Patrol 4x4 - Nissan Patrol Forum banner

1 - 14 of 14 Posts

·
Registered
Nissan
Joined
·
5,358 Posts
Discussion Starter #1 (Edited)
Does it make sense just replacing oil rings with new ones(and perhaps compression rings as well) without reboring+honing the engine bore?

If I'm to do partial bottom end rebuild like that, will it last long enough(few years or 50k etc)?
 

·
Registered
nissan gu td42t
Joined
·
625 Posts
If your pulling the pistons out you'd be mad not to replace all the rings and bearings, give the bores a hone and get the head checked out. Put it back together and it should be good for many years.
 

·
Registered
Nissan
Joined
·
5,358 Posts
Discussion Starter #3 (Edited)
If your pulling the pistons out you'd be mad not to replace all the rings and bearings, give the bores a hone and get the head checked out. Put it back together and it should be good for many years.
I was thinking more like approaching from the bottom of the engine, without having to touch the head.(head was reconditioned just over two years ago and got around 35k on it since then) Something like, opening the oil pan and accessing the pistons from underneath and pulling them out one by one(not totally sure whether I need take out the crank shaft as I haven't done it before). So, it's a budget overhaul I'm thinking of. Bearings, I would replace if they look bad. If that's the case, of course I would go for the whole proper rebuild job.
The reason I'm trying to avoid honing the bore is that I don't have any honing tools or experience, and for me, taking the block to a machine shop is a fairly heavy job(Nissan RB30)
 

·
Registered
nissan gu td42t
Joined
·
625 Posts
I'm not familiar with the rb30 but I don't think it's worth putting an engine back together with secon hand bearings or rings. Don't know about pulling the crank out to pull the pistons out, not without pulling the motor out anyway.
 

·
Registered
Nissan
Joined
·
5,358 Posts
Discussion Starter #5
I'm not familiar with the rb30 but I don't think it's worth putting an engine back together with secon hand bearings or rings. Don't know about pulling the crank out to pull the pistons out, not without pulling the motor out anyway.
I have a vague memory of doing it with a mate long long time ago. We didn't pull the engine out.
But, the car was on a hoist.
I don't have that luxury now for sure.
BTW, I would never put secondhand rings or bearings.
They have to be new of course.
Sourcing new bearing cheaply won't be easy.
I believe the rings are available for reasonable price?
 

·
Registered
nissan gu td42t
Joined
·
625 Posts
How do you pull the crank out with a clutch or an auto attached to it?
 

·
Registered
Nissan
Joined
·
5,358 Posts
Discussion Starter #7
How do you pull the crank out with a clutch or an auto attached to it?
Yeah, that makes sense.
That was very long time ago. I don't think we pulled the crank shaft out or may be he did.
I was a helper & didn't know anything about cars back then.
I think the scenario must have been different.
Gearbox might have been pulled out already for other reason, and perhaps he decided to replace the rings(he did some other stuff inside as well, that I can't remember)
So, I don't think he put the car on the hoist just for the reason of replacing piston rings.
That would've been a pretty back breaking way to go for that job.
But, it still was a back breaking job from what I remember.

Honing tool is pretty easy to get.
I guess I'm going to have to do some homework on how to use it properly and the measurements and stuff.

So, if I understood you correctly, it's not a simple quick job to pull the pistons out one by one from under the engine and replace the rings!
It's practical to pull the motor out and do a complete rebuild job properly.
If I presume re-boring is not necessary, then honing can be done with a honing tool and oil.

I'm praying the cylinder bores are perfect circles, no deep scratches and don't need re-boring.
If they do, then I might have to put off the back breaking whole rebuilding job as a slow moving back yard job, while I'm getting a low km replacement motor.
Well, that's pretty much how my diff rebuild job ended up.

Cylinder bores looked good cosmetically(though pretty shiny) when pulled the head out last time. I couldn't see any scratches at all, but that was over two years ago.
So, honing the bores sound like a good idea.
I'm not sure whether I can source the bearings(and rings) for a good price, to make the job worthwhile.
 

·
Registered
nissan
Joined
·
11,150 Posts
You can do rings and big end bearings in the car quite easily but sump has to come off. As does the head. New rings without honing is almost a waste of time. Replacing just the oil rings is crazy. Main bearings are pretty much an engine out job. Unless you remove the gearbox. In which case engine comes out easier.
So to summarise simple rings and bearings job easy enough. YouTube how to hone bores and the honing ball rods are cheap enough. Any more than that you may as well just rebuild it properly.
 

·
Registered
nissan gu td42t
Joined
·
625 Posts
If you don't want to pull the motor out and your on a tight budget then maybe just pull the head and the sump off, pull the pistons out, give the bores a hone.
Fit the new rings and put new big end bearings in as well.

Borrow a ring compressor to if you can. Makes the job easier and quicker.

Iv honed some horrible looking bores over the years, ones with multiple scores or should I say grooves and they have run fine without any visible smoke and good compression.
 

·
Registered
Joined
·
1,082 Posts
If you don't want to pull the motor out and your on a tight budget then maybe just pull the head and the sump off, pull the pistons out, give the bores a hone.
Fit the new rings and put new big end bearings in as well.

Borrow a ring compressor to if you can. Makes the job easier and quicker.

Iv honed some horrible looking bores over the years, ones with multiple scores or should I say grooves and they have run fine without any visible smoke and good compression.
This is pretty much what I have just been through with my td42.
Reasonably straight forward with a bit of thought and care taken to keep things in order.
Just running it in at the moment but already feels better.
Just make sure you keep things clean and plan out what you need before you get stuck in
 

·
Registered
Nissan
Joined
·
5,358 Posts
Discussion Starter #11
Thanks for all the useful advice guys.

I will pull the motor out and start from there.
Yeah, I'm on a semi-tight budget, so gota go easy on the pocket or I will be looking at a free energy 4WD, rather than a gasoline driven one, for my long treks. :D

I will have to pull the motor out anyway, 'cos I'm planning to replace the clutch as well as some other electrical mods(overheating alarm, oil pressure alarm, etc).
Once I'm finished, it should be an idiot proof 4WD trekker. :)
 

·
Registered
Nissan
Joined
·
5,358 Posts
Discussion Starter #12
This is pretty much what I have just been through with my td42.
Reasonably straight forward with a bit of thought and care taken to keep things in order.
Just running it in at the moment but already feels better.
Just make sure you keep things clean and plan out what you need before you get stuck in
Yep, I'm pretty much making a list of tools and parts needed.
I usually buy most of the tools, but might have to borrow some of them this time.
 

·
Registered
Nissan
Joined
·
5,358 Posts
Discussion Starter #13
You can do rings and big end bearings in the car quite easily but sump has to come off. As does the head. New rings without honing is almost a waste of time. Replacing just the oil rings is crazy. Main bearings are pretty much an engine out job. Unless you remove the gearbox. In which case engine comes out easier.
So to summarise simple rings and bearings job easy enough. YouTube how to hone bores and the honing ball rods are cheap enough. Any more than that you may as well just rebuild it properly.
Thanks mate. It will be an engine out job for me anyway, 'cos I have no hoist and besides the clutch need replacing soon as well. So, it will be week long job, if not longer.
 

·
Registered
nissan
Joined
·
11,150 Posts
No problems there. Don't need a hoist to do in chassis though. Plenty of height underneath to do so. But if it needs a clutch then out she comes. Just get a big plastic drip tray or similar cause honing and general stripping is pretty messy.

Sent from my C6603 using Tapatalk
 
1 - 14 of 14 Posts
Top