I'm smoking on the right too!

[Steverat]

Hi Steve,
Was the hole in the dump plate gauze in the correct place, ?
If the pickup pipe is obstructed by the gauze it will restrict it
If you place a large tray under the engine
and a jar of oil sitting in it with a transparent tube pushed on over the pickup pipe and into the jar
A brief run of the engine will check if the
Return pump is doing it's job
Previously I suggested bypassing the tank return pipe to remove any  restriction that might be there??

Yes John and it pumped oil quite fast, you could see it sending air locks back in the oil too. Already blown through the standpipe in the tank, that is still clear. Now going through the scavenge line cleaning and blowing through as I go.

John

[Swarfcut]

    Steve, the small dowel and the bolt securing the oil feed and return pipe unit should align all the holes. The gasket only fits correctly one way. The oil return pipe in the tank is the important one. The standpipe is just a vent to atmosphere.

   Chaterlea John...

    If Steve has set up the return tube extension to the pick up pipe, and it is always submerged below the oil level, there should be no air in the return. Any air indicates a pump/crankcase leak or a fault (air leak) in the scavenge pipe within the crankcase.

Your thoughts?

 GB...A timely reminder about those gears..they supposedly like to go back where they were.

 Swarfy

[trevinoz]

Maybe a silly question, is the ball in the pick-up free? Did you prime the pick-up tube? That's two questions.

[chaterlea25]

Hi All
Muskie,
Maybe ?possibly , I suppose it might take a little running to expel any air already in there ??

Did Steve say earlier that the pickup pipe needed straightening ??

Is there a magnet in the sump plate?  That has caused me a headache !!!!!!

I'll bet the solution is a very simple one

John

[Steverat]

Gone through the scavenge line today and blown everything through with compressed air. Pleased to say it is now scavenging back to the tank.

Just the back numberplate and the front mudguard stay to do and we wil have a complete bike ready for handing over to Josef on the 22nd.

Once again many thanks to you all for your interest and help.

[Topdad]

Glad that you've solved that problem ,along with many others and  can now see the winning post in sight! tell me after the A10 is handed over will you stop posting with us and indeed will Josef  be joining us ?  I hope not to the first question and yes to the second  as I've enjoyed reading your trails and tribulations but more importantly your ability to get them sorted , best of luck Bob.

[Steverat]

Glad that you've solved that problem ,along with many others and  can now see the winning post in sight! tell me after the A10 is handed over will you stop posting with us and indeed will Josef  be joining us ?  I hope not to the first question and yes to the second  as I've enjoyed reading your trails and tribulations but more importantly your ability to get them sorted , best of luck Bob.

Bob thank you for the unwarranted compliments. I have already recommended the webgroup to Josef, I don’t know whether he will feel confident enough to post. It’s up to him. As for me, I suppose it depends a bit on whether I get another BSA twin project. Anything out there I wonder. My favourite bike would be an early Rocket, with the single-sided “Goldie” brakes, I fancy they look a bit lighter than the later full width hub models.  Please feel free to tell me if you know of one that may become available!
Thanks again,
steve

[Swarfcut]

Steve... Well done, you have a runner at last. Chaterlea John reckoned it was simple. I had my doubts, so  now do you have you a firm diagnosis, and were those new piston rings from Hepolite actually not the whole problem?

 Swarfy.

[Steverat]

Swarfy,

Right! Well there were at least two problems and the rings were certainly one one of them. The symptoms, the methods and the solution to the rings problem are all in the thread in some detail, so if I concentrate on the second one...

... the delivery volume from the SRM pump is massive and will fill the crankcase at tickover in less than 5 minutes if left unscavenged. So if there is any weakness on the scavenge side, perhaps an airlock somewhere or (as I think in my case) a scrap of PTFE tape partially obstructing an oilway, there can be oil everywhere except the tank, and in very short order. That's about the best explanation I can give.

