839-06 Rebuild Help

[Sob Ro]

Hello,

I'm rebuilding an 839-06 engine, but am pretty new to these engines -and am in need of some guidance.

I've taken the head off, and it looks like one of the pistons shattered and there was water sitting in 2 other cylinders for who knows how long. I can't for the life of me find any 55.8mm sized parts-but there are lots of the 845cc parts. Would there be any issue with just replacing the liner and pistons with ones for the 800-01 engine? As far as I can tell it looks like everything will fit, except having to drill/resize the pistons with a 16mm pin hole.

Also, I had some trouble taking the head off, I ended up cutting a 14mm socket in half to fit under the rockers. I couldn't figure out how to pull the rocker shaft out to get the rockers out of the way. Do you need to remove the rockers before taking the head off, if so how? Maybe a special tool?

Thanks

 

[mr-reno-139]

Not my expert area I am afraid
Umlike social media I can't tag angel who can advise on this subject
There are 2 sizes of gudgeon pin on 845 cc originallythe early engines are same as dauphine
The trick for head bolts is remove pushrods and then rotate rocker arms upside down for clearance using shallow 3/8 drive socket

 

[mojobaby]

Hello SobRo
If your cylinder head is anything like the 845 engine, you have to loosen the adjusting stud and nut on the rocker arm completely. Slide the rocker arm a little along the shaft and remove the push rod. The rocker can then be pivoted upwards to allow access to the bolts.

On my engine (probably yours as well) the rocker shaft is actually 2 pieces, meeting in the middle.
There should be a small hole in the back of the cylinder head to remove the "back" rocker shaft. And a hole in the front of the cylinder head which can be seen once the water pump is removed for the "front" rocker shaft.

Have a look here:.........http://www.renault4.co.uk/forum/threads/tool-for-cylinder-head-bolt-removal.6856/#post-41856

 

[Sob Ro]

@mr-reno-139 and mojobaby,

It looks to be the same head you linked mojobaby-
Undoing, sliding, then removing the push rods makes enough room to fit the socket. This would have saved so much time over finagling it out with a socket cut in half with only 2-3mm of bite on it... Although, using this method avoids the need to remove the rocker shaft, how in fact would it be removed?
I may have the head sent away to have the valves re-seated/resized, as I don't have the equipment or know-how to adjust them, and the shops around here want the head completely striped first. (Although this is still up in the air, and may not be needed, I really need to clean it first to really evaluate).

As far as the using 800 parts, all the pistons I can find/have access to have the 14mm fully floating pin, instead of the 16mm press fit it currently has. I think I may give it a shot. The set really isn't that expensive, and drilling the pistons to accommodate a larger pin should be trivial.

 

[mojobaby]

The inside of the rocker shaft is threaded so fit the appropriate size bolt through the wall of the cylinder head and screw it into the rocker shaft and then pull it out.

I didn't know about this when I started so I tapped it out (gently) and then discovered the thread and also discovered that the shaft was actually 2 pieces meeting in the middle.

 

[angel]

16 mm pin pistons are way easier to obtain than early 14mm ones, so why going the hard way and drill them out? (ream should be the correct word as it has to be done very accurately).
Also, if you are going to use the liners supplied in the 14mm kit, they won't fit your block as it's not designed for copper base seals.