Tty bolts vs studs.....yeah....another thought.

[Robyn]

I was listening to an interesting video by Gale Banks the other day.

https://www.youtube.com/shorts/pySyCI1lRq8

Banks is not a backyard hacker like so many outfits that sell goodies for the various diesel engines.....

I am of the mindset that using head studs on the 6.5 may well be a waste of time....And very possibly counter productive....

The 6.2/6.5 was engineered to do a particular job and produce a specific amount of power/torque

Head gasket issues are not really a big deal until the idea of adding far more boost and fuel to the package than it was ever designed for came along.

Even the Herky 6.7 Cummins can be destroyed by the power hungry crowd...

My Son in law recently had to get the 6.7 in his big dog in the shop for a head gasket job....and it is not being tweaked all that hard.

Just some things to ponder.

The AMG P400 does not use head studs......If the TTY bolts were really an issue.....These guys would have dropped them in the trash years ago....


I think back to my days in the performance boat world....

An old saying comes to mind...."If it ain't moving...something is breaking"

When an engine is taken waaaaaaaaaaaaaaaay beyond the design envelope it will eventually fail.....And usually no manner of goodies will hold it together for very long.

Even the mighty Dmax will go away....Head gaskets can and do fail on these too.....


Just some thoughts.....

[More Power]

Yup.. Here's a link to a post I made a while back about this.

https://www.thedieselpageforums.com/tdpforum/showthread.php?46717-Duramax-Head-Gasket-Replacement&p=336296#post336296

What we need are serious data about which is best - long-term and under a variety of uses (i.e. stock vs high perf). ARP is in a good position to collect that data... if it was in their interest to do so.

[arveetek]

The guys over at Quadstar Tuning have been using head studs for several years now with great success. I've been following them for a few years, and have been impressed with what I've seen. They don't follow the typical hokey 6.5L aftermarket stuff (like bypass cooling mods and such), but seem to really know what they're doing.

Casey

[Johncockrell]

I used a 1/2 by 13 tap to clean the threads on one side of my 6.5 block before I found out they were metric. Are there 1/2 by 13 head bolts available for this engine. A 1/2” bolt will go through the head.

[More Power]

The guys over at Quadstar Tuning have been using head studs for several years now with great success. I've been following them for a few years, and have been impressed with what I've seen. They don't follow the typical hokey 6.5L aftermarket stuff (like bypass cooling mods and such), but seem to really know what they're doing.

Casey

Our 6.5TD Project truck (https://www.thedieselpage.com/finale.htm) accumulated nearly 300K miles over 7 years, using Fel-Pro factory equivalent TTY head bolts and Fel-Pro head gaskets. This was a performance engine, in a truck used to tow most of those miles. There were no head gasket problems during the time we had it. I don't know what else I can say to prove the case for TTY head bolts and Fel-Pro head gaskets (and a correct installation). That said, it's not my intention to discourage anyone from installing head studs. I'd simply like to see some real-world long-term data to compare, before suggesting that the far more expensive studs actually provide some tangible benefit.

I used factory TTY head bolts in Lil Red's Duramax head gasket replacement project in late summer 2021 and in Sarah's fall 2021 6.5TD build for her 1994 Blazer, and feel extremely confident in doing so. Extremely...

Incidentally... I learned during the two Duramax head gasket projects here at TDP in 2021 that the final torque for the ARP head studs was identical to that produced by the factory TTY head bolt torque-angle setting. I used a torque wrench to install the TTY head bolts so I could measure final bolt torque during the final torque angle sweep. I was curious... This final torque value for either the ARP studs or the factory TTY head bolts for the Duramax wound up being 125 ft/lbs - identical between the ARP studs and what the torque angle setting wound up producing for the GM factory TTY head bolts. So... there is no more/less clamping load whether using TTY bolts or ARP studs. I found that very interesting...

One of those Duramax 6600 head gasket projects I completed in mid 2021 included ARP head studs. I felt like I needed the experience, so I could add more to a discussion comparing studs/TTY. In so far as having an opinion about studs/TTY for the Duramax at this point 2-1/2 years into it, the only difference I can positively identify is that I spent $418* more for the ARP studs than I would have for TTY bolts. Jim Bigley

* current 1/26/2024 price difference - $613 for the ARP-2000 Duramax head stud kit at Amazon and $195 for 36 TTY head bolts at Merchant-Automotive.

[More Power]

I used a 1/2 by 13 tap to clean the threads on one side of my 6.5 block before I found out they were metric. Are there 1/2 by 13 head bolts available for this engine. A 1/2” bolt will go through the head.

Bummer... I don't have a suggestion for you, except for maybe installing inserts to allow using the correct metric bolt thread/pitch. An engine shop near you might have a better solution, or be able to install the inserts for you.

And, our Troubleshooting & Repair Guide specifies what tap to use. This Guide is not very expensive... See my signature below. It contains the best info you'll find anywhere for replacing head gaskets correctly, and lots of other parts.

[Kennedy]

Incidentally... I learned during the two Duramax head gasket projects here at TDP in 2021 that the final torque for the ARP head studs was identical to that produced by the factory TTY head bolt torque-angle setting. I used a torque wrench to install the TTY head bolts so I could measure final bolt torque during the final torque angle sweep. I was curious... This final torque value for either the ARP studs or the factory TTY head bolts for the Duramax wound up being 125 ft/lbs - identical between the ARP studs and what the torque angle setting wound up producing for the GM factory TTY head bolts. So... there is no more/less clamping load whether using TTY bolts or ARP studs. I found that very interesting...



There is quite a difference in clamping force yield between 125 lb/ft applied to and through the shank of a long bolt and through coarse threads using PST to seal versus a fine thread with a moly lube let alone the drag of the underside of a wide flange bolt.

I'm pretty sure we delisted the studs due to availability, price, and hassle. Not that I ever had an issue with telling someone they did not need something or biasing towards what I sold. If I were doing an engine that I wanted to last it would use studs.