Squirt hole or no squirt hole?

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Hueyjockey

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What’s the general consensus on rod bearing squirt holes? If you read bearing manufacture literature, bearings with squirt holes are no longer necessary due to the improvements of modern engine oil. Conversely, it is believed that squirt holes were removed primarily to improve emissions. I’m about ready to put the pistons back in the 273 I’m rebuilding and received bearings without the notch for the rod squirt hole. It’s primary use will be as a weekend cruiser. Would you send the bearings back to get notched ones, or would install them and not worry about the squirt holes? I would be interested in hearing everyone’s thoughts on the the pros and cons of squirt holes.
Thnx!
 
if there is any merit to the "improved oil" theory, the logical question is, flat tapper or roller cam?
because that will determine if you will use "improved oil" or not

at least, thats how i would approach it
 
I have a personal theory that the lack of a squirt hole is directly related to the high number of cam lobe failures we have experienced since the squirt hole disappeared.
I notch the shells to provide the hole, and have seldom had any cam issues at all.
JMO !

PS - I also quit usng Comp stuff after refreshing a few engines built by myself, and others, after finding un-acceptable wear on some items. .
 
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Squirt holes are part of chrysler engineering advantage over other big three! My dad being a mechanic in the 60's @ a chrysler dealer, in 16 years never saw any cam related issues. When he left to open his own shop he worked on all brands and ford and chevy were the one's with cam failures. 454's and many ford straight 6 were the popular cam destroyers!
 
I always thought that most modern flat tappet cam failures (not counting over-springing them) were due to the lack of enough zinc in todays engine oils. Is that not true? Is it really lack of oil splash?
 
I have a personal theory that the lack of a squirt hole is directly related to the high number of cam lobe failures we have experienced since the squirt hole disappeared.
I notch the shells to provide the hole, and have seldom had any cam issues at all.
JMO !

PS - I also quit usng Comp stuff after refreshing a few engines built by myself, and others, after finding un-acceptable wear on some items. .

I also subscribe to this theory. All the zinc/moly/other EP additive in the world has no effect if the oil film does not fail. More oil decreases the likelyhood. On a street engine running at street RPMs I believe more oil slinging around is better than less.
 
Just notch the bearing end to provide the OEM oiler design if your rods still have the oil port!
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360 Con rod bearing quick question
 
The rod bearings sold nowadays have no nitch/notch for the oil to get through, squirt hole or not.


Experience has shown some blocks lifter feed holes off the galley aren't finished entirely, or in a uniform fashion. Like that one song...'some lifter feeds are bigger than others'
The 318 i just assembled , i had to tap out flash from half of one lifter feed hole. It was not even as big as half your pinky nail. They need to be a least as big, 3/8-7/16

When you get a core with a bad lobe, check the feed hole size on the that lifter to rule that out...or in.
 
I always thought that most modern flat tappet cam failures (not counting over-springing them) were due to the lack of enough zinc in todays engine oils. Is that not true? Is it really lack of oil splash?

That's why it's a theory.
They came out with the roller lifter, no squrt hole, thinner rings, and less zinc, - all bout the same time.
So it's a proces of elimination .
 
That's why it's a theory.
They came out with the roller lifter, no squrt hole, thinner rings, and less zinc, - all bout the same time.
So it's a proces of elimination .

They started using roller lifter because they KNEW they were changing the oil. The squirt hole does nothing because the oil leaving the rod bearing around its diameter is much more than what the squirt hole does.

The BBC is a cam eater because the cam tunnel is much more closed off than most any other V8. I never saw many cam failures until the Clinton years when Romney capitalism came to the fore and made leverage buyouts the soup of the day.

Failures today are largely break in issues or worn out blocks or bad machining. Plus, today’s choice of FT lobes are much more aggressive than the were even in the early 1990’s.
 
If you are gonna run a FTcam with regular lifters, on modern oils, then;
IMO, you can't have too much oil trying to find it's way to the cam lobes, especially at lower rpms.
And I still add zinc at every oilchange.
My engine is capable of regularly seeing 7200, but it spends way more time just idling around, at sub 2000, which is about 15 in first gear, 24 in second, 32 in third. So I depend on the oil for valve spring cooling and to keep the lobes alive. Seems to be working for me as the engine has over 100,000 miles on the clock.
Happy HotRodding
EDIT
I provided extra oil volume to the top end, extra drainage at the back of the heads, and drainage down between every pair of lifters. One of these days, before I die, I hope to take this engine apart one more time, just to see what 100,000 plus miles looks like, in an engine I built. And to see if the chain tensioner is still together and functioning.
 
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If you read the FSM, it clearly shows the oil squirt hole is for the bottom of the cylinders. It's intended design has nothing to do with the camshaft. If there's benefit to the cam from the squirt holes, it's very minimal, IMO. If the camshaft doesn't get enough splash lube from the crankshaft and rods slingin around, somethin's WRONG.
 
That's a blanket statement. I can attest that king bearings are notched for the oil squirters.
That's good to know, if you care to run them.
Clevite's i use don't.
Acl, iirr dont.
They dont really matter imo. The rods are spraying oil @RPM and the cam is doused..as well as the lifter oil feed holes.
This starts to become the oil the timing chain more drilling holes, vs bolt with hole vs bolt with no hole and just drip plate. Lol

Ive run both ways, no issues either way on squirt holes and hole n no hole upper bolts etc..
 
