The restoration walks on… Engine is totally teared apart
Looking through the coolant inlet ports I’ve noticed some dirt in the cylinders coolant path… I’m pretty sure that a cleaning would be a good thing. Removing the sleeves is quite easy (warm up the alluminium and with a piece of wood and a hammer pull out the cylinder sleeves after unscrewing the top bolts.
Honda do not provide the 2 orings (one on the top, i guess Viton made… and one at the bottom, to seal the coolant path) did anyone do this kind of “core-cleaning”?
did you reused the original orings?
would it be hard to reassembly sleeves and cylinders block mating a perfect plan head surface?
ive had about 4 sets of cylinder liners removed for both cleaning the coolant area and for honeing the bores, ive never had to heat up the aluminium engine block to remove them, you can tap/drift them out from below easily enough with a heavy hammer and a mild steel drift
If the virton “O” rings look in good condition i would reuse them, possibly with a little semi-setting gasket seal on,
I did try scorseing new ones but couldnt get hold of the correct grade of virton, the genuine ones are very soft and supple. try not to get any contaminates like petrol/parafin or thiners on the “o” rings or they will expand and be un-useable…
And one last thing to think about, MAKE SURE YOU GET THE ORINGS IN WITHOUT NIPPING THEM, i nipped one once, which resulted in the engine coming back out of the bike, full strip down and rebuild… that was not a good day in the garage.
many thanks… I’ve found in a shop the top oring… the bottom ones will be reused…
Looking at your photos I think that this deep cleaning is really worthy …
I recently pulled the liners from a 1000F motor with a broken rod. They drifted out easily with no heating of the block.
There is a thin steel ring inside the upper oring which is removable if it is not rusted in.
So have you had liners bored out of the engine?
This would save a lot of hassles trying to find someone who will bore a V four.
The bottom oring (orange) looks to be silicone to me.
I will exchange the sleeves with ones from a spare engine…
At the bottom of the donor engine there were two black and two orange oring. But I think that in that place temperature is not a real issue, as It would reach like 80-90 °C, so… yes maybe they are silicone made.
I will not bore as the incoming sleeves-pistons-rings are in good shape… even if the main cause of the oil-eating were the tappet valve seals…
ive not had any of the vf liners re-bored but i would think removing them from the casings is probably the best way to do them.
you may be right on the “o” rings for the liners,they do have a look of a soft silicone/rubber but, all the information i read at the time regarding cylinder liner replacement in a number of different engine types all suggested that viton was the correct choice due to its reliability under high temperatures.
the problem i had with sorcing the viton “o” rings was they come in many different grades of “softness”… i ordered the softest i could find and that was still conciderably harder than the originals. this in turn made pushing the liners in a lot harder…
I am in this situation… I got the cylinder liners out to be rebored to 77.50 and am looking for the o-rings. Are you sure they are Viton? All Silicon (VMQ) o-rings I encounter seem to be orange, and IIRC viton is mostly brown?
May I ask where you guys ordered the o-rings? Which size did you order?
The lower ring is JIS G85, I believe, which comes down to 84.4x3.1mm. I could not find a correct JIS ring that corresponded to the top ring size, and am using 100x2.5 as a reference size…
my sleeves had orange oring on top (hottest place) and black on bottom (“cool” sealing from the coolant)…
usually Viton has a opaque surface… those have not…
so maybe they are not Viton. Anyway, I’m going to reuse the old ones, as they are very are to find with the right size. The top one doesn’t scare ma… but the bottom one has to seal perfectly…
I think I’m going to fill with normal water with the engine still open … to let some limestone (word from google tranlsate, don’t know if it’s correct) finish the seal…
but from what I’ve seen in coolant path removing the sleeves is a mandatory job in a complete restoration. A port was completely clogged
They are indeed not easy to find and I am torn between reinstalling 30 year old seals in a critical application, and sourcing aftermarket seals and risking that they are of the wrong material. In both cases, I fear for failure.
You say the top one does not scare you, but do mind that the whole cooling system is under pressure, so the top and bottom one are both equally critical I would say.
It’s “limescale” btw, the same stuff you find in water cookers and kitchen appliances. Might be a good idea, but I think you’re just going to rust the liners if you are going to let it sit with normal water in. Limescale needs time and heat to build, but rust forms realy easily.
