I searched the forum and other boards, Besides the obvious replies that 2.20 bearing has more clearance, has anyone had issues ?
I'm sure it varies block to block but I can get a great deal locally on a Molnar crank and rods. New in box. This will be for a street motor, approx 550-600hp.
Has anyone done it and how much did you have to grind into the mounting boss ?
I personally have no faith in 3/8 pickups supplying enough oil volume at speeds near or above 6000 rpm

Depends on the pickup. A 4.25 stroke with 2.20 journal clears most pickups but not all. A 4.15 with 2.375 journal is slightly larger than a 4.25/2.20 so you'll have even less room. If you haven't already drilled and tapped the block for 1/2 inch pickup you might consider just staying with 3/8. Or at least mock it up before you decide.

3/8" clears fine and will suck 7 quarts out of an oil pan with a stock pump and put it in valley in a quarter mile!

Strokers do not need a lot of rpm anwyay.

I use the Molnar 4.25 crank and 7.1" rods and it clears the pickup boss by ~ .060 as I recall.

On 66 and 67 Hemi blocks, with the factory half-inch pickup tube, the 4.15 crank with 2.375 rod journals will clear with a bunch of grinding on the pickup tube boss. I'm not sure if this information applies to your situation or not, but I would think so.

When my builder machined my block for the 1/2" pickup he offset drilled it away from the crank and IIRC it still required some slight massaging at the boss and the tube needed a touch to get what he wanted for clearance with the 4.15 stroke / Mopar rod. Bottoms of the bores need a little attention also.

If I had to do it again, I don't think I'd bother with opening up the block to 1/2". I would probably use the 1/2" tube that is swaged down to 3/8" at the threads if I bothered with a 1/2" pickup at all. I think there is more restriction between the pickup boss and the pump than the 3/8 tube anyway.

Kevin

"I would probably use the 1/2" tube that is swaged down to 3/8" at the threads if I bothered with a 1/2" pickup at all. I think there is more restriction between the pickup boss and the pump than the 3/8 tube anyway.

Kevin"
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This right here, what he said.

Although I bought the tools to tap for the big pickup and have done it a couple times....I think it's probably
Unnecessary for most applications.

Good luck with whatever you decide.

I've got a bunch of low deck and high deck stroker motors running with stock 3/8 pickups in them with no come backs on oiling issues So far, knock on wood
I do run loose bearing clearances with thin oil (5W20WT) and high volume oil pumps also so maybe it is the combination
I do have to trim the oil pickup boss a little with either a 4,250 or longer stroke with forged steel BB Chevy type rods

I was told while building my current engine unless you open up and radius the block you are wasting your time with a 1/2 pick-up. My Mopar rod journal 4.15 with with K1 rods clear the straight 3/8" Mopar pick-up.
I tried the 440 Source pick-up and it wouldn't clear my crank

Gus

Yeah the current 440Source pickup has a really thick section at the end and it won't clear the larger strokes. I've run into that a couple of times myself.

I use the 4.15 crank and stock Mopar journals. I also run a 1/2" pickup and it just cleared but was close to the oil pick-up boss. I did grind it for more clearance just to be safe because even though it cleared it was very close. Ron

It may not clear your pickup but so what? Just get a die grinder and take your time and do a nice job grinding it for clearance. Don't expect anything to fit now-a-days when there is 1,000 different people making parts that are supposed to work. 99% of the people making these parts weren't even alive when the 426 Hemi came out. No wonder they can't do anything right.

That's what I hear is typical... close enough to need some grinding on the boss... unless the original 3/8" pick-up hole was drilled & tapped offset to the crank side of the boss, which results in the 1/2" pick-up simply being too close to grind enough clearance.

There have been 4.15" cranks available with the 2.20" journals, which "should" be a no-grind deal. However, those aren't common as the 4.25" with 2.20" journals is far more popular.

I wasn't born yet

Now I have an excuse for doing everything wrong 😂

my old man always said : "a poor excuse is better than no excuse".

The 4.15" stroke crank with stock rod bearing size clears in my 400 block stroked to 500"
As mentioned, the 1/2" pickups with the large collar are a problem. I originally had a Milodon 1/2" pickup that cleared, then when I put the stud girdle on, I made my own pickup tube.
On the recent 505" 440 with 4.25" crank and 2.20 rod bearings, had to grind the collar on one of the 440 source pickups for clearance.
Both need a bit of grinding on the pickup tube boss in the block.
The 440 source H-Beam rods (RPM Brand) seem to have a bit more clearance than the old I-Beam rods did.