Jackrabbit501

iTrader: (3)

Hey guys, went to install the heads on my sbc and started to torque them, the lower bolts (outside valve covers) started stripping. First one of them stripped only at 25 ft lbs, I helicoiled it and it felt fine afterwards. The rest couldnt make it to the 60 ft lbs.

So heres the question, should I go ahead and helicoil all the outside holes? Seems a little bit exessive to me that I need to helicoil 16 threads. Ive read that helicoils help distribute the torque better than stock threads
(http://www.clubgti.com/showthread.php?256235-Why-Helicoils-can-be-better-than-the-original-thread!)
I want the best solution to this problem, so ill spend the money, but I want to know if anyone has any experience with something like this?

I was thinking of doing arp studs and helicoils. But since most of these holes are stripping, the rest of the threads make me a little nervous, they didnt feel very solid to me on while being torqued. So should I look into a new block? Keep in mind the engine is rebuilt, bored .030 over.
Is there another solution to keep the other threads from stripping? Should I see if they can handle 80ft lbs before I bolt the head into it at 65? I just need some help on what I should do, I dont want head gasket problems, its not a stock engine, read other threads of similar builds at 400+ flywheel horsepower.

t-top havoc

iTrader: (3)

Look at the threads in the block & the bolts. Any boogers will cause problems like stripping & false torque readings.

Chase the threads in the block.

Clean bolt threads too.


Use new head bolts if possible.

Helicoil type inserts for any holes that will not clean up.

Jackrabbit501

iTrader: (3)

I have all new bolts, I have chased the holes before I initially torqued them, and blew them all out with an air hose. When I initially got the engine I found that the heads were cracked, got the engine rebuilt and inspected by a local builder. It has been sitting a while as well.

Can the stock threads handle 80 ft lbs? I was thinking of getting a thread chaser/cleaner tool rather than using a tap as well.
But my initial thought was if the rest of them can handle 80 ft lbs then they should be fine at 65 with compression? I would hate to have to pull the heads after getting her runnin again.
Thanks for the input, much appreciated!

Jackrabbit501

iTrader: (3)

One more question:
Could I drill down only a little past the length of the helicoil and run the coil into the bottom of the threads to help secure it in the block? The difference in the old threads to the new threads im making is enough to really lock that sucker in there. Just a thought I was havin.. I didnt really read that in anyones helicoil experiences

Night rider327

iTrader: (13)

What bolts do you have? What brand, number, etc?

Something does not sound right. The threads in block should not be stripping like that.

This should not be a prob. at all. Something is wrong with the bolts or the block

Jackrabbit501

iTrader: (3)

I dont remember the number but I bought a head gasket kit from mr.gasket I believe it was. Came with felpro 1003 gaskets and felpro bolts with a sealant on them..

Im not sure why it happened exactly, they threaded fine, no crossthreading, torqued fine at 25 ft lbs (besides the one), torqued fine at 45, and then gave way right before 65 ft lbs.

redneckjoe

out of curiousity, what's the casting number of the block?

seems like i've heard of this problem a few times with the later roller blocks having a thin deck surface?

sorry to hear about your problem, that's a real bummer.

sofakingdom

iTrader: (1)

Install Heli-coils according to their instructions and common sense; which is, to a depth of about one thread below the surface. No deeper. They are designed to the appropriate length to support the clamping force provided by the size of the hardware they repair.

Head bolt threads frequently fail like you are experiencing, especially when they have sat around exposed to the weather for a long time. Heli-coiling ALL of them is a common practice. Nothing to be surprised or disappointed about. Just a normal and natural consequence of reviving old junk, automotive or otherwise.

Jackrabbit501

iTrader: (3)

Thanks for the responses, makes me feel a bit better about the situation, guess ill just order a pack of 30 helicoils and take my time on it.

I dont have the casting number on hand, I can reply later with the number, but I remember looking it up when I bought it, being from a first gen camaro, non roller block. Also ive read online about 277 lockstud, which us what I used the first time, but since that has been around is there any lockstud or locktite/equivalent thats works any better?

sofakingdom

iTrader: (1)

Probably a 010 or 014 block, or some one of those other real common 70s ones. Having been installed in a Camaro doesn't make it any different from any other.

