MQ P40 Lifter Specs

[Eddi66]

Have just replaced the head on a MQ P40 petrol engine and just need the specs and settings for the lifters. Can anyone help?

[go piggen]

valve lifter and push rod of p40 engine

Clearance between valve lifter guide and valve lifter
limit 0.15mm (0.0059in)

this is what it says in the book

[David_S]

valve lifter and push rod of p40 engine

Clearance between valve lifter guide and valve lifter
limit 0.15mm (0.0059in)

this is what it says in the book

Are you sure that is what Eddi66 wants and not the valve clearances? The valve lifters sit on the camshaft and are not normally touched during a head replacement and cannot be set or adjusted.

The Nissan Service Manual gives the valve clearance (hot) as 0.38mm (.015 in) and that is what I have used in my P40 for 25 years and have cursed every time when I have burnt my fingers adjusting them!

The valve lifter figures you quote are the specifications /tolerances
Standard: 0.02 - 0.05 mm (0.0008 - 0.0020 in)
Limit: 0..15 mm (0.0059

[Eddi66]

David_S, you were right, my mistake with the question,is that the inlet and exhaust clearances? We also would like the point clearance and timing setting if you can help with that as well. Once again thanks heaps.

[David_S]

David_S, you were right, my mistake with the question,is that the inlet and exhaust clearances? We also would like the point clearance and timing setting if you can help with that as well. Once again thanks heaps.

Inlet and exhaust valve clearances are both .015" and both set hot. With a cold engine set them to 15 thou and then check them when hot.

Points gap is 0.018" to 0.022", dwell angle is 35º - 41º

Plug gap is 0.028" - 0.031"

Timing is 10º BTDC at 500 rpm idle (with vacuum advance blocked) 10º BTDC is the centre of the serrated timing mark next to the crank pulley. There are 5 serrations on the timing mark. From bottom to top they are 0º, 5º, 10º, 15º, 20º BTDC. This corresponds to cylinder no 1 (the front one). Firing order is 1-5-6-3-2-4

That should get you going. By the way the P40 goes well with a Pertronix ignitor in place of points. No more points wearing out or fiddling with feeler gauges.

Cheers

David

[Eddi66]

David, thank you once again. You guys have been very helpful. Now my GQ has somebody to play with. One more question, where can we source the petronix ignitor system (Vic)?