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BestyBlue77

Need advice on replacing piston rings B210 A-14

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Hey gang! I'm ready to put in these new piston rings & I just wanted to get some advice or tips before I start on anything I should know from experienced Datsun folks. This will be my first time doing rings, and I run into any snafoos I'm blaming you all! Haha. Just kiddin'.

 

I'm pretty confident I can do a nice job on this project. I've done a few head gasket jobs, and also a few new timing chains, and they've all been successful. Plus a whole slew of other restoration type adventures involving the engine, complete cylinder head rebuild, carburetor & the entire fuel system, brake system, electrical, etc.

 

I'd like to start with how to remove the Pistons. So once I have the cylinder head and oil pan removed, what do I do next?

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1st, if you have a ridge on the top of the cylinders, a  ring job will do you no good. If there is no noticeable ridge, disconnect the rod bearing caps and tap the rods/pistons up with something like the wooden end of a hammer (something soft-ish). Once out, get a bottle brush hone and with some WD40 for lube go up and down at a steady, even pace until the walls are not shiny and have a cross hatch pattern. You will probably need to wipe the cylinders down a few times to verify. (Note, if after a minute or 2 of honing you still can see deep scratches or pits, you will be better off boring the cylinders and getting new pistons) I would suggest you only use cast rings as they are not so fussy about hatch pattern. Moly would probably also be fine, but avoid chrome unless you have a shop do the honing. Make sure you clean the ring lands in the pistons of any carbon buildup. Check the end gaps with the rings in the actual cylinder you plan to install them in (Oh, and you should make sure what size pistons you have. If they are oversize, they will probably be stamped on the top of the piston). When you install them on the piston, make sure the gaps do not align. Put a light coat of oil on the rings and piston skirts and install them using a ring compressor and tap them in with the hammer handle, noting that the arrow on the piston faces forward. I usually but a small section of fuel line on the rod bolts so they do not damage the crank. Install new rod bearings and tighten the cap to spec.

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Great! Thanks for the thorough reply! I forgot to mention I just had the head off about a year ago & haven't put many miles at all on it since. The cylinders are in excellent condition & still have the original cross hatching marks with no marks, scratching, or scraps of any kind visable on any of the cylinders. I have a buddy that's a mechanic & he came over to take a look at them & said they were good to go. I should have replaced the rings at that time, but I had a bunch of other projects going on & needed to just get it back together, so I could drive it a while. I did resurface the engine block, so that's good to go as well. Ya, I'm pretty much kicking myself in the butt for not doing it then, but we live & learn, right?! (Hopefully!)

 

That being said, I bought original sized rings to replace the old ones. I'll post a few pics here in a minute to show ya what I've got.

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These are the rings that I purchased: Sealed Power by Federal Mogul. E-365X Standard Piston Ring Set (2) 2.00mm, (1) 4.00mm; Iron; .75mm Oversize. These are recommended by Napa & Oreilly's.

 

https://napaonline.com/en/p/SEPE365X

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These appear to be cast iron. Cast iron rings will accept deviation in the cylinder better but have a much shorter life expectancy. They are the best option to put into an unprepped cylinder. They give about 20k miles. If you're good with then, then those are great.

 

BUT you shouldn't be using oversized in this scenario. You should be using STD size rings.

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all my rings were cast iron. My L16 in my 521 is now at 175k .

Bu yea I think you get same size rings or maybe .25mm over rings if you have a std size piston. But Im not positive I have my machine builder do this but have used sealedpower also

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These are the rings that I purchased: Sealed Power by Federal Mogul. E-365X Standard Piston Ring Set (2) 2.00mm, (1) 4.00mm; Iron; .75mm Oversize. These are recommended by Napa & Oreilly's.

 

https://napaonline.com/en/p/SEPE365X

 

They are recommended IF you overbore the block and use over size 76.75mm pistons.   Will you?

 

 

Measure your bore in three places. Measure the piston for each bore. Should be 76mm for an A14. Piston to wall clearance should be between 0.001" and 0.018" give or take. If much over that it should be over bored and over size pistons used. Using a 0.75mm over size ring to make up the difference is not advised. Certainly NOT without some measuring. When compressed the ends may touch or touch when heated up and they will break.

 

No mention of honing the cylinder walls. If the stock pistons and walls are withing spec the wall will be too smooth to wear the rings in. If using case iron for this you need a special hone.

 

If going to larger pistons and over boring the finish will be perfectly round and no taper. For this you can use chrome molly rings for much better seal and longer life.

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They are recommended IF you overbore the block and use over size 76.75mm pistons. Will you?

 

 

Measure your bore in three places. Measure the piston for each bore. Should be 76mm for an A14. Piston to wall clearance should be between 0.001" and 0.018" give or take. If much over that it should be over bored and over size pistons used. Using a 0.75mm over size ring to make up the difference is not advised. Certainly NOT without some measuring. When compressed the ends may touch or touch when heated up and they will break.

 

No mention of honing the cylinder walls. If the stock pistons and walls are withing spec the wall will be too smooth to wear the rings in. If using case iron for this you need a special hone.

 

If going to larger pistons and over boring the finish will be perfectly round and no taper. For this you can use chrome molly rings for much better seal and longer life.

I'm going to be using the stock pistons & everything is within spec. Should I still give the cylinders some fresh cross-hatching? Also what kind of rings would be the best in my case for best performance & longest life? Thanks everyone!

