I just got done a engine build for a chopper project. I started out with a 1984 Harley Evo and put the Screamin Eagle 10.5 comp. pistons, SE Heads, SE-57 Cam, Super E carb. I ran all the oil lines correctly. The only thing I did is plug the hole betweeen the Oil pump and the Crankcase breather. I beleive it was a chain oiler or something. now when I started the bike it sounds good but leaks from the rocker boxes. Changed gaskets twice and still leaks. Layed rocker boxes down on a piece of glass they aren't warped. anyone have any ideas why this is pushing oil out from the rocker.??

 

Exactly what hole did you plug Need a better description

 

What goes up must come down and what goes in must get out. Could it be blocked oil return passages. Sure the head gaskets are correct and installed the right way? Sure about the base gaskets?

 

I blocked the hole between the Oil pump and crankcase breather. I beleive it was a chain oiler supply or return. I have not checked the base gaskets or the oil return passages. I will first thing tommorow. I did bend copper oil lines for the bike but they dont seem to be kinked I do have about 20-30 lbs oil pressure at idle.

 

Just so I am double sure. If I am looking the the face of the oil pump on an 84' Evo the left nipple is the return and the right is the feed?

 

I can't remember back far enough to recall what opening is what on the EVO oil pump, but I think 20-30 pounds is too much pressure at idle. The book used to say the pressure should be set to just make the warning light go off at idle, which is much less than 20-30 pounds and more like 5-10. Check the pressure relief spring, which controls oil pressure. It's the one with the plunger under the spring right there on top of the engine case. The pressure relief valve is suppose to regulate overall oil pressure and various springs can be had to regulate that. If it's stuck, or otherwise too strong....it will allow pressure to build. Something may still be kinked somewhere, but I believe you are sending too much oil to the top end and the drain-back galleries just can't keep up with the flow.

I think you should be proud that you can actually get that much pressure out of the pump. We use to think putting an oil pressure gauge on an EVO would just scare you to death because it would not register at idle. The norm was to blip the throttle all the time at idle to keep the waring light from flashing sitting at a red light.

 

Early '84 EVO had three crankcase nipples. The middle one was for the front chain oiler. The top one for the oil tank vent and the bottom one for the crankcase vent.

Are the drain holes in the cylinder aligned with the drain holes in the crankcase and do the drain holes in the gasket line up with the drain holes in the case?

 

Yes .

 

Ok I let the engine warm up for a bit and the oil pressure dropped down to around 15. Still leaking oil pretty good from the rocker boxes. I am going to pull them right now and make sure all my gaskets are in line. Would running newer heads on and old evo not match up properly???

 

Another thing that has me confused. I put the gaskets back together for the third time last night with a light coat of RTV High temp silicone. I took the bolts that I had blocking the head breather out since I was running a crank breather I didn't need them.. And It still built pressure enought to make them leak...