Thanks FABO, always great feedback from the community. You all confirmed what I was thinking. Anything that moves a little more oil around the inside of the motor can’t be bad. For those who were wondering, Sealed Power makes rod bearings with the notch for the squirt holes.
C1D32DB8-F129-40AA-A515-C196EB416587.jpeg
 
Thanks FABO, always great feedback from the community. You all confirmed what I was thinking. Anything that moves a little more oil around the inside of the motor can’t be bad. For those who were wondering, Sealed Power makes rod bearings with the notch for the squirt holes.View attachment 1715641848
I think chrysler did this for a reason. Chrysler engineering was always ahead of the game back in the day.
 
Thanks FABO, always great feedback from the community. You all confirmed what I was thinking. Anything that moves a little more oil around the inside of the motor can’t be bad. For those who were wondering, Sealed Power makes rod bearings with the notch for the squirt holes.View attachment 1715641848


Just so anyone else who comes along and reads this will know...as RustyRatRod posted above that squirt hole was to put MORE oil on the cylinder walls. That was great science then, but bad practice today. And I’m not trying to talk you out of anything.

Cylinder honing and piston rings from the 60’s, 70’s and even the 80’s are Stone Age compared to what we have today. Not even close. Today, the last thing you want (or need) is oil blowing out of the rods onto the cylinder walls. All oil retention for ring and piston skirt lubrication is controlled by the honing process...that is the surface geometry including cross hatch angle.

Today’s cylinder wall finishes SHOULD have a measured surface finish that has the correct valley depth (Rk, Rpk, Rvk) and a plateau surface (part of the RA measurement) that gives the proper bearing area for ring seal and the correct valley depths for oil retention.

Crosshatch angle matters because the de facto 45 degree included angle is ok for quite a few applications. But, today it’s more involved than that.

A steeper included angle (say 50 degrees) will rotate the rings faster, which may be good, or not so good, depending on the application. As engine RPM increases, that 45 degree crosshatch may be too steep and cause the rings to rotate too quickly. So maybe a 40 degree crosshatch is called for.

The other fact of crosshatch angle is oil retention, or more correctly stated, how much oil is pulled down by the scraper (second) ring as the piston goes up and down. The steeper the crosshatch angle, the faster the rings turn, but it also allows an easier path for the scraper to pull oil down off the cylinder wall and back to the pan. The opposite is true. A flatter crosshatch angle will retard oil migration down the crosshatch and slows ring rotation.

So many times with power adders or certainly with alcohol based fuels and/or high RPM you need to flatten the crosshatch angle down to keep some oil on the cylinder walls.

My point is the days of just running a hone down the bore and calling it good are long gone. Even with the archaic 5/64 ring pack, there is power, reliability and ring seal gains to be found in a decent hone. As we slowly crawl away from (we should be sprinting to get there but adaptation to technology is hard for some...for me it’s computers and phones...I hate this junk so I’m slow to warm up to new stuff, but in the automotive world and specifically engine building I go for new tech like a baby to the teat) the old, nasty, thick ring packs to the new, thinner, better sealing, lighter ring packs the surface finish of the cylinder walls should follow that technology.

And to that end, even a marginal cylinder finish today requires much less oil on the cylinder walls than it did back in the day.

If your engine shop doesn’t have and use a profilometer on its bores (and deck surfaces too) you need to find a better shop.

In 1995 a profilometer was considered a luxury. Today it is mandatory if you want to know what you have and if what you have is the correct surface geometry.

Just my .02 for the day, and it worth less than you paid for it.
 
As a sidebar, the performance manuals and articles recommend swapping the pistons side to side for more performance. Do you swap the whole assembly or just swap the pistons on the rods for the offset?
 
Every 340 I built back in the day, I just swapped the pistons side to side so the notch faced the rear, but the rod/cap numbers still faced outwards. Did it help? I don't know, but the magazine guys said it worked.....lol.
 
I have a question. How do the cylinder bores and wrist pins get oiled if the squirt holes are eliminated?
 
As a sidebar, the performance manuals and articles recommend swapping the pistons side to side for more performance. Do you swap the whole assembly or just swap the pistons on the rods for the offset?
You swap them side to side. It unloads the piston skirt from the cyl wall, which was only done to make them quiet from the factory.
All you have to do is..
Make sure the thrust sides are facing each other. The rod bearing is offest to one side to clear the fillet on each side of the journal...otherwise the bearing ride partial off the journal and over the fillet.
I did it, according to smokey yunicks book years ago. Squirt holes smcholes, just make sure the thrusts face each other and its fine.
 
As a sidebar, the performance manuals and articles recommend swapping the pistons side to side for more performance. Do you swap the whole assembly or just swap the pistons on the rods for the offset?

You run the pistons backwards, turn them around on the rod......however, that only applies to factory pistons whose pins are offset. The offset pin from the factory was used to help put a "load" on the piston so they would not rattle so much. Turning them around backwards "unloads" them and frees up a little friction and does have benefits. It's an old racer's trick. Modern performance pistons have the pin centered, so there's no need to run them backwards.
 
You run the pistons backwards, turn them around on the rod......however, that only applies to factory pistons whose pins are offset. The offset pin from the factory was used to help put a "load" on the piston so they would not rattle so much. Turning them around backwards "unloads" them and frees up a little friction and does have benefits. It's an old racer's trick. Modern performance pistons have the pin centered, so there's no need to run them backwards.
Thanks for explaining that on modern pistons. Always wondered what you’d do.
 
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