After mulling it over for a long while, i finally decided to send my already machined block into a very reputable shop to have my lifter bores bushed. I am running a solid roller cam that i purchased from Duane Porter as he picked it out to go with my combo and indy heads that he did.
Problem is that i just saw in the mopar engine bible (mp b and rb engines) that they say to never bush the 2 lifter bores for the #2 cylinder because they claim it will significantly reduce oil supply to the mains and cam journals.
I have been doing a decent amount of homework on this and never saw this mentioned anywhere else. Is this true? Or has this been disproven? Otherwise i need to call the machine shop up asap and advise.
By the way, this is a 71 400 block

I've been building and racing BB wedge Mopars and 426 hemi motors since the early 1970s, I've never heard of anyone at the races or on the internet have oiling problems from bushing lifter bores, never
Me thinks your source is trying to blame a building error or part failure on some smoke and mirrors
Call Dwayne and ask him also, let us know what he says please
EDITED: The lifter is around .080, I think , smaller O.D. than most lifter bushings I've seen, do you think that .040 sticking into the oil galley will cause a severe oil restriction
I know breaking a valve spring or some other valve train part that allows the lifter to come out of its bore will cause instant oil pressure loss

Take the galley plug out on the passenger side front of the engine - the one behind the cam sprocket and see how big that galley is that runs from front to back. Then determine how thick the wall will be on those bushings. What's left is what supplies the mains. I have never seen or heard of an engine failure due to bushing the #2 lifter bores but if someone were to use a very thick wall bushing it may be possible. Each bushing on the passenger side theoretically reduces flow to the next main journal down the line.

On a street engine you will be fine.
If you are worried about it run a line from passenger side front galley to driver side rear galley. That's good for 9000 rpm drag motors.

Mr. Shepard made other mistakes in putting the bible together - and collecting info from the engineers.

Its a non issue. There were 2 sources that used to supply that information, but its proven to not be an issue.


If your shop has the fixture to do Mopar lifter bushings, most likely they know what to do.

Ok, thanks for the replies. I feel much better with your confirmation. I didnt think that info sounded right, but i wanted to just get experienced opinions. I didnt want to pay alot of $$ to prevent an issue if i toss a lifter and actually create the problem with the mod.

Installing bushing will not prevent a lifter from coming out of the bore if a push rod happened to break or come off the rocker for some reason. Most blocks are bushed because of alignment or wear problems. So if thats your reason , save your money.

no it won't but will help sustain oil pressure if you do loose one,that little .040 .060 hole in the bushing leak's a lot less oil than the big gaping hole that the factory intersection will, and yes my my block is bushed.

Exactly why im having it done. Save the bottom end just in case. Also correct any misalignment from the factory. Thanks to Duane Porter for advising me on this. He's the best!!

Been there done that, I had one of the great Smith Bros race pushrods fold up and break into two parts on the dyno at or close to 5200 RPM at WOT ,making a pull, it knock the high dollar Crower Ultra lifter out of its bore and broke the link to the matching lifter ruining that pair of lifters, the stupid upper half of that dang broken pushrod fell down into the lifter bore bushing gouging it and scarring up the cam lobe enough to have to have that cam lobe repaired and reground
No loss of oil pressure so no damage to the bottom end
Definitively worth doing the bushing on that motor
This is one of those pay me now or pay me later decisions, if you have to pay later it will probably be a lot more expensive and damaging

If this advice was written by the same author as the "thinwall block" horsepoop that was promulgated as official fact by Larry Shephard for so many years, then I'd say burn the book and buy Chuck Senatore's book and Andy Finkbeiner's book instead.

R.

Yes. Very true. I have them all. Problem is i read too much. Thats why i asked here because nothing better than real racers with real experience.

I had my lifter bores bronze bushed with oiling holes as almost all of the lifter bores were worn out. The burnishing tool just fell in the bores.
Nothing is burned or scored in the valvetrain.

I would think that in over 5,000 miles and plenty of TnT runs and a season of bracket racing if there was a problem it would have shown by now. Been together since 2012.

I go through the lights with just under 70 pounds of oil pressure at 6,000-6,100 at 119 to 121 mph......no oil presssure drop

Flat tappet cam