Smoking exhaust

I have a 95 flh and it is blowing bluish smoke which I know is for oil, I redid the rings last season when it did it before and this season it started again and I noticed it was doing it on de- acceleration so I figure the valve seals I replaced them and guess what now it's blowing smoke all the time. please help I can't believe I need to replace the rings again
Thanks
Rich
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how many miles on the bike? are you sure the rings were done right?

Valve guides/seals are known problem & that may be the answer. It's not real common, but I have seen H-D replace them even after a bike's warranty had expired.

Question - did you do a clean-up hone on the cylinders & double-check your piston-to-wall clearance before putting the engine back together? If not, the rings may not have seated right to begin with.

I did the work myself I did hone the cylinders but didn't check the clearance how do I do that, also did the seals and when I started the engine it still smoked
thanks Rich

i've heard that if the oil pump isn't lined up right it can smoke. did you do anything with that?

Cylinders change shape when you take them off & the only way you'll get a proper measurement & a good hone is to bolt torque plates on 1st. Those duplicate the stresses put on the cylinders when they're torqued down on the engine. You don't care if the cylinders are out-of-round just sitting on the workbench (they will be), you care about what the diameter is when they're installed.

Just one example is a set of cylinders I've got for a 4" bore engine - measured with a bore gauge after removal & again after torque plates were installed resulted in a difference of .004". Might as well be a mile. With torque plates the variance was only .0005" & that we honed to -0-.

Measure the pistons just below the bottom ring groove on the same line the wristpin is on with a micrometer. Measure the pistons 90 degrees on either side of the wristpin hole & you'll get a different measurement, which should be slightly less, but that area will grow as the piston heats up & the biggest measurement is what you're concerned with.

Then with a special bore gauge which a local machine shop should have, measure the cylinders all the way top to bottom & all the way around with torque plates installed & torqued to spec. See what the piston manufacturer says the piston-to-wall clearance should be & if you have to remove too much material from the cylinders to get them right, you'll have to go oversize on the pistons. I know you don't want to hear that, but PTW clearance is absolutely crucial.

For example, in a Sportster engine, Wiseco says .0025" clearance but KB says .0015" & you can go down to .001" if the machinist is really, really good. That's because Wisecos grow as they heat up & KB's don't. 1000th of an inch doesn't sound like much, but believe me it is - Wisecos rattle like a bucket of bolts cold.

Now there is one trick to use if you're not off very far & I just used it - I get my pistons coated with a Teflon-like substance by Calico Coatings (same co. the NASCAR boys use). The coating is applied to the piston skirts & can be from .0005" to .0015", but no more than that. Coat 1st, then hone.

Is all this nit-picky detail really necessary? If you expect the engine to last a long time it is. Just due to the basic V-Twin design, Harleys are bad about the pistons trying to turn sideways in the cyls. & the rocking action will wear the front & rear of the cyls. a lot faster than the sides. Take a typical H-D engine apart with 20,000 or more miles on it & while you'll still see the hone marks on the left & right sides of the cyls., they're usually gone from front & rear.

Measure even with torque plates & the cyls. are out-of-round. And they'll have a taper too - more wear towards the top. One rule is that the moment you start to use anything mechanical it starts to wear out. You can't stop it from happening, but you can sure slow it down. Detailed measurements, proper machine work, proper break-in procedure to set the rings, a good coating of quality oil on the cyl. walls (not the thin stuff for new cars) & you can go 60,000 miles easy.

But be off even a thousandth of an inch on PTW clearance & the wear will show up quick. I've seen "bolt on" conversion kits for more displacement wear out in 6 months - just because the assumption was made that the new cyls. are the correct size for the new pistons. Really weird wear patterns too.

H-D engines run over such a wide temp range & the parts made of different materials expand & contract @ different rates, heating up & cooling down, that it's not like a car/truck/van engine that warms up real quick & then runs the same temp in July as January.

