bushing lifter bores on 340

[EddieSketti]

im bushing my lifter bores on my 340 because i would like a tighter clearance than .003 and get rid of the chamfers also true up the lifter bores . what size hole should be drilled in the bushing for oiling the lifter. I'm going with either hydraulic rollers or mechanical rollers lifters . if i didn't bush the lifter bores the oil hole would be the oval hole from the factory which is about 3/8 tall by 5/8 wide.

 

[yellow rose]

im bushing my lifter bores on my 340 because i would like a tighter clearance than .003 and get rid of the chamfers also true up the lifter bores . what size hole should be drilled in the bushing for oiling the lifter. I'm going with either hydraulic rollers or mechanical rollers lifters . if i didn't bush the lifter bores the oil hole would be the oval hole from the factory which is about 3/8 tall by 5/8 wide.

If you use a mechanical lifter don’t drill any holes in the bushings.

If you decide to use a hydraulic lifter (I say don’t do it but it’s your build) then a .040-.060 hole MAX is all you need.

 

[EddieSketti]

If you use a mechanical lifter don’t drill any holes in the bushings.

If you decide to use a hydraulic lifter (I say don’t do it but it’s your build) then a .040-.060 hole MAX is all you need.

I am using eq heads that'll have magnum oiling system through the push rods does that matter at all compared to the original oiling system that oiled though the heads ?

 

[12many]

I am using eq heads that'll have magnum oiling system through the push rods does that matter at all compared to the original oiling system that oiled though the heads ?

Sort of in the same boat myself, LA block, EQ’s w/pushrod oiling now with a hydraulic. But I also have Trick Flow heads and a healthy mechanical cam (with other hardware) in the dugout for when my stroker motor comes out and gets inspected etc and a makeover. Also have a slightly bigger mechanical cam (than the hydraulic) that will work with the springs in the EQ’s that I’m thinking of sticking in without removing the engine, So I’m very interested in this topic you’ve brought up.

 

[512Stroker]

I am using eq heads that'll have magnum oiling system through the push rods does that matter at all compared to the original oiling system that oiled though the heads ?

Food for thought
If you run a hydraulic set up (not me) do you need a high volume oil pump to handle all the extra flow?

 

[12many]

Food for thought
If you run a hydraulic set up (not me) do you need a high volume oil pump to handle all the extra flow?

I’m wondering about the psi difference between as is vs doing the modifications and either drilling the .040”-.060” in the tubes or not. Hydraulic or otherwise, at idle and up. All this in general

 

[Wyrmrider]

you need oil holes for edm lifters

 

[EddieSketti]

I’m wondering about the psi difference between as is vs doing the modifications and either drilling the .040”-.060” in the tubes or not. Hydraulic or otherwise, at idle and up. All this in general

I called huge

Sort of in the same boat myself, LA block, EQ’s w/pushrod oiling now with a hydraulic. But I also have Trick Flow heads and a healthy mechanical cam (with other hardware) in the dugout for when my stroker motor comes out and gets inspected etc and a makeover. Also have a slightly bigger mechanical cam (than the hydraulic) that will work with the springs in the EQ’s that I’m thinking of sticking in without removing the engine, So I’m very interested in this topic you’ve brought up.

 

[EddieSketti]

I talked to Dave Hughes at Hughes engines yesterday and he said they drill the lifter bushings 3/32 for both mechanical and hydraulic roller lifters

 

[yellow rose]

I talked to Dave Hughes at Hughes engines yesterday and he said they drill the lifter bushings 3/32 for both mechanical and hydraulic roller lifters

That’s a pretty damn big hole to feed a lifter.

 

[EddieSketti]

I was thinking 1/16 after calling b3 racing engines and talking to mike

 

[yellow rose]

I was thinking 1/16 after calling b3 racing engines and talking to mike

First, calling Mike is always a good idea and 2 a 1/16 hole is good. That’s about a 31ish% percent smaller hole. I like that.

 

[davescuda]

I was going to say .035 hole. I think some new solid liters feed oil to the bearing now, so you need the hole.

