A customer brought me a set of Patriot 5.3 heads to install and when going to put the ARP bolts in, the bottom row of head bolts would not go in all the way. I could tell when torqing the bolts that something was not quite right on the bottom row because the torque came on to quickly and I could see the bolt head twist a little. I suspected that the bolt was bottoming out so I measured a stock used bolt to the ARP and the ARP is 0.125" longer (with washer). Not much but it must be enough. I put a stock bolt in the same hole and torqued it to yield and all was cool.

There have been a few posts here and there about people experiencing leaky head gaskets at the bottom of the head. When I do a search I see that they seem to be when using the ARP bolts.

I suspect that with milled heads, the ARP bolt is just slightly too long.

Has anyone else experienced this? Any machine shops here that can confirm as to why the ARP bolts only seem to bottom out on the bottom row of bolts?

 

That's probably exactly what's causing it, the bolt is too long.

Being that the bottom row is causing it would make one think that the heads aren't surfaced totally flat in the same plane, i.e. they are surfaced at an angle hence making the lower portion of the head surface thinner so the bolt is too long at the lower end due the discrepancy b/w the planed surfaces.

 

....My dealer re-uses the old bolts....it saves him money on warranty work...he claims no problems in years of this practice....

 

And we wonder why dealers get a bad rep.

 

Hey Mikey have you called and talked to anyone at ARP yet? We've never really used the bolts so we haven't seen the problem but it seems like it would be an easy thing for them to fix.

 

You're NEVER supposed to re-use a TTY bolt that has been stretched to its final torque. NEVER.

That's just diligent practice.

If a mechanic or person re-uses a used TTY bolt it is improper practice and greatly increases the risk of part failure.

Just b/c some people do it and get away with it (i.e. no reported issues that you or others know about) doesn't make it correct.

 

I've used the ARP head bolts and installed them on milled heads and have not had any problems. I do know that there can be no coolant in the bolt holes or it will act like its bottoming out early. I would measure one of mine for you, but I do not have any laying around.

 

I just torqued mine down Fri. Night. Have not started the car yet, but didn't run into any problems with the bolts hitting the bottom. But my heads are not milled 5.3's.

 

I've actually ran into the same thing.Torque'd the bolt and the head looked loose(bottomed out).Took it back off and measured everything up and had atleast .400 of room before the bolt bottoms out.Put it back on and it did the same thing.Since then I've done 3 cars and all were the same.Maybe the ARP lube is real slick and the bolt just has a little twist to it and you notice it after hitting 70 ft/lbs? This is a reason why I prefer studs over bolts.

 

Ive done 10+ head swaps and on my personal car i recently installed ARP head bolts.....and coincidently I had a leaky headgasket. My heads were milled 30 thousanths.

Maybe they are bottoming out, maybe they aren't. They're right on the edge if they are, because it does seem to mostly hold the head down, but the coolant use worried me.

Sounds like I'm gonna be putting stock bolts or studs in to see if it fixes my cars poor performance and coolant use.

 

The holes were all cleaned, threads chased and all coolant removed. It's very strange. I will no longer use the bolts, only studs or TTY stock bolts. Too many people with leaking head gaskets and ARP bolts.

Just wanted to post this as a "warning" to all who might want to use these.

 

Nice work "Mikey P.I." Sub the ferrari for a red TA though. I switched to studs for the install, and all seems well.

Jon

 

i just finished my H/C swap, and i used ARP head bolts. i started it up and it is leaking coolant. not sure if its the head, gasket, or what it is yet......

 

can you simply use more washer to take up the slack????

 

I have milled LS6 heads and thinner gaskets. No leaks here. I would shave the bolts down before I would use a thicker washer. Looks like the best argument for the use of head studs from now on.

 

I work at a truck shop that does warranty work. Are you saying that he charges out new head bolts to a warranty job and then uses the old ones to put the heads back on? And makes money that way? There is a word for that... I think it starts with f... I'll think of it in a second... Oh yeah, its FRAUD! That is illegal if he is basically telling the customer he is using new head bolts and using the old ones. Its stupid to use TTY bolts twice, and I hope he gets his *** busted for it.

 

Back on topic... I used ARP head bolts in mine, Its not leaking yet, but also my heads arent milled. Why couldn't you just grind an 1/8" off the end of the bolt if its that much too long? Or a rigger's way would just be to washer it up some to take up the slack.

 

just because the hole is deeper than the bolt is long doesnt mean the hole is threaded all the way to the bottom.

 

Using ARP head bolts here with unmilled heads with no problems.

 

Bingo.