waynos 521 work truck

[wayno]

I got a lot done in a few hours, first I removed the water pump/alternator belt and I loosened the power steering pump belt as it is trapped in there, it made no difference.

 

When I make a head gasket making the coolant holes and a drain hole is the issue, I tried a punch one time on a used gasket and it made a crater type shape on a very hard plastic material(1" thick), I thought that would just deform the gasket in 7 places, I bought 2 LZgaskets(89mm bore) recently and all the coolant holes needed were in the wrong place for my block.

 

The valve cover is not leaking, any oil on the block was caused when I ran the engine without the valve cover for about 10 seconds, it squirted oil on everything.

 

I do not think it is a rock in the transmission case although I had a transmission case collar come up missing so I expect that that could be a possibility, but it does not sound like it is coming from that area, I tried that screw driver trick on the oil pump and transmission case in two places today, it did not sound like it was coming from either.

 

This is what I did to the transmission clutch arm as it appears I am using a 521 clutch slave, and while it was running I pushed and pulled on the arm and at first I thought it changed the noise, I also watched slave move out till it settled, so I made an extension with a hole in the photo below, along with shortening the rod a 1/16", and then I added a spring, now it settles with the rod loose but the squeak is still there.

 

 

I removed all the rockers, jammed the timing gear chain and removed the bolt holding the timing chain gear on, the cam spins freely, I checked all the cam journals and felt inside the cam towers, everything appeared to be fine, but this is not something I ever checked before although I do know what a cam tower looks like when ran dry briefly, it did not feel like that at all.

 

 

In this photo below you can see the far end ball(#4 exhaust valve) that the rocker rests on is lower, I had to do #1 and #4 to get proper valve clearance.

 

 

This is what two cam lobes look like on my engine, I tried to get the same distance and angle but it was not to be but they are close to the same distance/angle, does either look wrong?.

 

 

 

I tried finding a shorter lash pad for them 2 valves but the ones already there were the shortest ones I had.

 

I will go outside now and check the exhaust, but it sounds RPM related and it does not sound like it is coming from under my seat.

 

I also had to lean the engine out, it was spitting black soot out the exhaust onto the side of the 720, I could see it do it, I do not think it is running lean even though the spark plugs are not black, after I put the carbs where they were before it did not spit out smoke anymore.

 

 

 

 

Edited May 14, 2021 by wayno

[Stoffregen Motorsports]

Ok, nice work.

 

The next thing to do is to check the wipe pattern on your rockers. The cam and rockers need to be clean and dry for this. Once everything is clean and dry, mark the rocker wipe area with a broad black marker (or sharpie or dykum blue, or whatever) and turn the engine one complete rotation with all the rockers in place and the valves adjusted. The cam will wipe away the area where it contacts the rocker. And that area needs to be inside the pad on the rocker. If it runs off the end of the rocker, this is bad.

[wayno]

OK, I have a question, are all rockers exactly the same?

 

 

[datzenmike]

No. The L16 in the 510 had two different rockers. This is also the earliest L16.

 

13258-22000

13257-21000 (with H C I pad) used on all '70 and up L series as in the 521 and L24 so sometime before '70 the 510 changed to them also.

 

What does HCI stand for? Don't know. 

[wayno]

So basically all L20b heads have the same rockers.

 

It is really hard for me to take this truck down for long, I hate making head gaskets for them, I have that head I had rebuilt 7 or 8 years on an L20b that was in the work truck briefly, then the engine/head was put in the 520, then when I found a 219 head for the 520 then that head was put on the Z20e block a few years, that I had running at one point, I believe I was told it was 10.8 to 1 compression ratio, it has an RV cam in it which I hate as it messed up the torque, it was not noisy like this head appears to be, I could remove that RV cam and put an L20b cam I have in it(I have 2 L20b cams to pick from) and put it on this engine, the thing is that head is better suited for a light duty truck, I had it in the 520 when I drove it to Blue Lake and Keith said it moved real good even with that cam in it, but I removed it when I found a 219 head that is in the 520 to this day and that engine is very quiet.

 

I do not remember if I mentioned that I took the damaged head to Ricks Cylinder Head to be welded/repaired if possible and rebuilt, the guy looked at it and thought it was likely repairable but needed to take it apart to know for sure, I have not heard back yet, that was 8 days ago, he told me he would get back to me within a couple weeks.

 

This head is very noisy, maybe it was not built properly, the intakes are 44mm, I have real money into this head, I would hate to not use it.

[datzenmike]

1/ With both rockers off the suspect cylinder push down with a wooden hammer handle on the valve spring. It should take over 100 pounds to lift the valves off their seats. Is it stiff? Does it move freely? Anything? Maybe compare it to another cylinder. Other than cam and rockers the only other moving parts on the head are the valves in their guides.

