Pull the head..A few questions before its offed!

[Buzzbomb]

I thought I'd have a few more questions before taking the head off :) ...I've watched Hainz's video a few times already, but wanted to clarify a few things after searching here to be sure I'm on the right track.

 

I have my engine currently set at 0 on the timing mark. TO verify I'm at TDC on #1, the exhaust lobe is at 10 and the intake at 2, right? I'm pretty sure that I DO have this setting right. I have 10 and 2, but honestly I'm not sure if it was E or I. I was sure at the time, but now I can't remember which lobes were what :o ... I'm sure this setting is THE most accurate way to check TDC since the distributor rotor might not be all that accurate in relation to how the cap is on? Just being sure on this since I understand this is critical.

 

I read a few things here about rotating the crank and valvetrain timing, hence my next question. I have an L20B, and I want to use the cam boss to help break the cam bolt loose. However, the only way you can get the wrench on the boss in the right position is to rotate the engine counterclockwise from TDC so you can butt it against the head. I don't want to be adding any unecessary slack to the chain before I add the chain stuffer. I want to move it CCW to set the wrench, break the cam bolt loose, and then rotate it CC right back to where it was since it's in such a great spot for ease of putting it back together. The bright link is right on the number one mark at 2 o'clock. If I go back 10 sprocket teeth or whatever to set the wrench, I'll get those teeth back when I move the crank back to TDC. However, will the timing setting still be reliable if I move the crank CCW to set the large Crescent wrench (ie. Hainz's video), and THEN move it back CC to TDC after I loosen the cam bolt?

 

Any tips on cleaning the thread holes for the head bolts? I know this is critical too...

 

Couple of unrelated questions since I have the stuff tore apart :lol:

 

Would a 190 thermostat help out for warm ups in cold Winter regions? It's recommended as "Cold REgion" but it doesn't say what the Cold Region is :blink: ..

 

Totally Unrelated question- on the throttle linkage for the carb where the cable inserts, what's that screw with the spring for? It doesn't look like it goes to anything!? It's not the fast idle screw, and not the throttle screw?! Just curious...

 

Thanks for the info so far..It's been a real help to have some idea of what to expect when attempting this job. I know I'm not setting any speed records here, but I'd like to do it ONCE and do it RIGHT. If I can pull this off successfully, I'm going to have to get a Ratsun sticker for my rear window :cool:

[datzenmike]

I thought I'd have a few more questions before taking the head off :) ...I've watched Hainz's video a few times already, but wanted to clarify a few things after searching here to be sure I'm on the right track.

 

I have my engine currently set at 0 on the timing mark. TO verify I'm at TDC on #1, the exhaust lobe is at 10 and the intake at 2, right? I'm pretty sure that I DO have this setting right. I have 10 and 2, but honestly I'm not sure if it was E or I. I was sure at the time, but now I can't remember which lobes were what :o ... I'm sure this setting is THE most accurate way to check TDC since the distributor rotor might not be all that accurate in relation to how the cap is on? Just being sure on this since I understand this is critical.

 

I read a few things here about rotating the crank and valvetrain timing, hence my next question. I have an L20B, and I want to use the cam boss to help break the cam bolt loose. However, the only way you can get the wrench on the boss in the right position is to rotate the engine counterclockwise from TDC so you can butt it against the head. I don't want to be adding any unecessary slack to the chain before I add the chain stuffer. I want to move it CCW to set the wrench, break the cam bolt loose, and then rotate it CC right back to where it was since it's in such a great spot for ease of putting it back together. The bright link is right on the number one mark at 2 o'clock. If I go back 10 sprocket teeth or whatever to set the wrench, I'll get those teeth back when I move the crank back to TDC. However, will the timing setting still be reliable if I move the crank CCW to set the large Crescent wrench (ie. Hainz's video), and THEN move it back CC to TDC after I loosen the cam bolt?

 

Any tips on cleaning the thread holes for the head bolts? I know this is critical too...

 

Couple of unrelated questions since I have the stuff tore apart :lol:

 

Would a 190 thermostat help out for warm ups in cold Winter regions? It's recommended as "Cold REgion" but it doesn't say what the Cold Region is :blink: ..

