Blowing Smoke

Burgs · Apr 26, 2016

Hi Dynodave
When I dropped the oil out I had around .4 ltr which also seemed excessive. Haven't had a chance to give it a run yet, might do today.

Gripper two streams of oil at idle had me concerned also, nearly looked like what you get after starting for a week or so, bores have been measured properly, I run a small machine CNC shop from home 5 axis machining centre and CNC lathe plus manuals, had a machine shop for 12 years previously also, so bore checks out, although I am not ruling out the big pistons yet.
There were no nuts missing just the stray nut, nuts on pump were tight and gasket was good, also prior to the run the crankcase was drained as I just changed the oil prior to the run. Stripped the pump down and had a look, looks worn but not that bad!

Torontonian got the pistons from the USA they are still listed I see Hepolite also are offering them, the ones I fitted were EMGOs (Hastings rings) they are still listed on Ebay, but If the oil pump doesn't fix the problem I will go for bore distortion, even though the bore witness marks look very even.

Anyhow I will fit the breather and make a run this morning and see what happens.

Best Regards
Burgs

Burgs · Apr 27, 2016

Hi All
Well today turned into a long day and didn't get to the bike till late.
Started up and oil return to tank looking good, went for an 8 mile run and still blowing smoke mainly the R/H side, running sweet and crisp.
Turned onto the highway back home and it started missing and eventually cut out just from home, luckily slight down hill to home so coasted home.
Now two things happened, one need petrol to make engine work

, two R/H plug slightly oiled, and L/H sooty.
Cleaned plugs refitted added petrol and started first kick, checked oil return looks like it should, oil air oil air etc, checked for oil leaks and low and behold engine is dry as, no great pools of oil on the floor and the engine not covered with oil head to foot

.
My thoughts at this stage is I am not convinced that everything is quite right yet, I will fit a new set of plugs, may go to a slightly higher heat range for a while, put up some more miles and see what happens.
Some of the smoke I am sure is coming from the exhaust system but not yet convinced all is, the breather flow to tank is not excessive and there is no smoke coming out of the breather, compression hot and cold is the same, as far as my leg can tell, oil pump definitely part of the problem.
The engine is starting easy, and is usually a first kick start as long as I remember to give it a tickle.

Best Regards
Burgs

gripper · Apr 27, 2016

You obviously know what you are doing from the engineering point of view. Any oil left in the exhaust won't return to foul the plug so oil is still getting in from somewhere. I had a cracked piston in the days of slotted oil ring grooves. Burnt a complete tank full in 120 miles. What clearance are you running on the bores? With 2mm extra on the bores you are effectively upping the compression ratio quite a bit. Everything is getting a bit strained in the barrel department.

Burgs · Apr 27, 2016

Hi Gripper
I have fitted a compression plate (RGM) to reduce compression, I know I should have measured the compression ratio but I didn't, it's on the list, problem is I broke my burette, and have to get a new one if I can find one!
Yep as I said in previous email I am not convinced yet, but the plugs have suffered a far bit, from the oil and the consequent bead blasting, so ever hopeful I will try everything prior to submission, I guess I could buy a set of sleeves, and fit along with standard pistons, or bore the barrels out and fit a heavy wall set of sleeves!

As a side note I paid a visit to an old sidecar racer once and he showed me the cylinders he made for his Atlas powered sidecar, he had made them out of iron sewer drain pipes, who would have thought, cannot remember the capacity, but is was beyond 900cc, and ran on Methanol. He also cast and machined his own pistons, as well as fabricated Manx Norton frames and magnesium brakes/hubs. Also made sidecar frames for other racers in Australia.

best Regards
Burgs

Biscuit · Apr 27, 2016

Burgs said:
As a side note I paid a visit to an old sidecar racer once and he showed me the cylinders he made for his Atlas powered sidecar, he had made them out of iron sewer drain pipes, who would have thought, cannot remember the capacity, but is was beyond 900cc, and ran on Methanol. He also cast and machined his own pistons, as well as fabricated Manx Norton frames and magnesium brakes/hubs. Also made sidecar frames for other racers in Australia.

best Regards
Burgs

Now there's a gentleman who saw WORLD'S FASTEST INDIAN and said "So, we all do that sort of thing in this part of the world".

BritTwit · Apr 27, 2016

Burgs said:
As a side note I paid a visit to an old sidecar racer once and he showed me the cylinders he made for his Atlas powered sidecar, he had made them out of iron sewer drain pipes, who would have thought, cannot remember the capacity, but is was beyond 900cc, and ran on Methanol. He also cast and machined his own pistons, as well as fabricated Manx Norton frames and magnesium brakes/hubs. Also made sidecar frames for other racers in Australia.