 

2/ Do a cam wipe pattern on the rear rockers.

 

If OK...

 

3/ You can change the cam and rockers without taking the head off. At the least you'll be able to examine the cam towers for lubing. If this cam/rockers change out changes nothing, then it's not those parts, and if okay afterwards then it was.

 

 

None of these require the truck to be off the road for more than a morning. 

[wayno]

I am looking at the wipe pattern right now, I am almost to the conclusion that the exhaust valves are too tall and the squeak is #4 exhaust valve, I can put it back to the way it was but then I will have to set the valve clearance between the lash pad and rocker as 12 thousands will not fit between the  rocker and the lobe.

I looked at the lash pads and I do not see a way to shave them as the bottom of the lash pads are counter sunk, maybe so they do not rest on the end of the valve, maybe they rest on the keepers???

Edited May 15, 2021 by wayno

[wayno]

OK, all the valves appear to be around the same height, but the lash pads sit different heights depending on the valve, exhaust valves they sit higher in position, now I have other lash pads that look the same, but they sit lower in the hole because the crater in the bottom is slightly deeper but I can see the difference with my eyes.

 

I also noticed another couple things, the wipe pattern on #1 and #8 is all the way to the edge while the others are more centered, these are the 2 valves I shaved the nut on to get more clearance, I have lots of them nuts that are not shaved, the other thing I noticed is all the rockers in the head now have texture, I can run my finger nail across them and some I can feel texture, others feel smooth, now I have another head I just removed the cam/cam towers to make it easier to remove a rocker, these feel smooth and look smooth, they appear to be exactly the same, I am thinking I should use these rockers.

I suspect the assembly lube I put on the cam lobes before I ever turned that engine over was not enough, I filled the oil pump on assembly and I turned that engine over without any spark plugs in the head until the top end was soaked, so it was not dry when it was started like my last engine that I only primed the oil pump, I thought this turning it over was a good way to get oil everywhere before it was started, maybe I was wrong, I really need to put this engine back together today so I have another day if things do not work out.

 

 

[datzenmike]

Assembly lube or oil poured all over before start up is enough. Filling the pump and filter doesn't hurt but I bet Nissan didn't go to the trouble. A few dry turns won't hurt it but avoid if you can.

 

The wipe pattern needs to be more in the middle of the rocker pad.

[wayno]

I put it together with different lash pads and different rockers that were smooth, I also put the full nuts back on #1 and #8 valves and I have clearance this time, then I put it all back together and started it and it sounds way better and the squeak is gone, but I really did not run it that long, before one could hear all the rockers like they were loose and the squeak, that is all gone, I can still hear the rockers a little bit which is likely normal, but not like it was before, I still need to warm it up and set the valve lash hot, I just did everything at 12 thousands, when I do that I will look at what the wipe pattern looks like, both ends were dark so if it is at the edge I will see it is not dark there anymore.

 

2 hours ago, datzenmike said:

Assembly lube or oil poured all over before start up is enough. Filling the pump and filter doesn't hurt but I bet Nissan didn't go to the trouble. A few dry turns won't hurt it but avoid if you can.

 

The wipe pattern needs to be more in the middle of the rocker pad.

 

Well more than half them rockers of mine had texture, these fine lines across them like it was vibrating that I could feel with my finger nail and I handed one to the neighbor across the street and she said it was rough, I do not know when it happened and it happened to several of them that I had no issue with wipe pattern or clearance, it appears to be better right now and if it goes bad again I will put another cam and another set of rockers in it, I think #8 valve was doing the squeaking, but that is just a guess, even the neighbor said it sounded better from when I would drive by her house, but maybe she was just being nice. :lol:

[Stoffregen Motorsports]

You keep mentioning removing the head. You don't need to remove the head to do what you're doing, but it sounds like you;re already ahead of me on that.

 

Yes, the rockers are dark at both ends, from years of wiping in the middle only. You can use scotch-brite to clean the pad and then mark it for your wipe test.

 

Adjusting the valves should be done at the tip of the rocker, not between the cam and rocker. .012" at the rocker tip is ok.

 

One last thing to check is the valve heights. With all rocekrs removed, do any of them look like they are sticking up higher than the others? Sometimes the intakes and exhaust valves may be set at different heights, so beware of that. If a couple are sticking up high, it may mean the valve seats are getting pounded, or the valves are thin.

[wayno]

OK, I did my valves today after I got home when it was hot, all are 12 thousands between the rocker arm and lash pad, when I started it it was even quieter than before which I like, before it was a squeaking rattle trap under that valve cover, now it appears all is good.

