It seems that some people DO need that firesuit!

No, they don't, but they fool themselves into thinking they do.

In my case it was because the lifter bores were scored badly from the debris when my SFT cam started eating lobes about 1200 miles after break-in. I wasn't fooling myself about needing to bush the lifter bores in order to salvage the block.

Another viable reason is when the factory lifter bores are not sized properly for the proper clearance with the chosen lifters, especially with rollers. I've seen close to .001"difference between body diameters of different manufacturers, yet the clearance is supposed to be only .002".

- a jig used just to install the bushing will not correctly locate the bushing centerline relative to the cam and crank center lines. A milling machine set up to locate off the mains will properly locate the lifter center lines.

Believe this is the setup used on mine.
Been together since 2011.
Seems to be running a-ok
With oiling holes in the bushings

I would not bush lifter bores on a iron or aluminium since the charateristics on cast material is porous and retains lubercation.Bushing lifter bores should be done to correct any misalignment such as spacing or angle.Bronze/bronze alloy bushings are hard and dense.Hard steel lifters on a hard bronze bore = wear.Before everyone goes off on my statement let me say that any race application can run that combination because of the run time compared to a long duration street driven engine.Nascar used to use a cast iron sleeve to bush the lifter bores for correcting production blocks,now most topline builders machine the bores in aftermarket blocks that they get with no bores so they can set the spacing and angles where they need for the specific applications.We have purchased blocks with bushed bores for specific customers at their request and found alignment issues since all that was done was the bores were bored and bushing pressed in.When having this done be specific to who is doing the work and have the spacing and angle refrences.There is a need for the process but not for street use,$600 can be better spent on other performance products and mods.
Respectfully Bob George

It's been my experience that the bronze wears on the street mainly from oil change intervals ..Street driving high per engines ie" big solid rollers and big spring pressures" you can not go a 1000 miles on oil on the street...I noticed that some guys were eating up oil pump drives in a month or two..when those engines came apart for a freshen the bores were toast..most others only showed a little wear..I asked Mickey at BHJ whats the deal..I was buying the bushings in 50 lots and thought maybe some were softer than others..He said no way it might be the oil...he was right...Guys with the same cam and more oil changes were getting 4-5 years out of their oil pump drives and their bushings only showed slight wear.
After that...only cast bushings for customers and myself..20-30 years NO WEAR at all..my oil pump drives still only go 4-5 years
just my take...

Rob

The R1 block in my car has bushed bores and after around 2000ish miles they "felt" good when I had the intake off not to long ago. I did over 1000 of those miles in 4 days on 1 oil change.

I killed a bronze gear in about 3000 miles back in 2012. I was running rotealla 15W40 and had more oil pressure than I needed. I went to a thinner oil to lower the oil pressure and I put 6000-8000 miles on the next gear and it still looks great.

Thank you for explaining it better than I did.
Mike

I'll maintain my position, thats it is not a problem, when done right. I understand the cast iron bore, and that thought, and wont argue that. Going back to what was said earlier, this is the reason a oil hole of PROPER size is used. The wear is almost nill at that point, as the oil helps immensely.

I still like the idea of 1) correcting the bores to where they SHOULD have been in the first place. If you do enough of these, and the other two corporate brands, you will see how bad they are.2) making the clearances where they need and should be to begin with. ( yes, same can be said for cast iron) 3) Controlling oil pressure to where you want it to go. ( this can go in a lot of different directions, but depending again, on the application, it may be more critical than you think. 4) If you EVER have the misfortune of popping or breaking a lifter, you are not going to trash your engine due to no oil pressure and 5) kinda goes along with # 2, making the holes round, mosty impiortant on used hi mileage blocks. Its not uncommon to see +.002-.003 wear or more.Do enough of them. and you will see it.

Bob, if your getting blocks that have just have bushing " popped in", without fixturing, you better find a new guy!( unless it is a Rottler type deal)...lol..as you know, thats no good. There are some places that offer a reamer to repair a single bore, which doesnt correct anything, but does make the bore servicable again. Thats a totally different deal.I have a shop that borrows my extended hone all the time to repair damaged bores.

