for sure.