Complete Misfire on Three Cylinders

[Captain Obvious]

I think you're right. I think it will have some tiny impact on the compression and performance numbers as well. But I'm only off by .003 on the intakes and .001 on the exhausts. I'm pretty sure that I'm leaving a tiny bit of performance on the table, but for the first batch of miles, I'm willing to take that tradeoff for the piece of mind.

Of course, I'm not an expert on the topic, but that's what I'm thinking!

Maybe I just need a padded cell:

Edited August 12, 2019 by Captain Obvious

[rcb280z]

Makes perfect sense to me. I would probably do the same.

Here's to no more problems with her 

[Captain Obvious]

Thank you. Appreciate the well wishes! It's going to take some time for me to regain confidence in the motor.

Now I have to finish pulling that F54 block.......

[Av8ferg]

Great job CO, glad she’s back on the road. I know it was a PITA but it’s a labor of love.


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[Captain Obvious]

Yeah, definitely a labor of love to put that amount of work into the lowly stock N47. But as you suggested, it was personal. Me against my PO. LOL!

Have to give it some time to wait for potential issues to surface, but I believe I won.  

[Captain Obvious]

So one of the closing items to bring up is that I did take some quick and dirty measurements on the valve protrusion while fully open, and according to the numbers, it's definitely an interference design.

The valves stick down about .200 beyond the bottom of the head when they are fully open. I didn't spend a lot of time trying to max out the lift to the thousandth, so it's likely that it's a little more than this. I just eyeballed it as I turned the cam and set the cam where the lift was the greatest. Could be a little more than .200, but it's certainly no less:

And my new (Nissan) head gasket is about .055 thick new (before any compression due to installation torque):

So even if there is no crush on the head gasket thickness, the valves will stick down .145 beyond the bottom of the gasket. And considering the .115 dish depth on the pistons, it's an interference design.

I've got some other closing items to document as I get the time. Things like my flying trapeze head lifting rig that worked out fantastic...