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I've got 6th edition Chevy power book, printed in 1988. I just went through it and there is no mention of the 010 or 020 blocks anywhere. When it talks about block selection, it mentions only checking for a good core based on block condition, cracks, core shift, etc. It then goes on to talk about the benefits of bowtie blocks, or aluminum blocks. The 1988 version makes no distinction between the 010 and any other blocks.
 

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David Vizard makes note of it in one of his books. If it has both 010 and 020 then its 1% tin and 2% Nickel in the casting, which according to him, the tin helps the actual casting process resulting in a more consistent pour. If it only has 010 or 020 then its 1% or 2% Nickel with no tin. ;) (I had to get out one of my books to refresh my memory about the tin part lol).
 

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Torquing the Mains

Boy do I feel dumb!:mad: Torquing the mains on my Gen 2 small block and twisted off one of the bolts. I'm using a torsion-bar wrench (not a clicker) and was going stages up to 80 lbs. One of the bolts on #1 just twisted right off at about 75-78#. Fortunately, I felt it begin to go and was able to back it all out in one piece. I guess I should feel glad that it happened now instead of later when it was running, but dude!! It has been a while (OK...a LONG while) since I last rebuilt an engine, but I like to think I am pretty good at following directions.:(

Am I torquing them too much?? 80# is what the manual I have says to use. Now I am wondering if I should replace just that one or all of them. What do you think??:confused:

I have read that if you change to main studs you should have it align-bored with them in place. Any opinions on that?

Thanks.......bummed:(

Dave
 

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Did you lube the threads and top of the bolts? Using a old beam torque wrench is like using a hatchet for brain surgery.......LOL. Old books say SB mains are 80 but the newer books say 70 for a SB. If it was me I'd go buy a new set of bolts, lube the threads with 30 wt oil and using a good clicker torque wrench torque them at 70 ft lbs. I torque 4 bolt SB mains at 75 and 65. and I use a Snap On clicker. I snug them up then go 40 lbs then torque to spec and don't have any issues. That would be my suggestion. RM
 

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Was you using oil or moly lube? the tourque specs are considerly different. I'm no expert by any means,but if the spec was for oil and you used moly lube, I would think that could have been the cause.
If you change over to studs you should have it align honed,the studs distribute the load different than the bolts and could pull things out of round.
Also if you go that route make sure you get a shorter timing set for align honed blocks because that process reduces the distance between the crank and the cam. don't make the same mistake I did,I went with a standard length set(I didn't know) It was borderline when I put it on but I thought it would be alright,after six 1/8 mile passes I put a timing light on it and and you would not believe how much it was moving around! I pulled the cover and the chain had 3 times the slop it had when i put it on. I changed it to a 5 thousanth shorter set and the timing is rock solid.
Gary
 

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I was using 30w not moly. Chased the threads and all. I guess I'll spring for a clicker but I honestly thought a beam (old but cared for, and a craftsman at that) was just as good if you knew how to use it.

Thanks for your advice. I'll stay with the bolts and stop at 70# next time.

But seriously, is a clicker better? I have heard they get off over time.:confused:

Dave
 

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Summit sells an ARP main bolt kit for $27.95 for 4 bolt mains and $17.88 for 2 bolt mains for SB. If you don't feel comfortable with the ones you have that is cheap insurance with the new bolts. Clicker torque wrenches are pretty reliable. I had one checked for calibration after about 15 years and it was only off by an avg of 2 ft lb over the range.
 

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Make sure you always leave it stored at zero! I left mine in the box at 75lbs. between engine builds. While cranking down the rod bolts(small journal) on one of my 391's.....SNAP!! AAARRRGGHH!!!! New rod bolts, re-grind the bolt heads for cam clearance, balance...........Cranking down the head bolts after repairing the other damage.........Pulled the threads out of the block because bolts were too short with new World Products heads AAAARRRRGGGGHHHH!!!!! Heli-coil the block, buy new head bolts..................................
 

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A beam torque wrench is reliable but a human isn't. It is hard to see the scale and be accurate and the clicker is a no brainer. The SnapOn torque wrench I use for motors and critical stuff stays in the cabinet. I use a decent Sears and a couple Harbor Freight cheapos for everything else. SnapOn checked and recalibrated mine once. RM
 

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Only some 10% of the applied torque generates preload - and herein lies the cause of most joint problems. Preload is what's left of the tightening torque after friction has absorbed the lion's share, since preload cannot be induced until motion has occurred. Anticipated variations in the coefficient of friction will thus have a marked effect upon the preload, and careful calibration of the torque wrench will do little to improve preload accuracy.

http://www.mech.uwa.edu.au/DANotes/threads/preload/preload.html

 

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Hello,

I agree with mike that the under head friction is what really throws off proper preload of the fastener when using a torque wrench. If you use the matching lubricant to what the torque spec was created with its generally (at least in my experience) pretty close.

