Broke arp headbolt ..... Well time for arp stud bolts

[cantbuytime]

I have seen that twice now with the bolts and once with studs. Always a lower corner one too. Def have the heads milled. No way it lifted enough to break that bolt and not warp the head some. Even if its just .001 off , its worth gettin em flat.

Go with studs but they are not that much better than the bolts.

Problem could be the block isnt square.

 

[Mrstangerbanger]

I would have a huge gasket leak if the head was warped and I dont the car is perfect just leaks a small amount of coolant from the bolt hole that it .. The studs are way better then the bolts and way harder .

 

[Mrstangerbanger]

I might just go ahead and easy out the bolt and install a new stud and run it .. The compresson is perfect so the gasket is still good.. Its just leaking because there is a coolant passage there... Will see all keep everyone posted ..Its only leaking through the bolt hole thats it ..

 

[ttocs]

arn't you supposed to put some RTV on the end of that bolt to seal it up from the coolant passage?

 

[Mrstangerbanger]

arn't you supposed to put some RTV on the end of that bolt to seal it up from the coolant passage?

No the coolant passage is at the edge of the gasket.. NO RTV on anything headgasket just lower intake gaskets ...

 

[quickstang_1994]

replace it and hope for the best but a compression test wont find it if it only happens under high boost. once its replaced just keep an eye out for boost in the coolant, you will notice the lines and hoses will be super tight and may burst and other coolant leaks (intake leaks, water pump, thermostat) and watch for overflow overflowing, the block will be out of coolant and pushing coolant out. sorry for the long speech but maybe i can help someone else out by my experiences.

 

[Mrstangerbanger]

replace it and hope for the best but a compression test wont find it if it only happens under high boost. once its replaced just keep an eye out for boost in the coolant, you will notice the lines and hoses will be super tight and may burst and other coolant leaks (intake leaks, water pump, thermostat) and watch for overflow overflowing, the block will be out of coolant and pushing coolant out. sorry for the long speech but maybe i can help someone else out by my experiences.

I dont think I am going to have any of these problems ... But good info .. The heads are brand new and the gasket is not busted just the bolt ..

 

[ttocs]

I would have to agree with them that getting them machined flat again would seem like a good idea.

 

[RichV]

Thats crazy. Did you follow all the ARP istall/torque specs? How many miles since it went together? Definitely not the norm. A buddy has a 700+ HP 5.0L Fox and has never seen anything like this, even when it was a 500+ HP street car, ran 14psi on a S-Trim for years with aluminum heads. I think he went to studs when he jumped to the 700 level.

Maybe the street racing gods are trying to tell you something.

 

[cantbuytime]

Dont have to have a leaking head gasket to have a warped head or block. The headbolts could be keeping the head flat now. That bolt didnt break because its weak , it broke because the head lifted or the block twisted. I use to work in a machine shop and most of the time when someone had a head bolt or stud snapped at the end of the block. It was a block that wasnt square from the factory or twisted under power. Which 302 blocks are notorious for both.. And we always ended up decking the block and heads..


Last I checked coolant comes out of the lower bolt holes because they go in the water passage. We use to use gasket sealer then we started using the white compound.

Just saying from experience.

 

[Mrstangerbanger]

The reason why the bolt broke is I upped the timing.. The gasket is not leaking and we are going to remove the bolt and replace it do a compression check on the cylinder and the cylinder in front of it and if they match and look good all run it.. If not all replace the head gasket and install new studs ... I started the car with the radiator cap off and no air in the coolant car did not smoke and there is no water in the oil so the gasket is still good I hope lol ...

If the head was warped the gasket would be leaking all over the place not just a little baby drip under pressure ..Also the car would not run and it runs pefect.. I understand what your saying but its my fault this happen not the head or boost .. I should have left the timing down and it would have never happen but then again its all a learning process and I love working on my car anyways..

I will have the head checked for good insurance but they were brand new in the box trickflow heads that have not even 1000 miles on them and im only running 8 to 10 psi...

But thanks for the info ..

P.S you never use anything on a headgasket you just install it no RTV or white stuff .. Your thinking about lower intake gaskets ..

 

[Mrstangerbanger]

I have beat the shit out of the car and not had any problems tell I upped timing and then this happend so all lower the timing and its all good.. I talk to good friend that owns performance shop and he said its because I was running to much timing and the head lifted up just enough to snap the bolt and he is 98% sure the head is fine and just needs new gasket or bolt installed its a 50/50 shot ..

