L16: Rocker Arm Pivot Guide popped out!!

[Figbuck]

This happened to me in 1977 with about 40K mi. ; I was pulling a long hill in 4th gear and all of a sudden a loud ticking sound started in the engine. I let off the throttle and the ticking slowed with the RPM. I pulled over, left it running, popped the hood and could tell it was from the valve train and not a rod knock. It was in the middle of the night, it didn't seem like it was going to blow up so I drove 20 miles back home.

 

The next day, I pulled the valve cover and saw the missing guide. I think it was ninty-six cents from Nissan. 

 

I have been changing my oil and filter right at 3K miles for a few years now.  So fast forward to last week. I changed my oil and filter, new fuel and air filters. Coolant got changed in the fall and looked good.

 

The last few tanks of gas seemed like I'm not getting good milage...  performance OK... not bad.

 

My maintenance log says plugs were 15K mi old, replaced the last time I adjusted valves.  I pulled the plugs and the #4 electrode was burnt and bent... but the other three plugs looked nice and tan!  Fuck, What's up with that. Never seen that before.

 

Stuck new NKGs in and off I went.  15 miles, I go in shopping, come out and start engine, let it warm up while I fool with receipts.

 

I take off driving 25 mph through a neighborhood in third gear. Out of nowhere there is a cut-out like a cough through the carb. But only for a brief second, then back to running smooth. WTF was that?

 

About ten blocks later the same thing happens, but like two coughs and the engine died. I tried to start it, but it didn't want to fire while I coasted. Fortunately I was on top of a long hill and got it running on compression... but now with a loud tapping sound in time with the Revolution of the engine.

 

I drove it home knocking like crazy. Finally today I worked on it. The rocker arm pivot guide for the #4 intake was just sitting there on the head, suctioned in oil.  Stuck the guide back in, adjusted all the Intakes. The were all too tight. Three of the exhaust valves were tight and #2 was still right on.

 

 Just took it for a little spin. Starts and idles nice...  winds out really strong for 266K mi.

 

 

 

SO... what happened? I can't understand how that little guide can come out of there?  

 

Any ideas??

[datzenmike]

 

You mean the lash pad???? Too much clearance and high revs will cause this. Weak or broken valve spring causing valve float..

[banzai510(hainz)]

I had lash pads fall out 3 times I think.

soon as a lose a cylinder I know its a plug wire loose fouled plug or a lash pad fell out or a tight valve or a burt valve(hasnt happen yet)

 

One needs to maybe adjust the rocker to get more slack in it , put lash back and lever the rockerarm back into postion ans readjust the lash. I run mine a little tighter so it hasnt happen it awhile

 

 

oh changing your oil every 3 k is overkill in my opinion.

I only do mine 2 a year(winter thinner)  I put about 12k a year on my 521. Im up to 180k on this motor

[Figbuck]

 

 

Why did your lash pad fall out 3 times?
 
My oil is usually nasty by 3K. 
 
 
So, I drove the same drive over about 12 or 15 miles. A mixture of city streets and freeway up over a 2 mile grade coming back. Engine sounded nice, ran fine, idled perfectly at stop signs, accelerated cleanly seemed to have good throttle response. Like I just dialed the valves in with new plugs!!!
 
But on my way back I rolled on the throttle from 65 to about 80 and I could hear a faint clicking, then bang I could tell I lost the lash pad again. I drove it about a mile up the hill in 2nd gear, coasted dead stick back home. Had to start it for a minute to get into my carport. 
 
I just took the valve cover off. The same #4 intake lash pad came out and is not to be seen laying on the head. On the intake valve #3, the rocker arm was knocked sideway off the lash pad up against the cam tower... with the lash pad itself rotated 90 degrees so that it trapped the rocker arm in place but still all askew. A chunk of the #4 intake rocker was broken off and it is nowhere to be seen either.
 
I was thinking about taking both rockers off the #4, pull the plug wire off so I could drive it to my friend's farm on 3 cylinders... so maybe I could work on it. But that was before I saw the #3 intake rocker all roached too.
 
