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My B210 keeps leaking oil from the head gasket. Why???


BestyBlue77

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Hey gang! It's been a lil while, but I need some advice. I have rebuilt two B210 engines on a '76 sedan and '77 sedan. On both vehicles the head gaskets have started leaking oil. I have also been rebuilding and restoring a '77 coupe. I have noticed the same problem happened with the coupe. It hasn't ran in 30 years, but I've been hard at work for months ripping it apart, and restoring the engine components one by one. I'm almost done rebuilding the cylinder head. I can tell that the head was leaking oil for quite a long time while still running and being driven. Then eventually the head gasket blew completely, she bent a rod, and then she sat for 30 years. The interesting thing is that this car only has 89k original miles on it. So why do these A14s keep leaking oil at the head? How do I keep this from happening again? I am insanely detail oriented and I double, and triple checked everything along the way. Torqued brand new cylinder head with sanded and trued engine block with new head bolts. Fel-pro head gasket kit. The engine and radiator were flushed thoroughly, new rear main oil seal installed at the auto shop, along with new clutch, rebuilt tranny (the bearings were worn), new water pump, carb rebuild, new fuel pump, new dizzy, new ignition coil, new plugs, oil pan dropped and gasket replaced. Drove it 100 miles then retorqued as recommended in Chilton's. I thought I covered every base. What am I missing? Wrong torque from factory? Idk. HELP!!!

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Any chance this is a drip from the valve cover gasket????

 

Was the head checked for flatness?

 

What was the torque specs for the head bolts? Aluminum head on iron block should be in the high 50s?

 

Doesn't the '74 and on heads feed the oil from the block up a head bolt hole???? The original oil feed hole is sealed up at the block surface and a horizontal hole drilled through the oil gallery into the bolt hole and the outside of the hole also plugged. Seems to me maybe the top plug may be leaking. You can drill and tap this hole and add a screw in pipe plug.

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Does the oil leak all around or only in one spot? As Mike said, one of the head bolts is an "oiler" and looks different from the rest (at least this is the case on A12 engines and I think it is the case for a "A" engines.

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17 hours ago, datzenmike said:

Any chance this is a drip from the valve cover gasket????

 

Was the head checked for flatness?

 

What was the torque specs for the head bolts? Aluminum head on iron block should be in the high 50s?

 

Doesn't the '74 and on heads feed the oil from the block up a head bolt hole???? The original oil feed hole is sealed up at the block surface and a horizontal hole drilled through the oil gallery into the bolt hole and the outside of the hole also plugged. Seems to me maybe the top plug may be leaking. You can drill and tap this hole and add a screw in pipe plug.

Hey Mike! Yes, I did the straight edge with feeler gauge, and everything was perfect. Also, yes there is an oiler head bolt and it is in that area on the side of the head where the leak always starts. The head bolt torque spec is 51-54 ft. lbs. I have a old school torque wrench, so I was right in the middle of that, and I retorqued after 600 miles. 

It's not the valve gasket. Everything is clean & shiny above the block. It's right under where the two meet that it's leaking just on the side where the oiler head bolt is. Let me snap a few pics to see what might be happening.

On a side note another Ratsun guy Noramost was a Datsun mechanic for over 25 years and mentioned that that oiler bolt should have had a red washer/o-ring that would have fit into that head bolt hole. I asked at the dealership when I ordered new head bolts, but he said he couldn't find anything on it. Hmm? Not sure on that one.

This is the most concentrated area of the leak. Just next to the outer oil plug: 20180904_102951_zps3tg2lwon.jpg

 

Edited by BestyBlue77
Added pic
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1 hour ago, KELMO said:

Does the oil leak all around or only in one spot? As Mike said, one of the head bolts is an "oiler" and looks different from the rest (at least this is the case on A12 engines and I think it is the case for a "A" engines.

Hey Kelmo! What's up?! I originally noticed a small oil leak right in the middle under the head at the oiler bolt area where head and block meet. At first I wasn't sure where the leak was coming from. And it was coming from more than one place. The oil filler cap cork gasket was shot on my old cap. Thanks for giving me back that other one. That solved one problem. The more I drove it the more oil it was using, and I thought maybe my mechanic screwed up when he replaced the rear main oil seal about a year ago. But now I think it's just been the head gasket since then. Anyway, it doesn't "overheat" according to my gauges but it's been giving off a lot of heat that I can feel coming up from underneath while driving. It's been using tons of oil, and know I know where from, just not sure why that keeps happening.

Edited by BestyBlue77
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I do know the head bolt for the oil feed hole is a reduced shank bolt, to allow oil flow around it. 

 

One other thing, did all of the A series have the oil feed galley at the same head bolt? Something tells me that there was a difference in galley location at some point. I may be wrong.

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21 hours ago, datzenmike said:

 

 

Doesn't the '74 and on heads feed the oil from the block up a head bolt hole???? The original oil feed hole is sealed up at the block surface and a horizontal hole drilled through the oil gallery into the bolt hole and the outside of the hole also plugged. Seems to me maybe the top plug may be leaking. You can drill and tap this hole and add a screw in pipe plug.

