lmills

I won't even bother to quote that last reply ABC. LOL

Anyway, sounds like a full days work LOL. Also, that gasket is the same one I am currently running. Seems to be the most popular one. It was also the one that was on the truck originally.

Don M

Once upon a time I worked with the guys at Cometic in hopes of a better gasket. After the ARP mess and the Cometic guys trying to get me to front the cost of the initial gaskets, (150 pieces paid for up front) I backed off. Cometic made them for the Ford guys without any up front, but decided Don M needed to pay for material for the Cummins. I politely declined. We all know how the ARP "thing" went for me.

I may learn slow in most things, but learned fast when the pocketbook got attacked. LOL The Ford PS gaskets from them were a dismal failure at best anyway.

We just need more RPM for the CR engines and to move the RPM band up some. Once we do that, stock bolt and gasket set ups will hold dern near anything.

Back to cylinder surface finish Kerry..... Make it rough. Chrome rings and oil retention make it mandatory.

Don~

AK RAM

It sounds like you plan to re-use your existing ARP studs? Did you know that ARP has a new set of 12mm studs out that allows you to torque to the same clamp load as the 14mm studs, but without the need to drill/tap the block? They are a little spendy though. You would want to bottom tap to make sure you get every available thread. The new studs and your 5-layer gasket would probably hold upwards of 150 lbs of boost!!!

AK RAM

Really? I thought the stock gasket was a 3-layer?

lmills

at least on mine it was 5. I have a nice photo with it blown thru all 5 layers. lol

banshee

Just my opinion, but I would stay away from those studs unless you had the block prepared correctly for using them by finish honing with a torqued deck plate. That much pull with the smaller 12mm footprint is highly likely to pull the cylinders out of round and give you some ring seal problems.

AK RAM

What is the general consensus for max stud torque? The standard ARP is 125 ft lbs and the new ARP is 150 ft lbs. You wouldn't think 25 ft lbs more would cause that kind of destruction. I guess the limit has to be somewhere. Maybe we are already closer to it than we think.

banshee

I don't have the numbers in front of me, but I have calculated all the clamping loads, internal and external thread stresses, ideal torque values, etc before. The extra 25 lbs of torque nets an extra 6-7k lbs of clamp load (off the top of my head). IMO any torque over the factory design torque will start to pull the cylinders out of round, so it's a fine line to walk between gasket clamp and ring seal when you throw a set of gnarly studs in a factory block with no prep for them. Also, if I remember right the block threads were getting up there when you lay 150 lbs to a 12mm hole.

lmills

So what do you recommend for ARP's? The 125 or less? I recently heard from a guy that had his 12V truck worked on at Enterprise that they took a set of the standard 12V studs off the shelf and torqued his to 150 ft lbs. And this came from a very reliable source.....

Don M

I slipped a new chrome ring down the bore of my engine I recently built for my own truck. The block was bored and honed using a Tq plate I bought from BHJ a few years ago.

Without the TQ plate bolted down you can see light gaps in a hexagonal pattern between the block and new ring.

For grins, I bolted the head up and basically all the gaps were gone.

The B is a stout block, but it has a seriously thin cylinder wall to allow the coolant a full 360 degrees of travel. It wiggles around more than many think. Heating changes everything as well.

Don~

lmills

that leaves a queezy feeling in yah

abc4yew

The only other studs I'd put other than what I have are the new A1's that offer something like 25% less bolt stretch with the same 125# of torque. Torque is one thing, Bolt elongation is the most important thing. With ARP Moly lube equally coated on the stud/washer and nut.... 120 or 122 # of torque will probably be close to 10% from yield point where elongation just keeps going. My original gasket only had 3 or 4 layers....definitely not 5.

Don, Compared to what the cylinders looked like before I started, They are as "rough" as I'd think would work. After running the same oil I use over them with no temp and just 12 or 14 times...the distribution pattern and retention of the oil looks really good. Before I started the oil would just form bubbles of oil like mercury on glass. After honing the oil would sheet nicely.


Compared to what I had before with the head finish out 3 thou and the variances in the block deck....I'm way ahead of the game. I'm sure I'll blow this gasket again but I hope not for a while. With my sanding, I'm now the proud owner of a 5.925 litre Cummins engine.

lmills, It was 4 solid hours of actual work, 1 hour of butt scratching, and 1 hour of running back into the house trying to inject enough coffee to get smarter. ks

"Just say yes to Tequila and Revs."

lmills

1 hour of butt scratching.

I'll leave that one alone.

banshee

With Moly I don't think I would go over 125 to 130 lb ft for torque. That would put you in the top 5% of yield strength for that stud... exactly where you want a long term clamping fastener. I have my Haisley studs torqued at 118, which from my calculations is 98% of yield. So far, knock on wood, no problems. I completely believe that you could take a set of off the shelf ARPs and crank them down to 150 lb-ft, but I also believe that it is wrong. At that torque the fastener is yielding, and you're going past what is a properly designed fastening system. You are also running the risk of breaking a stud off... something a lot of guys have done going too hard with the torque wrench. If you want/need that much clamp then you should either use the stronger studs in 12mm or bump up to the 14's. Not to speak for Don, but I think he may disagree on my opinion that the 14s are better when going for that much clamp on these blocks. Yes, you are removing material, but you are also taking a clamp from a larger area in the block, so you should have less overall distortion at equal torques for 14mm vs. 12mm. I haven't done any testing or measuring (similar to what Don stated about the gaps between the cylinder walls and the rings), so I have no hard data... just my opinions on what may happen (you know what happens when you assume). Also, as Don mentioned, that heavy torquing will pull the cylinders out of round, and the tighter you crank without building the block appropiately (torque plates) the worse it will be. I *think* our blocks are honed this way from the factory, so a little extra clamp from bolts to studs shouldn't make enough of a difference to hurt, but it's just food for thought.

John

abc4yew

Did you ever dream something was wrong and then you check it out and it is.....I fell asleep for 15 minutes after I had supper and had a dream that there was something wrong inside the engine....Soooo. Out I go to the shop and take all the untorqued studs out....wrestle the head gently off the block by myself and low and behold on top of cylinder 1 there is a big curl of steel from when the head was decked. In cylinder 3 and 4 there are metal shards and there is oil all over the gasket. I guess when they washed the head after machining it they didn't blow it out very well and I didn't blow it out I just wiped it clean as it looked pretty clean from the washing. The oil must have come from the stud holes? So I wiped the gasket clean and blew out between the layers. Vacuumed the head and cylinders out and put the head back on put the studs back in and torqued the head to 52# with lots of ARP moly on the washers, studs, and nuts. Tomorrow morning I'll let off a turn and then crank to between 118 and 122 .....whatever my dreams tell me cause they are always right.

Tomorrow my Hellfires will arrive by UPS if DonM got them done and shipped them out which with my luck I doubt it....Lots of work to do if they are running a little late...Jeez I could work on the sound system cause with the dual stacks and a big single turbo.......I'm gonna need something to drown out the whine. Bedtime soon. ks