That's excellent work on the cam housing bores! You could essentially get rid of the runout in everything and go to a lighter oil to pick up hp on the high end. That's the one area that makes it extremely difficult. You have a crankshaft grinder, wow would I love to have one of those.
And people wonder why competent shop service is so expensive, LOTS of $$$$ invested there in equipment as well as knowledge --great job as I am sure that is so often overlooked
You sure cover ALL the bases Mark, big difference between a quick hone and valve job then assembly VS checking EVERYTHING and knowing how to repair out of clearance issues--You sure know the BBC pros and cons
Oversize (O.D.) are available for certain engines, such as small-block Chevs, however all five bearings are the same O.D. and the cam tunnel needs to be line honed to fit. Are oversized bearings available for the big-blocks?
Surprised you didnt get into lifterbore straightness or maybe stepping up to a 55mm core if you already have a problem that needs machine work to fix...
hey mark is there a specific reason why the 454 eats cam lobes, ive pulled a few at the wreckers and when i take them apart a couple had flattened lobes.
Insufficient and/or shitty oil, excessive high-load/low-speed operation causing insufficient "splash" lubrication to the camshaft, crappy aftermarket parts used during a "rebuild", improper break-in and/or excessive "cranking" prior to startup of a "new rebuild" and/or lack of "pre-lubing" the engine, wear in the valve train leading to hydraulic or solid lifters having "excessive lash" and in the case of hydraulic lifters no more "travel" left in the plunger to take up that lash which leads to a lifter "hammering" on the camshaft and/or no longer rotating in its bore as well as being alternately "too high" and "too low" in its bore for proper lubrication from the lifter bore gallery which means it gets "starved" for oil as does its pushrod, rocker arm etc causing more wear and "slop" until the lifter "wipes" out itself and the lobe which then leads to excessive leakage from its gallery holes which starves other lifters on the same bank for oil very shortly after the fist lifter/lobe pair "dies" so "suddenly" the engine is missing bad on two or more cylinders and will definitely fail a compression test and/or cylinder leakdown test. Which is usually why big-block-powered vehicles end up in "junkyards" with their engines still installed. Somebody assumes that since the engine was "tired" and maybe being "abused" when it suddenly "fails" and starts missing that it's a major engine failure like "scuffed pistons" or something. Which is easy to assume if adjacent cylinders both fail comp tests and that "indicates" a "blown head gasket" and/or "scuffed cylinders" adjacent to each other due to "overheating". Pretty much the same shit that will "take out" a flat-tappet cam in any V-type cam-in-block flat-tappet engine IF the cam goes before something else does. Lots of people talk shit about the "small lifter diameter" in Chevy BBCs and SBCs but those small lifters fail "completely" pretty quickly when improper operation, maintenance or oil is the "root cause" and because when one lobe/lifter pair fails another cylinder or two are right behind it once they get starved for oil, having "small" and "weak" lifters actually "saves" the engine from further "destruction" if it were being abused and the lifters "lived" until something "died". Putting "high-volume" oil pumps in BBCs for any reason during a "rebuild" is a really dumb thing to do since those "high-performance" pumps are actually made for the tall-deck truck engines because OF the high-load/low-speed operation and "abuse" straight trucks often get so those tall deck engines with their high camshaft placement get "sufficient" splash lubrication at "low speed" thanks to the significantly higher pump volume. When you put one of those pumps in a "low-deck" BBC you go from "insufficient" splash lube at low speed to way too much volume at "high speed" and one of those pumps can and will pump the pan "dry" in 10-15 seconds of "high-speed" operation at WOT on the highway for a half mile or so. When those priority main lube systems run "short" of oil the "top end" of the engine goes "dry" first, lifters "drain down" and there's your excessive lash. Straight-truck engines typically have "8-quart" oil pans that are very "deep" and they rarely get that kind of high-speed/low-load operation and have more lube system to fill and have to pump the oil "higher" in those engines. Its kind of hard to "pump dry" one of those engines. Put that pump in a passenger car/light-truck BBC and especially take a "tired" engine with one out low on oil and/or "sticky" from not being run/worked much recently and go blast up the highway as hard as it'll run as long as you dare and if you're a "gauge watcher" like anybody running "stock" BBCs should be, you'll see the oil pressure "waver" where it drops a little and comes back and drops a little and comes back and keep that up for very long and it's going to drop and not "come back". The kicker is that the oil pressure will be "normal" like it has a "low-volume" pump because those priority-main systems are "full-flow" and "bypass" oil at the filter "base" with filtered oil on the clean side of the filter "relieving" to the "dirty" side to go through again and there is no real "pressure adjustment" to them and they just "bypass" the excess flow at lower speeds and/or with "cold" oil. Get them wound up and really "slinging" a lot of oil