A87 Cylinder Head Help!

[designateddoug]

Long Story Short - Purchase a '74  '73 620 two weeks ago and towed it home. I'm a complete novice when it comes to working on cars, I've changed a starter or two on a Civic when I was in high-school and basic maintenance. With that I decided why not buy a non-running truck and bring it back to life. Under the hood was an organized mess when I got it, car would crank but not start. I confirmed I had fuel and Spark and thanks to the Ratsun communities wonderfully archived posts I was able to check the timing and confirm everything seemed close enough the engine should fire. Still nothing, so again following older posts advise I got a leak down tester and found that all 4 cylinders had an exhaust leak which I thought was strange so I redid the test about 20 times confirming I was at TDC in each cylinder and still getting an exhaust leak... 

 

Then it hit me to check the valves, again relying on previous write-ups, I pulled the valve cover off and bought a set of feeler gauges. All 8 valves were so tight they couldn't possibly have been closing, causing causing such low compression it wouldn't fire. I adjusted as best I could, there are 2 exhaust valves that have no more room for adjustment. Turned the key gave it some gas and she fired up, down cylinder 3 which is the exhaust valve I couldn't adjust properly so assuming still no compression. 

 

Last night I went full send and pulled off the head and this is what I found:

 

Again I am a novice, is this what they mean by shaved head? The casting number seems to be almost getting cut off. 

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Shims on the cam towers.

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Valves

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Close up of #2 Exhaust Valve. Salvageable?

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Cam

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Pistons after a slight wipe down

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Spark plug hitting #1 piston (Spark plug was bent up as well, but I forgot to take a photo)

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Do you think this head is still ok? or should I skip the machine shop and just start looking for a replacement? I don't need anything crazy just a truck that runs smooth to jam around town in once in a while. 

 

Thank you for all the help, this forum is a lifesaver.

 

This is my first post, but only because I've found everything else I've needed by searching. I'll do another post soon with full story on how I found the truck and my plans.  

[datzenmike]

First, probably a projection tip plug.  Should only run NGK BR6ES I think.

 

These old engines used a bronze alloy valve seat that needed leaded gas to lubricate it. Running non leaded gas wears them and the valve slowly sinks (up) into the head removing the adjustment room. This is NOT a permanent fix .... but you can take those adjustment nuts off the pivot and carefully belt sand or have them ground down thinner. You may have to grind the pivot post down also to lower it some, but this will allow you to set the proper clearance again. I've done this and it works, HOWEVER... the valves will continue to sink up into the head but probably get another 20K out of it. If and when you rebuild, specify the hardened steel seats they use today.

 

Did you block the timing chain tensioner from falling out???

[datzenmike]

38 minutes ago, designateddoug said:

 

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This cam shows a lot of wear on the face. Bet the rocker under it is gouged also. Most likely from running today's oils that are deficient in the ZDDP levels that were used when this engine was new. Too late now, but try Shell RotellaT4. It's a diesel oil that retains the correct ZDDP levels. I run 20w15 but it does also come in 10w30. Shell Delo 400 is also good and any after market Racing oil. Any L20B cam will replace that L18 cam. They are virtually the same.

 

I advise you to look up the ZDDP controversy on line. ZDDP is being reduced yearly as it harms today's sensors and catalytic converters and new cars all use roller type lifters and don't need the extra anti scuff protection zinc supplies. Oil companies maintain that today's oils are reverse compatible but I think bullshit. I'm not grinding my precious Datsun cam and valve train. Check it out and make a decision based on knowledge. 

[designateddoug]

Thanks Mike! 

 

54 minutes ago, datzenmike said:

Did you block the timing chain tensioner from falling out???

 

Another Ratsun search find... So far the garden hose trick is working great. 😂

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I'm going to cut proper chain tensioner wedge out of plastic soon, overkill but I have a hobby CNC machine in my garage so why not 😀. Just need to draw it up and get some material.  

