Complete Misfire on Three Cylinders

[Mark Maras]

I wouldn't spend too much time trying to make sense of the PO's thought processes. They might start to make sense. That said, have you searched the top and the bottom of the block for the reference stamps that show the block's orientation in the car?

[Captain Obvious]

Haha!! I didn't see stamps on the block for that, but I did see a stamp in the head "F".

Here, you can see it to the left of the plug I put in up by the thermostat housing. I'm trying and trying to convince myself that it does not mean "Front":

[Captain Obvious]

So my valves were indeed AFU. Based on the wear patterns, they were all mixed up, and most of them were not sealing properly.

One of the exhausts (4E) was even bent a little and not sealing for squat!. And I can tell by looking at the wear patterns and carbon traces that it's been like that for quite some time. Probably since my PO messed with it. It definitely did NOT just happened when the cam snapped.

Today's progress was I got all the exhaust valves sorted out. As best I could, I matched the correct valves to the correct cylinder and lapped them into place. Thankfully I have a set of set of valves at my disposal that I stripped out of an N47 years ago. I saved them, because that's what we do. They were sitting on the shelf, and thankfully I've got 24 valves from which to pull the best 12.

So exhausts are done and (barring surprises) I think the intakes will be much easier since they are in way better shape.

[240260280]

 

 

[Dave WM]

HR puff and stuff / Sesame st were big with the heads in HS...

[Captain Obvious]

Three lids!  One. Two. Three.

Haha!!!

[Dave WM]

how are the guides? I was messing with my N47 and noticed I had NO play on the intake, some on the exhaust. Just wondering if exhaust typically show more wear.

[grannyknot]

7 hours ago, Captain Obvious said:

One of the exhausts (4E) was even bent a little and not sealing for squat!. And I can tell by looking at the wear patterns and carbon traces that it's been like that for quite some time. Probably since my PO messed with it. It definitely did NOT just happened when the cam snapped.

Once you sort out 12 good valves are you going to get the valve seats re cut?

[Captain Obvious]

No. That's exactly what they would they expect me to do. 

What I'm doing instead kinda goes like this. Under magnification and with the use of some sharpie marks on the sealing surfaces, I've tried to match up the correct valve with the correct cylinder. And then after that, I'm lapping them to match the seats.

For example... Here's one of the seats before I've done much of anything to it. The valve that WAS in this location wasn't even close to making contact on most of the seat. I managed to find one of the other exhaust valves that was pretty close. Here's what I'm starting with:

Here's my handy-dandy valve lapping "tool". I use double back sticky tape to hold the valve to the "tool":

Some 800 grit lapping compound:

And I work the pair:

until I have something like this. Smeared contact markings over the entire seal:

Yes, there are still a few pits on the valve seat, but I'm not looking for perfection here. I'm just looking to be able to drive a little bit more on this engine until I finish the F54/P79.

What I'm ending up with is 1000 times better than what I started with!!

[Captain Obvious]

11 hours ago, Dave WM said:

how are the guides? I was messing with my N47 and noticed I had NO play on the intake, some on the exhaust. Just wondering if exhaust typically show more wear.

All of the valves wiggle a little bit, but yes, I've found that the exhausts wiggle more than the intakes. I'm not going to measure them, because then I'd know.

I did measure the lengths of all the exhaust valves though, and found one that was twenty thousandths shorter than the rest. No idea why it's like that, but that one did not make my set of the six best exhausts.

[Dave WM]

I can't imagine you letting the wiggle go un measured....

:)

snorkle

 

need a procedure. If you come up with something I will try as well. I suppose a way to measure the bore would be best a series of go no/go round gauges would be best for the bore.

Edited July 17, 2019 by Dave WM

[Dave WM]