A good machinust can measure down to the 10/1000th of an inch & that's how detailed you want to get if you don't want to be rebuilding all the time.

well that is awsome info I guess I will be disassembling the engine again this time I will bring the cylinders to the machine show and have them measure and honed I should replace the pistons this time with the rings, I was wondering if I should install higher compression pistins since they are off? what do you thing 9:5-1 or 10-1 or just leave it? I do plan on installing a cam later this season to.
Thanks
Rich
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keep in mind that the higher the compression, the more of a beating the rod and main bearings take. compression is where alot of hp can come from along with alot of problems too especially if those clearences aren't right on. then to, fuel can be a problem. you may have to go with a more powerful starter too.

good to know I need to really think this thru I want some power. I mostly ride around town and some highway, I just want alittle pep not a drag racer.

Contrary to popular belief, increased to compression does not automatically = increased power. It's cylinder pressure that makes power & the mechanical compression ratio is only part of the equation. But of you do have to replace the pistons (you may not) then it wouldn't hurt to go up a bit on the CR. 10.5:1 is about as far as you can go to run normal pump gasoline without serious work on the heads.

With respect to changing cams, look @ the rpm range you actually ride in before you buy any. Aftermarket cams are always a compromise - you must give up something to get something else & cams that make big top-end HP will cost you torque @ lower rpms. For example, if you normally ride in the 2500-4000 rpm range, you do not want cams that make power from 4500-6000, as in the 2500-4000 range you will actually lose power.

thank you for all the info.

getting the heads properly ported will probably do more than just more compression and you never have two do it again no matter how many times you rebuild the engine. so its money well spent. i plan on doing the heads on my 03 fxdx soon.

It will. Head work is always good, even if it's just basic cleanup, matching ports & combustion chambers. If you go with more substantial work, including opening up the combustion chambers a lot, you will end up buying new pistons since the heads & pistons must be designed to work together, but you don't need to go that far for a great-running street bike.

well I just wanted to let everyone know how things are going. I brought the cylinders and heads to a machine shop and had them look it over and guess what the cylinders were worn quit a bit they had to be bored 10 over and the head were cleaned up and checked out ok, replaced the seals and good to go. I considered doing head work while they were off but dur to money and the itch to ride I choose to have them just inspected. I plan on bringing the whole engine back and having them do a complete job and increasing the hp to about 80. I hope this is it for the season I will keep the forum updated as I do the work on the projects part.
Thanks to all for the great info.
Rich
halligansffmc.org

There ya go !! It's nice to be able do things yourself, but there are times where a good machine shop is indispensible. Doing detail work is not really all that difficult - if you've got the tools & equipment - but those are VERY expensive.

There's a little shop about 5 minutes from me & it'd take @ least 1/4 million $$$ to buy what's inside. And while a H-D dealership which doesn't have all that equipment or even the knowledge to use it charges $85/hour, the retired NASCAR fabricator charges $50/hr. with no minimum, so it's a "no-brainer" where to go for specialized work.

1 HP per cubic inch is not hard to get from a Harley engine, but after that, each additional HP costs progressively more until you get into the insane category (been there). And as I mentioned before, see what rpm range you actually use - bet you're in lower ranges where torque is a lot more important than top-end HP.

And HP is just a mathematical function of torque & rpm - the formula is:
HP = (torque x rpm) / 5252. Look @ dyno charts - the torque should fall off @ 5252 rpm although the HP may still be climbing. But are you riding above 5252 rpm all the time? I know I'm not. And if I'd wanted a Yamaha I'd have bought a Yamaha (had one in my younger days). You use a different formula for engines that scream 13,000 rpm & higher & the torque peak will be higher up the scale, but that doesn't apply to Harley engines.

I've seen several big twin dyno charts where the torque fell off @ around 4500 rpm & that ain't right. And I've also seen a 13 HP increase on a Dyna from just taking the SE 2-1 pipe off (re-badged V&H "Pro Pipe") & putting a simple set of 2-2 pipes with Cycle Shack slip-on mufflers on. (2-1 pipes only work in a narrow rpm range - typically 3000-4500 on a Harley).

So you don't need to get fancy or expensive to have a fun & dependable bike - just stick to the basics & tune it right. Go to the machine shop for detail work you may not have the tools for, but it's not "rocket science" to get a Harley to run good & I'll bet torque @ 3000 rpm is a lot more important to your ride than HP @ 6000 rpm is.

