45" case baffles

[handyman]

Has anyone out there removed the case baffles on a 45" motor and has it resulted in better oiling and cooler temps or does it make them smoke?

[sirhrmechanic]

Can't speak directly from experience on a 45 motor. But I believe that it is fairly common to leave the baffles out. Certainly it's rare to see a set still in place on a rebuilt engine. The Chief motor I am redoing will have no baffles and I don't expect issues. And all the later (mainly shovels) I rebuilt years ago did not have baffles... again, no issues.

I can speak from car experience that we leave the baffles out of all the big sixes we rebuild. Mainly because they are a major PITA to deal with, especially with mono-block cylinders (no heads.) Have never had any problems whatsoever with smoking or any other issues for that matter. Of course, this is always with new rings, good cylinders, etc. If anything, the skirts get better lube from splash. But the baffles on our car engines are tin inserts... easily left out.

Can't speak for better cooling... ours are water cooled!

Not sure any of this is helpful... there are likely folks here who will know exactly how to best handle a 45.

Cheers,

Sirhr

[rwm]

call paul at american cycle fab in berwick pa. he has some great oiling tricks for a 45. but as hard as it is to say i must say it. listen to cotton and fix your manifold leaks. harley built that 45 motor for decades and left the baffle in.

[T. Cotten]

Folks,

Let's ponder for a minute why there were baffles in the first place.

The flywheels spin from the rear to the front.
So they pick up oil from beneath (hopefully there isn't a full puddle after it has run for a few minutes,...) and spray it. Some call that "windage".

The rear would get most of it, so a scraper peels off what it can.
But that slights the front.

The solution was the baffles.

Think of it this way:
Take a sip of your favorite beverage, getting your lips real wet, and then purse your lips and suck air.
A little is drawn in.
Now dip two fingers in your drink and hold them to your lips and do the same thing.
You will taste more drink, because the suction is concentrated, and so it the fluid. Particulalry if it puddles on top of the baffles for a reservoir.

Indians poked holes in the baffle to get exactly this effect.

Sure, they will run without baffles, but there is no need to chew them out if they aren't cracked.

If you are scorching pistons, something else is amiss!

...Cotten

[sirhrmechanic]

Cotten:

Excellent explanation...

Did HD ever use 'tin' baffles? Or were they always cast in. Must be having memory loss because I don't remember Shovels as having baffles cast in but they had oil control rings. But I remember dealing with sheetmetal baffles. Or maybe that was only in car engines?

Of note, I did some more digging and came across this old thread... some familiar faces and some really good posts by Cotten, including some tests he did with clear plexiglass simulating an engine case. Ignore the arguing.. this thread is great reading.

http://www.sscycle.com/tech/viewtopic.php?f=12&t=11502

Should be noted in a broader sense that up until the 1930's when pressurized oil systems became the norm... there were a lot of strange ways engines were lubed.

One was drip lube with little pipes to every bearing and a 'clockwork/mechanical dripper on the dash.' You had to watch the drips as much as the road. And on a
"heavy" car like a big Loco or Simplex, you might have 8 or 12 drip feeds to watch at once!. Even the early HD's had a sight glass drip lube. I used to have a 1903 Curved Dash Olds and it had several glass drip oilers that you had to fill and 'get to dripping' right before starting on a trip. You had to count drops per minute then start the car and off you would go. If your drippers ran out or stopped dripping, you lost a bearing (which I did once, melting out the rod bearing.

Another method of oiling was by using dippers (as on Model A Fords). The idea was that the dipper literally 'dipped' into the sump oil and picked up oil that went into the bearing as the crank flew around. That lubed the rods. Wrist pins were just lubed by splash.

Model T Fords basically just used oil churned up by the crankshaft to lube all the bearings... no pressurized oil system at all. It was called Splash lubrication. And 15 million of them ran reliably. They do have a sort of oil pumping action using the flywheel, but that was mainly for lubrication of the timing gears. The engine basically just dipped into troughs in the sump which were kept filled by runoff from the timing gears. Model T's are proof positive that a LOT of oil flies around inside an engine. Enough to keep low performance engines running with zero oil pressure and what seems to be zero oil feed.

At another extreme, all the engines we work on put full pressure oil not only to the bearings but even to the wrist pins through an oil line that runs up the con rod. And they have 'extra oil' valves that squirt oil on the piston skirts under load.

The 680S supercharged Mercedes engine we did a few years ago... used Hollow cylindrical con rods that were 'pumped up' with almost6 ounces of oil to lubricate the wrist pin and bearing... and were filled by a 'spray' of oil between journals that came out of a tiny drilling through the Babbitt. No pipe, it was supposed to squirt! Across 2 inches and into another big hole! It was an insane system, but it worked.

The 1900-1930 timeperiod was one of ideas and experiments with lubrication that ranged from the brilliant to the delusional and everything in between. There were some really goofy ideas that probably seemed like a good engineering, but I liken some of these concepts to Victorian Plumbing. Looked really impressive, but really was not great at getting the crap out of your house. And I would argue that sometimes the concepts that engineers thought were right or valid because they worked well in thought experiments or on paper... were pretty theoretical at best. There were a lot of way-out ideas, some of which sounded better in the marketing literature than they worked in practice.

I would also argue that the companies that are still around today... are the ones that got it right, either by genius or luck or a bit of both. It's one of the things that makes working on old engines fun. You really do get inside the heads of those who designed them.

Cheers, Sirhr

[Rubone]

No Shovelhead engine ever used baffles. They were phased out on OHV engines by '41 and never were used again.

[Steve Slocombe]

I've stopped repairing VL baffles because it's easy to make things worse rather than better. Many baffles seem to have been deliberately removed rather than the result of an engine failure. The flywheels rotate clockwise seen from the right, so throw oil preferentially into the rear cylinder. Harley's response was to put half baffles at the rear and full baffles at the front, to create more suction and draw oil mist up preferentially into the front cylinder. These were bikes without pressurised lubrication (like all pre-1936 models), and probably without oil control rings. So why are the early 45s different, with holes drilled in the baffles and a different engine breathing system? And there were numerous changes 1936-40 for the pressurised oil systems, which mostly ended up removing the baffles and reversing the front and rear con rods. I agree with the 'thought experiment' statement that different engineers had different ideas. If you've ever left out the timing plug on a VL then started it up, you'll realise just how much oil flies about in the crankcases. In your bike I'd leave the baffles as is unless they are broken.

[T. Cotten]

SirHr!

I am totally clueless about early model motors, and if any had "tin" baffles, but I would guess probably not.
Again, the baffles were important for stiffening the castings, and well within the foundry's art of the times.

Many of you are aware of cracking problems of pre-'41 OHV left cases at the rear bore, which lacked half a baffle. There are even many cases that show where there are pattern marks that appear like cracks, as it was apparently a delicate area even for the sand.
For '41, of course, they introduced stiffening ribs upon the outside.

This corresponded with the reversal of the rods, and subsequent improvements in rings, etc.
Through the Pan era, cases were made sturdier and sturdier, and by the Shovel era, cases were massive compared to the pre-War productions. So comparing them to 45" flatties is apples'n'oranges.
The 45" design had little need for re-patterning.

....Cotten
PS: Thanks SirHr for referring back to that old discussion, and to Chris Haynes for his photo that reminded me what pre-War cases looked like inside, as my own haven't been apart in decades.

And thanks to this forum for its wide window for edits!