My maintenance log says I blew a head gasket towing my utility trailer... then got a re-manufactured head at the beginning of 2012 @ 230K. I re-torqued the cam towers and head in a few miles... then again around 243... so it wasn't that many miles ago that I adjusted my valves. Now is 266K so it's 36K miles plus/minus.  That kinda sucks.
 
I don't know what to do right now.  looked on OfferUp and saw a guy in Vancouver Wa. who is doing a 620 KA swap... is selling a clean looking l16 with tranny for $350. Even if I could beg him to let me have it for $300... I don't have any money. I saw a nice looking '95 hardbody some chick is selling as a part truck because no title and she needs it gone. She said it's her DD and runs good, but can't insure it and needs to git legit. $500. I could harvest the engine and wiring harness and get my money back parting the rest of it. 
 
Yeah, I was just barely making it... now I'm on "Mare's Shank"!
 
 
25 years ago I did a bathroom remodel for a stark raving mad man in a sprawling estate name Irving. I met with him twice to talk about doing the work and then to sign a contract. His office had enlarged photos of him standing in front of old aircraft and in the hall photos of the first sports car races held on the 17 Mile Drive in Carmel California in the early 1950s. He had a Caddy powered Allard and a Cunningham, that he raced to 3rd one year. Man that is motor sports claim to fame right there.
 
 
Irving's estate was inherited from an Old California Gold Rush family. He had so much money that no matter how much he tried to blow it he couldn't. He was a decorated WWII Flight Surgeon, went on to teach and lecture at both University of California Berkley and Stanford. One wing of the house was chocked full of first edition books worth millions. There was a secret vault behind a book case that had really rare and valuable things... like one of the two original California Constitutions. Both UC Berkley and Stanford Libraries were fighting over why he should sell it to them, Not even donate it, just take our money.
 
This old guy was a stone alcoholic now and polished off at least a bottle of Absolut every day. He had a house keeper who shopped and made food for him noon to four. She refused to buy him booze and told me immediately not to fall for his bullshit. If he talked me into getting him booze or cashing his bouncing checks... I would regret the outcome.
 
Boy was she right. The day I showed up to start at 9 AM, he was already into the second bottle. He had a deal with a 16 year old neighbor kid totally on the sly. He conned this kid out of his allowance money or anything the kid could swipe from his Mom's purse, so he could drive Irving's Jaguar. He owned a 1950 Jaguar 120 roadster that was all original down to the leather belts holding the bonnet. It was rode hard an put away wet. Nasty dirty but he had a local British Car shop keepin' it running and tires on it. Nasty dirty, but not fucked up at all... all there... and sounding great!
 
He got convicted for drunk driving like seven or eight times, so he was permanently revoked. He couldn't risk going to jail so he didn't try driving any more. Everybody he came into contact with refused to buy him booze or let him have any cash money. The cashier's at his bank wouldn't even cash a check for him... or one of his own checks that he wrote to anybody. As I found out when the housekeeper told me to cash his checks at his bank right away. He had a lawyer who tried to keep him from killing himself... or at leas not kill anybody else. But he made this end run with the kid, who just started driving and couldn't wait to drive this big old V12 beast into town! Shit, I wanted to drive that thing.
 
So one day Irving asks me to drive him to the Post Office. Ya mean the Post office next to the Liquor store Irving?

 

He goes, "Yeah, I'm on Mare's Shank!!"
 
What? Mare's Shank?? WTF?
 
Right Old Chap... I got no wheels... so I is HOOFIN' IT! 
 
 
Anybody want to give me a lift to Canby? I is on Mare's Shank.

[datzenmike]

Check the valve springs are not broken/damaged or possibly very soft and you're valve floating. Next the valves might be sticking allowing too much clearance when revved up.

[Figbuck]

The springs all look good. The head is only 36K mi old?  

 

If some how there is a failure in the oil getting back there... I could see maybe a valve sticking in a roached guide... I guess. 

 

No matter what, the head has to come off. The best thing I can think is to try and talk my friend into sticking it in her barn until I can find some money. I don't even know how I would get it out there. I can't work on it here. 

[Roadster-ka]

The retainers can be damaged with the rocker pounding on them and then allow the lash pad too much clearance.

