The replacement roller lifters I have, have smaller oil hole on the side than do the factory lifters, is this gonna be ok?

 

More than likely it will be fine. What replacement lifters are you using?

The reason for the oil hole difference in size is because different mfgr's all have different ways of valving the internals of a hyd lifter and they all need different amounts of oil (and pressure) to operate correctly.

Also don't be alarmed if the oil hole placement on the lifter body is different than stock. Some mfgr's are putting the oil hole 90* to the lifters axel and some are putting it inline with the axel...

If the oil hole is inline with the axel you should put all the oil holes facing the rear (bellhousing) of the block. If it's 90* to the axel you should face themall towards the centerline of the block (facing each other).

Will

 

Will, that's interesting. I've never come across anything before that specifies the oil hole placements. I've been asked about this a few times on other Forums but couldn't help.

What's the advantage in doing it that way or disadvantage in installing them a different way?

Can you point me to a write up/tech article on this so I can get more details?

Thanks for bringing this up.

Jake

 

The advantage is that the physical path of oil flow runs back to front thru the lifter galley in a SBC. Placing the lifter oil feed holes towards the rear of the block puts them in the direct path of oil flow and oil pressure, so they get oil sooner.

If the feed hole is 90* to the axel you install with the hole towards the cam centerline (up) so that after a period of not running the oil level will be higher in the lifter itself - if they were outwards (down) it allows more of the oil in the lifter to drain out.

As to where I came up with it. I really never thought much about it with mech roller lifters - because with vertical tie-bar lifters the oil hole use to be 90* from the axel on the side with the link bar (which always face inboard towards the cam centerline) so you can't really install them wrong. Like these:



Back in the mid 1980's we got away from vertical tie bar roller lifters and started running the Crane "Pop Up" lifter that you could install either way.... I asked my dad about it one day when I pulled an engine apart that had those pop up lifters in it - because the lifters oil feed hole orentations were all mixed up... Dad told me it didn't matter because of the oil pressure in the lifter bore but it got him thinking if one way was better than the other... So he called John Reed (who was our cam grinder at the time) and John told us that he had to call Crane (who supplied him cores and lifters) about it when he started selling those pop up lifters because people were ringing the darn phone off the hook about it. Crane gave him the orentation method and reasons I use to this day.

In all honestly it really won't make any difference in a regular street car. Heck flat tappet lifters rotate in the bore when an engine is running and they rarely have any oiling problems in most applications....

The reasons he gave us back then make sense and I haven't ever had a noisey lifter or valve train oiling problem. I've always liked things to be all the same - even if it's something as simple as which way the oil feed hole in a lifter points.

I looked really hard on the web to see if other people think it's an issue and couldn't find much in support of one way or the other - Safe to say it's definatly one of the less important things in the world.
Will

 

This oil hole positioning comes up from time to time on other forums too and I've tried to find anything that advocates placing them in one direction or another - Up until now ZIPPO! I've often wondered why even GM hasn't made mention of lifter positioning in all of their manuals I've read.

I mean, when you think about it, GM makes mention of such things as the positioning of the little sleeve that connects the water pump to the block; the positioning of the hub on the crank snout; etc., but no mention of lifter placement. Initially I thought it was just an over-sight, but after pondering my ponderer I concluded that over the many years, "some" mention should have been made, if not in GM literature but in at least one of the other manuals like Haynes or one of the many "How To . . ." books, etc. Still ZIPPO!

Yours was the first post I've ever seen saying they should be oriented in a certain direction and I wanted to know know more - you know, the science behind it. I'm an avid reader, but (probably like you) I don't automatically believe everything I read. I've got one of those "questioning" minds; probably as a result of my career choice.

I'm NOT trying too imply I dis-believe what you posted, only that I want to know more -- how it came about, who said it, what difference it makes, etc. Thanks for supplying that information.

Of course, this isn't the first thing I've missed. I'd never come across anything in the literature saying how long the fuel pressure should hold without dropping until recently when someone posted he found the 1/2 hour time period in some manual he referenced.

If you come across anything else on this lifter placement issue, be sure to let me know. It's something that should be passed around.

Thanks,

Jake