Yeah.
I've heard some of those chaps down under make their own cylinder heads too.
:wink:

gripper · Apr 27, 2016

The barrels are pretty thin just above the base flange. I would have thought that boring any more would make them very weak in that area. I'm sure someone on this forum will be able to advise you as to the way ahead regarding re-sleeving.

Burgs · Jan 28, 2017

Hi All
No closure on this one yet, but due to other commitments I have not done much since last posts.

I have bought a set of liners, pistons, rings and gasket set, but I am going to concentrate on the head first.
Pulled the head off last week, and sat and looked at it for a couple days, pulled one inlet valve out, checked rocker shaft was correct way out, sat and looked again today, spent a couple of hours looking at previous "smoking posts" on the site, rechecked valve and guide and noted the valve is covered in a light coat of oil (both are coated), checked around the valve guide on the inlet side and noted a lot of oil, cleaned with brake/carby cleaner then contact cleaner and if I am not imaging it I think I have oil passing on the outside of the guide?
I am thinking now of using Loctite Super Wickin to seal the guide.
Another thing is the valve stem oil seal, while it is still in place appears to be next to useless, compared with what is on offer these days with the technology that is built into them, that is the high end offerings.
So I reckon from here I will do one valve guide at a time cleaning and sealing, pop the head back on, I can do it in my sleep now :lol: , clean the exhaust pipes and mufflers out and go for another test run.
This will take me a couple of weeks as I need to keep the machines running to make a Bob or two to pay these bits and bobs.

PS the bore looks good so I am concentrating on the head at this stage and if all I do there fails I will admit defeat and rebore and sleeve the barrels.

best regards
Burgs

myjota · Jan 28, 2017

I would be concerned the the camshaft thrust bearing tang had come off and blocked the scavenge side oil pick up. I've had this before on a 72 engine. The combat type breather does a good job of scavenging for a while but at high speed the crankcase fills up with the oil tank contents then if you run a bit slower the tank level goes back up!

Burgs · Jan 28, 2017

Hi
That sounds interesting, how did you end up finding the broken tang, sounds like a complete tear down?

Burgs

myjota · Jan 28, 2017

Noticed smoking after a bit of a run. Had previously spotted oil level was up and down a bit. I was lucky and tang was stuck in oil pump scavenge inlet port. The tang is just the right size to block the oil way though.

Burgs · Jan 28, 2017

Hi
That was a lucky find, I need to fit a new timing chain and adjuster, so will pull the pump off and check for any blockage as well. I will need to familiarise myself with the passages first.

Regards
Burgs

acotrel · Jan 28, 2017

Burgs said:
Hi Gripper
I have fitted a compression plate (RGM) to reduce compression, I know I should have measured the compression ratio but I didn't, it's on the list, problem is I broke my burette, and have to get a new one if I can find one!
Yep as I said in previous email I am not convinced yet, but the plugs have suffered a far bit, from the oil and the consequent bead blasting, so ever hopeful I will try everything prior to submission, I guess I could buy a set of sleeves, and fit along with standard pistons, or bore the barrels out and fit a heavy wall set of sleeves!

As a side note I paid a visit to an old sidecar racer once and he showed me the cylinders he made for his Atlas powered sidecar, he had made them out of iron sewer drain pipes, who would have thought, cannot remember the capacity, but is was beyond 900cc, and ran on Methanol. He also cast and machined his own pistons, as well as fabricated Manx Norton frames and magnesium brakes/hubs. Also made sidecar frames for other racers in Australia.

best Regards
Burgs

Burgs,
Do you know this guy ? He built a lot of the better Australian sidecars in the 60s :
https://www.youtube.com/watch?v=sWddRZmrba8

Burgs · Jan 29, 2017

Certainly know Lindsay, but he wouldn't know me, we both ended up in the same hospital a couple of Easters ago from our offs at Broadford Bike Bonanza, Lindsay came off a bit worst for wear then I did by the sounds of it?
In my youth we used to watch Lindsay race at the Easter Bathurst meets.
By the way it was Brain Payne I mentioned earlier.

Best regards
Burgs

baz · Jan 29, 2017

Burgs said:
Hi All
No closure on this one yet, but due to other commitments I have not done much since last posts.

I have bought a set of liners, pistons, rings and gasket set, but I am going to concentrate on the head first.
Pulled the head off last week, and sat and looked at it for a couple days, pulled one inlet valve out, checked rocker shaft was correct way out, sat and looked again today, spent a couple of hours looking at previous "smoking posts" on the site, rechecked valve and guide and noted the valve is covered in a light coat of oil (both are coated), checked around the valve guide on the inlet side and noted a lot of oil, cleaned with brake/carby cleaner then contact cleaner and if I am not imaging it I think I have oil passing on the outside of the guide?
I am thinking now of using Loctite Super Wickin to seal the guide.
Another thing is the valve stem oil seal, while it is still in place appears to be next to useless, compared with what is on offer these days with the technology that is built into them, that is the high end offerings.
So I reckon from here I will do one valve guide at a time cleaning and sealing, pop the head back on, I can do it in my sleep now :lol: , clean the exhaust pipes and mufflers out and go for another test run.
This will take me a couple of weeks as I need to keep the machines running to make a Bob or two to pay these bits and bobs.

