Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board Very heavy smoking right side on new 64 a65

Hey guys,
some of you may recall I've been building this 1964 a65 motor for quite a while now. Newbie clutch, SRM oil pump, mapp rods, the head is new everything (mostly kibblewhite) including new valve seats pressed into it.
I'm getting very very excessive oil running through the right side. Super smokey, white not blue. Damn near dripping out the exhaust. I have an inline oil filter and oil cooler on the return. I really don't think that's making any kind of difference but it's just information to get a clear picture. I don't think it's sumping as there wasn't oil sitting in the bottom after running.
Pulled the head and cylinder cause thought it must have been a broken oil ring but the rings are good. They also are in correctly and not upside down..
I did have to remove the worm gear on the SRM oil pump to prime it. The worm gear didn't want to come off really easy so I loosened the oil pump to get a little more play for removing the worm gear. However after tightening it back down and priming it it seemed to not have a problem .
I had read online ( somewhere at some point) somebody mentioning that if the oil pump isn't tightened down correctly or is miss-aligned it can create situation where it will smoke...?
Also I can hear the breather working as I kick the thing over...
I'm stumped..
Tomorrow I'm going to pull the head apart and see if the valve guide is loose but it' seems to be a LOT of smoke for that scenario..

Because there are no oil seals on the intake valve BSA's tend to suck a lot of oil down the valve stem
Having too much oil splashing around in the head makes this worse
My assumption is your nice new high capacity SRM pump is putting too mcuh oil into the rockers
Remove the oil line for a test ride of a couple of miles and see if it clears up
Back in the 70's when oil cooling was "the" thing on race engines all of us who knew more than the BSA engineers used to block the oil return line in the tank to force more oil into the head
End result was a lots of smoke, heavy oil / carbon deposits on the head

I'll try blocking it and running it for a minute to see..

Single or twin carb?

Single

Unless the valve and guide are really bad the oil is not coming from there. Is the rocker feed before or after the filter/cooler?
Copper head gasket? Did you anneal it and keep it perfectly flat afterward? Any bending will harden the copper. I use Gasket Eliminator around both sides of the drain holes and tunnel to fill any imperfections.

Check the drain holes through the head and barrel, they are only small and easily blocked by gasket goo.
If blocked they will stop the oil draining and also allow pressure build up in the rocker box

Will look to use that upon reassembly.

"If blocked they will ... and also allow pressure build up in the rocker box" - cannot happen. There is a large hole in the bottom of the pushrod tunnel into the main case. Oil will fill up in the exhaust spring pockets to the top of the guide if the hole in the cylinder got blocked.

Have you done any porting ? aggressive port cleaning ? when refurbing the head. I had a similar problem with a ported head. Small pinhole near inlet valve collar pocket that had broke through to inlet port and letting oil into inlet port. Once warmed up it smoked like a bastard. Took some head scratching to find the cause. Filled with JB Weld now and no further issue. Could have a similar issue on the exhaust valve side if you say "it's dripping", Inlet side is more likely to burn most of the oil off and then give smoke, exhaust side wouldn't burn it off much but would smoke and have more oil residue. Worth considering as you seem to have done everything correctly.

My guess is that either the head gasket isn't sealing and oil is being sucked into the cylinders from the drain holes, or the rings aren't sealing.

I would get the cylinder head surface checked for flatness and also the top of the barrel. Both of these surfaces need to be exactly flat to ensure the head gasket seals. A very tiny amount of high temp gasket sealer used around the drain holes can be useful in stopping oil from being sucked in.

If you are using the grey cast iron rings you may have missed the running in window, which is to start the bike after rebuilding and go for a spirited ride with plenty of throttle in low gears. Hopefully you haven't started the bike and let it idle whilst admiring your work. The rings need to bed in against the coarse cylinder surface with high cylinder pressure from acceleration for a few miles

I would be interested to know the type of pistons and rings fitted, the latest Hepolite pistons come with a decent set of rings and a good oil control ring with a spring loaded tensioner. Older piston types come with simple cast iron rings which can be hard to bed in. If you have the older rings try using hasting rings or total seal which are much better.

bypass the oil cooler and just have the return lines joined up .... wouldn't mind a side bet the problem will vanish. Its possibly creating to much "resistance" to the return to the tank

always try the easy stuff first

Leaking around the guides???

A common mod is to use two small o-rings on the drain holes in the head gasket if
you have trouble with oil leaking at that point.

If it's a large amount of smoke i would put my money on a leak from the rocker box
into the inlet port or a badly fitted guide/scored guide hole.

It's impossible to get the standard setup to deliver too much oil to the rocker area
without totally blanking off the oil tank return, the restriction of both the actual head supply
pipe and the fitting into which it fits will never allow enough flow to flood the rocker area.
Plus as David says, there is a large aperture at the base of the barrel allowing draining.
The worst thing that can happen is you increase the sump oil level, that can make it smoke
but it would be both sides.

My thoughts as well re: inlet would have burnt most of it off.

that much smoke has to be from a head gasket leak unless there is a hole in the head drooling into the combustion chamber, a "leakdown" compression check might give a clue because you can hear where the pressure is going. for a guide to pass that much oil the valve would be hanging in the hole like a bell clapper. as mentioned... head and barrel connections must be flat and true. anneal the gasket so it is good & soft

My thoughts as well

Not sure but that is my next check for sure

Got emgo pistons but hasting rings. I've had good luck with that combination in the past.