The Stovebolt Site Forums The Shop Area Engine Shop where to find GOOD main caps bolts for 292?

:confused:

Of course I could order from the dealership, but they want 2.79 per bolt, plus 3.50 for oil pickup stud.

Any place on the web? I tried Summit and all their ARP bolts were for the v8.

Thanks!

ftyler: go to site- www.arp-bolts.com

order the complete set from the factory. There will be freight cost involved being shipped from California to you. Don't hassle with your old worn and abused bolts, just toss them. You will have piece of mind and know you did the right thing. Used main bolts that have overtightened and or abused are highly suspect.

Bolt stretch (often referred to as yield) is defined as the bolt stretching to a length beyond where it is able to return to it's original length, when loosened. All bolts have a recommended torque value, based on diameter and material composition. From mild steel (30,000psi)
to aircraft alloy (over 200,000psi) ratings. When this proper torque value is reached, the bolt will have stretched to it's peak length, typically 75% of the yield length/strength. Any more torque and the bolt will not return to the proper length, and is toast. This torque value is determinded by Chevrolet engineers during the design of the bolt and the part and the stresses that the part most undergo.

Too much torque, and the bolt will yield, or permanently stretch and lose it's holding ability.
Too little torque, and the bolt may loosen and may unseat the main cap and cause bearing and or crank damage. This condition also puts great strain on the other bolt on the cap as this will put a sideload stresses on the cap and bolt. As you can see either of these conditions will lead to bolt and/or other part failures.

Point to remember- Bolts are rated in psi (pounds per square inch), which equate roughly to the amount of force needed to literally stretch or pull the bolt apart. As this psi rating increases so does the tightening torque needed to put the proper amount of optimized stretch or (preload) on the bolt. This higher rating will also put a greater clamp load on the part because of the higher load holding ability of the higher rated bolt. Also with the higher rating this means the bolt material is that much tougher and harder, and will be able to withstand greater shock and
thrust loading.

Always clean and chase all threaded holes. All threaded holes in the block should be chased with the appropriate size tap. First use a pick, or small screwdriver and dig the crud out of the bottom of blind holes. Then use a good quality bottoming tap to clean and straighten out the threads. Use care not to remove any material as all you want is to clean the threads to fit your new bolts. Always oil the threads, when you torque any bolts, as dry threads or damaged will yield false readings and fail.

Follow ARP torque recommendations as they may be higher than stock hardware. Piece of cake!

Good Luck!

Think Chevy!

Thanks for all the information, Chevyman.

It appears that ARP is a wholesaler and doesn't sell directly to the public. They don't have a price list or a means to place an order online. Unless I missed something. :confused:

Give them a call. I know I can buy the through a local parts store.

This was on your other thread. 53 4 me is right. Torque them dry - NO OIL. And as Chevyman said, do clean and chase the threads.
This is my opinion.
You're rebuilding a stock engine, right. Go to the wrecking yard. Pull a couple bolts out of a 250, put them in and forget about it. This a stovebolt rebuild, not a NASA project. I broke the stud off my oil pickup stud/bolt 10 years ago and I sleep nights with a used bolt in there.

In that case Richard, why not just pick up a pair of "hardened" bolts from Ace Hardware and use? Just grab a manufacturers bolt from one of the other mains and use it along with it.

I'm actually not going this route, someone suggested to me. A MACHINE SHOP at that! Supposedly very reputable in my area too.

I was (and still may) replace all the main bolts. I'll pick up a couple new at the dealership at a minimum.

Thanks,
ftyler

The extra rigidity of the new bolts will ofcourse throw the internal balance off and most likely back out the left handed thrust bearings.

I would find bolts with similar age and kharma and stop at 65 lbs this time.

ftyler: Hello again. I checked back on a couple of your past posts to see if I could figure the status of your rebuild, and exactly where you are in regards with your project. I don't know exactly what you have done yourself, and/or what you may have jobbed out to a machine shop, and/or what fasteners you/they may or may not have replaced?

I did read your post about over doing things, and having to remove the broken bolts. Don't know what else in your 292 that you may have overdone (too much torque), or possibly reused as far as bolts that may be suspect or might cause failure?

As a general rule in engine rebuilding there are four areas in the engine where the bolts are under constant stress and load. In order of stress loads and fatigue they are-

1. rod bolts (all)

2. head bolts (thermal,distortion)

3. main caps (all)

4. valve train (thermal,distortion)

Bolts used in these areas are subject to thermal expansion, cyclic thrusting, shock loading, side loading, and distortion. Bolts can distort by any or all of these effects. To eliminate any suspect fasteners and the possible effects of failures of same, it is standard practice to replace them with new.

If you have not properly prepped your block with regards to cleaning/chasing the bolt holes on the mains or deck, or you have assembled your block with stretched or suspect rod bolts, or maybe you possibly have mis-torqued somewhere along the way you should stop where you are and take stock of what's happening. All your hard work and bucks may end up along side the road, BROKEN. If you have any suspect hardware, just toss it. Not worth the risk of future trobles.

Contact ARP by phone and talk with them. They will do you right. They may not have 292 listed, but I know for a fact they sell just about any diameter and length bolt or stud you could need. Talk with them and tell them your needs. They have the resources and technical people to help you. They can fill your order and ship direct to you or the nearest dealer to you. Follow there advise, and you can't go wrong.

To you others that responded to this post: I realise that this is a Chevy engine and not NASA! But all Chevy engines are only as good and dependable/reliable as the parts and pieces of the whole. And most importantly the craftmanship that is applied to those parts and the assembly.

I work in an automotive machine shop. I have been a machinist all my adult life. I have assembled many, many engines. I have machined several hundred engine blocks and heads through the years, so I think I might know a little of what I am talking about. I realize that we all mis-speak, or are in error on occasion. But I try to share my knowledge and imput when and where I can with some on the board that have questions. I do try to give the facts as I know them.

For all interested to know the proper procedure on the installation of either headbolts and/or main bolts, go to site- www.arp-bolts.com

and click on products.Check out the main bolt,
headbolt installation procedures as per ARP. They explain about chasing the threads with a tap, and
to lube the bolts before installation. They reccommend a Moly lube that they sell as they say it will give more accurate torque readings. ARP is the standard of the industry, as there are millions of engines with there products in them. I think they could be on to something!
Thanks for listening.

Think Chevy! :rolleyes:

Regarding the advice to replace suspect bolts, sounds like good advice to me. Some may have read about my rebuilt 235 which is now toasted because of a broken lock wahser on the rod's small end pinch bolt. Not only elongated the small end of the rod but the wrist pin did a number on my cylinder wall. 5 cent lock wahser-$1500 rebuild toasted all in the time it took to shut it down from 3500 rpm. Sooo, anyone know if replacemt rod bolts are available for a 261 I'm now building. They are a odd looking bolt on the big end.

Grant: I know of a stroker shop that rebuilds the 235 and 261 rods. Go to site-

www.speedomotive.com

They rework these rods, and also sell crank kits and master rebuild kits for these engines. I am not sure whom they would source 261 rod bolts and clamp bolts from, maybe ARP or Eagle, but you should inquire. Give them a call. They do excellent work and I have purchased several kits from them and used there services on many occasions. This is the same shop that is doing Ken's 292 rods/pistons. Good Luck!

Think Chevy!

ARP will sell you anything in their catalog. Just call and talk to somebody in their tech department.

Grant, several inliners have reported that Chevy big block rod bolts can be used in a 261 with a minor mod to clear the camshaft. Might be worth looking into.