 

Totally Unrelated question- on the throttle linkage for the carb where the cable inserts, what's that screw with the spring for? It doesn't look like it goes to anything!? It's not the fast idle screw, and not the throttle screw?! Just curious...

 

Thanks for the info so far..It's been a real help to have some idea of what to expect when attempting this job. I know I'm not setting any speed records here, but I'd like to do it ONCE and do it RIGHT. If I can pull this off successfully, I'm going to have to get a Ratsun sticker for my rear window :cool:

 

Loosen the cam sprocket first before setting to TDC.

 

Looking at the #1 cam lobes is only to check that you are on the compression stroke and is in no way meant to be used to guess where TDC is. Use the timing notch on the rear crank pulley and the timing scale bolted to the timing cover. Turn the crank clockwise and stop at TDC. If you go past, return the crank to well before TDC and try again. The crank must move ONLY clockwise and stop at TDC... If you over shoot TDC do it over again until it's right. This method keeps the tension side of the chain tight and gives the most accurate readings for chain slack.

 

If the bright link is on #1 it's just a fluke. Be sure to magic mark the chain and the sprocket so they go back on exactly the same position.

 

To clean the thread holes you can use a suitable bottoming tap OR get an old head bolt and grind a narrow notch lengthwise down the threads to remove them. Rub a little grease in the notch and thread the bolt into the block. Tighten in lightly with a wrench and back out going deeper each time. Take it out and wipe off the old grease which has collected dirt and gasket crap on it. You may have to grease it and do a second time till it's clean. Spray out with WD-40 and blow out with air.. do not get that shit in your eyes!

 

Put rags in the #2 and #3 cylinders and buff the block surface clean with a wire wheel on a drill or angle grinder. Do the same with the head but be careful... the aluminum is softer. In both cases you cannot get either surface too clean. Clean and smooth is vital.

 

A 190 won't warm up faster but will run hotter which is good for defrosting windows. You didn't put your location in your profile so I can't help you there.

 

TIP: block the wheels and leave tranny in NEUTRAL. While working on vehicles it's too easy to push or bump against it and if in gear it could bump the motor off TDC and loosen the chain wedge.

Edited February 21, 2009 by datzenmike

[Buzzbomb]

Looking at the #1 cam lobes is only to check that you are on the compression stroke and is in no way meant to be used to guess where TDC is. Use the timing notch on the rear crank pulley and the timing scale bolted to the timing cover.

 

OK, I hear you on this..I'm definitely using the timing tab and crank notch to set TDC, BTW. I just want to verify that I'm right on, that's all. Both of my number one cam lobes are off of what are basically the "pushrods" (sorry, I'm used to V8 terms :o ), so I assume my valves are closed and I'm at TDC on the compression stroke.

 

Turn the crank clockwise and stop at TDC. If you go past, return the crank to well before TDC and try again. The crank must move ONLY clockwise and stop at TDC... If you over shoot TDC do it over again until it's right. This method keeps the tension side of the chain tight and gives the most accurate readings for chain slack.

 

This is where my confusion lies...I want to use the Crescent wrench on the cam boss to help loosen the cam bolt instead of a screwdriver through the sprocket. However, it appears the best way to get that wrench tight to the head is by rotating CCW until it hits the bolt on the head, as Hainz shows in his video. If rotating it only in the CW direction to TDC is primarily for checking chain slack, I DID do that a few days ago. My concern now is more with the wedging the chain than with checking chain wear. It just looks like the wrench on the boss is much easier than the alternative, but I DO want to keep the chain tight, obviously. I'm also not planning to take the front cover off.

 

I guess what I'm asking is could I do the wrench on the boss/hit the wrench on head bolt/loosen cam bolt by going CCW, THEN rotate back to TDC going clockwise, and still have the chain tensioned properly? Sorry for the confusion here..However, I know this chain business is serious when it comes to this job.

 

If the bright link is on #1 it's just a fluke. Be sure to magic mark the chain and the sprocket so they go back on exactly the same position.

 

I know it's a fluke..but it sure would make it that much easier! I thought I got lucky with that, so why fight it :D

 

Thanks for the other tips! Is it possible to buy a single right sized bolt at NAPA or ? I wonder if the bolt size is in the Haynes manual. My guess would be a used bolt isn't an option here. Also, I'm assuming that the wire wheel should be brass?