[Rays74]

Optical illusion or what the hell happened to #2 ex valve seat? From that pic it looks like some evil has been there

Wondering what pistons those are too, we L18 owners are always on the lookout

Edited May 24, 2019 by Rays74

[wayno]

I have never seen them pistons before, is that an L18 block?

[Stoffregen Motorsports]

Looks like a stock cam, so I can't see someone cutting those valve reliefs in the pistons. May be a BMW piston or some other OEM brand.

 

Something tells me that Nissan used a piston like that in one of the later L6s. 280ZX turbo maybe?

Edited May 24, 2019 by Stoffregen Motorsports

[designateddoug]

16 minutes ago, Rays74 said:

Optical illusion or what the hell happened to #2 ex valve seat? From that pic it looks like some evil has been there

Wondering what pistons those are too, we L18 owners are always on the lookout

 

No illusion, not sure what happened. Looks like the engine was opened up before I bought the truck and possibly before the previous owner he only had it for a bout a year. I believe it is an L18 but i can't remember the casting mark anymore I'll check tonight. 

 

Here's a picture of the engine bay from the ad when i bought it. "Running and Driving" of course not running or driving when I got there, but he had a video of it running at some point...

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When I got the car home I realized the electronic distributor he put on was not held down by anything, it was just sitting in there loosely and the plug wires were not in the correct firing order. There was also an open vacuum port near the intake I plugged. I doubt it was ever running with the carburetor and electronic distributor the previous owner installed, he also installed the correct cam gear with timing marks so I assume he or his mechanic was the one that messed up the valve adjustments when they were in there. 

[designateddoug]

Man I feel dumb... But hey I'll be the first to say I am a total noob to Datsun's. Title says 1974 and I never thought to look at the plate in the car. It's a 1973 620 with L16 block numbers match the block and the title.... Is the A87 Head ok on the L16 or should I consider finding a different head? I measured the cylinder bore with my crap digital caliper at 82.9mm the top of the pistons are stamped 0.50

[datzenmike]

An open chamber head on an L16 will have a dismal 7.72 compression. Needs a 210 head.

 

 

[Rays74]

19 minutes ago, datzenmike said:

An open chamber head on an L16 will have a dismal 7.72 compression. Needs a 210 head.

 

 

Yeah a bit underpowered but I built an L16 15yrs ago that is equipped exactly like yours Doug and it just turned 100k (std dish pistons, A87 open ch head, EI ignition etc) This is also a '73 truck with D21 rear gears for lower freeway rpms. It's no speedster but the owner has been very happy with it and reports avg of approx 27mpg using a late Dch340 Hitachi that I tuned.

As a side benefit that motor is very tolerant of any grade fuel and a bit more initial timing 😉   Would be a good turbo build lol

[Crashtd420]

13 hours ago, datzenmike said:

An open chamber head on an L16 will have a dismal 7.72 compression. Needs a 210 head.

 

 

Look at the pistons though..... definitely not stock L16 pistons.. . Maybe the dish on those is less so the compression ratio might be ok.....

 

[datzenmike]

 https://www.ebay.com/itm/Datsun-L14-an-L16-4Cyl-Piston-83-mm-020-and-030-sizes-sold-one-each-/222265876992

 

[wayno]

Well that is likely why I don't recall seeing them pistons before, L16 engines do not interest me at all.

If that were my truck I would find a complete L20b and install that, best upgrade I ever made, even better than a disc brake upgrade although if I went from what I had for brakes on the 521 work truck when I bought it(drum all around) to what I have today that would be the best upgrade without any doubt, but there were several steps in between.

You already have everything you need if you can find an L20b short block, but I would just get a complete running engine if possible as that head needs major work which will cost money that could be spent on an L20b, a Z20 block might also work, a Z22 block would work also, but that would need modifications likely above your experience right now.

The L16 is a gutless engine, if you drive it like you stole it it may seem like it is fast, but an L20b will leave it behind, best upgrade I ever made at the time.

