[Dragncar]

I ran .030 restrictors in my 455 and drove it on the street and to the track for years. No problems. sft.
You can get a lot of oil through that .030 hole. If you have a issue with it run a .040-.060 hole.
No lifter company is ever going to tell you to restrict oil to their product, ever. All they care about are their lifters.
They do not care a lick about your main and rod bearings.
I see it all the time in industry. A sprocket might have a keyed tapper lock holding it to the shaft. And the maker says if we use Anti Seize on it it voids the warranty Never mind in the 35 years of doing this have I ever seen one returned for warranty issues. If we have a problem, I cut them off with a torch. And you can ruin the very expensive and hard to change bearing behind that sprocket with a torch. .
So I run restrictors on my Pontiacs and Anti Seize on my tapper locks.

[scott70]

So I just installed a HR in my street engine,,, evolution lifters and did not restrict the pushrods even though butlers recommended it. What’s the average size hole in a standard aftermarket pushrod?

[chiphead]

Great questions. Is the oil metering to the pushrod a lot different between a HR lifter and a HFT lifter, for the same oil weight?

I know a HFT will put a LOT of oil up top on a Pontiac. Is all that oil flow needed to cool the valvesprings? Is it different when using the shields vs using a modern Viton seal? Seems like all that oil increases the chance of oil pulled past guides or valvecover oil leaks. Just on my stock type 400 with the valvecovers off, the oil will overflow the heads above idle. The guides are swimming in oil.

Is the point of restricting the pushrods to limit oil starvation in the pan? What about a case where you can keep the pick up covered with oil?

[Mike S]

Correct me if I am wrong. If you restricted flow thru the push rods wouldn't you still see full flow at the lifter? You would just be limiting oil to the valve springs and rockers.

My restrictors for a solid roller are .030 but tapped into the oil feed to the lifters in the block. But this is a mainly strip car with occasional street driving. Myself, I would rather have restricted push rods.

[jhein]

Originally Posted by Mike S

Correct me if I am wrong. If you restricted flow thru the push rods wouldn't you still see full flow at the lifter? You would just be limiting oil to the valve springs and rockers.
.

That's what I was wondering too.

[P@blo]

Spring cooling would be a concern on engines expected to meet warranty or make higher mileage. For engines that see low mileage the trade off to provide more pressure below makes sense.

I am in the water industry and a short neck down does not affect flow much. Is the entire push rod orifice restrictedor just a portion? Also, If pressure increases on a smaller orifice so does flow as they are they are related.

[Singleton]

Originally Posted by Mike S

My restrictors for a solid roller are .030 but tapped into the oil feed to the lifters in the block. But this is a mainly strip car with occasional street driving. Myself, I would rather have restricted push rods.

Here’s a recent video from Powell’s Machine Shop, where he says the same thing about not restricting flow to the lifter, and shows the damage done to a customers roller lifters by restricting the lifter bore. http://https://youtu.be/KRt55CphSqU?is=zWZhVwuzjss33_W_

[Jay S]

Originally Posted by Singleton

Here’s a recent video from Powell’s Machine Shop, where he says the same thing about not restricting flow to the lifter, and shows the damage done to a customers roller lifters by restricting the lifter bore. http://https://youtu.be/KRt55CphSqU?is=zWZhVwuzjss33_W_

That guy in the video had his oil restricted down to about 1 gpm with his .1” orifice before the oil even made it to the lifters. Maybe he had 2 plugs on each bank, maybe 2 gpm at most. Either way, is a lot of restriction before the oil is even close to getting to the top end.