Numbers stamped on engine block surface?

Since the old single thread was getting too long again. Creating a new forum where you can ask your questions and if you get them answered -please indicate the issue was resolved or not.

Moderators: notoptoy, S Allen, Solex68

Post Reply
User avatar
Florida Roadster
Site Supporter
Posts: 341
Joined: Tue Apr 12, 2022 6:08 pm
Location: Tampa, FL
Model: 1500/1600
Year: Low Windshield-64-67.5

Numbers stamped on engine block surface?

Post by Florida Roadster »

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!
IMG-3593.jpg
You do not have the required permissions to view the files attached to this post.
-Jeff-
1967.5 SPL311 Datsun Roadster 1600/2000 (Full Restoration Project)
1970 Triumph GT6+ (Full Restoration Project. Waiting up on the shelf.)
User avatar
Nissanman
Roadster Fanatic-Site Supporter
Posts: 3364
Joined: Mon Apr 16, 2007 8:07 pm
Location: Adelaide, South Australia
Model: 1500/1600
Year: Low Windshield-64-67.5
Contact:

Re: Numbers stamped on engine block surface?

Post by Nissanman »

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, just trying to help.
1965 SP310 Engine No. G-93326 Car No. SP310-10817
https://photos.shutterfly.com/album/60141836519
On the road again!
User avatar
Florida Roadster
Site Supporter
Posts: 341
Joined: Tue Apr 12, 2022 6:08 pm
Location: Tampa, FL
Model: 1500/1600
Year: Low Windshield-64-67.5

Re: Numbers stamped on engine block surface?

Post by Florida Roadster »

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.
IMG-3598.jpg
You do not have the required permissions to view the files attached to this post.
-Jeff-
1967.5 SPL311 Datsun Roadster 1600/2000 (Full Restoration Project)
1970 Triumph GT6+ (Full Restoration Project. Waiting up on the shelf.)
Daryl Smith
Roadster Fanatic-Site Supporter
Posts: 1623
Joined: Wed Sep 08, 2004 1:53 pm
Location: Not Here
Model: 1500/1600
Year: Low Windshield-64-67.5

Re: Numbers stamped on engine block surface?

Post by Daryl Smith »

Irrelephant
Last edited by Daryl Smith on Tue Jul 25, 2023 2:29 am, edited 1 time in total.
User avatar
Florida Roadster
Site Supporter
Posts: 341
Joined: Tue Apr 12, 2022 6:08 pm
Location: Tampa, FL
Model: 1500/1600
Year: Low Windshield-64-67.5

Re: Numbers stamped on engine block surface?

Post by Florida Roadster »

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.
-Jeff-
1967.5 SPL311 Datsun Roadster 1600/2000 (Full Restoration Project)
1970 Triumph GT6+ (Full Restoration Project. Waiting up on the shelf.)
Daryl Smith
Roadster Fanatic-Site Supporter
Posts: 1623
Joined: Wed Sep 08, 2004 1:53 pm
Location: Not Here
Model: 1500/1600
Year: Low Windshield-64-67.5

Re: Numbers stamped on engine block surface?

Post by Daryl Smith »

Irrelephant
Last edited by Daryl Smith on Tue Jul 25, 2023 2:28 am, edited 1 time in total.
User avatar
Florida Roadster
Site Supporter
Posts: 341
Joined: Tue Apr 12, 2022 6:08 pm
Location: Tampa, FL
Model: 1500/1600
Year: Low Windshield-64-67.5

Re: Numbers stamped on engine block surface?

Post by Florida Roadster »

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!
-Jeff-
1967.5 SPL311 Datsun Roadster 1600/2000 (Full Restoration Project)
1970 Triumph GT6+ (Full Restoration Project. Waiting up on the shelf.)
Daryl Smith
Roadster Fanatic-Site Supporter
Posts: 1623
Joined: Wed Sep 08, 2004 1:53 pm
Location: Not Here
Model: 1500/1600
Year: Low Windshield-64-67.5

Re: Numbers stamped on engine block surface?

Post by Daryl Smith »

Irrelephant
Post Reply