For What Its Worth +-

You Tube

 

Interesting, makes sense to myself the novice..Many true engine builders on here do not agree these restricters do anything..I would be curious to hear there thoughts on this video

 

Start at 6:30 and pay attention to 7:40 when the myth about no oil in the pan because its all up on top. I don't think 3 restricters going to cam bearings will make a huge difference. Let the others chime in.

 

my thought was there are certain places that need more volume while other areas dont. The restrictors keeps oil where its needed the most. I dont think the idea to keep pan from being empty is true.

 

A little vague on how the distributor gear gets oiled. Is the galley plug drilled?

 

the galley plug is factory drilled for distributor oiling and timing chain..

 

Yes, as is the plug at the timing chain at the other end of the other oil gallery. 0.040" hole in each.

 

So those two galley plugs are exact size hole at 0.040? Somewhere I thought I read one was 0.040 and the other 0.020?

 

The gallery plugs have 0.040" holes.

 

Rear plug for the distributor gear.






Front plug for the timing chain. Note that all three are different and cannot physically be installed incorrectly.

 

Thank you…

 

Correct.
As I’ve mentioned many times, block the drain backs in the heads and pour 2 qts of oil in each valve cover and tell us what you see. It’s not realistic.
In addition, how will the restrictors, which don’t have holes much smaller than the ones in the cam bearings, really effect oil VOLUME at all, especially when the cam journal is basically laying on the hole in the bearing?
I’ll await your answers.

 

So if I am reading this correctly then there is only one plug on each end with threads in the block making it impossible to screw up..correct?

 

I don't think there is a drainback problem in any GM head. I've routinely poured 5 quarts of oil out of a five quart jug, with a wide mouth, into a wide mouth funnel, and put the entire thing in in maybe 15 to 20 seconds and the head drained it all into the pan with no complaints. This is on Chevies that have the fill hole in the left valve cover.

I think these restrictors were thought up when someone put a larger pump on an engine. I don't know where the pumped oil would go that isn't the pan. One would think that, if you pumped oil faster, it would come flying out of the exits of the pressurized system correspondingly faster. That's at your timing gear, the distributor, and the valve train, plus whatever bleeds past the bearings. If the way home is wider than the way out, it would take a hell of a pump to beat gravity.

 

Anyone with a brain who spends 30 seconds looking at the Olds oiling diagram can tell by inspection that the restrictors that go in the passages that feed the cam bearings won't do squat as far as restricting oil to the rockers. If anything, they will (admittedly by a minuscule amount) INCREASE the amount of oil pumped upstairs because a fraction less goes to the cam bearings. Most of the time these restrictors are really good at causing premature cam bearing wear.

 

For arguments sake only, not doubting you..Mondello thought it did something and he seemed to have a solid brain.

 

And I'll ask it again. How does any oil get from the cam bearings to the rockers? Sorry, but this ad pegs the meter.

 

I hear ya, your an engineer, I am not..my thinking on a common sense level is the following…if your objective is to keep too much oil from flowing to the top, thus emptying the pan at higher RPMs. Then simply using restricted pushrods will restrict the push of oil up into the top end..unless you have a very high pressure pump the system equalizes itself simply by having smaller orifices in the pushrods keeping more oil down below. I guess my curiosity is did JM develop this as a potential fix or just a marketing thing to sell small widgets..curiosity killed the cat

 

You are correct that restricted pushrods or restrictor plugs in the 16 holes that feed the lifters are the only way to reduce oil flow to the rockers. Oil through the passageways to the cam bearings only feeds the cam bearings then flows back into the pan (via the spinning crank, which splashes that oil around to help lube the cam lobes). These restrictors that go in the cam bearing feed holes do exactly NOTHING to reduce oil flow to the rockers and nearly nothing to increase oil to the mains (which is not how they are advertised anyway).

 

Just for FYI. I know in the past that the galley plugs that came with the Pioneer kit did not have the .040 oil hole for the distributor oiling. They may have corrected this but not sure because it's been a while.

 

Is the argument that, without these, the pump will put oil faster to the top end then it will flow back down via gravity and starve itself when you are running max rpm for x amount of time?

It's amazing that no one quotes max volumetric flow rate out of a pump when selling them. One place claims 6.8 GPM. Over a, let's say 12 second drag race, and we'll assume the engine is at max rpm the whole time, which it is not, that's 1.36 gallons of oil moved in an ideal system,
i.e., just spraying it out into nowhere, no restriction. The stock pan is 4 quarts or a gallon, so, in a 12 second race, you will need to get back .36 gallons, or a little more than a quart, to avoid starving the pump. I think that's perfectly reasonable.

The proof would lie in seeing what the jet boat dudes do for long runs flat out.

 

Would be interesting to log actual GPM at a given RPM using a remote oil filter kit and a flow meter.

 

If you suspected "oil starvation", then an aftermarket oil pan with a SIX quart sump would fix the problem. And guys like Cutlassefi would be selling Canton pans like hot cakes.

 

You are not reading it correctly. The plugs are all threaded. They all have different size/pitch threads and cannot be installed incorrectly. The plugs at the back of the oil galleries are pipe plugs with NPT threads. The one on the driver's side has the hole and is behind the freeze plug. The one on the passenger side is on the exterior of the block and if it had a hole in it you'd be pizzing out oil. The plugs at the front are hex head with straight threads and they are different diameters, so you can't install them incorrectly.

 

Gracias JP

 

Aftermarket cam bearings 40-50 years ago had fairly large holes. I used to drill a new 0.150" hole about 120 degrees away and used it instead. Today's cam bearings have a smaller hole, iirc even smaller than 0.150". I believe the entire purpose of the restrictors was to generate income since you can't sell a hole but can sell a part. I have quit drilling the hole both because the factory hole is small enough and because like above in this thread, I have not seen any benefit. I am still using a block I modified in the 1970s with 0.040" restrictors to the lifters since solid lifters often meter too much oil. That helps, and so does making custom metering plates for the lifters with one offset hole of about 0.050". It most likely also helps to use the higher pressure Melling purple relief spring in their high volume oil pump, if you are seeking more oil pressure.

 

DING, DING, DING! We have a winner.

 

Nope. All the freeze plug kits just come with generic NPT plugs. Have to re-use the old one (which has a square drive instead of a hex!) or drill a hole.

 

I run zero oiling mods on my sbo and I run it to 7k rpm and it barely makes 60 lbs of oil pressure at that rpm. When I took it apart to freshen up everything was like new. 200 passes and 3k or so street miles. Just fwiw.

 

My 307 gets to 7k in the lights with cam oil restrictors and 40 lbs of pressure. No issues. I made mine from bolts. Cut to length, center drilled, tapped tunnel to screw in and peen over to aid in staying in place

 

That’s funny

 

when you’re making about 350, no kidding.

small blocks that make 500 plus survive just fine with 35 to 40 at 8k+ How is this possible?

 

and guess what? It doesn’t matter.

the dizzy gear is flooded with splash oil…take a look where it is?

 

I have a question for the lubrication engineers on here. Why does a small block eat up or destroy the timing chain way more often than any big block?

it’s a known fact,, yet it’s the same timing gear and chain set in both blocks.

 

I've never eaten up a timing chain on an sbo

 

thats because you are special and tear it down once a year.

how many miles does your track engine get before you pull apart that bad boy ? 🤣

 

Let's see 200 quarter mile passes and 3k street miles. But my cruiser has a 350 olds I put together 13 years ago and the timing chain is total fine. That engine has well over 20k on it. And I pulled the engine apart to re do some gaskets when I had the engine out and body up to fix the frame.