Previously I wouldn't have been a fan of using sealant in there, but the testing that I’ve done with this new pump suggests that sealant might be a very good thing with some engines.
E: Engine stop valve assembly
- Thread starter ash1960
- Start date
I agree, But the type of sealant is the answer.......I use Threebond on these engines in most case and cover joints......A lot would argue that silicone type sealants is a big No No.....Again I would agree......but it depends on what type and more importantly, how much is used......Experience dictates that me thinks.......after years of restoration, you work out what works and what doesn't......The pump bore is a tricky one at best......probably one of the hardest parts of the entire engine that needs special preparation and attention on assembly......Just like the crank...... Take your time and get it right.......taking short cuts will bite you not all, but most times.
If you think a Vincent sumps you should see my 1935 KSS Velo I have a tap and a 'curly worley' line to the front brake lever but then its not an everyday bike.
I find pulling the engine back on compression when overnight parking helps
Failing that the sump plug is the same thread as a petrol tap !
I find pulling the engine back on compression when overnight parking helps
Failing that the sump plug is the same thread as a petrol tap !
I worked in Honda shops and Honda Bond (3 Bond) was the go to sealant along with a few Loctite recommendations. I’m very cautious about how much I use and where it’s used. When mating the cases, I inspect the joint from the inside and make sure there isn’t anything that could escape and find its way into a passageway. I’ll check out that Aviation 3. So far (and I don’t plan on doing any more), my pump installations have been ok. The bores were in good shape.
If you think a Vincent sumps you should see my 1935 KSS Velo I have a tap and a 'curly worley' line to the front brake lever but then its not an everyday bike.
I find pulling the engine back on compression when overnight parking helps
Failing that the sump plug is the same thread as a petrol tap !
Hi - is there a technical explanation as to why "pulling back on compression" helps prevent wet sumping?
Is there any difference between "pulling back" and simply cranking the engine on the kick-starter "forward" to achieve the same?
Regards,
Julian
Julian I have no idea but it seems to work for me on the Comet
Thinking about it, the position of the pump rotationally and in the pump position up sleeve is dictated by the keyway in the worm drive (hence the crankshaft) but I guess it depends where the worm/crankshaft is when the pump is "shoved up there" initially and then rotated for the driving screw to be inserted so it may just be my good luck ?
Thinking about it, the position of the pump rotationally and in the pump position up sleeve is dictated by the keyway in the worm drive (hence the crankshaft) but I guess it depends where the worm/crankshaft is when the pump is "shoved up there" initially and then rotated for the driving screw to be inserted so it may just be my good luck ?
I have worked it out and all is good no more Sumping the problem was T32 oil stop valve was completely stuck so I ground it in, now everything is working good I have a little bit of oil in the sump but engine does not smoke when I fire her up and it scavenges that little bit of oil back in the oil tank/UFM so thanks for the info I love solving problems and fixing them, also no more oil tap to worry about wicked. To Vibrac dont worry mt theres always a way worrying dont get you no where. Ash.
I have heard about that several times, but never tried it myself. The intake port on the pump in fully closed before the pressure port opens. My guess would be, assuming crank position actually makes a difference, if the pin is at the top, the oil is not going to try and siphon out into the sump. If the pin was at the bottom of the stroke, that would help create the siphon effect. I’m reasonably sure some oil finds it way past the quill regardless of crank position. Especially if the timing cover is mismatched and the side of the quill is worn. My Comet sumps fast enough that it would be a good candidate to measure. Drain the sump… let it sit for a week at BDC… drain and measure. Repeat the test for TDC and measure the difference.… but I’m all tested out for a while.
If you are referring to the valve in the main feed from the oil tank (that screws into the screen filter) then that is not an anti sumping valve Turning it into one, might lead to problems!
Reread the first reply from Timetraveler.
Last edited:
It has been done! If I recall correctly the result was that a newly rebuilt Shadow engine was turned into a very damaged Shadow engine in a hurry.
Glen
Glen