No need for any kind of locking compound on any of those threads. In fact, they all go into the water jacket; once you get the Heli-coils in there, use the "high-temp automotive pipe thread sealer with Teflon" from Permatex on the bolts.

I would recommend by the way, NOT torqueing them to 65. Stay on the low side of the spec. Tighten them incrementally, as you describe that you were doing; stop at 60 WHILE THE BOLT IS STILL MOVING (that is, as opposed to, the peak torque required to break them loose from a standstill and get them turning again); once all 17 are torqued to 60 in sequence, go back over them and re-tighten them again, you will find that the first few especially are loose; but DO NOT exceed 65 UNDER ANY CIRCUMSTANCES. Over-tightening them warps them, and will cause the gaskets to blow, the most common place being between the center 2 cylinders. That's one of the advantages of the sealer I described BTW: it's a SUPER GOOD lubricant, so the torque readings you get are actually an accurate reflection of the actual true real clamping force.

Jackrabbit501

iTrader: (3)

Are you sure? Brodix reccomends 70 ft lbs on their ik series heads..

http://www.brodix.com/heads/small-block-chevrolet-compatible-heads/ik-series

sofakingdom

iTrader: (1)

Yes I am sure.

The block bends too.

Jackrabbit501

iTrader: (3)

Alright cool thanks for the help, glad I didnt follow that website on that one, the less problems the better.

Lurbie

iTrader: (3)

Be sure to lubricate under the head of the bolt too. Do NOT use engine oil for this. I used the ARP bolt and thread lubricant under the head and the Teflon sealer mentioned previously on the threads of the bolt.

Also, check the length of those Fel Pro bolts. I bought a set of Intake bolts while doing gaskets on a GM 3.4L engine, those bolts were 2-3 threads short and that lack of additional contact is what caused me to strip out intake threads just before they reached torque. I'll never buy Fel Pro bolts again because of that experience.

Jackrabbit501

iTrader: (3)

Thats exactly what I noticed when I pulled them out, they looked really short to me, you could see how far they went in from the teflon. I plan to buy MANLEY 42313 bolts as recommended by brodix in the same link as above ^

The upper bolts (underneath the valve covers) did have more threads in contact than the lower ones, I think ill go through a more thorough cleaning and helicoil the lowers and see how the uppers hold out with the longer bolts. Thanks

FRMULA88

Are you sure the threads are stripped? The washer can slip on the head bolt and it will feel like you lost the torque reading. Did you try to tighten past that another 1/8 turn? Did you lube the washers and install them with the chamfers on the ID facing the chamfer on the shaft of the bolt heads? this will keep the washers from spinning and slipping the torque reading.


Better yet, throw the heads bolts away and use head studs.
they will provide much better clamping force and you will never strip the treads in a block because you torque the nuts to the studs. the studs are simple screwed into the block until they bottom out (not torqued)

Jackrabbit501

iTrader: (3)

I bought some manley bolts recommended by brodix. I compared the felpro to the manley and there was a major difference, im certain now that the stripping was caused by the felpro bolts. I really wanted to get some studs, but the cost of manley bolts ($40) compared to arp studs ($180) I thought I would try the bolts out first. If I ever have to tear the heads out ill definitely go towards the studs though.

James Sutton

iTrader: (2)

Welding on a stud is what I did, to keep water jacket from leaking through bolt holes, but couldn't at #1 piston because of clearance issues.

FRMULA88

you welded a steel alloy stud to a cast iron block... amazing.

This is one I just gotta hear, please elaborate

James Sutton

iTrader: (2)

Yeah, amazed me, too, but I didn't ask how. Had it done at engine machine shop.

FRMULA88

sure you did

James Sutton

iTrader: (2)

Harvey did it--Harvey's Machine Shop, Norwalk, Iowa, where racers from Newton Raceway get engine work done.

CatmanFS

I recently went through an ordeal removing a bolt broken off flush with the exhaust ports, tried an extractor, it broke off inside. Had to remove a half inch of material around it to get that out. Luckily I didnt grind into anything else ad there's about a half inch of unused thread that the original bolts don't even get to.

Used a diamond tipped dremmel grinder thing with a spiral pattern, after breaking half a dozen 1/16" cobalt bits.