out of the mains and rods and pumping oil as fast as possible to the top end and the "bypassing" ends without the pressure changing until it starts "wavering". And if you want to know something else about BBC camshafts, bearings etc its this. This "expert" doesn't have a clue WHY there are "loose" bearings in SOME BBC engines but not others or he'd MENTION the TRUTH which is that "Mark IV" BBC engines have the different sizes of bearing bores AND bearings as he DOES mention and measure but earlier BBC engines do NOT and the REASON for the DIFFERENCE is so that the factory roller camshafts in "Mark IV" engines can't be "swapped" into an earlier BBC since the "roller cam" blocks have different cam bearing/lifter lube systems for the "longer" roller lifters to be properly lubricated. They also oil the lifters and top-end of the engine less in order to minimize "windage" and obviously don't need as much "splash lube" but MUST have SOME AT ALL TIMES or the "axles" in the roller lifters go to hell in no time and a "wiped" roller lifter will put a bunch of "shrapnel" in the pan in a hurry and may just seize in its bore and hold a valve off its seat just long enough for it to get "tagged" by the piston. So the smart move was to make it impossible to do "cam swaps" from Mark IV engines to earlier engines and vice-versa by using the different bearing bore sizes and bearing IDs. That also ensures that the RIGHT bearings get in the RIGHT bores since there are multiple oil holes in some bores/bearings and only one in others. The bearings are often "slotted" around their OD so even if the holes don't get lined up correctly there still won't be an oil starvation issue leading to catastrophic failure. There's nothing TO "fix" IF you make sure to get the RIGHT PARTS FOR THE ENGINE and there is sure as hell no need to "measure" cam bores if the old ones were still "tight" in their bores. Of course SOME "engine builders" elect to "save time" by leaving the cam bearings in a "core" block while its "hot-tanked" which if the "real thing" as far as "hot tank chemical" is used WILL "dissolve" the cam bearings right out of the block. Then if some "engine builder" doing his first Mark IV "build" tries to go back in those "clean" holes with standard "early" cam bearings there will be some LOOSE ONES. But there's literally NOTHING ELSE that's going to cause a "loose bearing bore" since even a "spun cam bearing" isn't going to hurt the BLOCK and that spinning bearing will quickly be "resized". Not that its a "common" or even "every now and then" deal to have a cam bearing "spin" since only a lack of lube causes bearings to spin and the engine should "eat cam lobes" before that occurs. And cam bearings are so "tolerant" of "fit issues" that the"standard procedure" for an installed cam bearing that's really "tight" on its lobe is to literally "scrape" away some bearing "surface" to "make clearance". They're steel-shelled babbit bearings but being one-piece bearings that need to be "locked" firmly in place without "locking tabs" like on rod/main shells, they have to fit "snugly" into the block and it's much better to have a "tight" bearing show up as "tight" on the cam journal and "scrape" a little clearance into it than have a "loose" bearing. Cam bearing shells are CHAMFERED specifically to "start" them into even "tight" bores and "pilot" them decently I'm a diesel mechanic by trade but a "Chevy guy" by birth and although I heard about the "scraping" thing 25 years ago in "tech school" and like my classmates though the instructor was putting us on and I went lots and lots of years and dozens of "rebuilds" of "real" engines made by John Deere, Caterpillar etc and haven't ever put cam bearings in a SBC/BBC, I HAVE had to "scrape" at least one diesel-engine bearing in a Deere 450-series engine and had to do so AFTER replacing ONE "tight" cam bearing and finding the same problem with the second. It was just a slightly "tight" bore and I ended up "rolling" a slight "bur" onto the bearing on the "driver" side pounding it in and had to "remove" that bur to get even the used camshaft into the bearing. In tech school they really did say "scrape" the bearings and I've since seen "old" service manuals mention and picture doing exactly that with a "bearing knife". But fine emery cloth is really "better" than "scraping" them with a "bearing knife" as long as you can keep clean/get clean the engine in that area and it usually ends up being just a small "ridge" that is easily removed. So there's your long, complex answers to a "simple" question plenty of "experts" couldn't answer if they've never personally "wiped" cam lobes/lifters in a BBC or SBC engine. And yes, SBCs are prone to the same thing for the same reasons if not a little MORE SO than big-blocks because their "wedge" cylinder heads and "straight" valves and valve trains perpendicular to the deck of the block tend to put "more" load directly on the lifter/lobe "junction" which IS the "highest unit pressure" found in an engine. And "flat-tappet" lifters are actually CONVEX and "dished outward" on their "feet" with the LOBES ground with a "taper" to them so its like a "knife edge" of contact and THAT is what causes "rotation" and keeps the lifters from IMMEDIATELY "wiping" the cam lobes. That's another reason why mixing and matching roller cams with flat-tappet lifters and vice-versa is a big no-no even if looks like it would be perfectly alright. Roller cam lobes are "straight" and roller lifter rollers are also "straight" and don't "mix" with flat-tappet parts.
