Jim, I certainly concur that the stock main bolts are adaquate up to the power levels you mentioned. Beyond that a main support would be in order as things would really start moving around. We originally ran partial main girdles that supported #2, 3 and 4. This worked very well, the difficulty was fabricating an oil pan with steps to go up and over the girdle. We were probably only in the 560 hp range back then with Stage 2 iron heads and cam lift was never over .600. I recall Jim Bell taking a large screwdriver as Dennis Manner suggested and easily moving the main caps by prying between a crank counterweight and an adjacent main cap. Dennis indicated that even the four bolt blocks were not up to the task as the block webbing was not thick enough. Doug Jones
Apologies to Ray if we're venturing off-topic. I find the subject of main bolts vs. studs in regards to repeatable roundness measurements in the case of the big blocks fascinating; unfortunately there are so many variables involved the "why" may never reveal itself. The fact that enough work's been done by one person to see trends is relevant in my opinion. The broad-sweeping argument that there have not been "failures" attributed to the use of studs, inferring that they therefore must be superior to bolts in this application holds less water than a sieve. I can likewise argue that many engines survive 15,000 mile oil changes without "failure", but in no way is that proof that the practice is not detrimental. There are too many variables in both cases. When another builder publishes similar observations on this subject, we'll have that much more to go on, regardless of whether or not they help to confirm or contradict what we have so far. Frankly I don't care either way, I just want to know more as a career researcher/engineer and big block Buick fan. Let's be more scientific about this and look more closely at what's happening to the main bores dimensionally rather than broadening the subject three orders of magnitude to the subject of engine "failure", a term that wasn't even defined when it was so casually tossed out. That's one helluva leap all by itself. In my opinion, "failure" has already been defined as a condition in which repeatable main bearing bore measurement is not possible within the conditions that were reported. For goodness sake, it's a report of observations, not necessarily those of an experiment using the scientific method. We take what we can get in cases like this, and we should be thankful for the info. Devon
No apologies from anyone needed Devon. I enjoy the responses and reading the practical experience Jim has. This is why I went with the bolts. You sure won't read this in some mag.. Ray
If your housing bores are moving around a bit you may be using the wrong lubricant. Oil is about the worst choice.
We should be more concerned how round the bores are at 5000 rpm, not at rest..... measuring that would be a real challenge!
Here's ARP's chart for moly lube vs oil. http://www.arp-bolts.com/catalog/Catalog.PDF/ARPCatalog_0024.pdf I only use moly lube for all bolts/studs ect on mains, heads, intakes, timing covers ect.. the quick answer is ARP lube and 90 lbs, as the main bolts are 1/2-13 with a factory torque spec of 110 ft/lbs. Lube the threads, and under the bolt heads. It's very important that you tell your machinist that you prefer moly lube and 90 ft lbs on the main bolts. If they use oil and 110 ft lbs, it can be hard for you to duplicate their torque settings, if you try and use moly lube and less torque. A high quality torque wrench is a must of course.. if yours cost less than about $300, you need a better one. This is the one I have had for about 20 years now, and it goes back to Snap on for calibration about once every couple years. http://buy1.snapon.com/catalog/item...2&group_ID=958&store=snapon-store&dir=catalog Mine is actually the 50-250 Ft/lbs version of this type of Snap on torque wrench, but there was no picture on that one. JW
We have the 50-250lbs. Snap-On wrench at work - what I used on my motor. It works great. I also have an older Snap-On torque wrench (TQ-15) that has a dial on it (non-clicking, 0-150lbs.), but only use it for smaller projects. It was my grandpa's and I don't know the last time it was calibrated. Ever hear of "Plum" tools?
Not to hijack but whenever a discussion of main cap walk comes up I'm always amazed no one has ever tried aluminum main caps on a 455. These are pretty common for a 440 mopar to solve main cap walk and extend the HP limit up 200 HP before the main webs crack. They soak up all the harmonics. I know it sounds crazy but it works. http://www.bcrproducts.com/maincaps.html
ARP Ultra-Torque Fastener Assembly Lubricant. Available from TA. I torque mains to 100lbs, gives me room to adjust for bearing clearance. No less than 90lbs, no more than 110lbs. Threaded bosses in the main webs won't take much more than 110. They will crack if over torqued. If anyone has questions about main line or rod housing bores feel free to give me a call.