PS the bore looks good so I am concentrating on the head at this stage and if all I do there fails I will admit defeat and rebore and sleeve the barrels.

best regards
Burgs

i have come across valve guides that tapered before ie they fitted tight in the head but but we're letting oil down the outside, you could actually move the guide a little with a bar inserted into the guide, I took them back to the shop ,and with my micrometer went through a whole box of them to find four guides that were parellel, you can disconnect the oil feed to the head to see if the smoke stopps if you suspect valve guides or seals , cheers

baz · Jan 29, 2017

Burgs said:
Hi All
No closure on this one yet, but due to other commitments I have not done much since last posts.

I have bought a set of liners, pistons, rings and gasket set, but I am going to concentrate on the head first.
Pulled the head off last week, and sat and looked at it for a couple days, pulled one inlet valve out, checked rocker shaft was correct way out, sat and looked again today, spent a couple of hours looking at previous "smoking posts" on the site, rechecked valve and guide and noted the valve is covered in a light coat of oil (both are coated), checked around the valve guide on the inlet side and noted a lot of oil, cleaned with brake/carby cleaner then contact cleaner and if I am not imaging it I think I have oil passing on the outside of the guide?
I am thinking now of using Loctite Super Wickin to seal the guide.
Another thing is the valve stem oil seal, while it is still in place appears to be next to useless, compared with what is on offer these days with the technology that is built into them, that is the high end offerings.
So I reckon from here I will do one valve guide at a time cleaning and sealing, pop the head back on, I can do it in my sleep now :lol: , clean the exhaust pipes and mufflers out and go for another test run.
This will take me a couple of weeks as I need to keep the machines running to make a Bob or two to pay these bits and bobs.

PS the bore looks good so I am concentrating on the head at this stage and if all I do there fails I will admit defeat and rebore and sleeve the barrels.

best regards
Burgs

seattle##gs · Jan 29, 2017

Check the oil pressure release valve. I had one stick shut and caused lots of over oiling problems. It even took the crankshaft oil seal in the timing cover and inverted it.

Burgs · Jan 29, 2017

Hi
I have taken the timing cover off this afternoon, and tried undoing the cam nut to remove the sprocket, chain and idler, but it has been a bit of a lost cause so far, might have another go tomorrow, time permitting.
Removed the oil pump and so far all ports appear clear, at least oil is coming out of them, sump is full again.

Baz, I never checked the guides for taper before fitting them but I am learning that I should check everything, the valves are good but slightly oversize on the stems, no problem as the guides were reamed to suit. Looking at them in the head it appears they may have been a tad big as there are slight score marks on the guides as they enter the inlet port.
Have resealed one inlet guide with Loctite 290, but need to purchase some dissent valve stem oil seals before moving onto the next valve. the valve guides leaking externally maybe a wild goose chase but I am not going to leave anything t0 chance this time.

Seattle, I will check the relief valve as you suggest as I have always been suspicious of the oil pressure readings 70 PSI at idle cold (not really cold where I live) and about 30 PSI hot, my previous experiences with British twins makes me think something is not quite correct ie to high, hot at idle!
Best regards
Burgs

Burgs · Mar 31, 2017

Hi All
I can now finally close this one off, I have only had the chance to get back to the bike in the last month or so.

After measuring the pistons, rings and bores, all I could find was that there was no or too little pressure being applied to the rails by the expanders (3 ring oil control Rings) so I contacted Hastings as to what I had found.
Hastings got me to fit the oil rings only to the pistons and fit them into the bore, and see what resistance I had (should have been 14 - 15 lb seems a lot?), basically there was none.
Hasting supplied a new set of 3 ring oil control rings as they thought the current oil rings may have been packaged incorrectly, but they turned out to be the same.
I thought the pistons were too easy to fit in the first instance!
Hastings are sending out another two different sets of oil control rings for me to try, certainly good assistance and cannot really complain.

In the meantime I have refitted the original Hasting 2 piece rings and no smoke, and all is good

, there was certainly a big difference in the force required to move them in the bore compared to the 3 piece ring set.

The other problem I had was when the exhaust push rods were too long the rocker arms had side loaded the valve stems and flogged the bronze guides out.
I have refitted another set of cast iron guides I had on hand that were still within spec, also fitted a set of Manly Viton valve stem seals all round, just to make sure.

Regards
Burgs

rx7171 · Apr 7, 2017

I got tired just reading all you had to go through just to find out a supplier had given you crap rings!
If you had been working for money on this someone would have gotten a huge bill.
Well done.

Blowing Smoke

Similar threads