Dry liner advice 845cc

[SJC400]

Well people, you have been very helpful with everything else, so what about this one?...........
I'm completely rebuilding my 845cc R4 engine, new Liners and pistons ready to go in.
Question: With these liners comes 8 'Paper' seals that go under the liners before they go in, so does that mean 2 seals per cylinder, or does it depend on individual fit, also, does there need to be any sealers applied, or just fit dry?
Anyone with info, I'd be grateful :-)
Steve

 

[Jurjenz]

Hi Steve,

I really enjoyed working on the 845cc! I also did a complete overhaul, and I learnt some lessons which I would like to share:
1. Make sure you refurb & polish the contactarea of the liners with the engine block. Then I used some grinding paste and an old liner to smooth out the surface. Twist the liner with gentle pressure.


You will achieve smooth surface:


Then you can put the liners in without seals. You need to measure the distance of each liner with the engineblock surface. I used a special feelinggauge (range from 0,01mm - 0.02mm - 0.03mm etc.) to exactly measure the distance. You can use a clock micrometer too if you want.
Like these: https://www.autogereedschap.com/a-24557616/voelermaten/voelermaten-midlock-extra-fijn/

You need to know this in order to use the correct seal thickness.

At my first try I used the paper seals provided by the parts supplier. It didn't worked out for me out as they were not thick enough to overcome the distance between the liners and engineblock. Result: leaking coolant through the engineblock direct into the carter. Second try I used
aftermarket paper gasket & cut to the proper dimensions.

And to be dead sure I used an heat resistant and fluid gasking seal.


Or

You have an 845cc B1B so that means to you need a tolerance of 0,04-0,12mm of the liners (with the seals included) sticking out above the engine blocks surface.

Then I put in the liners with some liquid sealant & paper gasket in the engine block. Then I placed the head gasket and cilinder head & bolted it with the correct torque. This will make a firm fit pressing the liners down. Then I flipped the engine in order to connect the piston rods to the crankshaft.

So, if I had to do it again:
-throw away the paper gaskets, and cut down your own
-measure, measure, measure
-use a small amount of liquid sealant

For a test if the seals work properly, I filled the coolantsystem, and opened the carter. If coolant comes out, you know you can do it again. Just be sure of this before you fill the engine with oil & first start. I was happy I did it first to to test..

Good luck and I would love to see your progress. Cheers, Jurjen

 

[harbourseal]

I have used the paper seals provided with gasket set.
Worked fine for me.
As Jurjen said put the liner in place after making sure that both surfaces are clean and free of any blemishes then put an angle iron over the liner and measure the gap under the angle iron.
Keep on going until you find the right tolerance.
Each liner can have another liner seal. Don’t settle for a red striped one for all the liners if on the first measurement you need a red striped liner seal.

Good luck.
After a successful rebuild you’ll be ecstatic when the engine comes to life.

 

[SJC400]

Great advice, very in-depth description Jurjen, very impressive!
Thanks also to Breda, nice to know others have experienced these funny little engines!

 

[SJC400]

All done now, just preparing the cylinder head/vales etc for refit.