 

 

[Rays74]

Aww the little L16 ain't so bad 🤩...... good for a self described "noob" to learn on and at least get running and enjoy the truck as is since it's already in the truck THEN find another engine (L20B) to build up in the mean time.

Get your truck running as is Doug, hard to know if the pistons and rings etc are any good without a healthy cylinder head so start there first. A decent 210 head shouldn't cost you a little bit of nothing since they aren't anyone's choice for HP but will be good for your build, a closed chamber A87 would good too but that will be more $$ as now we're looking at a more desirable piece. 

Don't discount the fact that to be able to drive your project as you work on it is the coolest part of owning a vintage Datsun .......  don't tear it down unnecessarily 🙂  

 

Edited May 25, 2019 by Rays74

[wayno]

I had an L16 in my work truck when I first bought it, it didn't like going 70mph on the freeway except going down hill, but the straw that broke the camels back for me was when I tried following my friends in their Dodge diesel up the hill(logging road) to fly our hanggliders at the local flying site, even in first gear it didn't have the torque to keep moving, and once it stopped I could not get it going up that hill again, I was able to go back down the hill to a flatter spot, turn around and wait till I knew my friends were at the top and drive it up the hill as fast as I could in first and get to the top, but there were 90 degree cliff corners I had to get around, I bought an L20b in the next couple days and installed it to have it ready for the next weekend, that L20b would go up that hill in 2nd gear following anyone going any speed, that L16 could not do that in first gear.

I kinda look at it like why spend the money on a lost cause when one would be so much happier with a better engine, my machinist told me that my valves were sinking into the head because of where my foot was all the time(floored), it wasn't because of the seats, yes the seats are not made for the gas sold these days, but if your not floored all the time they will not sink near as fast, but I was always floored with that L16 in the truck as most my driving was on the freeway driving to hanggliding sites and driving up hills to get to the top of the hill, and putting money into a A87 head is not a lost cause, but in my opinion putting money into a daily driven L16 is.

 

[Crashtd420]

5 hours ago, datzenmike said:

 https://www.ebay.com/itm/Datsun-L14-an-L16-4Cyl-Piston-83-mm-020-and-030-sizes-sold-one-each-/222265876992

 

That explains that..... 

 

[datzenmike]

On a good day....

L16 70 HP

L18 80 HP

L20B 90+

 

This would be Net. My L20B says 110 HP but if you remove 18% for losses.... and this does not tell half the story. With increased displacement comes increased torque.

[Rays74]

1 hour ago, wayno said:

I had an L16 in my work truck when I first bought it, it didn't like going 70mph on the freeway except going down hill, but the straw that broke the camels back for me was when I tried following my friends in their Dodge diesel up the hill(logging road) to fly our hanggliders at the local flying site, even in first gear it didn't have the torque to keep moving, and once it stopped I could not get it going up that hill again, I was able to go back down the hill to a flatter spot, turn around and wait till I knew my friends were at the top and drive it up the hill as fast as I could in first and get to the top, but there were 90 degree cliff corners I had to get around, I bought an L20b in the next couple days and installed it to have it ready for the next weekend, that L20b would go up that hill in 2nd gear following anyone going any speed, that L16 could not do that in first gear.

I kinda look at it like why spend the money on a lost cause when one would be so much happier with a better engine, my machinist told me that my valves were sinking into the head because of where my foot was all the time(floored), it wasn't because of the seats, yes the seats are not made for the gas sold these days, but if your not floored all the time they will not sink near as fast, but I was always floored with that L16 in the truck as most my driving was on the freeway driving to hanggliding sites and driving up hills to get to the top of the hill, and putting money into a A87 head is not a lost cause, but in my opinion putting money into a daily driven L16 is.

 

 

I get it Wayno, your circumstances dictated no L16's for you....... extreme circumstances 🙂    The folks that had to deal with Model T's shortcomings speak the same way LOL 😛

Do what you want Doug, you know how I feel about the small bore short stroke revvers....... 😉 holler at me if you need help, I'm not far.

