L20 bottom end rebuild... tips on rings and main & rod bearings...???

[hessianben]

K, I've already searched the searches and read a couple of different versions of service manuals...

...but nothing beats hands-on experienced advice!

 

Does anyone know of tutorials on how to install crank and rod bearings, as well as piston rings?

 

I know that for me, when I first got into Datsuns, Hainz sent me a DVD with step by step instructions on how to rebuilt an L20 top end / timing set. Invaluable tool.

 

I learn easier from seeing than from reading, but that's just me...

 

anyhow, any tips or info are greatly appreciated.

 

thanks guys

 

[motavated]

Sorry ben... I dont know... But i get first race.

[mr68gts]

Bearings are easy, just locate the bearing tang side first and then kinda push/rotate the bearing into the rod, main whatever. Make sure you have top and bottom in proper relation and also there may be main #'d bearings. Thrust bearings are usually in the middle. Groove sided brg with holes with go in block. Some brg's may be full groove. Pay attention when installing the brg's.

 

Rings are bit trickier. There's 2 ways to do it. both are easy to ef up if not paying attention. There's the ring expander method ( a tool avaialable) or the spiral method. tool can open up the rings too much if not careful and the spiral method (most engine builders I know including me use this method btw) can warp the ring. There are top rings and 2nd rings. And there are also top sides to the rings. usually marked with a dot or line. The rings should come package and marked top,2nd, oil. Start with the oil rings and work up.

What you do is start the ring in the land it's supposed to live in by catching a corner of the ring where the split is and then kinda spin it around in place while slightly open it up to get in in place.

Paul

[hessianben]

haha deal Adam.

[hessianben]

 

 

Rings are bit trickier. There's 2 ways to do it. both are easy to ef up if not paying attention. There's the ring expander method ( a tool avaialable) or the spiral method. tool can open up the rings too much if not careful and the spiral method (most engine builders I know including me use this method btw) can warp the ring. There are top rings and 2nd rings. And there are also top sides to the rings. usually marked with a dot or line. The rings should come package and marked top,2nd, oil. Start with the oil rings and work up.

What you do is start the ring in the land it's supposed to live in by catching a corner of the ring where the split is and then kinda spin it around in place while slightly open it up to get in in place.

Paul

 

 

Ah so...

 

these are the little tricks that the FSM doesn't tell you!

thank you!

[mr68gts]

No problem. once the rings are on, dont line up the gaps and then you have to use a ring compressor to install the pistons in the block. be careful not to pinch the rings though. Oil them up compress em and then oil the bores and install with a soft mallet.

hope this helps.

paul

 

Ah so...

 

these are the little tricks that the FSM doesn't tell you!

thank you!

[banzai510(hainz)]

remeber when installing the rear seal you have to put sealant on one side of the block where those side seals go in.

 

be honest I have never done bearing but I would just install them as it LOOKS pretty EZ. they fit in the locating groove. Center and end ends are pretty EZ to figure out.

 

PS put the oil feed holes in the correct place. I took apart a L motor and the MOFO blocked the oil feed bearing. He had them on the oppisite side.

 

remember to Gap rings also.

 

also if using a 620225mm clutch to use the 620 TO/bearing and sleeve.

If you have a 200mm(get roadster PresPlate) you can just use the 521 TO bearing and sleeve

[hessianben]

remeber when installing the rear seal you have to put sealant on one side of the block where those side seals go in.

 

the oil feed holes in the correct place. I took apart a L motor and the MOFO blocked the oil feed bearing. He had them on the oppisite side.

 

 

 

by the rear side seals, do you mean these?

 

where do the metal plates go? anybody with pics? (i'm a simple learner)

 

 

Also, by oil feed holes, do you mean the holes on the bearings?

