Does it matter which direction the lifter is located in the bore on a TC88? There is a hole in the side of the lifter...wont it pick up oil no matter which 180* direction it's installed in the bore?? My thinking is the lifter bore has a slot all around it and the oil will find it's way into the lifter ---true?

 

I was wondering the same thing last week when I installed my cams. I installed them with the hole up (inboard) thinking they won't bleed done when stopped. I checked my manual and couldn't find any reference. I marked which holes they came out of but didn't notice the hole till I went to install.

 

The oil feed for the lifters and the piston oilers comes from the outboard side of the lifter galley. Some have their own little idiosyncracies about lifter orientation and may tell you different but it doesn't matter which way the lifters are oriented in the bore; they will get oil either way.

 

Many guys (myself included) will orient them both facing outward. The last two motors I broke down had the oil holes facing each other. I can't say I've ever seen a motor where the oil holes were both facing inward, but there's no reason to think that wouldn't work just fine, too.

If you're re-using your lifters, the only thing that matters is that they go back in the same way they came out.

 

Curious why is that?

 

JMHO but I see no reason other than the "feel good" factor to worry about what lifter came from what bore; here is why.

The factory spec for lifter to lifter bore clearance is .0008"-.002" and the tolerance for service limit is .003". With the two different coefficients of expansion, the lifter to bore clearance on start up will increase as the engine approaches operating temperature. The greater the clearance between lifter and bore, the harder it becomes for the lifter to stay pumped up.

You could actually improve the situation by installling lifters in different bores. The OEM HD steel lifter OD is .8422"; you can grab a handful and measure if you doubt it. The OEM lifter bore ID averages .8435"-.8440" which sets up a clearance spec of .0013"-.0018". So if you happen to pull a lifter from a bore that measures .8440" and drop it back in to a bore that measures .8435"' that's a good thing. Of course, the reverse is true but the point is that on motor with relatively low mileage and stock valve train, if you mix/match lifters and lifter bores, it won't matter; all will be well within the clearance specification.

Introduce hi lift cams, stiffer valve springs, higher than stock compression and the same prinicpal applies but the lifter to lifter bore clearance will open up faster.

I am as **** as they come but what lifter in what lifter bore is one I can let go. If I had a situation where I could not eliminate valve train noise after trying all the known fixes, I would get out the dial bore guage and check the lifter to lifter bore fitment. Too much clearance can contribute to bleed down and a noisy valve train. Oversize lifters are available.

 

As far as orienting them the same way they came out, I got that tip from the gentleman who teaches the factory-sponsored HDU classes up at Lake Washington technical college. ( He certifies new H-D techs, and teaches the follow-on training for the local dealer techs. ) The rollers in the lifters have broken in, turing one direction. Reversing their direction would accelerate the wear on the roller. It only takes a little attention to detail to put them back in the same way they came out, and I can't see any reason not to. It's not about which bore they came out of, it's about the way they are oriented in the bore. That's the discussion we were having.

 

Ok that part sound logical. I was just curious.

 

Funny, I've got the same question. New cam, new lifters. The bike is an '01. Lifter part number = 18538-99. Latest version of number now ends in "C". Service manual states "...with the oil hole on the inboard side and the flats on the lifters facing forward and rearward". Problem is the new "C" lifter, the oil hole is inline with the flats, therefor it can't be inboard. So forward or rearward? Line it up with the holes in the bores? Front lifters forward, rear rearward. Or as stated earlier, does it matter?

 

My bad if I interpreted the above statement wrong but without clarification it's pretty easy to assume you may have been referring to lifter to bore matching.

I make it a habit to install new lifters with new cams so no issues there and when I am pulling lifters, usually pullling them because new cams are going in, so I don't often find myself reusing lifters; I must have five or six sets in the parts bin. I have, on occassion, reused lifters on my own bikes but paid no attention to match lifter to bore or lifter orientation in the bore. I guess time will tell if I should have.

No disrespect intended to you or your subject matter expert but I wonder how many of the techs he has certified installs the lifters rotated 180* from the original orientation when installng gear drive cams?? What exactly does "accelerate the wear" mean? Has this hypothesis been tested? Any data to support his claim? What wears prematurely; the axle or the roller surface, or both?

Always willing to learn but would like to see some data.