Would a leak down reading show the valves aren't seating tight or the rings are worn? I've never performed one so I am curious and just to get more Z dialogue on the forum I'll wait for your reply and not use google.com.

Thanks for any information about our cars.

24 minutes ago, siteunseen said:

Would a leak down reading show the valves aren't seating tight or the rings are worn? I've never performed one so I am curious and just to get more Z dialogue on the forum I'll wait for your reply and not use google.com.

Thanks for any information about our cars.

I believe its mainly to show the valves seating tightly. I wont google either just to add to the fun 

15 hours ago, jalexquijano said:

running BP5ES in all 6 cylinders, should i consider getting a BP4ES for cyl 4? 

Has No use at all..  (It's like bringing a dead horse some water..)

Guys guys..  it has no use at all.. when my engine would give me 80's psi's i would revise it or throw it away.. as this is a completely dead engine.

Write a letter to california Datsun and thank him for the useless engine, with the measured compression data.. and tell him you are going to make a lot of "advertising" for him..  If he is wise he should help you as i understand the engine was always crap!?

 But first recheck the compression with the throttle wide open.

You can hold the throttle rod, carbs, wide open by tying or wiring the loop to the fuel rail. That way you stand outside the driver's door and reach through the window to turn the key. Make sure and pull the coil wire off at the coil. It's kind of hard to mange all at the same time by yourself but it is possible to turn the key with your right arm and hold the gauge with your left arm to see the reading of the needle on the gauge. A helper is best but like me, hard to find when you are ready to do the test. Good luck. Hope for higher numbers. 

Edited March 2, 20232 yr by siteunseen

You might figure a way to put a screwdriver through the loop on the throttle rod and keep it pried open?

23 hours ago, Mark Maras said:

 The only thing I can add is I remove the plugs and turn the engine over until I see oil pressure, then test. When I didn't start with oil pressure #1 would read low the first time and higher on the second test. Good luck.

Just bought this one. Hope it does the job following your instructions.

That should work just fine. Good luck and I said earlier, build some oil pressure with the starter, plugs out, first.

I have one of these, not this exact one, and it is very useful for adjusting valves, checking compression, etc.

 

https://www.amazon.com/Performance-Tool-W80586-Remote-Starter/dp/B00OPVYHZ4/ref=sr_1_5?keywords=remote+starter+button&qid=1677800656&sr=8-5

40 minutes ago, emccallum said:

I have one of these, not this exact one, and it is very useful for adjusting valves, checking compression, etc.

 

https://www.amazon.com/Performance-Tool-W80586-Remote-Starter/dp/B00OPVYHZ4/ref=sr_1_5?keywords=remote+starter+button&qid=1677800656&sr=8-5

Big help setting valve lash by yourself while they're hot. Hell when they're cold too! I do mine cold now after a few years break-in.

 

2 hours ago, Mark Maras said:

That should work just fine. Good luck and I said earlier, build some oil pressure with the starter, plugs out, first.

Ok first i remove all plugs including the one that goes to the coil and crank the engine by turning the key? How do i build that oil pressure?

14 minutes ago, jalexquijano said:

Ok first i remove all plugs including the one that goes to the coil and crank the engine by turning the key? How do i build that oil pressure?

 Remove the coil wire, remove the spark plug wires and spark plugs, get comfortable in the seat and turn the engine over (wide open throttle) with the starter until you see oil pressure on the gauge. It shouldn't take long. Then proceed with the test.