 

Good idea about putting it in Neutral. I already have 4 wheels chocked since I'm on a steep driveway.

 

I guess I'll keep my thermostat..I don't need my truck running hotter. It ran fine before it blew it's stack.

 

Thanks for the help, Datzenmike..I sure appreciate it. :thumbsup:

Edited February 21, 2009 by Buzzbomb

[datzenmike]

Loosen the cam sprocket first before setting to TDC.

 

Lock the cam any way you like. Not critical. Loosen the cam sprocket bolt (don't remove yet) with a Johnson bar or ratchet with handle extension. Remove the locking device you used.

 

NOW, set the TDC as described. Setting at TDC is a precaution should anything get mixed up. Knowing where you started from will help.

 

The cam sprocket retaining bolt can be re-used indefinitely.

 

 

There are two TDCs Compression and exhaust. You want compression... both valves closed. The rocker arms are under the cam so if both lobes are up at approximately 10 and 2 o'clock then both valves are closed and you are on compression.

 

A brass wire wheel is good on the softer aluminum.

Edited February 22, 2009 by datzenmike

[Buzzbomb]

Thanks for the clarity, Datzenmike .... :w00t:

 

The next few days are supposed to have better weather, so I'll be hitting it again, armed with more info and confident I'm following the right process :cool:

[what]

I bought a 160 thermostat for mine. My pickup always seemed to run a little warm and buying the 160 thermostat was the answer. Hope this helps.

[Buzzbomb]

I bought a 160 thermostat for mine. My pickup always seemed to run a little warm and buying the 160 thermostat was the answer. Hope this helps.

 

That's good to know just in case...My truck really never had problems going to the higher end of the warm end of the scale until recently. I think the reason for this is that my headgasket was slowly becoming a problem and for whatever reason was causing it to run hotter than it usually did. It was more of a problem over the Summer, but last month before it blew its stack, it was running warmer than normal. I was normally 1/4 to just less than 1/2 way up the scale, but lately I had been getting into the over 1/2 to 3/4 up the scale range. Of course when my gasket truly blew, it was about 2 or 3 needles short of hot, but I stopped half way home and filled it back up to buy some time to get home.

 

I used the CCW turn/Crescent wrench to loosen the cam bolt like Hainz shows in his video. I had nearly a full turn back to TDC via CW, so the chain seems as tight as it was when I checked the slack. Next up is to stuff the chain with the stuffer I bought, take the head off, and clean it ALL up real nice :blink: . I can't complain too much so far. It seems intimidating when you've never attempted a project like this, but I'm honestly glad I decided to try to fix it right instead of using the quick fix. I probably would have had to do it soon anyway :o

Edited February 22, 2009 by Buzzbomb

[Buzzbomb]

Had some time today, and pulled the head off..It was pretty easy. ONly thing is I forgot to use the chain stuffer!?! :eek:

 

Just kidding :D..Maybe I shouldn't joke about that-it's not back on the sprocket yet :eek: ! It went pretty good, and my gasket was garbage. There is no way any leak stopper could have fixed it. I can't believe it wasn't smoking. Now to shine it all up real nice, and maybe source myself some head bolts for a decent price. I know you can sometimes reuse them, but honestly, some are pretty ugly lookin' :rolleyes: .. It could be worse, though.

 

Thanks for all the help so far...All the great info has been spot on :cool:

Edited February 24, 2009 by Buzzbomb

[Phlebmaster]

Glad you are getting her fixed...how about some pics of the work??

[Buzzbomb]

Thanks for the encouragement!

 

I'm just waiting and cleaning...Waiting for the gasket set, and cleaning the gasket surfaces as much as I can. I had some head bolts that were really nasty, and honestly I was afraid to reuse them. Long story short, there is a shop that specializes in Nissan, and the guy knows about the old stuff. I called him up after being referred to him from the local NAPA, and he gave me 1/2 dozen nice long and short head bolts! Pretty :cool: . A few of my bolts were beyond cleaning up, and I'm super glad this guy helped me out.

 

Out of curiousity, I've been doing a little reading about the heads for these trucks/cars, just so I'm familiar with what I have. Turns out I have a W58 closed chamber head, which is kind of neat. Even more reason to try to pull this off successfully.