You can use a lathe to do the same thing. First make a washer out of aluminum that is approximately the same OD as the finish size of the bearing (slightly bigger is fine), make the washer about 3/8 to 1/2 thick and drill a 1/2 hole thru it. Chuck up a piece of aluminum that is larger OD than the ID of the bearing, turn it so the bearing fits on the aluminum spud with .001 clearance, make the length of the spud about .030 shorter than the bearing length, drill and tap the spud for 1/2 -13 threads then use the washer you made to hold the bearing on the spud, don't over tighten. Turn the bearing taking .005 cuts to within .001 to .0015 of the size you want and use 180 grit emery cloth to bring it to size. Not everyone has a crank grinder sitting in their shop and this will work just as well. FYI- Do not remove the spud until you have turned the bearing, it will be difficult to indicate it back in so it runs true. I own a machine shop and use this method often for bearing fits.
I not trying to be rude but only people who own machine shops can do this stuff in these videos. Can u make sum videos for guys building engines at home thx
Mark V 454s have different size bearing bores so its impossible to "mix and match" Mark IV or earlier yet bearings from a "409" or "348" in a Mark IV. You don't swap Mark V and Mark IV BBC engine cams/lifters in those "roller cam" blocks because there are differences in the cam/lifter lubrication system and passages that would "starve" flat-tappet lifters for oil if used in a "roller cam" block even if a "flat tappet" cam were used. And the same situation prevents "creative" cam swaps from flat-tappet to roller cams in earlier BBC engines since those wouldn't work out well either. How do you determine if a 454 is a "Mark V" from just looking at it in "passing"? If it doesn't have the "fuel pump boss" machined for a mechanical fuel pump its a Mark V engine. And if you try to fit "early" cam bearings you're going to find "loose" bearing bores that don't need to be "fixed" by anything but getting the RIGHT BEARINGS. The size differences also ensure the bearings end up in the right bores as far as oil holes/grooves "matching" even if the "engine builder" doesn't get them precisely "lined up". Roller-cam engines don't "need" as much top-end oiling and "over lubricating" the top end of BBC engines and pumping the pan "dry" at "high-speed" is just as much of an "issue" and a "cam killer" in a "tired" and/or "abused" engine as excessive low-speed/high-load operation is a "cam killer" because of a LACK of "splash lube" and "pressure lube" to the cam and lifters. The main reason you typically see "low gears" in BBC-powered vehicles that don't need them for "pulling power" is that they help keep the engine "wound up" fast enough and/or often enough during "short trips around town/farm/ranch" that the cam and lifters at least get a little "lube love" now and then IF the oil and filter are kept changed and full and the engine doesn't get OVERFILLED with oil which aerates the hell out of it and THAT'S bad too. And of course "low gears" are required to end up with ring-and-pinion sets "big and beefy" enough to handle "big-block torque" while reducing the need for it. My '85 K30 dually with its early 70s oval-port "car motor" only "mildly" built with 10:1 pistons in standard cylinder bores, a "healthy" cam with noticeable "lope:", Edelbrock 2-O intake, headers and Holley "fuel dilution dispenser" a previous owner/buddy of mine rejetted with "alcohol jets" just to make sure that while pulling around his backhoe on a big tandem-dual 5th wheel flatbed for his concrete business the old girl never "leaned out" certainly doesn't NEED its 4.56s in the 14-bolt and Dana 60 to go along with the Muncie SM465 "granny low" trans and NP205 "HD" transfer case "direct driven" off the trans output shaft with no "coupler" to break under "spirited towing/driving/pulling" and especially not with its "small" stock-size tires and wheels. But like pretty much every 454 Chevy in a "truck" I've ever heard of, it gets 10 mpg loaded or empty, ran hard or babied. And it'll do HELLISH burnouts lighting up ALL FOUR rear tires. The old 454 that has been "rebuilt" with new rings and bearings a few times but never "overhauled" IS fairly "tired" and definitely is probably ready for a "full overhaul" to "freshen up" that old "car motor". And