I'll leave my information intact, but won't comment further in this thread. I don't want to start an argument or create a distraction from the issues that need addressing here, and so will let the others fill in the blanks with information. Oiling mods are great, grind your crank to whatever it needs, if it needs it. Check and double check everything for correctness and accuracy (even information--especially information). Bore it, stroke it, fill it, use 5 sets of bearings so each one is perfect with the rest, forged rods and pistons, mill the block and heads and get your compression ratio within .000000001:1 variance so you'll be safe with your stock engine revving to 5000. My information still stands and I hold fast to it (unless it can be proven inaccurate, then I will happily concede and will be all the better for it). Everyone likes to make sure everything is safe (engine builders should always over-engineer/compensate so their reputations are not tarnished and/or destroyed) and this is no exception. Auf Wiedersehen und gute Nacht, Gentlemen.
I must of missed where someone called a sbb a piece of junk? The 12" oil passage from the front of the block to the around 4" deep hole where the pickup mounts to is ONLY 7/16" diameter!(not 1/2", if in it were that would of been ok) Sure its big enough to suck oil in but only just barely enough for the RPM it was designed to run because that's how the bean counters let them do things. I'm sure the train drivers wanted that hole drilled out larger but the bean counters seen an opportunity to save a couple of pennies per block with one less drilling operation.(that hole is NOT cast in the block) Another thing, drilling the oil passages does NOT increase the oil pressure as some people are writing, it increases the oil volume. The bearing clearances still dictate actual oil "pressure". Extra volume will aid in oil pressure recovery because of the increased volume being sent to the engine though, which means the oil will get to the bearings faster. Increasing the pickup passage in the block makes it easier on the front cam bearing, distributor gear and the oil pump gears & housing because of the extra volume available that is easier to pull in with a larger pickup diameter so less strain on the mentioned components. That's why Guy Fox can get away with using the high volume pump for 20 years in his sbb 350 because of the oil mods that were done so there is less strain on the oil pump drive parts. I really don't see any downside to doing them, especially when the block stripped down all the way. Don't get me wrong though, if its a "stock" already running engine I wouldn't go out of my way to strip the block all the way down to do the mods. Unless it needed to be stripped down all the way for an unrelated issue then I wouldn't hesitate to do them while it was apart.
I don't think anyone is suggesting the need for ultra-micron-super-magnified accurate machining here. There were preferred tolerance suggestions to ensure good oil pressure from people really knowledgeable on the subject. If the two entities (OP and shop) were using the same micrometer, it is literally a mile wide target to hit with a grinder. Easy-peasy right? No. I've already discussed what happens when that theory and the real world meet... and how common it is. The OP has concerns and originally intended a backup plan to ship the crank back and forth a second time(!)...despite the desire for an extremely tight budget. If that happens, he may as well have bought a custom stroker crank. Bye-bye cheap SOB budget The OP has to ship stuff around the globe to stay with his Buick. The normal tolerance range encountered with a simple crank grind and accompanying assembly 'could' present problems. I've already opined that 'it would run...' with light scoring and no grinding. Hey...the OP has a lathe. How about a light polish and call that part good? (gaaasp! it's not done 'right'!) Look that up on the 'Net, it's been done for a hundred years. You don't even need to worry about the social pressures of NOT using a CNC crank polisher....because nobody does that! Of course the crank doesn't need .020" ground off of it! I just personally don't care how much is removed from that inanimate piece of metal and it was a suggestion to ensure success the first time....based on the OP's concern for not seeing any scoring or battle scars after the first British tour . How many times does the forum see the dreaded second trip to the machine shop and associated frustration? Just offering an idea to make the ordeal less frustrating, sheesh.................... Can anyone imagine a garage full of fellows after a few empty kegs trying to either rebuild this using a hacksaw blade, chisel and bench grinder or maybe YouTube a hydrogen conversion?
