L20B Head dilemmas; Rebuild? Swap? Cam?

[KlassicMotion]

if you have a later L motor there is 2 knobs on the center cam. put a big adjustable on it turn the motor till the Wrench locks up on the head bolt loosen the sprocket bolt then turn head back to TDC and loosen up everything

Like in my Vid I explain this

 

Gotcha. Thanks.

[KlassicMotion]

Closed Chamber W58?? 

 

[banzai510(hainz)]

Looks like it!!!!!!!!!

[budsaipan]

Closed Chamber W58?? 

 

 

 

Hey was it you that bought my l20b in kansas? 

[wayno]

Yep, looks like one, sure are a lot of them around considering they are suppose to be rare, I have 2 of them myself.

Closed Chamber W58?? 

 

Does your A87 have the same size valves as this one?

[KlassicMotion]

Hey was it you that bought my l20b in kansas? 

 

Yeah Tyler, that was me.  I still have that engine back in Kansas at my Father's house.  Have you gotten settled down in Washington?  How is the 620 project? 

[KlassicMotion]

Yep, looks like one, sure are a lot of them around considering they are suppose to be rare, I have 2 of them myself.

Does your A87 have the same size valves as this one?

 

I don't have the A87 head on hand to physically measure, but from the pictures I posted, they look pretty close....  There is a car show this weekend, so after seeing that the W58 is a closed chamber head, I think I'm going to throw it back on and see what happens.  As easy as it is to pop the head off, I can always go back and swap things out.  I didn't realize just how easy it is.  It took me 20 minutes and that was being careful.  I'm used to small block V8s that require a lot more time taking off the intake and sealing it back up.

[budsaipan]

Yeah Tyler, that was me.  I still have that engine back in Kansas at my Father's house.  Have you gotten settled down in Washington?  How is the 620 project? 

 

Hey wassup man, looks like you're making great progress. I'm settled in washington now, got a place and the 620 is getting there slowly. Been too busy trying to settle but things are progressing now that I'm situated. 

 

Are you in alaska now? Keep up the great work.

[KlassicMotion]

Hey wassup man, looks like you're making great progress. I'm settled in washington now, got a place and the 620 is getting there slowly. Been too busy trying to settle but things are progressing now that I'm situated. 

 

Are you in alaska now? Keep up the great work.

Great.  I can't wait to see some pics of your progress.

 

Yeah, we're just settling into Alaska.  I'm finally getting some good work in on the 510.  It should be back on the road in a couple days.  After that, my suspension parts should be in and I can get the car lowered, then polish the paint, then a headliner, on and on...

[datzenmike]

I found a closed chamber W58 in a yard once marked '79 200sx. I checked and the '79 200sx the A10 and 620 all used the same head. I don't think we got them here and they came on import motors from Japan just like all the Hitachi SUs and intakes.

[KlassicMotion]

I found a closed chamber W58 in a yard once marked '79 200sx. I checked and the '79 200sx the A10 and 620 all used the same head. I don't think we got them here and they came on import motors from Japan just like all the Hitachi SUs and intakes.

 

You know, my engine is a 1980, I was wondering if it was a last year run, thing.  Maybe like 1979-1980 used closed chamber?

[datzenmike]

No the only L20B engine in '80 was in the 720 truck... or the Canadian A10. In the states the Z20 was used for that year car. If all 720s had closed chamber heads we would all be looking for them, they weren't.

[KlassicMotion]

Ok.  My theory just seem to explain maybe why there are so many W58 closed chamber heads out there.  A quick search on here turns up 5 or 6 accounts of W58 peanut heads....

[datzenmike]

Very rare to find. Trust me only the closed chamber heads are mentioned, what about all the 620/720/A10 and S10 cars and trucks with open chamber heads out there not worth mentioning? 

[KlassicMotion]

Back to the issue of using a square port header on a round port head:

 

If you consider the position and diameter of the steel sleeves inside the exhaust ports, and match that to the positions of the square ports, there really isn't that much miss-alignment.  Again, it may not be "ideal", but it sure seem to run well.  Especially when you consider the non-availability of a round port header.  And, if I wanted, I could spend some more time cleaning up the ports on the header, but they look good enough for now. 

 

[Ranman72]

you can go round head to square manifold but square head to round manifold is no good 

so your set up is fine

[cruznude]

Your build is looking good. Do or can I say, do you have a pic of your PVC install?  I noticed you made some blocking plates where smog was on intake.  What is that connected in the middle of intake with a hose.  Looks kike it goes through fender or something.  You see I also have the w58 and I stripped all the smog shit and am doing the header(round port) and installed a 32/36.

[KlassicMotion]

Your build is looking good. Do or can I say, do you have a pic of your PVC install?  I noticed you made some blocking plates where smog was on intake.  What is that connected in the middle of intake with a hose.  Looks kike it goes through fender or something.  You see I also have the w58 and I stripped all the smog shit and am doing the header(round port) and installed a 32/36.