The lesson I have learned is to blow everything through with compressed air immediately before assembly, and be extra vigilant when using PTFE tape. I am a fan of PTFE for sealing threaded joints, and had used it on the union between oil return pipe and the tank. When going through the system with the air line I found a "tail" of the tape was actually in the pipe. It might have impeded the flow. Can't say for certain though.

Now then, anyone got a '54 Rocket for me to play with? 

Steve

[Greybeard]

Excellent job Steve. I reckon you will need a lttle lay down after this!

[chaterlea25]

Hi Steve,

Now then, anyone got a '54 Rocket for me to play with?

Not a rocket but I think this one shouldn't take you too long 

https://www.ebay.co.uk/itm/BSA-Engine-And-Gearbox-1952-53-Spares-Repairs-A7/312513609967

John

[Colsbeeza]

Hi Steverat,
I followed your saga with great interest. My 1961 Golden Flash has not been ridden since 11th November, as my endurance had come to an end and I haven't wanted to face it for a while. It has been smoking from the LHS since I got it going in 2016. In November I took it on a 40 mile round trip, but after starting the next day the LHS smoked badly ( and I mean BADLY - with bluish white smoke ) after about 30 secs running - same old story.
I had new original Hepolite pistons and rings, but after the first 80 miles the smoke would not settle down, so replaced the rings with new AE Hepolite from SRM after honing the new bores etc and overhauling the head with new guides and valves (which were not great). No sign of oil leaking down the guides, but the plugs are wet and black. The only thing which throws me is that the RHS has not burnt oil at all. Everything else has been ruled out, so your experience has encouraged me to try Gandini rings.
Don't suppose you measured their dimensions did you.?? ie Ring thickness and depth.??
I will get hold of a set of Gandini rings and pull the cylinders and pistons off and have a thorough examination of both pistons, alignment etc. Seems I should also try some Engineers Blue on the Hepolites and Gandinis whilst I am at it.
Colin

[Steverat]

Hi Colin

Given the amount of evidence out there about oil starvation on the drive side I think there must be a significant fault for it to be smoking so heavily on its own. Have you had the head off to take a look at the bore?

My Gandinis had about 0.0015” side clearance and ring depth slightly less than the “Hepolites”. Sorry I didn’t measure the depth exactly but I did measure the radial spreading force of the closed ring, the Gandini compression ring is 1400g and the “Hepolite” is over 2000g. I haven’t been on the road with the bike but it’s had about 20 minutes of intermittent running in the garage and can report the Gandinis are settling in, they hold compression well and there is no oil smoke.

[Colsbeeza]

Thanks Steve,
Yes. When the problem was evident, the Forum advice was that I had probably glazed the bores due to long periods of idling whilst I sorted out a magneto problem. I stripped it down, honed the new bores and fitted new AE Hepolite rings from SRM. There were other problems such as gudgeons so tight that the rear of the bores was scuffed on both cylinders, and I could not rotate the pistons by hand without considerable force. I rectified all those and also had the head done up. When re-assembled, the excessive smoke continued as before.
I e-mailed FW Thornton yesterday - He replied just now to say -
"I would suggest your problem lies elsewhere. Hepolite rings are usually very good.  The Gandini rings won’t work as you’ve found out as the radial depth is too great. Best regards, Duncan Rowley
F W Thornton - “The Automotive Parts Specialists”[/b]
So that places me back to Square 1 as far as FWT are concerned. I am not convinced yet that the rings are the problem.
I am in the process of eliminating external issues which I am not 100% happy with - carb, clutch and timing. Then I will strip it down again and study the top end in depth with the ideas presented to you by Forum members with your problem. I will leave the ring purchase until then.
Seems I will need to check the alignment and verticality (is that a new word? ) of the bores, and the parallelness (ditto?).  Also the alignment of the conrods and pistons relative to the head surface. Many things to consider.
Col

[trevinoz]

Col, what grit was used on the latest hone?
I have a barrel here which is from an engine I am currently working on and has only 500 miles on it with new Hepolite pistons and rings.
There is evidence of excessive oil burning by the deposit on the tops of the pistons. Far too much carbon for 500 miles.
I am considering having the barrel honed lightly with a coarser grit.