 

thanks

[mr68gts]

If I remember right, the metal plates are so you can slide the rubber in a then tap the plates in to swedge the rubber. Also like Hainz said, use silicone on the sides. Some people have no luck doing the side rubbers in the rear main cap so they just fill it with silcone. Either method works, one is just better than the other. Also lightly wipe silcone on the bottom of the cap from the edge of the rear seal to the sides of the cap and it shouldn't leak. (by light I mean it shouldn't be squeezing out of every orifice the rear cap has! It's a machined surface! It dont take much!) But you should see some come out up along the sides and a bit in the corners

Paul

[mr68gts]

Lol, that makes for an expensively bad day! (equals no oil to crank or rods!)

Paul

 

[quote name='banzai510(hainz)

PS put the oil feed holes in the correct place. I took apart a L motor and the MOFO blocked the oil feed bearing. He had them on the oppisite side.

[hessianben]

can i get a clarify on 'oil feed holes' ?

 

I don't want to be 'that guy' hehe.

 

thanks everyone

[mr68gts]

Look at the block side of the main saddle. There will be oil feed holes. Holes in brg's have to line up with those holes or no oil to crank and rod. Also, if rods have have squiters, there will be hole in the rod brg saddle also. Buy a strip of plastiguage and check the rod and mains by torqing the assy together like normal and them remove caps (without spinning over) and using the paper cover for plastiguage to read clearance.

Paul

can i get a clarify on 'oil feed holes' ?

 

I don't want to be 'that guy' hehe.

 

thanks everyone

[hessianben]

I gotcha. just wanted to make sure there weren't oil feed holes to deal with that i didn't know about. THanks!

 

as far as sealer, I've got a can of this stuff:

 

or should i stick with black RTV?

[datzenmike]

 

remember to Gap rings also.

 

 

Good advice!!! Place the top two rings, one at a time, into the bore they will be installed in and using a piston push it down the bore a couple of inches. Measure the end gap. Too loose will leak compression, too tight and the ring will expand, touch, jam and break. Try different rings to find one that is closest. A thin whetstone can be used to remove excess ring to increase the gap. Generally the top ring is hotter and needs more gap. A turbo or very high performance motor will need slightly more.

 

[hessianben]

Nice! got a whetstone already. (I was gonna use a file, but this is probably a better idea)

[mr68gts]

RTV for gaps. Thats used only when you have a paper gasket or a multi layer gasket (mls steel) with no coating. Rear mains cap's will always use silicone pretty much. (depending on block design)

Paul

 

I gotcha. just wanted to make sure there weren't oil feed holes to deal with that i didn't know about. THanks!

 

as far as sealer, I've got a can of this stuff:

 

or should i stick with black RTV?

[mr68gts]

Man, someone needs to make a video! lol

(Paging Hainz! :P )

[datzenmike]

I gotcha. just wanted to make sure there weren't oil feed holes to deal with that i didn't know about. THanks!

 

as far as sealer, I've got a can of this stuff:

 

or should i stick with black RTV?

 

I'm not keen on spray gaskets and a little RTV goes a long way. The factory doesn't use it and getting apart is a bitch.

[banzai510(hainz)]

mr68gts pretty much said it in above quotes.

 

I have the Nissan side seals so it dont metter which way. As it isnt the 2 pc type as you have photoed. this was recently discusse on which way it goes and Datsunaholic knows for sure.

 

the silicon on the rear bearing cap. The Haynes datsun 510 manual will have a drawing of this. But I havent dont this myself. Or was it the How to rebuild your Nissan/Datsun motor

[datsunaholic]

The shims go in the back of the notch, away from the seam. Since the notch is in the bearing cap, the shim goes inboard (toward the crank). Put the seal in first, then install the bearing cap. THEN drive the shim in with a hammer.Some folks put RTV on the seal, which is fine if you never intend to remove the danged thing ever again (even if you have to) because it's a bear to get the bearing cap out with RTV on that seal. A dab on each END is OK. I just oil the seal.

[hessianben]

... so the metal shims wedge the seals toward the center, hugging the rear bearing cap.

cool

 

man, I love this forum. so many other places (no names hehe) are clogged with nonsense, flaming, and general douche-ery...

 

thanks again everyone.

[datzenmike]

Douchery ? ....... oh.