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If you are sure they are stock size get standard size cast iron rings and hone the cylinder walls. The fresh roughing of the walls will wear the rings in for a good seal to hold in compression. Cast iron are best on a used, non perfect cylinder wall.

 

Make sure you put the rings for each piston in the cylinders they will go in and carefully measure the end gaps. Generally the amount is 0.0045" for every inch of bore. Too much gap looses compression. Too little gap and the rings will expand with the heat and touch breaking them and the piston. On a used bore this is unlikely but... For a 78mm bore that would be 0.0045" X 2".99 = 0.013" of gap. The second ring can be the same or a little tighter.

 

Follow the ring maker's recommendation for position of the ring end gaps when installing the pistons. The last thing you want are the gaps lined up and loosing compression.

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I rebuilt lots a A-14's at the dealer they would overheat and the rings lost their spring tension but the cylinders where usually OK unless the #3 piston swelled up and scratched the wall. The biggest problem we had was the #3 intake seat falling out of the head so we always peened it in with 6 punch marks. Hot Hot Hot in Phoenix and they only held 3/4 of a gallon of coolant so we added AC for a nail in their coffin.

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I rebuilt lots a A-14's at the dealer they would overheat and the rings lost their spring tension but the cylinders where usually OK unless the #3 piston swelled up and scratched the wall. The biggest problem we had was the #3 intake seat falling out of the head so we always peened it in with 6 punch marks. Hot Hot Hot in Phoenix and they only held 3/4 of a gallon of coolant so we added AC for a nail in their coffin.

"3 intake seat falling out of the head " 

Oh god, do I remember that particular failure mode, had it happen once to me and I've seen it on quite a few junkyard engines.

 

Just to ask, but why do you think the rings are bad? Smoking? When you had the head off did you do the valve stem seals? 

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since the rings lost their tension we could always tell by using our finger tips and moving the piston forwards and backward in to hole with the piston up, no trouble with factory valve seals or guides, Honda reserved that rite.

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"3 intake seat falling out of the head " 

Oh god, do I remember that particular failure mode, had it happen once to me and I've seen it on quite a few junkyard engines.

 

Just to ask, but why do you think the rings are bad? Smoking? When you had the head off did you do the valve stem seals?

 

They've never been replaced. The compression is not so great, but mainly the spark plugs keep fouling at #2 & #3. I clean the plugs off on a regular basis. One has oil fouling, the other lots of white stuff. The dizzy cap keeps getting whiteish/light grey gunk on the tips, and I just keep scraping it off. Can't get it to run right for very long. I think the carb also has something to do with it. I take it apart and clean it, and it runs great for a while, then out I nowhere it runs like crap again. No power.

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I rebuilt lots a A-14's at the dealer they would overheat and the rings lost their spring tension but the cylinders where usually OK unless the #3 piston swelled up and scratched the wall. The biggest problem we had was the #3 intake seat falling out of the head so we always peened it in with 6 punch marks. Hot Hot Hot in Phoenix and they only held 3/4 of a gallon of coolant so we added AC for a nail in their coffin.

That actually happened to my head. My machine shop guy said it looked like one of the seats fell out, bounced around, did some damage, and re-seated itself. It would've have cost too much to repair, so I found a NOS one right here on Ratsun classified. Bought new valves and springs and made her all purdy again.

 

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The compression can be misleading if your rings are bad it is like a wet test, a leak down test is more accurate but it doesn't matter you need rings and peen in #3 intake seat. Use Hatchi cap and rotor and there are 3 different rotors, sounds like the distance between cap and rotor is too great which is not so great.

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My best day!
I always got paid commission as a teck, each job paid a certain amount, for instance a Z clutch paid 4 hours and took 20 minutes, an electrical system test paid ½ hour and took 3 minutes unless we had to recharge the battery then it took 2 hours. If it took 3 days to find an electrical short they usually paid you 3 hours and called you stupid, if you had no cars to work on that day you clocked 8 hours and they paid you $0. I was a single father and the first and only time my daughter was with her aunt on her mom’s side on a Monday morning I showed up for work at ABC Datsun an hour early so Mark, the dispatcher rewarded me by giving me two A-14 ring and valve jobs. I could push them both in my stalls myself and got started. They both dropped #3 intake seat so I checked out 2 new heads, 2 intake valves, rings and rod bearings and a overhaul gasket set for both from the parts room. What took the longest was transferring over the manifold studs. Well they paid 18 hours each and I had them both parked out back by 5 that same day so I started that week with 36 hours on my flag sheet.

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Tips - I guess you know about the center rocker arm head bolt that is tapered and different than the rest and the factory had this separate red o-ring that inserted into the oil feed hole block to head = good stuff. The machine shop ABC used was crappy and did a rough mill on the head so we had to fill the groves with 3 coats of aluminum paint.

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Tips - I guess you know about the center rocker arm head bolt that is tapered and different than the rest and the factory had this separate red o-ring that inserted into the oil feed hole block to head = good stuff. The machine shop ABC used was crappy and did a rough mill on the head so we had to fill the groves with 3 coats of aluminum paint.

yeah luckily those head bolts (I use plural because I have two of these cars) for the oil feed we're still in good shape so I kept them, and the dealership didn't even have the special ones as an option to buy. that's not good for anybody that breaks them. I did not see any o-ring however, so maybe I'm missing that. I don't know.

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