- Art

How's 1.67 HP per cubic inch - on gasoline with one carb & no blower or nitrous oxide? In theory, 1.75 HP/c.i. is possible, but nobody's ever done it with the 50-year-old pushrod engine design.

"hotroadking" hit the nail on the head with a framing hammer there. What works @ the racetrack often doesn't on the street & torque is what you actually use. Betcha throttle response @ 2500 rpm is a heck of a lot more important than what the engine might show on the dyno @ 6000 rpm.

In some respects that's true - "bragging rights" winning the "dyno shootout" @ some shop or dealership doesn't mean a lot, although it might get you a $50 gift certificate to spend on something. And while I like the dyno for tuning purposes, it is not the absolute.

One reason why is it can't figure in aerodynamic drag, which increases @ the cube of velocity. That is not precise as there are several variables, but basically it takes 33% more HP to go just 10% faster & 8 times the power to go twice as fast !! But a dyno with a good operator & an air/fuel ratio "sniffer" will help you get the tuning right - or darn close.

Absolutely & may very well be why you bought a H-D bike to begin with. Low rpm torque, nice smooth powerband, don't have to rev the engine high or shift gears all the time. Not a lot of maintenence either - other bikes require a lot more.

Absolutely & may very well be why you bought a H-D bike to begin with. Low rpm torque, nice smooth powerband, don't have to rev the engine high or shift gears all the time. Not a lot of maintenence either - other bikes require a lot more.[/QUOTE]

well this is the very reason I went from a suzuki to a harley.
I guess I have alot to learn. what type of advice and work would you suggest to get the most from my motor, I ride at around 2500 to 3500 some times 4000 rpm and I want to make it reliable.
thanks
Rich

well this is the very reason I went from a suzuki to a harley.
I guess I have alot to learn. what type of advice and work would you suggest to get the most from my motor, I ride at around 2500 to 3500 some times 4000 rpm and I want to make it reliable.
thanks
Rich[/QUOTE]

1st thing to do is get the factory service manual if you don't already have one. I don't buy online, but I think places like Chicago H-D & Zanotti's give a discount if you do. The parts manual is a good one to get too. Other manuals (like Clymer) cover many different years & models & are nowhere near as specific as the factory manuals.

Moving from a Suzuki to a H-D is a MAJOR change - just dealing with the engine moves you back about 50 years !! Good old-fashioned "bigger is better" American thinking & long-stroke engine making torque down low.

The design of a Japanese motorcycle is so different from a H-D that they don't even fall into the same category & for example, a pushrod engine bike like a H-D doesn't run in the same racing classes an overhead-cam bike with the same size engine does.

And while you can see well over 13,000 rpm with a short-stroke, small piston, double overhead cam, even-fire 4-cylinder engine, you'll never see that with a 2-cyl. odd-fire Harley - the engine will come apart long before. With the best parts $$$ can buy you can run 7500 rpm with a Sportster or Buell engine, but forget about it with a "big twin". And the XB9 Buell will rev higher & faster - shorter stroke - same bore as a 1200 though.

V-Rod? Whole different ballgame. 60-degree V-Twin rather than 45 & developed by Porsche with internal balance shaft, shorter stroke, 4-valve overhead cam heads, electronic fuel injection & liquid cooling. Engine runs the same temp in July as it does in January.

Think more along the lines of semi-truck than Corvette. Torque is what gets you up the hill, gets you going from a stoplight, etc. & a bigger engine running @ lower rpms lasts longer.

That's what H-D engines like. Torque falls off @ 5252 rpm & you can go higher, but believe me, you don't want to know what it costs to make a H-D engine live much over 6000 rpm. It certainly can be done, but you can buy a new bike for less.

H-D's have gotten continuously more reliable so that's not a concern. I run around on a '95 Sportster I bought used in '99; the '00 Sportster I play with I bought used in '01; 1 Land-Speed-Record bike was a '94 Sportster with 103,000 miles on it bought as a project bike & another a 1990 frame I got from a guy who looks for deals on used bikes. You can see both those race bikes & my street bikes in the photos I've posted.

You want to "Pay the Harley Tax" with improved air-cleaner & exhaust so the engine can breathe, but unless you go insane (& broke) like me, you don't need to do any more for daily riding & a H-D is more dependable than any other bike made.

- Art