9,000 rpm?

[testingtesting]

Do datsun spirit still use Kameari parts?  they look exactly the same still.  should mean that they're well proven parts.

[DuffyMahoney]

I know their valves aren't Kameari.  Maybe their springs?  

[testingtesting]

Pistons look exactly the same plus loads of other bits.  Didn’t they use to call their engines spl also? I know they use to sell Kameari parts.

[Tony D]

On 11/20/2020 at 1:44 AM, AydinZ71 said:

I might be wrong, but I also recall the shorter stroke on a stock L24 contributes to better reliability at higher rpm’s? Typical high-rpm engines run larger bore and shorter stroke for that reason. Less rotational inertia? 
 

once you start modifying crank, rods, bearings, Bolts, etc. then the L24-L28 trade off probably diminishes. 

Yep, you would be wrong. At least you're open to that idea. There is no reason whatsoever why an L28 isn't an 8,500-9,500 powerplant same as an L24. No "large bore" necessary, we were limited by class rules to no more than 3.0 and if anything we would have stroked it for power more than bore it.
The L20A was pretty much capacity classed at 1998CC, needed stock bore and stroke on that one, and it went to well over 12,500 without any valvetrain issues whatsoever.

The limitation is breathing ability of the head N/A moreso than anything in the bottom end. That's benchracing in the extreme.

We built both the L28 and the L20A in a home garage in Clairmont, CA. The head work was farmed out, everything else save the balancing (which was done by Electronic Balancing in Long Beach, just down the road from the old Datsun Alley and with a nice view of the C17 taxing area at Long Beach Airport)... Fitting the pistons to the combustion chamber, pre-balancing weight matching, deburring, polishing or grinding internals, etc... all done at home with Sears Craftsman Tools and whatever I and Andy had kicking around our tool boxes.