I have a 1984 FXR Shovelhead. It's one of the last ones made with the 5 speed early Evo gearbox. I have owned it since 1993 and have done just about every job & repair possible over the years including a rebore with new pistons, guides, valves in 1996. In September last year (2014) I had some issues with smoke from the exhausts. I removed both cylinder heads and replaced valve seals to the guides (1982-84 Shovels have valve seals). The bike still smoked a lot so I removed the heads an barrels and fitted new rings.
I rode just 18 miles and suddenly there was smoke everywhere, white / blue smoke. It was blowing from every orrifice including tappet blocks - the oil holes at the bottom of the pushrod tubes. I looked into the oil tank and smoke bellowed out from there; oil was returning and the oil level was normal. Just lots of smoke and heat. The next day I started the bike from cold and all the smoke appeared straight away. People told me it was blowby and that there was a lot of crankcase pressure built up probably from badly fitted piston rings. There was no oil leakage or drips from the breather pipe.
So I rebuilt the engine: new pistons, rings, valves, guides, seals, gaskets etc. An engineer fitted the valves & guides and he is very competent. To eliminate all possibilities of the cause, I emptied the oil, checked every oil pipe including breathers, cleaned / replaced them, checked there were no blockages or splits - they were all ok. Checked the oil pressure valve (ball & spring), removed the timing cover, examined / checked the breather valve and all oilways in the cover & engine. Replaced the oil pump with a new one just 'to be safe'. So it's basically a new engine. Everything was ok for about 30 miles then the rear pipe started smoking, but there was no heat or excessive oil pressure like before. I was 99% sure it was a bad valve seal. I removed the rear cylinder head and one of the valve seals was loose on the guide. I have always used the small metal valve seals with the rubber ring round but this time I had used more modern ones with rubber seals on the inside of the seal. I replaced them with the original metal ones.
My bike has been ok all summer and I have 'run the motor in' and done about 900 miles. There have been no issues.
2 weeks ago I was getting a little smoke from the rear pipe which only appears when the bike gets warm. It's slowly been getting worse & worse so once again I replaced the valve seals. The problem has not gone but getting worse. A few days ago the smoking got excessive after just 6 miles and by the time I got home it was starting to smoke from the front pipe. Smoke also coming from oil tank when the cap is removed and there's lots of heat......just like last year. Everything points to 'blowby' again (build up of crankcase pressure) but why? I don't want to remove the barrels, I'm sure the rings are fine but there must be a deeper routed problem. The cylinder head is not cracked and all parts are good. Why after 900 miles when everything has been replaced? Any help please.

 

Who did the Cylinders??? They do have torque plates and Know how to use them right?
Washed the cylinders properly,and did Not oil the piston Rings ...Right?
That kind of smoke does Not come from my Shovel, nor my Ironhead, and Neither have Valve guide seals at All!

 

Sorry, forgot to mention, yes I had a rebore last year with the new pistons / rings etc.
Today I started the bike. After a couple of minutes the rear pipe started to smoke. I removed the oil tank cap and smoke came rushing out. With the bike still running it just carries on smoking, the rear pipe emitting more smoke so basically the longer you run it the worse it gets. Oil is definately returning ok and the crankcase breather does not blow out oil. The breather pipe to the oil tank is pumping out a lot of steam / smoke / vapour into the oil tank. The breather pipe connects to the engine just above the oil pump (not on the oil pump) and is known as the vent line to oil tank and chain housing. Within the timing case is 'low oil pressure' so this pipe is just a breather (to the oil tank) but it's blowing really strong.
Tomorrow we are doing a leak down test on the rings and with everything being new, I am going to presume the leak test will be fine and not give any bad news.
So why is pressure filling up in the crankcase and blowing out the vent pipe (not blowing oil, just pressure) and why has it started again after 900 miles of trouble free riding?

 

is it possible the oil return is blocked by the base gasket?

 

No, and I've done 900 trouble free miles.

 

as i read this i can only say the rings are the issue - 2 types of pistons and the difference is the rings - one has 5 /32 compression and the other has 1 /16 compression rings and they come in two different materials on the top rings face - one is cast iron both compression and the other is moly top cast iron second

another is the oil control rings USA rings are 3 /16 - 3 pieces two stainless rings top and bottom and a expander in the center --

then you have the china junk - some kind of metal top rings and a ONE PIECE oil control ring - is this what you have ????????

then you have the possibility the the hone was done indifferent to what we do - and if so the possibility that the piston rings have turned around and are now in alignment with one another - this wil cause all kinds of issues you would not expect

Question - please explain how and what you did to install the rings and the way they were placed on the pistons if you can

 

I'm hearing ring problems, do a compression check rings may have been installed too tight and broken on you. She'll smoke like crazy when this happens.

One more thing look real close at the rear valve guides the exhaust in particular and see if they appear wet with oil when cold, guides have been known to work loose in the heads and push oil past.

 

The pistons & rings used last year are Twin Power, distrbuted by Nempco which came in red, blue & white boxes. I still have the boxes. The label reads: TR / NEMPCO # 49-3133. Twin Power Cast Pistons for Big Twins.
1340cc Std. Comp. (8.1)
78-84 Shovelhead + 0.30".
Mfg 70706P.

With sticker 'Made in Taiwan'.

There's plenty for sale on ebay at the moment from the U.S.

Rings were installed as per workshop manual. There was no ring gap at the front or rear of piston. Gaps were spaced at 10, 3 and 7 o'clock.
Will let you know the result of the compression test later today.

 

in 1998 nempco changed its name to bikers choice but lots of old stock as still around - if you find a ring could have been at issue - hastings piston rings in moly is the USA indy shops choice for long life just use a 3 1/2 inch ball hone and re install

 

Note here John...This is an '84 FXR...decidedly Not a Shovelhead...
Unless that info is Incorrect....

I stand by my original post assuming this really is an '84 FXR.