the original "peanut port" truck motor is safely stashed away in another buddy's shop where it "landed" when they jerked that "smog dog" motor out way back when in order to have more "pulling power" for that trailer and backhoe and concrete forms and skid-steer and such. That the "pulling power" increase to what I'm fairly certain is/was an "honest" 350-375 horsepower at maybe 6250 rpm ALSO helped "Old Red" develop a bit of a "reputation" as a "stock class" pulling truck (sled-pulling to "city boys" but just "truck pulling" to the rest of us that knew what it was before diesel pickups became a "thing") not to be fucked with in southeast Nebraska at "farm pulls" back in the day. It STILL kicked ass after sitting in the weeds at ANOTHER buddy's place for several years while he ws the intermediate owner between me and the concrete guy after I "stole" it from him for $2500 and after some "minor" fuel system "upgrades" with a new Holley "blue" pump and pressure regulator and "dual-feed" fuel "log" for the Holley and "updating" and "cleaning out" the "side saddle dual tanks" and "supply line" from tank "splitter" to electric pump got it "running strong" again after getting "embarrassed" with it at its first pull "back in action" where it ran like shit due to my laziness and assumption that it would run good because it always had way back when. And a serious "relaxing" of the "rules" at the local "farm pulls" so duallies were "legal" AS duallies and there was no need to pull the flatbed AND two rear wheels to get it "light enoug" for the 5800 and 6300 lb "stock" classes both with 5800 having gone "bye-bye" definitely made the truck a lot more fun TO PULL and way easier to "look at" since it looked plain goofy all those years as a "chassis cab" with the inside duals removed and the outers dished out as normal to get them "outside" the front wheel tracks. After I got my shit together and fixed the fuel system, we went "undefeated" for the rest of the "season" and nothing came closer than 20 feet and THAT was kind of a "fluke" since at the other three pulls if we won by five feet we won by fifty. Here's a little clip of what a tired old "car motor" just a little "hopped up" in a "work truck from hell" '85 '"tonner duallly 4WD" with all the right parts to hook onto and drag just about anything "mobile" with a place to hook a chain anywhere you want to drag it. 2:42 at THIS video - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE--mYxBqXYy34.html For the record there was no "stock class" so I pulled "exhibition" against and BEAT damned near all the "Modifieds". I also got "DQed" before my exhibition pull for having two "passengers" with me. Including one super-hot MILF I never met before or after that night and one of my TWO priest buddies who "led his flock" including her down to northeast KS from "east central Nebraska" up in "rich farmer country" to see how the "other half" lives and "plays". The "official" DQed me for having passengers and I kind of "rudely" told him I didn't give a shit since I was pulling exhibition and just for "fun" anyway as long as he still let me pull. No problem he said. So we pulled. Pretty damned well, too.
Its damned hard to go that "deep" with a dial bore gauge and get a decent, accurate measurement and the much easier method is to use an ordinary telescoping or "snap" gauge and an outside micrometer so you can get a good "measurement" and then read it properly. The only situation where a BBC is going to have "loose" cam bearings if it came in with "tight" cam bearings is if its a Mark V 454 and the "engine builder" is trying to install Mark IV cam bearings. As for a "snug" but not "tight" cam bearing causing "oil leaks", there isn't any bearing in any engine that ISN'T A BUILT-IN "OIL LEAK" and a "spun" bearing would be the only REAL concern. And if the old bearing was tight, the CORRECT NEW BEARING WILL BE AS WELL. If you INSIST on using "seasoned" blocks and trying to get "super precise" with your poorly chosen and operated "precision measuring tools" you're GOING to find "issues" with dimensions and "tolerances" that are going to be found in even BRAND-NEW ENGINES IF YOU LOOK "HARD" ENOUGH. There's nothing "impressive" or "professional" about "nitpicking" shit at a "customer's" expense when if you want "perfection" you shouldn't be using "seasoned" factory parts in the first place.
