liner seals

[mojobaby]

Next week when my new rings arrive, I'm going to be inserting the liners into the block along with the pistons.
The paper liner seals that were in the gasket set (Franzose) come in 3 different thickness and are colour coded, red, black and white. Red is the thickest and white is the thinnest. I read somewhere on the forum that they are 0,08mm, 0,10mm and 0,12mm.

I'm not entirely happy that these seals are going to stop water from seeping down into the engine-they are so thin and flimsy! I would be more happy if I could seal the seals with some kind of silicon product.

What actually happens when the seals come into contact with water? Do they swell up to block any imperfections in the liner base or the seating? Like plumbing fittings?

Any thoughts would be appreciated

 

[André4Renaults]

From my experience of fitting wet liners into old Skoda engines there are 2 critical things to bear in mind when fitting them. First, the seating area in the engine block onto which the gasket sits must be perfectly clean and free of any grit or muck. This helps prevent any water and oil mixing. Second, the measurement that the liners sit proud of the cylinder block is critical and must be even over all the liners. It doesn't really matter what gasket is used on which liner, providing that this measurement is equal on all the cylinder liners. Skoda dealers had a specific tool to measure this and I suspect Renault dealers used something similar. As the head is torqued down onto the block the equality of these measurements become important, as the liners are then all equally sealed by the head.

I've never thought about your question about the seals & their reaction to water! If the were to swell the effect would be to tighten the seals in their position against the bottom of the liner itself.

Hope this helps.

 

[angel]

They are more than adequate, provided you take all precautions Andrew lists.

Renault's "special tool" is simply a straightedge and a set of feeler gauges. Provided you follow the manual and take measurements carefully, liner base sealing will be perfect.

 

[mojobaby]

Thanks Andrew, I've cleaned the seating and the bottom of the liners as well as I can, although it's a bit difficult to fit my hand down there. A few blemishes are all that remain.
Angel, I used a straight edge and feeler gauge, with different thickness liners, however, I may have a slight problem which I will leave for the experts to advise me. There is definitely a difference in the gap from one side of the block to the other;

Cylinder --------------------1------2------3------ 4
Seal colour--------------- Red--- Red---Black----Black
Dizzy side clearance----- 0,05---0,05---0,05----0,05mm
Carb side clearanc------- 0,08---0,08---0.08----0,05mm

It looks better when I write down the inch equivalents--0,05mm is 0,002inch and 0,08mm is 0,003inch

Can I assume that when the head is torqued down, the difference will be taken up by the gasket? I hope so!

 

[angel]

Check that the cylinder block locating faces are perfectly clean with no corrosion or debris, and also make sure the liners have seated down when measuring (tap them gently with a mallet). Also, try rotating them 180 degrees or changing their position in the block.

 

[André4Renaults]

Try cleaning the seating area again, using something that won't scratch the area, such as a wooden stick or similar. It's important not to abrade the seating area but equally you need to ensure it is clear of all grit etc. It's possible a small piece of grit is upsetting the positioning and seating. If you're confident that everything is clean and smooth then use a wooden mallet to G-E-N-T-L-Y tap the liners a little to seat them properly.

 

[mojobaby]

Cylinder 1,2,3 are now perfect at 0,05 on both sides of the block Thank you!

You were correct, it just needed more cleaning, not the block surface so much, but more at the base of the liner itself. Number 3 needed a little gentle persuasion with a mallet.

Not so pleasant in the workshop today

 

[André4Renaults]

Now your liners and gaskets are all perfectly in place the head sould be put on and torqued to the correct settings. Make sure you torque the new head bolts evenly and in the correct order.

I'd wait for the weather to warm up a little before carrying on....