I've got some Plum tools in storage that were my grandpa's. I think I remember him saying once that they were, basically, bought out by the Snap-On founders when Snap-On got it's start. Not 100% sure, though. Anyway, I'll dig them out sometime and get some pics, then start a new thread. Sorry about the hijack . . .
Be careful. There's threads on SpeedTalk about the "new" ARP moly lube vs. the "old" ARP moly lube. Seems ARP changed the grease formula, which changed the lubricity, which changed the torque values. http://speedtalk.com/forum/viewtopic.php?f=1&t=21728 and http://speedtalk.com/forum/viewtopic.php?f=1&t=22146&hilit=ARP+Moly+LUbe
Holy lifter crash Batman: not if these trends lead us to false conclusions based on inaccurate measures or confounded procedures. This is not a knock on Jim, but not every one can afford a CNC torque measuring machine (like ARP has) at 100K or a team of ME's with PhDs studying these things (like ARP has). Yet, based on these questionable procedures, conditions and measures he recommends against a product on a major Buick website. That is harmful; not relevant. I don't know he would feel the same in their shoes. I do know a representative from ARP (Chris) called me today and was very concerned over the issues in this thread. No, that was your inference. We know head studs are superior main studs as they: "increasing bearing life by preventing main cap walk, while giving additional strength to the bottom end of your engine. Studs will draw down more evenly producing better clamping force." (TA website). Start here maybe? Yes, That is why I have challenged Jim's procedures and measures. How do we know he is measuring what he is measuring, and is there is a failure if we can not trust the meaures or procedures to be accurate? Maybe you missed that part? But is it still a failure if the measuring procedure is actually causing the failure. What degree of change is a failure that has relevance to engine life. I can't imagine a few .0001 would make a difference. Yet this seems to be reason enough to be classified as a failure in the posts above and ultimately disparage the product. So bad information is better then no information? We should take the hard earned reputations of a family business that spends hundreds of thousands of dollars in research lightly when we encourage people not to use this product based on these "observations?" I had an email from one employee and a talk with another from ARP today. They are very proud of their product and the work that goes into them. They wanted to assure me that "they have not heard of any problems with the studs if done properly in this engine" and that they continue to improve their lubricants to reduce torquing issues. The current lubricant torques to the targeted preload on the first torque cycle: more information here. I think there is one apology needed in this thread and it is not from you or to me. I just don't think he is man enough to do it! Cheryl
Babeola, the point we engine builders with lifetimes of experience are trying to make is why spend money on parts that you don't need and could possibly lead to problems in the long run. Studs do not clear stock windage trays without modifications, they can interfere with oil pans, etc.,etc. Please tell us what your personal experience and credentials are.