 

Just as an FYI for those that choose to pull heads without the front cover..I found this timing chain tool at Checker on clearance for less than $5. If you go to your local store and order it, you don't pay shipping. So far so good with it...Hopefully it stays that way.

 

http://www.partsamerica.com/ProductDetail.aspx?MfrCode=PBI&MfrPartNumber=648831

 

Here's a semi-current pic of the truck causing me all these headaches :D ..Looks a little nicer in the pic than it really is. I guess that's its good side :P

 

 

Here's my truck right after it was painted YEARS ago...

 

Edited February 26, 2009 by Buzzbomb

[Phlebmaster]

Try changing your pic settings to show full size. I am not sure about webshot...but if you upload your pics to tinypic you can choose the pic size.

 

I have a W58 closed chamber too...I like it alot. :D

 

 

Edited February 26, 2009 by Phlebmaster

[Buzzbomb]

I just overlooked the tab for the size of the pics..Thanks for changing it :)

 

Way back when, I drove a '79 Toyota with a 20R? 2WD, and honestly it felt like kind of a dog compared to my truck. I don't know if that's the combination of gearing/head/trans or what..The L20B engine and the 5 speed tranny + some pretty steep rear gears make for a pretty peppy little combo, plus I was pulling around 30 mpg with it before it got angry :o . I had a 2.25 exhaust put on from the manifold back with a turbo muffler, and I'll tell you what..That really woke it up. My truck made me a total Datsun/Nissan fan years ago. I'm always excited to read about something like the GT-R because I think Nissan is a great car maker.

 

Although this whole undertaking wasn't exactly planned, it's neat learning about how to do stuff to these cool little engines. I have always wanted to put a Weber on my truck, but don't know whether or not it pass the sniffer test. If it would, that might be my next project :) ...

 

Just got to get my gaskets now, and make sure everything goes back together CLEAN and RIGHT.

Edited February 26, 2009 by Buzzbomb

[datzenmike]

. Turns out I have a W58 closed chamber head, which is kind of neat. Even more reason to try to pull this off successfully.

 

They (closed) didn't come on the '80 trucks but this may have been a factory replacement done by the dealer. Very cool to get a closed to replace your old open one!

 

Oh, get a picture of it too!

[Buzzbomb]

They (closed) didn't come on the '80 trucks but this may have been a factory replacement done by the dealer. Very cool to get a closed to replace your old open one!

 

Oh, get a picture of it too!

 

Since you guys asked, I took some pics of the head...It's a work in progress; I'm still trying to clean the gasket surface. I think some of it is stained and just isn't coming off. It's hard to clean with all the intake and exhaust on, so I never cleaned it while it was on the truck :P . I inherited some machinists tools, and have checked the head here, there, and there some more, and it doesn't seem to be warped..PHEW.

 

Funny thing is if I look at it from the side, it's like a mirror. Anyway, I am going to get at least try to get some of the outside crud off too. I took these pics with a phone camera, so the quality might not be that great. The phone cam also makes the intake valves look darker than they are since it isn't a detailed pic. They look pretty nice, really.

 

My intake manifold also has the W58 number on it, so maybe it was all swapped as a unit?

 

THe whole head:

 

 

 

The closed chamber:

 

 

The head#:

 

Edited February 27, 2009 by Buzzbomb

[datzenmike]

Nice! Has exhaust liners right?

[Buzzbomb]

Nice! Has exhaust liners right?

 

It does have the liners in the exhaust ports. Those are for emissions purposes, right? Maybe to burn stuff off? So this was more than likely a dealer installed replacement head? I'm only the second owner of the truck, and the first owner wasn't all that mechanically inclined, although he was meticulous about regular maintenance. I guess at some point for some reason the original head was replaced...but with something a little better :cool: .

 

I know it looks kind of cruddy at this point on the outside, but I am trying to get years of crap off of the outside of it. It's cleaner on the inside than out, and for that I am pretty happy. It never burns oil or anything, so I suspected it might be oK, but you never know.

[datzenmike]

I seem to recall Doug saying something like that. Maybe not him though. ???

 

I had one I saved from the wreckers. Had a tag with '79 200sx on it ... so maybe IT was a replacement too??