 

I might do it a little different next time.  I cut the L20B crank tube shorter than I think I like.  I used the stock crank tube elbow since it goes from a large diameter to a smaller diameter.  I can't remember the sizes, but I think it was like 1" down to 5/8".  Then I used a "T" adapter I found at O'Reilly's to connect the fuel vapor line into the system.  I had to use another hose diameter reducer to connect the fuel vapor hose into the "T" adapter.  On the intake manifold, I drilled out the center hole larger and tapped it to accept the original PCV.  I then drilled out the other two holes and tapped them to accept plugs.

 

[cruznude]

That actually looks real good!  Does the PCV run back into the exhaust?  This is just to release the gases correct?  You actually took good pics.  Since I'm striping the smog, would something like this benefit me?  On my last 79kc I ran dual sidedrafts with a header and stripped it all down also and had no problems.  Do I need the PVC or would I just be wasting my time?  Whats it gonna benefit to me?

[flatcat19]

Yes.

You need the PCV.

[wayno]

That actually looks real good!  Does the PCV run back into the exhaust?  This is just to release the gases correct?  You actually took good pics.  Since I'm striping the smog, would something like this benefit me?  On my last 79kc I ran dual sidedrafts with a header and stripped it all down also and had no problems.  Do I need the PVC or would I just be wasting my time?  Whats it gonna benefit to me?

 

Yes you need a PCV, and this is why, before the PCV valve was introduced, you would be lucky to get 100,000 miles out of an engine.

After it was introduced, it is common to see rigs with over 200,000 miles, and when the engine is pulled apart, it is clean compared to an engine without a PCV valve, I have seen an engine with an inch of sludge everywhere inside the block.

[KlassicMotion]

I can't explain it as well as the manuals do, but under certain circumstances, the PCV system on the Datsun requires the carburetor to suck the gasses out of the valve cover.  So for the system to work properly, you need the valve cover port to hook up to the air cleaner area.  I drilled a hole in the air cleaner base plate and found an elbow adapter that fit.  No problems thus far.

 

In my picture you can also see the fuel vapor line hooked up the same way.  If your going to use the fuel vapor system, the 32/36 carb should have a brass port that my 38 DGES does not have.  It should be in the location I'm pointing to on the carburetor.

 

All the hardware I used was from O'Reilly Autoparts, or Ace Hardware.

 

[flatcat19]

Man.

I like your motor.

[KlassicMotion]

Thanks.  I'm still cleaning things up, and still trying to work out some of the issues....

 

New head gasket on:  Fixed coolant leak, shaky vacuum gauge reading, and idles smoother now.

 

I've still got some issues that feel like fuel related.  I will look into those tomorrow.  One reason may be the high fuel pressure showing on the pressure gauge there in the picture.  Float level may be the other reason. 

 

But most concerning is the valve noise.  It was there before and after the gasket replacement... Maybe the engine's running lean?....  It seems to tick after it gets warm.  Sounds like it's coming from #4.  I used my stethoscope, but I think the noise went away at that point... I will check again tomorrow.

 

Also, I've set the valves three times now since I started really driving the car in the last month.  First was cold, most were way loose (which I expected since I don't know if the previous owners ever set them).  Second was hot, and some were tight, some loose.  Third, was after I put the head back on from this gasket replacement, most were too tight.  I will get it hot again in a few days and check them again.

 

My process:  I check the gap, from the left and right.  I set it with a decent amount of friction on the feeler gauge, but not so much that it sticks.  I loosen the jam nut, set the adjuster nut, tighten back up, test again.  .008/.010 cold, .010/.012 hot.

 

The timing chain is within factory specs.

[oldskoolvws]

It is actually the square port header..... Before anyone gets their panties in a bunch, I thoroughly experimented with the setup first.  I tried a few different gaskets, studied them on square and round port heads, then I Gasket matched the header to the gasket itself.  It may not be a perfect fit, but at most, there is only maybe 3% "restriction".  I ended up using the Felpro gasket *MS22801* for the round port L20b.

 

First off let me rant on the quality of the Top-End header.....  It came to me as pretty much junk.  Who ever welded the primary tubes into the flange did not get full penetration, but they obvoiusly tried to cover it up by adding more weld.  The ports were tiny.  So I took my carbide bit and cleaned them up and re-welded the areas that did not get full penetration.  Next was the flange itself.  Again, who ever welded the header obviously had some pretty sloppy welds, because they took a grinder to the flange and totally warped it.  There was no way, even with a thick header gasket that it was going to seal.  So I took it to my machine shop and had it planed back to true.

 

Anyone considering this header should be ready to re-work it, or take it to someone to have it re-worked.

 

I just finished almost the same with this header and can second the statements above. On mine, I also welded the exterior of the flange to the tubes. Because they ground down the matting face of the header and tried to semi-port the insanely small ports, its thin in a lot places, it had no strength. Out of the box, pretty poor assembly. The materials are good, just the assembly and craftsmanship leave a little to be desired. I would not dare run this uncoated. The welded areas would be gone very quickly.

 

Regarding the gasket, in every car I can possibly run it in, I only run Remflex exhaust gaskets. They are pricey but you will not leak unless it's your fault on installation. These things will make up some serious gap and seal hardcore. If you need a custom install and your good with a razor and punches, they also sell blank sheets.

 

Here's the Datsun / Nissan link: http://catalog.remflex.com/category_s/50.htm