Just bought a '72 Shovel. It has a 98" engine built in a delkron case. The former owner built this bike but got really frustrated when it came to the oil system. He replaced the original oil tank with a more current horseshoe tank.

the problem: he purchased an oil cooler/filter combination and when that is installed, it will constantly puke oil out the crankcase breather. Right now, we have the engine set up with no filter but I know I can't keep it that way. I'm told that puking out the crankcase breather is "normal" if the bike has been sitting for a few days. From what I undestand though from my friend, if he has the filter/cooler installed then it pukes constantly.

I doubt I've provided enough info but I'm not sure what info is needed. Hopefully this is a start and I appreciate any direction.

 

98 ci ? What is the bore and stroke ? The oil filter/ cooler combo Who is the manufacturer ? just curious as to what it looks like How much oil does it puke ?

 

Yeah I guess I kind of threw that in there without thinking about it. The engine was built out of all new parts so it wasn't really "bored" but built to be 98ci to start with. I think its 3 5/8 bore and the stroke is either 4 1/4 or 4 1/2 (prob 4 1/2). I'll have to look into the oil filter/cooler combo. I'll take some pics of it when I get home in a few days. When the filter/cooler is installed it pukes constantly from what I've been told. Like I mentioned, it isn't installed right now.

thanks for replying. this will be an adventure getting it going like it should. I'm pretty excited about it.

 

Look at the feed and return lines to this cooler/filter system Maybe reversed?

 

when you say constantly, do you mean every time you start it or it won't ever stop puking and empties out the oil tank? The scavenger side of the oil pump has nothing to keep the oil in the line from running back into the gearcase slowly, so if your oil line from the return goes up higher than the cooler/filter and the oil pump in between the 2 or if the filter is much higher than the oil pump it may drain or siphon back into the engine, but this would clear up after running for a few minutes.

 

I'm always learning as i can't afford a mechanic. I bought a 73 shovel. I put in a wraparound tank, oil cooler, spin on oil filter. I verified everything is hooked up right. Then I went down to the breather hose which was plugged off with a bolt. I put on a new breather, attached it about 1/3 the way up the bike. started it. runs great, but Yes, now it's puking oil thru the breather. should I put it up higher?

 

sorry i meant a 73 shovel, not a 72.

 

HoustonCH73,
If you have a 98" engine with a 3 5/8" bore, then you have a 4 3/4" stroke set of wheels in that thing. That is a long stroke engine. There are longer strokes to be had but that is a very long stroke.
I know this because I had one back in the 70's. Mine was built with S&S stuff.
It sounds to me that the filter/cooler (that can only be put in the oil return to the tank) is too restrictive.
Back in the days when I had my big bore/stroker Shovel, I did not run a filter at all. If it causes problems having one, I would think seriously about a different make of filter and cooler or not using a filter at all and just staying on top of oil changes every 2500 to 3000 miles.
Is this filter cooler the one you had a picture of a while back in here trying to ID it?

 

Reading a bit more in this thread I see you mentioned finding a breather hose plugged. That doesn't sound right to me. You should have two breather hoses on your bike. One from the engine that goes to the oil tank AND if you have a the original style primary chain oiling system, it should tee off to the aluminum primary case.
The other breather hose should just go to atmosphere. It is nothing more than what used to be called a road draft tube on older car engines prior to PCV valves. Both of those hoses need to be in service. The only thing that may not be hooked up is that the breather to the oil tank may not have a tee in it to the primary case if you are running a belt drive or the primary has been isolated from the engine oiling system and has it's own oil poured into the primary case enough to be splashed around by the clutch shell as it whizzes around in there, to keep the primary chain oiled.
Where these two breathers come off your Delkron engine cases, I can't tell you but it would be wise to learn which one is which and make sure they are hooked up correctly. Contact Delkron and/or a knowledgeable mechanic to make sure you get that stuff hooked up correctly.
That engine needs to breathe out of the case...they all do, but a bigger engine all the more!
I had very little oil coming out of the breather to atmosphere on my 98 incher. Almost nothing at all.
You seriously need to get a genuine HD service manual for your bike. Even with an aftermarket engine, it will show you how the breather and oiling system works for your engine. The hoses may not be in the original engine's location with your Delkron cases, but how the system works should be the same...unless Delkron has made some improvement/change somewhere. I'd definitely talk to somebody at Delkron at the very least.

 

My 81 would dump oil on start-up after sitting for a few days. One recommendation indicated the check ball in the oil pump can stick due to corrosion or other causes. The fix included removing and cleaning the check ball and the check ball seat. I dismantled and cleaned the entire pump including the check ball/seat and had no further problems. Not sure if your pump has the same set-up, but good luck and let us know what you find.

r/81L