[Stoffregen Motorsports]

20 hours ago, wayno said:

I had an L16 in my work truck when I first bought it, it didn't like going 70mph on the freeway except going down hill, but the straw that broke the camels back for me was when I tried following my friends in their Dodge diesel up the hill(logging road) to fly our hanggliders at the local flying site, even in first gear it didn't have the torque to keep moving, and once it stopped I could not get it going up that hill again, I was able to go back down the hill to a flatter spot, turn around and wait till I knew my friends were at the top and drive it up the hill as fast as I could in first and get to the top, but there were 90 degree cliff corners I had to get around

 

Reminds me of that Albert Finney movie "Two For the Road", where the MG they were driving wouldn't make it up the hill going forward, so they drove up it in reverse.

[wayno]

I didn't even think of that, I was very upset about having to unload the guy and his glider onto another truck so he could fly, I started down the hill and when I seen that semi flat spot in the road at a hair pin turn(180), I decided to try one more time and made it to the top screaming up the hill in first gear, but that was the last trip that engine ever made, the next weekend I had an L20b in it, and soon it also had dual SUs, that truck would climb steeper hills in 2nd gear with that engine, I was very happy about that upgrade.

That was in the 90s, and I upgraded to an LZ23 around 2011 as that poor L20b was beat to death, when I added oil every morning(yes every morning) and started it there was a cloud from some of that oil getting by the valve seals, and it had major blow-by.

It's been about 8 years now on the LZ23 and it hardly uses any oil, and I have another one already made to replace it but it has never run better since I re-curved the matchbox distributor, I should have done that years ago.

 

[datzenmike]

The L16 521 uses a 3.657 first and a 3.638 reverse so reverse was  virtually the same.

[designateddoug]

 

@Rays74 leaning towards your suggestion of just getting the truck running and so I have a driving project truck while I look for an L20B. Engine was a thought initially when I wasn't getting the engine to start. I forgot to mention the worst part of my truck... It's an automatic. I had looked for L20B's with manual transmission package deals and found a few but they were all in the $1,000 range and no idea if the motor or trans would be any good to begin with. 

 

A friend suggested an SR20DET swap which is what he had in his 510 prior to selling it. I was leaning more towards an SR20DE since I wouldn't have to deal with the turbo and a JDM SR20DE with Manual Transmission in SoCal straight from the importers run around $1,800... But I also like the more period correct thinking of the L plus it being a really straight forward swap would save me time and money. 

 

With that said, searching for a 210 Cylinder Head, I've only found 1 near me and he's asking $450 on a "Slightly" used setup... http:// https://losangeles.craigslist.org/sgv/pts/d/datsun-4-6-cyl-heads/6896070842.html

 

Seems like a lot on a Cylinder Head that doesn't sound like it is in high demand. 

 

L20B's have also been slim picking on CL and Facebook Marketplace. I just messaged this add inquiring about the motor and trans https://orangecounty.craigslist.org/pts/d/mira-loma-79-datsun-nissan-720-truck/6869913173.html

 

We'll see if he gets back to me and how much. 

 

What would be a good price on L20B? I've seen a couple in the $500 range but they look like they been sitting out in the elements for a bit, and maybe more work than they're worth. 

 

The other options that pop up for cylinder heads or complete engines are from California Datsun, I plan to research more on the company. From the few things I've seen their reputation isn't that great and even then by the time I add accessories to a long block and buy a 5 speed I could buy a SR20DE and the @]2eDeYe mounts... Or a second 620... haha

 

My head is spinning. 

[datzenmike]

 

This head has been milled down some. If you remove 0.060" from a stock head this would remove about 8cc from the combustion chamber making it just a hair smaller than the stock 210 and this would bring your compression back up to over 8.6, and you'd have the larger valves and ports.  Accurately measure down from the valve cover surface to the bottom f the head. An uncut head should be 4.248" If less it's been cut.

[docbainey]

Complete L16 & 4sp in the Ratsun classifieds for $450