1964 panhead lifter noice

[lhcycleinc1]

My 1964 panhead motor newly rebuilt w/ velvet touch lifters & belt drive primary. After motor gets hot, about an hour, the tappets start nockin'. Also I have excessive oil coming from breather hose which I routed behind & above oil tank w/ small filter on it. Chain oiler screw shut off. Does oil get into the breather passage from anywhere else besides chain oiler & crankcase? Could these two problems be related? Thanks in advance for any help anyone can give me. Thanks, Fred.

[RooDog]

Two things come to mind regarding the oil blowing out the breather:
1) Are the hoses connected and route correctly? &
2) Do not over fill the oil tank as this can promote the problem you are experiencing. Be sure not to add oil when the engine is cold as some may still be in the bottom end and once the engine has warmed up and scavenged all the oil back to the tank the dipstick will often show a higher oil level than when cold. Only check the oil level when warm after it has run a while.... RooDog

[Buddhahoodvatoloco]

Such a blessing reading these empirical pearls, gracias..

Two things come to mind regarding the oil blowing out the breather:
1) Are the hoses connected and route correctly? &
2) Do not over fill the oil tank as this can promote the problem you are experiencing. Be sure not to add oil when the engine is cold as some may still be in the bottom end and once the engine has warmed up and scavenged all the oil back to the tank the dipstick will often show a higher oil level than when cold. Only check the oil level when warm after it has run a while.... RooDog

[lhcycleinc1]

Thanks guys, Oil tank & lines original except breather passage to oil primary blocked off & hose barb w/ 3/8" hose in case routed behind & above oil tank. I have the oil level a little low now while I try to solve this problem.

[PanPal]

Are you running the original oil pump? Some of the billet pumps dont have the correct pointed chain oiler screw.

[lhcycleinc1]

Yes. Original HD cast iron pump. Thanks.

[RUBONE]

Those filters on the breather line are always a problem and create restriction. Route the breather line to oil the rear chain and make sure there is no restriction in the line. Make sure you are not having an internal leak in the oil pump or check balls.

[Excalibur]

Verify the operating oil pressure, it might yield a clue.
Book specs reading at operating temperature:
25 - 28psi at 20mph,
35 - 38psi at 30mph and over.

Is the tappet oil screen clear and the assembly order correct? (if so fitted)

[Andygears]

Probably the breather hose should not be routed "up" at all. The motor breathes oil vapor & air out and also sucks air in through the breather hose, if you create a puddle in the hose the motor will breath out (or attempt to) but cannot breath in because the oil blocks the passage. Try a short piece of hose on the breather, putting your thumb on the end you should feel just a slight pressure and suction sometimes almost even. If you have a lot of pressure, like to pop your thumb off the end, you have a problem. Just a quick test.

Andygears

[lhcycleinc1]

Thank you for all the idea's. I will shorten the breather hose & remove the filter to start. I'll post the results. Thanks again, Fred.

[socalrider]

On the velva touch lifters , they should be totaly quiet if everything is right. Dave at bmo ( guy who makes the velva touch lifters) recommends changing the oil pump drive gear in the cam chest if you are using the cast iron oil pump. I believe its a smaller gear to increase flow. I have velvatouch set ups in both my stock spec pans 63 & 65.On the 63 i did change the oil pump drive gear, the 65 i did not. Both run great, lifters have never leaked down over night. Oil light never comes on at idle
( including the 65 with original drive gear) and are VERY quite. I am also of the impression that my oil pressure went up a bit which is why no oil light at idle. I would not ride the bike until you figure out the problem. You may ruin the lifters even though they are very stout. They are NOT CHEAP to replace. Good luck

[lhcycleinc1]

Thanks for all your help w/ my excessive oil coming from my breather. I did shorten the breather hose & put a regular size breather filter on it. Also, I realized that the needle screw on the oil pump to ajust oil flow to the primary chain was too short & did not shut off oil flow which flows through breather port in case. I changed adjusting screw to a longer one that was in my original pump that bottoms out correctly. { running a belt drive primary.} Problem solved, Thank you. Now I still have the lifters that start nocking after about an hour of riding when it gets hot. I have velvet touch lifters & cast iron oil pump. I think my next move is to change oil pump gears to increase oil pressure. Does anyone know exactly what gears I need to change for this. Thanks, Fred.

[lhcycleinc1]

After reading more posts I am thinking maybe I should check my oil pump gear clearance before I change gearing. Any opinions?

[Doc37W]

lhcycleinc1, If you can ride an hour before they start to knock, I would say that the oil pump clearances are fine. I've put the '73 & up gears in my earlier engines and they will definitely will help flow to the lifters. What weight oil are you running? Have you cleaned the tappet screen yet? Sometimes it's the little overlooked things that cause the biggest headaches. Doc

[lhcycleinc1]

Hi Doc, Straight spectro 60 w. tappet screen clean, Thanks.