Guys, guys, guys!! please.. don't start fighting.. I get all the information you say, it has been an awesome learning curve for me, and I thank you all for so many options on what to do. Believe me, this engine will not be revved and trashed.. I have spent 2 years driving it a long like a granny. I don't drive fast, I dont rev it high at all. Most of the time I have my 6 year old daughter with me.. I live in the middle of the country side, in England! not the US... the roads are narrow and twisty, not long straight roads like over there. I have no power steering, no power brakes, no top of the range suspension... I have to be careful in the way I drive.. the only time this engine gets a bit of revving is when I spin the wheels coming off the traffic lights. I think some of you are giving the advice (which is good advice and I appreciate it) taking in account probably the way you drive and you use your cars.... that's not me at all. it's also a 5.7L V8... does around 12mpg... the petrol over here is really expensive! so can't afford to be driving like a lunatic everywhere hahahaha I don't want to lose any of you to this thread as you have been so helpful. we are almost there on this journey... I will do the crank as you say. As now thinking about it, it does make sense. Get the bearings, torque them down, measure it all, tell the machine shop how much to grind off each journal. I'm going to my friend hot rod shop today, that's where I left the crank to be sent off. he rebuilds engines all the time, but I want to do this on my own. I will ask him for advice on this crank/bearings matter. Please... let's all keep together on this one. and bear in mind this engine will see very little abuse.... that's why it survived 2 years with all that junk in the oil pickup.
My post was meant with 100% sarcasm and humor, nobody is mad at each other When you send your crank on that countryside vacation tour, could you grab Robin Trower's autograph? Always wanted that one.
Ah well. Please accept my apologies if I upset or offended anyone. As anyone can attest to who's been here a while, we all do MUCH better at conversations than we used to! haha I'm still standing by my statements on oiling for a stock/mild engine. The big blocks were the ones with marginal oiling, and this was for performance oriented engines. The small blocks, to the best of my knowledge, do not need a thing other than making sure the oil pressure is adequate and you do the usual bearing check for orifice alignment and chamfer where needed. The (older) stock cams are well capable of revving to levels the 212 can do. My point here being simply that it's overkill to mod the oiling further for this particular application, but hey it certainly won't hurt it. This group of people are awesome, knowledgeable, and offer up great advice. None of the information here is too far off the mark, though we can all differ in opinions from time to time. Either way you choose to go, you'll be fine. Peace!
There's no downsides, the debate is whether or not it is necessary for stock-moderate engines never seeing past 5500 RPM (pick your cam). Using Guy's engine is a nice example of how a good oiling system for a performance engine should be, but his engine is FAR from stock and he revs it well past 6000 on his shift points. On this particular build, it would be highly recommended for oiling mods. A few things to consider: 1) what you say about the bean counters and the holes having to be drilled post casting does make perfect sense, so I'll give ya that one. Even if it's not completely accurate, it does have merit. 2) even at 7/16 it was still adequate for the intended purposes, which was 5500 RPM or less. Every running, non-bearing-spun Buick 350 in production is testament to this. 3) the reason it was drilled out larger with a larger pickup later on for post 'black air' engines was simply the increase in power levels seen on turbo v6's which could out-perform big blocks with a few simple modifications. The strain on the oiling system to keep that turbo cool would have definitely called for more oil volume, not to mention the added stress on the bearings. If oiling mods existed prior to this, it would have probably been due to standard protocol and tooling mods to blocks across the board to keep things simpler and more cost effective, in anticipation of the upcoming turbo Buicks. (wasn't there a turbo v6 made in '76? This would have certainly been about the time all engines saw oiling improvements, not just the v6's, which reinforces my point)... 4) the front cam bearing wearing is the number one problem with ALL Buick engines, which is a problem mainly deriving from the locations of the orifices and lack of groove, not the oil journals (again, for sub 5500 RPM usage) 5) it would be nice to know the exact threshold where oiling modifications were actually needed for higher-end power builds, instead of doing it all across the board on every engine build, much like using more expensive parts when cheaper ones would be perfectly fine for the particular application (forged rods, pistons, etc. etc. on a stock/mild engine that would seldom see past 5000 is a waste (imo), for example). Outside of this, it simply becomes a matter of preference for a stock or mild rebuild, and not a requirement, as was the previous innuendo. Good conversation here guys. I appreciate all the dialog.
I've said before, but the new "like" feature seems to help appease the conflicts. It's entirely possible to enjoy someone's post and add your own from an completely different perspective. I think that before you could "like" someone's post, they probably thought the drastically different point of views expressed meant outright disagreement and an insulting demeanor.
