ARP Head bolts versus OEM

[atom_c]

Is it worth it to put out the extra money for the ARP product? I would prefer to do what I can to prevent future head gasket failure, but I also don't want to throw away more money.

Thanks,

Adam

[Robyn]

The ARP products are good.

Their headbolts are a standard type bolt that can be reused many times.

The Felpro gaskets will hold well along with the ARP bolts. Studs would actually be a better investment if your gonna spend the $$$$

The studs take all the spreading action off the holes in the block.

You then use hardened washers under the nuts (comes with the setup)

The hardened washers give an even and predictable torque value to the nuts.

The machining on the heads is sketchy at best (under the bolts)
Along with the silicone sealer also changes the torque value.

Install the studs in the block with a good sealer to keep coolant from migrating up the threads and into places you dont want it.


best

Robyn

[atom_c]

Sounds like it is worth it to get the studs then. I will probably go that route.

Thanks,
Adam

[john8662]

Before you consider head studs, consider these issues:

http://www.thedieselpageforums.com/tdpforum/showthread.php?t=34843

[Robyn]

If the studs are installed in the block with a good High temp RTV on the threads (threads must be cleaned with a substance like brakeKleen first) you should do fine.

I have mulled this subject over many many times. I dont really like the TTY bolts as I am old school and hate to toss out parts just because they were used once.

On my rebuilds, I use the Felpro Gaskets and Felpro TTY Bolts. Reason being, they are inexpensive and work well.

Make sure as has been mentioned, that the block is clean and the decks true. (any errosion around the fire ring will kill the job before it starts)
Same goes for the heads.

Follow the instructions from Felpro on the gaskets and the bolts and your job will do fine.

Using as set of the trick studs or bolts is fine but, the sealing procedure is still paramount to keeping antifreeze out of the oil.

The GM Big Block has the same issue. The bolts go through to water and must be sealed or they will leak.


The ARP bolts used with sealant will do fine, still the threads need to be coated with RTV to assure a no leak job.

ON the BBC's I have used high tack on the threads with zero failures.

This should work here as well.

Overall unless you really have a need to spend the Bucks $$$$ on the trick parts, use the Felpro stuff and spend the extra $$ on some goodies for the rig.

The biggest reason for gasket failures on these engines is not the bolts, but instead the errosion of the block around the fire ring on number 1 and 2 cylinders.

There is no passage of coolant through this area, so the coolant lays in direct contact with the deck. over time electrolysis sets up due to the dissimilar metals (stainless gasket ring and the iron block. The iron errodes over time and then Poof, the gasket blows.

The new generation of Felpro gaskets has a much heavier and redesigned section in the area of the water ports both front and back. This greatly reduces the failure potential at these points.

Almost every 6.5 engine that I have had apart has shown the errosion at the number 1 and 2 cylinder areas around the front water port in the deck.

The area right under the fire ring will generally be etched and erroded on the front side of the cylinder.

Hope this clarifies things.

The info the John8662 presented is spot on target.


My feeling is that ARP makes some good products but likely they are not needed for this application in a daily driver.

Missy

[SmithvilleD]

If you do go with studs, put the sealer on the lower threads that go into the water jacket. Thread in the studs. Then put the gaskets, heads on, & go thru the torquing procedure right away, and let things set up that way - even if you'll still have the heads off later.

This way the sealant or locktite sets up on those threads under the same tension they'll see when the engine's completed/running. Some also recommend this procedure to help ensure all the studs "set" as parallel as possible, for easiest head removal/install.

Some also recommend going thru the tighten/loosen torque sequence a few times believing this will achieve the most consistent/repeatable torque reading & more importantly the most consistent stretch/tension on all the studs. Could well be true & I don't see any downside other than a bit more time spent on the torquing procedure.