As far as the torque wrenches are concerned, I have a bench mounted tester that I use to check wrenches, and I find a lot of variation in some of the clicker style wrenches. The Craftsman wrenches with the small windows you look through are about the worst, I will not even let any of those in my shop. The snap on wrenches with the adjustment on the side are very reliable as long as you never use them in a counter clock wise direction. If you do it may through the calibration way off. The dial type are generally the most dependable in my experience, but I agree with you that the beam style wrench should have been pretty close, if you can get the correct viewing angle.

It may have just been a defective bolt. I would certainly feel better with a new set. I not sure the ARP (i know this will be controversial) bolts distort the mains as much as is generally feared (studs seem much worse on distortion-but still not generally as much as implied). I have checked a lot of blocks that have been converted to the ARP bolts and (knock on wood) found very little difference in bore concentricity. Im not against align honing the blocks, I just don't think a simple fastener upgrade "always" makes it a "must". I guess this is just my opinions I'm not making a recommendation either way-- you can check the bores with a gage before and after- but it takes a good gage and some time.
Good luck
Jeff
 

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I was helping my brother put together his LT-1 350 years ago. It used a windage tray and one of his bolts snapped in two torquing them down. The bolt snapped off at about 40lbs on the first round of tightening down. Hw replaced all the bolts before final assembly. I think bolts are like anything else; sometimes you get one thats bad.
 

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Well I just ordered a set of ARP bolts and a clicker torque wrench from Summit. That may have been the only bad bolt but for $17 and change it is a no brainer to replace all of them. I know this engine was rebuilt once before I got it and did the machine work on it, so I'm thinking someone may have gotten enthusiastic when they put it back together before. I should have just replaced them to begin with...duh!! I feel d**n lucky that I felt it go and was able to back the whole bolt out of the hole. With these replaced it means every bolt in the engine is a new ARP. Just dumb of me not to replace these when I did all the rest.:(

Thanks for all your advice on this.

Dave
 

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Bolts fatigue over time and repeated loading. Bolts are like very heavy springs. Every time you torque them they stretch (elongation).
Bolts, Springs or paper clips all have a finite life (2) as stress can build up and exceed limits (4). You can stretch them only so many times before they break (5). Prior to breaking the material Yields (3) or doesn't spring back to it's original shape.

This is when the bolt feels like it's not tightening or the bolt stretches longer than normal.
If you have any bolt that Yields then you should replace ALL of them.
 

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Hi Guys,

Not to be down grading tools, but if the clicker torque wrench is an import I would rather use your old beam style. The imports are all over the place, even when brand new. If you dont want to buy a Snap On or Mac etc. (and I dont blame you) SK and the standard style Craftsman seem to be OK.

Im certainly no expert on fasteners (or any thing for that matter), but I think a lot of fasteners (especially automotive) must have a specific amount of elasticity in them at their specified stretch (torque spec?). I have seen several applications where a fastener that had too little elasticity cause failure. An example would be a head bolt where expansion of the head at temperature and load will actually pull the threads in the block because the bolt would not flex with the head.

I personally will not use a fastener higher than a grade 5 on a cast exhaust manifold. I have seen a lot of harder bolts actually break their heads off after a few cycles of heating and cooling. The manifold will expand and basically the bolt wont match it and something has to give.

I really like to leave the design of the bolts up to the experts. I wont even use a couple brands of aftermarket bolts because of what I perceive as poor quality. ARP seems to be about as good as you can get at reasonable money.
Just my opinions

Good Luck
Jeff
 

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Cornwell Quality Tools
667 SEVILLE ROAD
WADSWORTH, OH 44281
TEL: (330) 336-3506
FAX: (330) 336-3337
 

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Yesterday the new torque wrench and mains bolts arrived from Summit.

SWEET!!:D I LOOOOVE that wrench!! Micrometer adjustable, so easy to use, what a difference it makes. Followed the ARP instructions, used their lube and torqued the bolts to 65#. Slick!! What a difference a good tool makes!!

Thanks guys!

Dave
 

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I love tools:D If I was a billionaire I'd buy a new tool every day, like drinking a cup of good coffee. :) RM
 

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That is so true, Mac!! It just felt like an early Christmas!!:D :D :D

Dave
 
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