I plugged mine. I also plugged the big return hole from the timing case into the engine to raise the oil level in the timing case. I am using 8:1 low expansion pistons. I have ridden about 10,000 miles now with these mods and have had no trouble at all with pistons. The pistons still look pretty much like new. They are running .0025" clearance. The reason I plugged the oil off to the cylinders, was to try to fix the excess wear I was getting on my cams. I wanted more oil to the cams. The Vincent oil pump has a very low circulation rate. The main wear problem was with the rear inlet cam and to a lesser extent the front inlet cam, these are the ones where the cylinders are really going to steal the oil from (the cylinder oil holes are at the inside ends of the cam spindles right after the outlet holes for the cams. I altered the cam bushes so the oil would be emitted constantly from the cam oil hole, instead of just the brief instant when the holes lined up. This wear was most likely caused by valve springs that were to strong, as it is working well now. Also I have Garry Robinson 105 stelite cams I guess they never wear out. I know tons of people will say that Tony Rose went 100,000 miles with a stock engine etc, but the factory did have some problems with cam wear. My engine isn't stock, so I can't expect it to work just like the original one. The newer pistons probably don't need as much oil as the old .006" clearance ones.
ET: Engine (Twin) oil hole
- Thread starter Lanzbulldog
- Start date
To really reduce wear fit a Honda step-through pump, now over 300k miles on a set of NOS Mk2 cams and stelited followers fitted 1970, maintaining a pressure of about 1 bar in the cam rail, liner lubrication blanked off 1990 when pump fitted by Harve' Hamon when sleeving my main bearing housing, pressure in the cam spindle exits the holes which are in line with cam holes on the opening side squirting oil under the follower right where it is required.
These pumps are all very similar it is just the width of the trockoidle gears inside that differ.
I do not intend buying double start pumps any more as one of these fitted will supply significantly more oil and if directed into oil filter chamber first then back to a restricted quill feed and up to cams, one could run a plain B/E like Royal Enfield.
Vincent remarked in his writings that he wished he had kept the series "A" gear pump.
bananaman.
THE PUMP NOW FITTED BIGGER CAPACITY this is from a 90cc my first was a 50cc
The inlet is on the RH side of pump and outlet is fed into front cylinder follower blind spindle but the banjo feeds into hollow end into cam Rail. The jet holder has had the jet removed and a 4mm ball fitted and jet replaced. If Honda pump fails what little oil pressure is coming from the main pump can still lubricate cams to a degree.
a suction pipe from inside the catchment area for main pump scavenging
weir created by tube taped and stuck into scavenge hole and end of pipe 1/4 of pipe diameter away from sump floor. As last year my weir (I believe fell over) as the thickness of the casting at the side is higher so I'm still sucking oil with Honda pump.
pipe into timing chest then plastic pipe through pipe clip (top LH bolt of idler boss)
These pumps are all very similar it is just the width of the trockoidle gears inside that differ.
I do not intend buying double start pumps any more as one of these fitted will supply significantly more oil and if directed into oil filter chamber first then back to a restricted quill feed and up to cams, one could run a plain B/E like Royal Enfield.
Vincent remarked in his writings that he wished he had kept the series "A" gear pump.
bananaman.
THE PUMP NOW FITTED BIGGER CAPACITY this is from a 90cc my first was a 50cc
Honda High Capacity Oil Pump suitable for use with C50 C70 C90 Cub 90 (12V Only) | eBay
This oil pump is compatible with 12V CDI engines only.
www.ebay.co.uk
The inlet is on the RH side of pump and outlet is fed into front cylinder follower blind spindle but the banjo feeds into hollow end into cam Rail. The jet holder has had the jet removed and a 4mm ball fitted and jet replaced. If Honda pump fails what little oil pressure is coming from the main pump can still lubricate cams to a degree.
a suction pipe from inside the catchment area for main pump scavenging
weir created by tube taped and stuck into scavenge hole and end of pipe 1/4 of pipe diameter away from sump floor. As last year my weir (I believe fell over) as the thickness of the casting at the side is higher so I'm still sucking oil with Honda pump.
pipe into timing chest then plastic pipe through pipe clip (top LH bolt of idler boss)
All good , but the stock cams seem to just about go forever if the metallurgy is right.
Having said that I plugged the oil holes to the cylinders on the 1360 as T Prince suggested. 5500 miles and OK so far. Two start pump on that engine.
There is a lot of mileage on the OZ Rapide cams. The oil holes to the cylinders are open on that bike and it ues a standard oil pump.
I've done 60,000 miles on those cams to date, however they were well used when I got the bike. I've only adjusted the valves a couple of times to take up a couple of thou ea time.
It does have the oil level raised in the timing case as Nigel mentions.
John M did not care for that mod as he felt it was unnecessary and would add some drag.
I don't find the bike lacking power so it can't be much loss.
Glen
Having said that I plugged the oil holes to the cylinders on the 1360 as T Prince suggested. 5500 miles and OK so far. Two start pump on that engine.
There is a lot of mileage on the OZ Rapide cams. The oil holes to the cylinders are open on that bike and it ues a standard oil pump.
I've done 60,000 miles on those cams to date, however they were well used when I got the bike. I've only adjusted the valves a couple of times to take up a couple of thou ea time.
It does have the oil level raised in the timing case as Nigel mentions.
John M did not care for that mod as he felt it was unnecessary and would add some drag.
I don't find the bike lacking power so it can't be much loss.
Glen
Marcus, Care to explain the half time pinion arrangement you have there?
Martyn
Martyn
Martyn my handsome,
the half time pinion is normal with three extraction holes but what you see is an "A" 3/4" 20 tpi nut (bigger hexagon) with two 2 BA tappings which I fit grub screws into when finished tightening and drilled recesses to locate grubs
the half time pinion is normal with three extraction holes but what you see is an "A" 3/4" 20 tpi nut (bigger hexagon) with two 2 BA tappings which I fit grub screws into when finished tightening and drilled recesses to locate grubs
Thanks Marcus. For a moment there I thought you had a nifty vernier adjustment setup of some sort.
Martyn - Going crazy in isolation!
Ditto here in sunny and HOT Covid California. Rolling electrical blackouts due to the HEAT! Took my first ride on the Shadow today since blocking the cyl oil holes. Only 30 miles or so. No worries.
Best.
Russ
998cc
Hi Russ,
current covid restrictions in Melbourne prohibit anyone travelling any further than 5 Km (that's 3 miles) from their home and even then you are only allowed to leave your home for one of 4 reasons. Essential food shopping, attending medical appointments, travel to work provided you are a government defined essential worker or for exercise that must be on foot. Did I mention the 8 pm to 5 am curfew?
Been like this for weeks in Melbourne and expected to remain so for at least a couple of months.
Not much riding being done.
But lots of drinking!
current covid restrictions in Melbourne prohibit anyone travelling any further than 5 Km (that's 3 miles) from their home and even then you are only allowed to leave your home for one of 4 reasons. Essential food shopping, attending medical appointments, travel to work provided you are a government defined essential worker or for exercise that must be on foot. Did I mention the 8 pm to 5 am curfew?
Been like this for weeks in Melbourne and expected to remain so for at least a couple of months.
Not much riding being done.
But lots of drinking!
Marcus, what drives the Honda pump?