 

Sorry I forgot to look to see how much black had been wiped off the rocker arm that was on there from the past, my only issue areas were #1 lobe and #8 lobe, both exhaust valves, I expect these 2 valves were making the squeaking but I expect #8 was the worst, all that is gone now, how them original rockers got texture is what I would like to know as most of them had them lines across them as you can see in these photos, I used other rockers this last time that were smooth, have any ideas how the ones I removed got rough?

 

 

 

I checked the valve heights the last time I had the rockers out, at first I thought the exhaust valves were higher, but when I put a straight edge on them they were even, I checked every keeper when I put the slightly shorter lash pads on each hole, between them rockers and the lash pads I was able to put the normal un-shaved nuts back onto the posts the rockers sit on and still I had lots of adjustment for valve clearance unlike before, I will remove the valve cover again(maybe today) to see if the black has been wiped off the #1 or #8 rocker surface on the intake side as that them are the ones that the wipe pattern was not in the middle, the posts I shaved the nuts on.

 

Fact is this head had zero miles on it when I started it the first time, if the valves have been pounded it has happened in the last maybe 400 miles, both the ones with clearance issues were exhaust valves, I do not know why, maybe the guy at the machine shop was tired of working on it as I was pushing for it to be done as it had already been there a while(6 months), he was working on race cars most the time back then, them race car parts/engines/heads took priority.

 

6 hours ago, Stoffregen Motorsports said:

You keep mentioning removing the head. You don't need to remove the head to do what you're doing, but it sounds like you;re already ahead of me on that.

 

Yes, the rockers are dark at both ends, from years of wiping in the middle only. You can use scotch-brite to clean the pad and then mark it for your wipe test.

 

Adjusting the valves should be done at the tip of the rocker, not between the cam and rocker. .012" at the rocker tip is ok.

 

One last thing to check is the valve heights. With all rocekrs removed, do any of them look like they are sticking up higher than the others? Sometimes the intakes and exhaust valves may be set at different heights, so beware of that. If a couple are sticking up high, it may mean the valve seats are getting pounded, or the valves are thin.

 

Edited May 17, 2021 by wayno

[datzenmike]

wayno I went through a bunch an picked out the best. I used wet sand paper to smooth the already smooth surface so they had a fresh start on a different cam.

 

 

I think there were several that looked like this...

 

 

You couldn't feel it and it wasn't measurable.

 

 

Meant to ask. Where did you measure your lash? At the lobe or right at the lash pad. The FSM says VALVE lash not LOBE lash. I always use the lobe it's easier but 0.010" on the lobe is going to be wider at the lash pad. If the rocker ratio is 1.48:1 wouldn't 0.010" be 0.0148"??? I would think 0.010" at the lash pad would be quieter but you would have to cut your feeler gauges up to fit.

[wayno]

I am not sure I understand what you said, I set the valve clearance between the rocker arm tip and the lash pad this time, when set there I cannot get that same feeler gauge in between the lobe and the rocker pad as 0.012 at the lash pad is way less between the rocker and lobe.

 

Put another way Saturday I did it  at 0.012 between the lobe and rocker pad, the 0.012 gauge easily fit between the lash pad and tip of the rocker, I had to raise the post the rocker sits on over a half a turn up, they were really loose.

 

The fact is I have always ran my rockers slightly loose(more than 0.012) for more than 20 years measured at the rocker/lobe, having them set at the tip of the rocker/lash pad is a change for me, they are what I used to consider way too tight now, but I used to have the radio blasting to drowned out all the exhaust leaks and other noise the engine/truck made, this is the first time I got a rebuilt/modified head from this machine shop that needed work other than the seats needing to be replaced with hardened seats on my damaged head back in the 1990s, I have never had an issue with any of the heads this shop had done for me except this one.

 

I have a feeler gauge that fit in the lash pads all the way, it is a very small feeler gauge, I have to search in the drawer to find it every time I want to use it.

 

 

Edited May 18, 2021 by wayno

[datzenmike]

I may have said it wrong but I got my answer. Set at the tip would likely run quieter.

[Stoffregen Motorsports]

Wayno, if you're happy, I'm happy.

 

The rockers in your pics probably got that way from engine harmonics. The very squeak that you heard is most likely the vibration that caused those rockers to get scored like that. Lucky you found the problem in time.

 

The tall valves could be from machining. Maybe he just sank those two valves deeper in the head, instead of buying two new valves. Whatever.

[wayno]

They were brand new valves across(intakes 44mm), hardened seats, guides, this head was made out of a W53 closed chamber head.

 

What is to stop it from happening again?