[datzenmike]

Take the rockers off and try to gently pry the valves down with a long screwdriver. Set TDC and then turn 1/4 crank turn. This will put all the pistons half way down the cylinder and out of reach of any valve.... see if they are close to the same stiffness. You can change springs without taking the head off. You might even notice a valve that is tight in the guide.

[banzai510(hainz)]

Why it popped off?

I dont know just did.

Wa slazy and didnt ck the valve lash. It was a beat 510 this happen too. 100$ 510 I had

[don51o]

loose valves, valve float, bent valve not fully closing; wore-out motor;  valve retainer wrong depth for lash pad; lash pad caught between top of retainer and rocker arm- "extra lift"; bent valve

[don51o]

figbuck: retorqued the cam towers?  cam wasn't binding?

[don51o]

show them some respect. these aren't Detroit lumps 

[datzenmike]

Use extreme caution tightening the cam tower bolts. They are 3 to 6.5 ft lbs!!! They easily strip the soft aluminum threads. The head bolts do most of the work and the cam 'bolts' just locate them.

[Figbuck]

I have a really nice inch/lb torque wrench for all that low-torque stuff. 

 

Anyway, I been on the Mare's Shank for almost two months. It sucks, but I'm slowly making progress. When I think about working on my Datsun, there is nothing logical or rational about it. It's an emotional thing. Plus there is some deep-seated deep seated delight in circumventing the DMV emission rules. 

 

So, I looked at the maintenance log that lives in my glove box and fished out my receipts. It looks like I put a fresh head on it in 1992 @ 166K mi. when I rebuilt the engine. It looks like in 2012, @ 230K I blew the head gasket. It is hard to tell if the head was machined. The shop that did the work noted a price for machine work, but the description only says, Replaced Head Gasket. 

 

I went to a couple of machine shops close by. The first two were too busy to talk to me. The third one, was Aluminum Head Rebuilders on SE 24th x Holgate. Family owned, red blooded American racer guys. It took them a while... nothing ever goes right it seems. Not their fault I beat the shit out of it!  But I got it back... It's a thing of fuckin' beauty. They seemed to think it had never been surfaced before. It had been hot but not bad. The machinist said it was .003 in a couple spots, 004. in a couple, and he measured plenty of material to give it a little trim job.

 

I have been beating the crap out of my engine for 100K miles. I was thinking I put a fresh head on it 36K miles ago. It was 100. Hahaha I change the oil and filters, and keep it tuned up, new plugs in it, but I still work it. No wonder the valves were floating and popping out the lash pads! The Valve guides were hammered, some exhaust seats were all sunk in. It was used up. A real testament to how much abuse these mighty L16s can take... and still run OK!

 

 

 

New cam, bearings, valve guides, seats... springs, pivot guides, retainers and other stuff...

 

 

 

Can I reuse my head bolts? Should I? Should I even care? 

 

  

[datzenmike]

Long as they and the block threads are clean and undamaged most certainly. Not like today's stuff.

[Stoffregen Motorsports]

Look for wear caused by corrosion, usually near or on the threads. If they look fine, then you should be able to re-use them.

 

BTW- it's never a good idea to set your cylinder head face down like that. There's at least one valve open far enough to get bent.

[Figbuck]

Look at the rocker arms... there is daylight between the pivot guides.  ok my head bolts are clean, look good.

 

I ordered a Fel-Pro gasket kit, and new thermostat and temp sender from Napa. 

 

I'm trying to find a kit for the intake/exhaust studs. Not NAPA, not any of the local parts stores and not Carr Nissan in Beaverton could help me.

 

The browser on my old laptop won't let me either load websites or else won't open pages. I can't search RockAuto or any Nissan parts sites. I've wasted a bunch of time and frustration searching "Datsun" restoration sites. Lots of stuff for Z car engines. Can I use a stud kit for a six cylinder L engine?