I find that highly insulting. (Nah, just kidding.) I understand Gary's point of view, do not agree with it, but that's coming from the BOPR perspective (Buick, Olds, Pontiac 215-V8, Rover V8) which are also part of the SBB family. They DO very definitely have oiling problems and so I have a little trouble seeing where the 300, 340 and 350 would be much different. It's not worth arguing about though because a little insurance is a good thing. However, insurance used to be discretionary and if you didn't want it you could take your chances. I miss those days and respect other's wishes to do as they please. However, BOPR owners also spout this drivel about the factory assembly being good enough, and it isn't. Not even close. So I'm a little prejudiced in that regard and I didn't mean the word "drivel" as giving offense, it just seems like the right word. Sorry Gary. Didn't mean to piss you off (If in fact I did). Personally, I find the oiling mods take so little extra effort and expense that I would never build an engine without them. I've just seen too much difference in oil pressures to ever feel comfortable below a certain level, regardless of what the engine was to be used for. YMMV obviously. Also never meant it to be taken that a bigger suction galley boosted oil pressure, what I mean is that if you do not cavitate the pump trying to suck goo through a straw it will make more pressure. Why not make it easy on the beast? But seriously, an easy supply and tight bearings will do more for oil pressure that everything else combined. Seen it over and over again. So why not do it? Frankly I'm amazed that in the UK a crank grinder is not within driving distance, but I'm here, you're there. Do you have gage blocks? Often 2 and up micrometers come with them, or you can buy them from Shars or somebody cheap. Practice with them until you hit the zero mark every time before you do your measurements. The snap gages are the trickiest part but this can be done, you just need an accurate reference. Jim
Thanks for mentioning my oil mods, and I do think that is why it had lasted this long. I tried to use 4 qts of 15-50 Mobile One and 3 qts of 10-30 mobile One and I had oil pressures going up to 80 just off idle at about 1000 rpm so I went back to 2 qts of 15-50 and 4 qts of 10-30, that knocked the pressure back down some. Here is a pic of one of the oil mods that was done, I think this got drilled to the crank to make sure it got oil to the crank no matter what. To tell you the truth on this I am not sure if this is correct as it has been over 20 years. I do run the larger gears and I have not noticed any wear on the cam or the dist gear. I put some pics of this in my SP3 install section. So if you want the engine to last forever do the oil mods, but if you are close to stock and plan on not revving as high as I do then just do the plate on the pump reset the gears to the cover with the correct gasket and you will be good to go. It took me 10 years on a near stock engine to break it and I ran it fairly hard. I had 150,000+ miles on the original motor before I had it rebuilt 20 years ago.
I'm not pissed at anyone. <--see, smiley face. I'll let all the Buick 350s speak for themselves. We all know about how often we hear/see/read about spun bearings due to oiling inadequacies on stock-moderate engines that wasn't the cause of taking RPMs too high on a relatively large camshaft capable of sending the engine that far up. There are issues to be sure, but its usually due to the cam bearing oversight. Oil pressure irregularities can come from a few reasons, which is why TA offers up an 'oiling recipe' using an oil pump booster plate and an adjustable pressure regulator, which solves a lot. Let's not forget the aluminum timing cover that all Buick's share, which is another issue, and can usually be solved with the aforementioned oiling recipe. All these things can add up to poor oiling, and it isn't because of the oiling journals being used on stock engines. Even with all this, still no spun bearings. We only read about this sort of thing with engines regularly taken to the track or otherwise ran hard using aftermarket parts to make them go faster and make more power (and always when being spun over 5500 on a regular basis), but never for a stock-moderate engine. Fixing a few things will go a long way, even if you don't hog out the oil journals on stock-moderate builds. In fact, even if you did hog out the journals, you'll still need to address all other things or your journal mods will be for naught. I wonder where the real issues lie then, hmm? You're free to disagree with this all you want though. lol But then, how often do people build these engines wanting to push them and see how much they'll do? Of course there will be modifications one would want to do in this case, and for every engine, so I think this whole oiling issue is stemming out of some biased points of view, which is understandable. Anyway, more drivel from Gary. haha (edit: typos)
My viewpoint is biased. I'll admit it. But in my experience a gear pump isn't great at creating suction so I really scratch my head when I look at the 7/16" suction journal to the pickup and wonder why. The conclusion I reach is that they really must have kept the engine clearances very tight when they built them to keep the oil from escaping on the pressure side, and that is born out by the factory tolerance specs. So here we have a situation where, because of the need to ship out the crank for grinding he's got to open up his bearing tolerances to avoid doing the job twice, plus normal wear everywhere else in the engine where oil can get out, and suddenly that 7/16 feed line doesn't look so good. Lots of people don't have a clue how much more oil will flow out of a bearing with .002 clearance than one with .001 but it can easily be ten times as much. You do that with 9 bearings and all of a sudden that flow that was adequate no longer is. All I'm saying is that it's cheap and easy insurance. 5 minutes with a hand drill and the other mods don't take much longer. Altogether I might have an hour in it, and I see good oil pressure across the board. That gives me a lot of peace of mind. I've built engines where I only did part of the job, and only got part of the results. And I worry that the oil pressure might drop below acceptable levels. Personally I'd rather not worry. Jim