If I do need new heads all buy them no big deal Im about ready to buy a R block and build a 331 and make 600 rwhp lol .. Its funny I beat a 450rwhp corvette the other night from a roll so Im thinking with the extra timing I was over the 500 rwhp mark and thats what breaks bolts lol .. The ARP studs are way stronger and better for boosted apps after installing them I should be good.. Its funny the car feels slow to me thats why I upped timing but should have left it shit ...

 

[Mrstangerbanger]

Also could have come loose or been a bad bolt who knows ....

 

[g36 monkey]

I put Pipe sealant on the head gasket bolts that run through the water passages. If you read the haynes manual, it calls for it (at least on v6 models, basically 5.0's with 2 cylinders lopped off)

If you do end up pulling the head, tap the bolts with a hammer before removing them. Since that one already broke, as already stated, you may be in for some fun getting the others out. GM's are notorious for having the bolts break on removal.

The main reason I wouldn't just try to change that one to a stud is the tightening order is very important for heads. And now it would be all off. But I'm pretty anal about doing it by the book.

 

[modo]

the head bolts / studs going into the corners of stock 302 blocks need thread sealant as they do go into cooling passages. i highly doubt the change in timing had anything to do with causing the bolt to break. if you were rattling the motor that bad due to detonation you would have ate the head gasket or a piston and not broke a head bolt. unless you started pushing a lot more boost i doubt the heads were lifting either.

i would try a easy out first and just replace the bolt. then pressurize the coolant system to make sure it keeps pressure. if you do decide to pull the heads go with studs and only have the heads decked if it is needed. as for what head gasket to use i would not use a mls gasket, just go with felpro 9333-pt1s.

 

[twovalveterror]

mrstangerbanger, everyone is saying that you should put sealant on the bolt. not the head gasket.

good luck getting this problem sorted out.

 

[ttocs]

I thought I read about it in my hanes manual and that was why I asked. I also thought it was another reason DI water was recomended to be mixed with the rad fluid was to prevent corrosion?

 

[Mrstangerbanger]

the head bolts / studs going into the corners of stock 302 blocks need thread sealant as they do go into cooling passages. i highly doubt the change in timing had anything to do with causing the bolt to break. if you were rattling the motor that bad due to detonation you would have ate the head gasket or a piston and not broke a head bolt. unless you started pushing a lot more boost i doubt the heads were lifting either.

I would try a easy out first and just replace the bolt. then pressurize the coolant system to make sure it keeps pressure. if you do decide to pull the heads go with studs and only have the heads decked if it is needed. as for what head gasket to use i would not use a mls gasket, just go with felpro 9333-pt1s.

Thank you great info and straight to the point thanks ..

Also I have built 8 5.0 mustangs and the only thing I have ever put on my head bolts were lube and I have never had any coolant leaks ..

I added over 5 degrees more timing and tightened the blower belt really really tight so who knows.. I have blown a head gasket before and its not blown the car runs 100% perfect and shows no signs of problems besides I broke the bolt and its dripping a little coolant through the bolt hole . Also If I kept driving the car after I seen the coolant leaking there would have been a 99% chance I would have warped the head but I had the car towed . I built the car and I'm very thank full for the info but I will fix it..

All your info is great and good but its hard to give me info without seeing the car and building my car . If the head gasket was blown the second I started the car in the morning it would have smoked like crazy because the cylinder would have been full of coolant and it started fine and did not smoke or poor water out the back.

But I might just pull the heads and send them off and have them CNC ported and buy a R block and build a 331 Im still thinking or I might sell the car and buy a 04 cobra ..

But all your info is great and I understand your all just trying to help thank you ...

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[ttocs]

just out of curiosity, if the coolant is comming out of the bolt hole doesn't that prove that it is not sealed? Maybe on previous builds you somehow got the bolts tight enough to keep them from leaking or something but again if you read in the manual, it says to do it right there. What will it hurt other then maybe saying that you didn't do it on the first 8 motors you built? If water is comming out of the top, then where else is it going between the channel and the top of the bolt? Have you considered its possible that the exposure of the bolt to the coolant and water caused its premature failure. Again for the price of a dab of RTV/sealant I am nore sure why you would not want too?

 

[RichV]

The bolt has no pressure on it anymore, so the seal is just not there. I have never done any sort of sealant either on my motors. And the heads come off before any sort of corrosion sets in. I have removed head bolts with a lot of corrosion and some of them can be a pita. All the lower head bolts on a 5.0 go into coolant passages.

Look at it this way, had the thing never leaked, he likely would not have seen the issue until terminal damage.