[Stoffregen Motorsports]

Studs can be found at specialty fastener shops - https://www.clipsandfasteners.com/Cylinder-Head-And-Manifold-Studs-s/182.htm

 

...or in kit form for other applications - https://www.ebay.com/p/ARP-400-8012-Stud-M8-X-1-25/681755904?iid=261423604071&chn=ps

 

...or at places like McMaster Carr - https://www.mcmaster.com/#studs/=1e2hd3d

[banzai510(hainz)]

The Felpro headgasket is OK for the L16 83mm size. I heard mixed results in the 85mm size as the ring edge is really close to the piston bore.

Otherwise I would try to see if you can get the grafite one from Nissan if 85mm

 

all other Felpro gaskets seem fine

 

I got my Headgaskets from Datsport Australia  Durapro brand its a Made in Japan 87mm Graphite ,they also sell a standard one also, I bought 10 at the time for 25$ apc about 10yrs ago

Edited August 8, 2018 by banzai510(hainz)

[Doctor510]

Use the one for an L18 or the L20B  If the gasket bore hole is .020" (.050mm) larger than the block hole you are good to go.  Good read above.

[Figbuck]

7 hours ago, Stoffregen Motorsports said:

Studs can be found at specialty fastener shops   ... can't open page

 

...or in kit form for other applications -  confusing... is that for exhaust?

 

...or at places like McMaster Carr - Could probably make a set if I knew how many, what sizes... all the studs got wasted removing them... then tossed.

 

 

I searched California Datsun but for some reason this didn't come up. Bad search words, I don't know.  I kept searching for some combination of Nissan/Datsun  1973 L16 Cylinder Head, intake/exhaust stud kit.

 

 https://www.californiadatsun.com/exhaust-system/datsun-intake-exhaust-manifold-studs-l16-l18-l20b.html 

 

 

I could go to O'Reilly's Auto Parts and order intake and exhaust studs If I knew what the sizes were. I have tried looking for parts numbers or any info on studs in 1973 L1600 Datsun service manual and some other places and I'm not finding anything.

https://www.oreillyauto.com/shop/b/performance-16477/exhaust-16555/exhaust-manifold-header-bolts---studs-17878/1ae38bae6636  

Edited August 9, 2018 by Figbuck

[datzenmike]

There are 3 exhaust studs. The rear most one is longer? for the engine hoist bracket.

 

Nissan Part

Qty 2..... #08214-82510

Qty 1..... #08214-82810 I imagine three of the top one would work just fine and leave the hoist bracket off.

 

 

The  studs are M8 X 1.25

 

[Stoffregen Motorsports]

I would be cautious of auto parts store studs. If they are bright (meaning silver or gold finish) then they are probably not the best quality. The better quality studs tend to be black or very dark from heat treating. The McMaster-Carr link I gave has studs with slightly larger fixed end threads to help them stay put. I like those.

[Figbuck]

I found a website that my lame bowser could open... http://www.allensfasteners.com/default.asp

 

I got ARP 300 Stainless studs, nuts and washers for the intake and exhaust manifolds. There are eleven of them. I'm doing pretty well cleaning parts and fixing things that I can't buy new or replace. The thermostat housing was frozen solid with rust. It was a lot of work to get it apart and cleaned up. I got a new temperature sender, thermostat and new stainless studs, nuts and washers to put it back together. I was so lucky... I could have destroyed the housing five different  times... I broke off two easy-outs and a bunch of drill bits.

 

I got the deck of the block cleaned off, chased the head bolt threads and cleaned them out. I scraped a thin layer of carbon off the piston tops and cleaned them up. When the head gasket failed, it took a couple little chunks off the edge and pitted the top of the #3 piston crown. Also took one chunk off the edge of the #4. I sanded them some to remove sharp edges and cleaned really well.

 

 

The next problem is to replace this part, that bolts to the intake manifold. One hose connects to the BCDD on the Carb and the the other connects to a splitter on the firewall. Is it a solenoid? Can I delete it some how? Is there another aftermarket part that can replace it?

 

The only thing I can find that seems relevant, doesn't really look like my parts. NOS part but it doesn't look right. Is this part shown mounted on the carb body?

 

Here are oics from my truck;

 

 

 

 

What is this called?

 

What does it do?

 

Can I find the OEM part?

 

Can I find an updated Nissan part?

 

Can I delete it?