Datsun Roadster Forum-311s.org

I have a quick/small/stupid question. On the (driver's side) engine block surface there are small numbers stamped along one side, they are 2,2,3,3, as listed front to back. I'm not as much concerned about the meaning of the numbers as I would like to know since they are still present that would indicate the block has NOT been machined/decked? This would be helpful when I do take the block to the machine shop then I will know exactly how much is machined off from stock. Combining that information with the measurement of the head will help me choose the correct head gasket. Thanks!

Factory stamping to indicate what piston to use in the bores.
They use a grading system during initial assembly.
Their presence would indeed indicate an untouched block.

Nissanman wrote: ↑Tue Jan 24, 2023 7:07 pm Factory stamping to indicate what piston to use in the bores.
They use a grading system during initial assembly.
Their presence would indeed indicate an untouched block.

That's great news, thank you for confirming that for me! It all makes sense now since there are also stampings on the top of the pistons, indicating 2,2,3,3.

Irrelephant

Daryl Smith wrote: ↑Tue Jan 24, 2023 8:57 pm "... then I will know exactly how much is machined off from stock."

Not sure how you are getting that figure as I've looked over the years and NEVER have seen a published figure for the block deck height....
I know from calculations and measurements it is around 227 mm, but, have not seen an official figure.
If you have that, I would sure like to know where you found it...?

Sorry for the confusion. What I meant is that I now can confirm that the block has never been machined/decked/re-surfaced. It is stock block, stock deck height, whatever that measurement may be. (My block deck height measures 11.125 in. or 282.575 mm.) I thought I saw the value listed in the Tech Wiki section somewhere??? So now when I take it to the machine shop they can tell me how much they actually do machine off the block surface, ie: .010 in. or .020 in. Then after the head is machined I can measure the head deck height (Standard (uncut) Head Thickness 3.246 in.) (Minimum Head Thickness (cut) Before Significant Issues (-.060 in) and then calculate the overall differences so I can choose the correct head gasket to maintain compression ratios. Hopefully, this makes more sense now.

Irrelephant

Daryl Smith wrote: ↑Tue Jan 24, 2023 9:52 pm
Block "deck height" is measured from the center of the crankshaft....and should be very close to 227 mm or 8.937" for the R16 engine.

You are probably correct, I just measured from the bottom flat surface of the block to the top. I DID NOT measure from the center of the crankshaft as the engine is completely disassembled. I could probably eyeball it, but I'll just take your word.

Not a lot of gasket thicknesses to choose from, you might want to check with the vendors, if you have more than one to choose from I will be surprised.
You could get one special made ...maybe...

I believe there are a few options with the vendors, I would just like to be within the safe clearances.

Thanks for your help!

Irrelephant