 

Earlier than '74  'A' series fed oil straight up from the block into the head just like the L and Z series.

 

15689.jpg

 

'74 and later blocks were modified to flow oil up the bolt hole.

 

22073.jpg

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Here's #3, my current project. All the tell tale signs are there. Oil leak starts at oiler bolt, the damn things keep running for years sometimes if you keep feeding it oil, and if not repaired the gasket fails to keep coolant where it belongs, then the overheating begins, etc, and POW bent rod. Ugh.

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Mike has the right idea. When I was looking at the head gasket pics, I noticed that neither of them were OEM Nissan. The OEM gaskets are graphite coated which helps them seal. I have never been a fan of un-coated aftermarket head gaskets on Nissan motors, but if you must use one, you need to spray it with copper coat.

 

Back to the o-ring. I do seem to remember something about that. My memory is very hazy on this, but I think there is supposed to be one around the oil passage.

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I grabbed some pics from RockAuto because they had the biggest selection of head gaskets to choose from for my engine. I compared the gasket holes near the oiler bolt and found three different patterns. A few had 2 large holes and one small hole. One of them had 1 medium, 1 large, and 1 small hole. Another had 1 large hole and 1 small hole. The last being the one that would be the perfect match for my engine. Not sure that even matters, but an extra large hole cut very near the leaky area with an uncoated gasket might just be the problem. Or just the fact that the gaskets were uncoated may be the issue OR it could be the missing o-ring. However, if you look closely at the first pic you will see what I believe is this notorious red o-ring in the Beck/Arnley Head Set #0321463 which is the "recommended" set for my ride. Some of the head gaskets appear to be coated and some don't. Which of these gaskets would you guys recommend as the best to choose for my situation if I didn't use the copper spray you guys mentioned? And I have never heard of this spray copper coating. What brand or where could I purchase said coating? Thanks!!!

Screenshot_20180905-010153_zpsvia2jn9z.p

 

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Screenshot_20180905-010254_zps21wrb0a9.p

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Edited by BestyBlue77
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3

 

 

On 9/27/2012 at 5:45 PM, Dirttrack510 said:

Contrary to belief Copper Coat will not make the head or head gasket hard to remove in the future, it's sort of like a spray on anti-seize that simply fills in imperfections in the block and head. I used it on my car and removed the head later with no problem. If your using the Felpro head gasket it already has a "sealant" made into it, if your using a cheaper or off brand I'd recommend it. You can use it on the Felpro if you want and it won't hurt anything, it'd just be extra "insurance" against leaks. Many old school hot rod guys still use it. It's not anything like silicone sealant and it doesn't harden up like that Indian Head stuff either. I actually use it on my intake/exhaust manifold gaskets now too, just as a precaution. Just spray a thin, but complete coat, wait a few minutes to let it cure a little, and then slap the gasket on and torque it down.

 

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I would use whichever set is recommended. The first one you showed definitely has the o-ring, and it sounds like that's the recommended gasket, so the choice seems clear. If the gasket in the kit is not graphite coated, I would try the copper coat for sure.

 

Your block isn't heavily bored, is it?  If it is, you may need a gasket with larger bore.

 

Have you tried Nissan for the correct gasket? I really don't like using aftermarket head gaskets on Datsun motors, but I also don't know if Nissan still has these A motor gaskets available anymore.

 

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Cool! Thanks guys!! This is really helpful. I never thought to try to dealership for a head gasket. They have a very limited selection of items available for my car, and usually when I do call them for something 8 out of 10 times they don't have it. But I'll call them up just to check. I usually go with the Fel-Pro simply because they include ALL the gaskets I need for the restore, and I don't have to hunt and peck around trying to find everything I need. Also, they have excellent customer service, and you can call them up and ask a tech questions on any of their products which is rare these days. I've already got 2 head sets around now I'd like to use first. They are both Fel-Pro. One is a brand new modern style set, and the other is NOS with paperwork dated 1979. It's definitely old school, and the head gasket is printed like Mike mentioned above. Just got it in the mail yesterday.

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Edited by BestyBlue77
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It looks uncoated on the other side, so I'm definitely grabbing a bottle of the copper spray. It has great reviews all around as well. I'm going to see what the dealership offers, and who knows theirs may include the o-ring. I do wonder about that o-ring though, where exactly should it be installed, and if it is installed, wouldn't that block the flow of oil coming up from below? Hmm?

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On 9/7/2018 at 8:34 AM, Stoffregen Motorsports said:

I would use whichever set is recommended. The first one you showed definitely has the o-ring, and it sounds like that's the recommended gasket, so the choice seems clear. If the gasket in the kit is not graphite coated, I would try the copper coat for sure.

 

Your block isn't heavily bored, is it?  If it is, you may need a gasket with larger bore.

 

Have you tried Nissan for the correct gasket? I really don't like using aftermarket head gaskets on Datsun motors, but I also don't know if Nissan still has these A motor gaskets available anymore.

 

No, never been bored out. It's all original. They all are. The cylinders are all in amazing shape luckily.

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