LIFTER BORE SIZES IN AN ASSEMBLED SHORT BLOCK
 

So, I was going to bite the bullet and order solid roller lifters for my assembled RAV short block that I had received delivery of to me about last summer. I figured before I do, I should measure the existing lifter bores which had sleeves installed. I purchased and set-up my dial bore gauge and took the following measurements, and my results are in the drawing attached.

I wanted to get a consensus about these numbers because I'm really concerned about the
Intake lifter bore for Cylinder number 3.

Your Thoughts????

Since your assembled, easy solution isn't so easy. That one is big, I might re-set your gauge and just measure them all again. If consistent, then you really have 3 choices. 1. Measure your lifters and see if you "get lucky" and have 1 big one. It does happen. If your using high end lifters, like Jesel, they will make you an oversize one or a pair. Mass produced ones like Morel, I doubt it. 2. disassemble and drive the bushing out and put a new one in. 3. Run it and don't worry about it. It's not ideal and you will have some leakage. But I doubt it will be the cause of a failure on it's own. My guess, looking at your measurements, is the bushings were not honed to size. I bet they were just reamed and possibly a ball hone run through them for a finish. A flat stone rigid hone is really the only way to get really straight, consistent size on the bushings. Iron blocks especially, push the bushings all over the place when you drive them in. Aluminum blocks are a little easier. How do they look for out of round and taper?

MGARBLIK,

I must have checked the gauge against a my micrometer multiple times especially after I came across that one bore and freaked, then checked it another half dozen times to make sure I saw what I was seeing before me.

I haven't checked it for out-of-round or taper yet, but I'll get to that.

I don't see anything down inside the sleeves or into the block to restrict oil flow, so I'm assuming I'll have to use oil restricting pushrods.

I will check this out, but does Jesel actually make custom ordered diameter lifters??

Have you ever heard of anything like this situation before??

I haven't run this short block at all. If I can get a custom lifter I may go that route, but I know there's $$$$$ in that. Having to take apart a newly built short block is not what I really want to do, I but may have to face that fact. If I have to go that route, I'll have to call the engine builder and let him know what I found and drive it all the way back down south rather than having it shipped.

You need to look very closely in the bronze sleeves for a tiny oil feed hole drilled through the sleeve. This would be oil for the lifters. A .030" hole is a large enough feed for solid rollers. If no oil feed hole at all, that's another issue. That would mean no oil to the lifters. If it has a giant hole in it like the stock lifter bores, then that's another problem. No restrictor pushrod in the world will be able to block enough oil with some of those clearances. Putting 16 bronze sleeves in a stock block Pontiac is a big job. Did they have a Pontiac BHJ Lifter True fixture to install them? If not, the only other way to get them all in straight would be a semi-auto CNC mill or a dedicated full CNC Milling center with a program for a Pontiac V-8. This would be a rare situation. If they just drilled and reamed the bores for bushings with a giant magnetic drill or a manual mill, without a fixture, the lifters could be going off in every different direction. I would like to know a little more about the shop, what equipment they used to bush 16 lifter bores, stock block or aftermarket, iron or aluminum. Not saying an average really good machine shop couldn't put bushings in but this is a major machining operation that has to be done right. This is typically a $1000.00-1200.00 operation by itself to install 16 bushings on the crank centerline and hone to fit. It's an all day job with the fixture and a manual mill.

Ram Air V.

If the bores were opened large enough, Ford .875 lifters also have a high oil band. Dunno.

Depending on the wall thickness of the bushings, Crower has a .903-.904 lifter and a .937" as well. If enough wall thickness and the bushings have an oil hole in the right place, that's a good option. .875, I have never used in a Pontiac. But worth investigating as well.

If it was my RA V block it would come apart and have all 16 bushed.FWIW,Tom

OK....

The block is an original cast iron V block.
I took all my stuff about a year and a half ago to the our guys in Lawrenceburg, Tennesse that I know have an exceptional amount of Pontiac knowledge.
All 16 lifter bores were bushed with new bronze sleeves. I just need to look down into them to check out for the oil restrictors and whether or not they're out of round and if bores have a taper.

Knowing who these guys are I had a lot of trust in them....and by the way I still do!!!
I will check out a couple of different ways to deal with this and the last resort would be to have a discussion with them on how best WE can resolve this since this is a finished, unrun, off the pallet short block build with no time on it, still on the engine cradle it was delivered with.

I was wondering about a .903 Mopar but was unsure of wall thickness.

What was the reasoning for bushing in the first place?
Was there a problem to begin with, Just wondering what the reason was?

GT

I would be very concerned with the high levels of side loading that roller lifters place on the the stock passenger side lifter bank in terms of there thickness no less with then now being thinner due to the sleving.

I hope at a minimum that your running some type of lifter brace?

Ram Air V.

https://forums.maxperformanceinc.com...1&d=1679913549

Yup, I know, but still how much meat was taken out of the bores to get the sleeves in?
The factory engineers never dreamed that open spring pressures could be used that would need to top 600 psi.
I just don’t want to hear of yet another super rare factory V block of someone’s suffering broken off lifter bores.

my 428 block has bronze sleeves,when built 25 years ago it had 200 on the seats and 600 open and never had a issue,now has 160 and 350 open as I went to hyd rollers.NO joined lifter bores.I have only seen one V block with a broken bore and it had not been sleeved.FWIW,Tom

Every PMD 400-455 should have been made like that. It was 25 cents more iron.
Bean counters won.

Anyone notice that RA V block has a transfer lug?Tom

I might be more of the opinion that these vertical rib reinforcements where done to help keep the block from splitting up through the mains like Arnie and Jess Tyree and others where experiencing.

Anyone recall the lifter bores ripping out on the earlier supercharged nitro drag cars?

So the RAV block and the early 389 motors have this rib in the crankcase on the passenger side, does the SD455 have that rib also?

What we could use is a stock looking aftermarket block made of the same grade of iron as the RAIV and V blocks. No need to have iron like a IA2 has. Solid lifter galley like a sbc with 1/8" more materiel around the lifter bores and the extra rib along the pan rail like the 59-60 blocks. Siamesed bores too. With splayed ductile iron main caps like Milodon sells.
That ought to do it.
Bet you could make 1000 NA HP with a block like that and still look OEM.

Sooooooooooo.........

I called Jesel and had a discussion with the folks in the Custom Shop.
They will make me a custom bronze bushing if needed, but not a custom diameter lifter.
So that's out.... Nice dream, but shot too S--T.

Didn't check for taper or out of round because I used a camera to get the best view I could of the inside of the bore and what didn't I find????????

The oil restrictors. So I guess my mind is made up for me and I have to get this short block disassembled. So back to the engine builder it goes....After I have a discussion with him this week.

Stay tuned.