Everyone will have a different " opinion" on this. As always, I will go with what has worked for me without fail over 25 years.Would I take a new block and put bushings in it " just to feel good" ? Hell no. You get a feel for who's stuff is good and who's isnt after doing many other the aftermarket blocks like Dart , World etc, for BBC, SBC and BBF and so forth. Most hi end BBC and BBF etc are running Mopar .904 lifters and bigger anyways, so if its a Ford Motorpsorts block, or a Dart Big M, and it wasnt running anything other than STD bores, most will bore and correct to .904 to begin with to take advantage of that lifter size and how it can help.

I am of the opinion, the oil is an issue, but again, I have not seen the wear with oiling holes for the most part. I do believe along with RobR about the street driven oil, but a couple things come into play along those lines. Most street drivers, will often buy more generic oils. Racers typically buy a bit more robust oil.( No , please dont get the oil debate started again..please dont) Couple that with the fuel dilution that is much higher in a street application, and the oil simply isnt doing the job it may in a race motor.( which also are often higher viscosity, although that trend is slowly changing a bit) Couple that with racers ( the good ones...lol) change their oil pretty religiously. A street guy, maybe, maybe not.Like I said, a lot of fuel contamination, and dirt infiltration from street driving.

Lets face it, much of the Mopar machining left a lot to be desired in the factory stuff.

Is there anything wrong with cast iron bores? Nope. Does every street engine NEED bushings? Nope.Is there anything wrong with taking advantage of the positives of bushing a block? Nope. The debate will rage on after we're too old an tired to talk about it, so it comes down to builder/owner interaction and discussion, and somewhere in that , they decide what they want to do.

Thanks again for all the replies! All of them are greatly appreciated.

What I did not say is that this is a brand new cast iron block and the lifter bores are terrible. This is not from normal wear but from bad machining.

The bores have a surface finish of between 100 and 115 microinches Ra. They should be around 32 Ra although I do know enough about surface finish to know that Ra doesn't tell the whole story but 115 is so bad that it doesn't really matter what the peaks and valleys are. I have significant experience with cast iron surface finishes and understand the significance of poor surface finish. 7 of the bores also have a nasty taper - 0.0014 inches down about 0.5 inches.

I considered trying to run these bores since the short block was already assembled but I came to my senses and no way do I want to run the bores in this condition.

The block is now disassembled and in good hands and will get the bores bushed along with some other corrections.

Bob, if your getting blocks that have just have bushing " popped in", without fixturing, you better find a new guy!( unless it is a Rottler type deal)...lol..as you know, thats no good. There are some places that offer a reamer to repair a single bore, which doesnt correct anything, but does make the bore servicable again. Thats a totally different deal.I have a shop that borrows my extended hone all the time to repair damaged.


I understand,blocks are offered from manufactures and suppliers with bushed lifter bores.Even though they may have corrected to the correct specs for the engine design,it may not be for the end users application ie: changes in rockers& geometry,changes in deck height and angle or a different head design.
We ran into these problems when using StageV Millinium Hemi heads on a standard deck and a standard cam height block and found that the pushrod holes ran into the cylinder liner.We had to tilt the angle of the lifter a few degrees up to get the hole away from the bore.Now we get the raised cam block with the lifter bores spread .050 and upward angle tilt and no need for bushing.This was why I commented that the correct specs for a specific application needs to be considered for bushing bore.I still maintain that for street use it is not necessary.
I respect everyone opinions and experiences that have been shared here,a lot of good info,and agree lets not get into an oil debate.
Respectfully Bob

Boy, we could really go off into hyper space if we start talking about current quality control issues couldnt we????....I dont think I have enough blood pressure medicine for that.

Here's the good news, from my birds eye, head janitors position view, here at CWE ( I like to better refer to it as Janitorial Executive,although I may be fired today, we were out of crapper paper this morning)......lol...the original poster, is now better informed, has made a decision, and I think everyone feedback has helped, we all shared some different viewpoints and thats a
win for us all.