Cheryl, I would hope ARP is concerned and that they will help in getting to the bottom of this, no matter the outcome. No other fastener supplier has been able to step up the way they have for years. But please try to put an objective hat on right now as I go on. First, we cannot condemn measurements made by Jim or anyone else until we know what the assembly and measurement methods are, instruments used, instrument resolution, calibration, etc. Second, We do not know if ARP has performed their measurements using their equipment on big block Buick engine blocks. If so, how many? If many, what variety of modifications as the ones mentioned by Jim? Therefore, one party's results are as questionable as the other's for lack of information based on the two points above. You or ARP or any other party may not have enough data to scientifically say "we know" because the possibility exists that there are other variables affecting the way the studded big block Buick's main bores behave as designed or with a variety of other block modifications. Scientifically we don't know until we get info regarding my two earlier points. Third repeat: What testing has ARP done on big block Buicks? On how many? If many, with which modifications if any? I did miss your challenge to Jim, because it didn't happen. An impartial and friendly way to do this might have been to say "what is your procedure for measuring the main bores and what instruments are you using? What is their resolution? What is their frequency of calibration?" It seems to me you missed that part, and that may have been a less confrontational way to open that dialogue. Again, we don't know anything about this from any party, Jim and ARP included. Your impartiality is especially important here. We have more than one set of observations now, and they conflict. There is nothing wrong with this, it is interesting and is just as exciting to pursue as if it was one vs. ten or vice versa! What should be interesting and exciting to understand is why one fastener is spot-on and why the generally accepted superior fastener yields the variation. Even if it is a symptom of one party's experience, it is interesting to find out WHY, regardless of the root cause. As an impartial outsider, I don't see disparagement, only one party expressing observations based on their own experience. Personally I like this because it makes me wonder and want to find an answer, regardless of the root cause of a potential problem. I hope ARP's engineers have the same interest, even if the outcome validates their data, or vice versa. Cheryl, we don't know if we have bad or good information. We have observations and from a purely scientific standpoint we need more information from everyone including ARP to even begin to draw any conclusions. ARP's fastener engineering is no doubt incredibly thorough, but I don't know if they have had the opportunity to experiment with a sample size as big as a dedicated, one-make engine builder. Likewise we don't know what our engine builders are using for measurement methods, instruments, etc. For an informative outcome, the bulders and ARP reps need to get their heads together if the interest is there on all sides. This may reveal that there is no problem with the product itself of which they're rightly proud, but with application. Likewise, they may learn that some factors unique to the big block Buick need to be reconsidered. Because of their passion this possibility should be interesting to them. In my opinion there are as of yet no apologies owed to anyone. This may be a chance for us to learn on all sides involved. And for what it's worth, I have ARP rod bolts, head bolts and main studs in my Buick 455 and couldn't be happier with its performance and durability to date. I even torched and beat the hell out of my oil pan in 1986 to make their nuts fit in the front because I believed in the superiority of studs vs. bolts generally (still do); this was before TA worked with ARP for a clearance solution years later. Devon P.S.
Why not spend money on a part that provides increased protection and prevents issues associated with bolts? Maybe the 4 or 5k in a 500-600 HP rebuild is not worth protection? Modifications are generally part of all increased horsepower applications: why avoid them? Studs are proven to be superior to bolts and should be considered to be so until disproven. My issue is that Jim concluded studs should not be used based on limited research without consideration of methodological or confounding issues on his conclusion. It would have been fine to report the observations, but it was irresponsible to draw a conclusion! Although my credentials are not in question here, I am a GSCA member since 1986 and am a performance enthusiast. I have rebuilt and maintained at least 25 Buick engines including the 300, 340, 350, 401, 425, 430, 455 in that time, and had raced a 600+ HP 462 driven to the track in the heavy class for over 5 years every weekend before moving on. You know as a builder that racing requires regular tear-downs for modification and inspection. So, you wind up rebuilding the same engine multiple times and generally have it apart more then together to make it faster. You also find out what parts are not up to the task in short order and sometimes in a spectacular way. Slowly, a time tested basic package evolves. All of my modified rebuilds have included ARP rod bolts/capscrews, main studs and head studs as part of that package. None of these products have failed or caused failure in my performance engines (and I am not nice to them). I am currently interested in SC and TC applications and am involved in a 850 HP 4.6L SC Modular Ford project and a 550 HP 2.5L TC Subaru project. In the case of the 4.6 engine, the head gaskets are failing under extreme boost by actually lifting the head off the cylinder block when stock bolts are used. Studs under the same condition do not allow the head to lift. I will continue to use ARP mains studs, head studs and rod bolts in my modified engines. Good luck to those of you who don't. I do hope that Jim and ARP connect at some point to discuss his concerns and repair damage. I do not have any more to say on the subject as too many projects await. Until next time - Cheryl