 

[EddieSketti]

First, calling Mike is always a good idea and 2 a 1/16 hole is good. That’s about a 31ish% percent smaller hole. I like that.

should I have that hole centered in the factory oval hole that are there ?

 

[yellow rose]

should I have that hole centered in the factory oval hole that are there ?

Doesn’t matter. A hole anywhere is golden.

 

[Brian Hafliger]

im bushing my lifter bores on my 340 because i would like a tighter clearance than .003 and get rid of the chamfers also true up the lifter bores . what size hole should be drilled in the bushing for oiling the lifter. I'm going with either hydraulic rollers or mechanical rollers lifters . if i didn't bush the lifter bores the oil hole would be the oval hole from the factory which is about 3/8 tall by 5/8 wide.

I highly recommend enlarging the lifter galley that supplies oil to the mains/lifters before you bush the bores...the bushings encroach the oil galley and do slow down the volume of flow.

 

[EddieSketti]

sweet thanks for the info I have been stressing out about what size hole and where to put it. Machine shop what's to know come Monday

 

[EddieSketti]

I highly recommend enlarging the lifter galley that supplies oil to the mains/lifters before you bush the bores...the bushings encroach the oil galley and do slow down the volume of flow.

what size should they be enlarged to and can you just drill threw the oil gallery with the same size hole to take out any bit of bushing that's hanging down once its been bushed?

 

[EddieSketti]

I highly recommend enlarging the lifter galley that supplies oil to the mains/lifters before you bush the bores...the bushings encroach the oil galley and do slow down the volume of flow.

what size should they be enlarged to and can you just drill threw the oil gallery with the same size hole to take out any bit of bushing that's hanging down once its been bushed?

 

[yellow rose]

what size should they be enlarged to and can you just drill threw the oil gallery with the same size hole to take out any bit of bushing that's hanging down once its been bushed?

When you bush the lifter bores or tube the gallery the oil demand goes WAY down. I don’t open that passage up ever. More work than you need to do. Make sure all the feeds from that gallery are opened to 9/32 and send it.

 

[EddieSketti]

I did drill the feeds to 9/32 but did not do the cross over tubing

 

[Wyrmrider]

if your lifter has an oil band you want the hole in the band area when the cam is on the base circle
i drill the oil passage, keeps the velocity down
for those using solid roller you can bore and hone for os lifters
or you can use os lifters and a bigger wheel with bushings

 

[RustyRatRod]

Didn't Mopar Performance make a kit to do "all this" once upon a time? I remember using it back in the early 80s. It consisted of a ling drill bit and some other goodies.

 

[Wyrmrider]

I welded a piece of round barstock to a drill with a pilot made on the end
matching reamer slightly bigger

 

[gregcon]

IMO, the big issue you face with a pushrod-oiled top end and restricted lifter bores is the need to get oil up the pushrod. You need an oil path to do that...so if you drill a small hole, you should consider the placement of the hole as important as the size.

This is compounded by a hydraulic lifter's need for oil, if you are running hydraulic lifters (which is never a good idea unless you are a 68 year old woman named Agnes).

What I'm saying is....a small hole (like .046") is a good thing, but not if you keep it covered by the lifter body at all times. It needs to align with the lifter's oil hole at some point in time.

The factory 'hole' in the lifter galley is huge - not just in terms of oil flow but also in meaning that it helps ensure the oil hole in the lifter will be fed oil. It's also pretty forgiving when different lifters are used...various lifters usually have their oil holes in different locations along the lifter body.

So....you should drill the hole small but you should also have the lifters you plan to use 'in hand'....with the cam installed, drop them in the bore and measure where the hole sits then use that to position your lifter bushing hole.

I drilled mine at/around .046" but I first dropped the hole (using a 1/8" end mill) 1/8" down. This gives the .046" drill bit a flat surface to start against, and it also gives a much bigger 'landing zone' for the oil holes to align. In other words, the holes is flowing .046" but the lifter 'sees' a .125" hole which makes the alignment more forgiving.

See pic:

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