 

I did something with this engine that I never done with any other engine in my life, I broke it in with 10/30 motor oil, the machinist told me to use that, the other Z22 engine I had punched out to 89mm(Z24 pistons) I used 20/50 motor oil and never had an issue, this is the only engine ever that I used 10/30, it is also the only engine ever that I turned it over with the starter without spark plugs until the top end was soaked with oil and I had oil pressure on the gauge(electrical gauge), they are the two things I did differently.

 

2 hours ago, Stoffregen Motorsports said:

Wayno, if you're happy, I'm happy.

 

The rockers in your pics probably got that way from engine harmonics. The very squeak that you heard is most likely the vibration that caused those rockers to get scored like that. Lucky you found the problem in time.

 

The tall valves could be from machining. Maybe he just sank those two valves deeper in the head, instead of buying two new valves. Whatever.

 

[Stoffregen Motorsports]

Honestly, if the cam was wiping off the end of the rocker, that could do it.

 

Loose valve lash could too.

 

I never turn the engines over without spark to get oil pressure. The fastest way to get oil pressure is to fire that bitch up!

[wayno]

Only 2 were wiping off the end of the rocker pad(#1 and #8) but most of them had them lines/texture.

 

I only turned it over without the spark plugs with the starter because it was easy to do, it did not take very long and I could could tell when the bearings got oil as the RPMs picked up slightly, I took the oil cap off and looked inside and everything was soaked with oil so I called it good.

 

I put other rockers in that looked and felt smooth, I will know if it ruined the cam soon enough.

 

I need to time it again as it has premium non-ethanol gas in it and it did not knock on the freeway today timed at 5 degrees BTDC, it seemed like it has less power than my other engine also, maybe it is the timing.

 

I put assembly lube on the cam before even installing the engine in the truck because the old assembly lube had dried out sitting in my back room(part room) for 6+ years.

5 hours ago, Stoffregen Motorsports said:

Honestly, if the cam was wiping off the end of the rocker, that could do it.

 

Loose valve lash could too.

 

I never turn the engines over without spark to get oil pressure. The fastest way to get oil pressure is to fire that bitch up!

 

[wayno]

I got a call about my damaged head the day before yesterday, they said it was done, they never called me to tell me how much it was going to cost, I asked how much I owed them and thought I heard wrong(I was not awake yet), so today I went over and picked it up, I could not believe my eyes when I seen it, it was so clean and I could not tell they even welded on it.

 

 

It cost $190.00 of which $40.00 was for the welding and the rest was for the valve job, I left and turned around and went back and asked them how much they took off it from when I left it with them, he said he was careful and only milled it 5 or 6 thousands off of it.

 

I called the machine shop that suggested I go there and asked if they wanted to see it and in the middle of leaving a voice mail AC(owner) picked up and said yes they wanted to see it, they appeared impressed themselves, I am not sure if they were happy with how little I paid, but they did say they had customers that took their heads to Ricks and they did the block, they did point out a little tiny hole from the welding but thought it was inside the fire ring and not under the fire ring so it would not matter, once I got it home I checked and it was not that close to the fire ring to cause an issue.

 

Here is a photo of that tiny hole, looking at it I wonder if it could cause detonation issues???

 

Edited May 21, 2021 by wayno

[datzenmike]

Rub some JB in there.

[wayno]

Seems like JB weld would just come out, I thought about how the engine ran fine until coolant started escaping the coolant jacket, there was a huge trench in one of them cylinders for who knows how long and I could not tell, so I though maybe use a drill to take off the sharp edges making a small smooth dimple, but then I thought about that I cannot really see how deep it is, so I went and got a pin and it appears to only be maybe a 1/16" deep, the guys at the machine shop did not seem to be worried about it other than it not be under the fire ring, I do think that that hole has sharp edges, do you think JB Weld would stay in there?

 

I do not want this cylinder to have detonation issues, I did not even see that tiny hole till it was pointed out to me, I did not see the head was damaged until it was pointed out to me either.

 

3 hours ago, datzenmike said:

Rub some JB in there.

 

[mainer311]

I don't think anyone mentioned it here, but the valve stems on the intake and exhaust valves are NOT the same length. I discovered that recently after rebuilding the W58 head for my L20b. Due to this fact, I had to use two different height lash pads to get the wipe pattern centered for all valves. 

[datzenmike]

Exhaust are 1.2mm longer just a hair under 0.050". It's curious that the exhaust valve seat is almost exactly 1.3mm taller than the intake. Has anyone ever measured to see if the exhaust valve sits 1.2mm more into the combustion chamber? They look even.

[banzai510(hainz)]

9 hours ago, wayno said:

I though maybe use a drill to take off the sharp edges

Im thinking the same thing!!!

 

 

thats a good price. I get spare heads done up there if you got them

Edited May 21, 2021 by banzai510(hainz)