Two points need to be clarified: 1. I am a fan of ARP products, and have used hundreds of sets of Main studs, head studs, rod bolts, and the Buick Specific bolts made by ARP for TA in areas like oil pan mounting, timing cover, intake bolts ect. I believe that ARP makes a superior product. 2. I never said that "you should never use ARP Main Studs in a 455 Buick". I challenge anyone to find that statement, word for word, on this, or any other website. What I said was geared to the vast majority of the enthusiasts who read this site. They are not engine builders, and most of them don't even own a dial bore gauge. That's not a knock on them, it's just reality. In a nutshell, I simply said this " I have seen repeatability issues with the block, on a 455, related to the use of main studs." I say this because, over the years, I have seen an occasional issue with main studs in the 400/430/455 engine. Because of this, the average enthusiast in his garage should be wary of them. This guy is relying on his machine shop to find irregularities like this, and not every machine shop out there is going to follow the procedures as they should. So for that guy, building a 500 HP 455 in his garage, because there is a possibility that there could be an issue, that main studs could cause in this engine, and normal "platsicgauge" type checking won't find, it might be better for him just to stick to the very good Buick Main bolts for his engine. Especially at that type of power level. I have a proven, verifiable track record of 550+ HP engines with factory main bolts, to back up that statement. And probably the most accomplished builder of the 455, "back in the day" when the cars were new, Doug Jones, seems to hold the opinion that at the power levels we are discussing here, studs are not required. That is enough for the wise reader to see, and understand that he can get studs and put them in his mains, and he might be just fine. But he needs to be aware that there could be an issue, and to be wary of it. Or, because of this awareness of the issue, he discusses it with his machinist, to avoid any potential problems. And to also understand that there are those knowledgeable, experienced folks out there, that will tell him he doesn't need them. The weak main webs will fail before you walk a main cap enough to hurt the bearing. ______________ Now.. all that being said.. Two things need to be added to the discussion. 1. If there was never an issue, why would ARP go to the lengths they apparently have, to create this new "Ultra Lube"? They apparently have tracked the problems that they have seen with bolt stretch and bore size repeatability, to the lubricant used. 2. Being always open to new information and products, I already have secured the new "Ultra Lube" from ARP, and we will be using it on upcoming engine builds, with both studs and bolts in the mains, to evaluate it's effectiveness. While I stand by my statement that studs are not required up to 600 HP, I am interested in the use of this new product, for the block girdle motors that I build, which of course have to have studs. And I will give it a shot on the bolt motors, there is no reason not to use the best materials out there, to achieve the most consistent results. And even on those motors, if ARP Main studs, used with their ultra lube, provide the best results, then that is exactly what TSP motors will have in them. JW
Thanks, Jim! The air needed some clearing. There must be a reason why ARP makes bolts for the Buick 455 mains. That's what I have in mine. http://www.summitracing.com/parts/ARP-125-5201/
Personally, all this ARP stuff and bolt vs stud stuff aside, I like how a woman, who has ZERO EXPERIENCE BEING A MAN, is questioning the manhood of someone who has been a man for decades. Nothing makes me laugh in a woman's face harder than when they try to get all uppity and attempt an insult by trying to subject a man's "manhood" to doubt. It's the most pathetic, petty, and down right ABSURD attempt at an insult I've seen any adult try to pull. Personally, a certain someone seems to have a deeply centered issue for some other male in her past and is targeting JW as a likeness of said foe from yesterday. Was it dad? A boyfriend that made her feel like a princess til she finally put out and got dumped? A teacher that ignored come-ons that seemed immature? We'll probably never know! As for someone's veneration of levels of education... as a college student, I've personally met some PHDs that have made mistakes. I've had medical doctors be wrong, Ive had a professor who had a PHD in english linguistics (this guy could dissect a sentence in ways that blew my mind) still speak with faulty grammar, I've had history professors that were mistaken on something they were fairly positive about from the same material they taught. Graduate level educations do not make you some mystical being that is impervious to mistakes. And lacking that level of education doesnt make someone a fool either, look at bill gates, einstein, edison. And I find it more absurd at the simple faith put into any company, regardless of its prosperity or lengthy success. Look at Ford or Toyota and their recall monsters. Look at Firestone back around the turn of the century. PS I like making indirect and subtle insults that make me feel smart for making, like it makes me all superior and stuff while putting the other person down, so that I am doubly above them, muahaha! :TU: btw that absurd statement was made with 100% sarcasm. The theme here is absurd, if anyone failed to notice.