I think you hit the nail on the head there Jim.(Buick pun intended even though a sbb isn't a Nailhead) I definitely would want more volume of oil sent through the engine to ensure it lives that I did all that work to! And like you said, its an easy to do mod. Another point to consider combined with what I previously mentioned in an earlier post than less stress on the gear drive parts and supporting parts(the front cam bearing) is with the suction holes opened up is it takes less power to spin the pump so how much HP is not being taken away now from the less drag from those components? If anyone has primed a sbb with and without the oil mods with a powerful hand drill would notice how the engine without the mods the drill tries to break your wrist because of the resistance when the drill's trigger is pulled all the way. The same setup with the oil mods done there is WAY less twisting of the drill motor when the trigger is pulled. This simple example is telling me that oil is getting to the 18(not 9) bearings faster because of the less resistance.(5 main bearing, 5 cam bearings and 8 rod bearings) There is another point that "the stock oiling is good enough" people have not considered with a rebuild that doesn't get the clearances refreshed; The lifter bores. If there is wear in the lifter bores, that will bleed oil pressure like Jim mentioned, as much as 10 times faster with an extra .001" more clearance! Not very many people have bushings installed in the lifter bores with a rebuild to restore the clearance there. The extra volume with the mods would go a long way even with the proper bearing clearances to compensate for the loss of pressure there. More ways to loose oil pressure than just from bad bearing clearances. If the oil mods weren't a good idea to do when the block is already stripped down anyways, I wouldn't recommend doing them. But they are a good idea to do as well as easy to do so that's why I recommend doing them even for a "mild" or "stock" rebuild. Tearing a factory "stock" engine down to just do the oil mods and assemble the original parts back in is something I would NOT recommend doing. Only if the engine needs to be taken down to the bare block is when I recommend doing the mods for any kind of rebuild with any kind of parts being used("stock" replacement, aftermarket or custom). Its always a good idea to take the weak link out of the equation or upgrade(update) a poor design. Its bad enough that these engines don't have main priority oiling systems, they're combined with the dinky 7/16" 4" hole with a 90* turn to a 12" 7/16" suction hole before a couple more extreme angles until it even gets to the oil pump through the timing cover. Dealers choice. GL
I guess the Buick engineers had something figured out, even if we scratch our heads trying to keep up with their thinking. Nothing wrong with improving anything, if it in fact needs it. Protect your reputation and hog out oiling journals for stock 4500 rebuilds. It won't make it last any longer when it isn't a required modification, however. What it WILL do is save your ass should something go wrong with one of your customer's cars. Spinning your engine beyond 5500 RPM regularly and/or putting boost to it or otherwise making serious power? Absolutely use oil mods. You can't convince me thousands upon thousands of stock Buick 350s with no spun bearings are ticking time bombs that never went off and we all need to wipe the sweat from our brows and thank the gods they managed to last this long until we could come along and 'fix' them.
Trying to be the voice of reason and get both views to see the other side here... Rebuilt engines have areas that are worn, and not addressed at time of rebuild. Factory engines are more often tolerance matched than 'all over the place', like rebuilds are (more often than not). This includes lifter bodies, oil pump end clearance, bearing clearance....etc. While working for an OEM, I dealt with entire batches of parts sometimes made out of tolerance for one reason or another. One way to 'save them' was to make a batch of mating parts on the other end of it's tolerance spectrum. Imagine if this were a rebuildable thing like an engine and the problems it might cause. Under this paradigm, the example of a perfectly operating and long lasting factory engine rings true. Also under this paradigm, local shop machined rebuilt or home assembled engines suffer various failures the assembler never quite solves, and sees as various shortcomings and trouble spots.
I pretty much see things the same way. No need whatsoever to worry about an engine that is making good oil pressure. Never said that. But if it has to be torn down, like Derek said why not take out the weak link? I think that's what we're talking about in this case, and whether the pickup was the problem or just part of it, the fact remains that this particular engine did have an oil pressure problem. So why gamble? Especially if you are already throwing the dice with the crank. All I'm saying is that it IS a recognized issue with rebuilds. Heck we always have a few threads about low oil pressure on this forum, do we not? Jim
