Anyone run these on a vehicle they have owned? Have they caused any problems? Did you have to retorque them any at all after they were installed? Long story behind this question .

 

HI!... All I'll run on a modular engine is a COMETIC (MIL) head gaskets. I would strongly recommend that you do a series of re-tq's on any MLS gaskets. With my ARP head studs, I do a final TQ of 92FT/LBS. I do the recommended tightening sequence that FORD states. I start off at 20, 40, 60. 80, and finally 92FT/LBS. Now this is where I change things a bit. When I was building my 5.4 I was waiting for parts so the engine sat on the stand for periods of time. The next day after TQ'ing my heads I decided to double check them again. I did the final TQ of 92FT/LBS .............. and found that just about all the nuts took another 1 to 1-1/2 more full turns!!!!! I let the engine sit for a few hours while I was working on other things on the truck it'self. Went back and re-TQed again at 92FT/LBS. Again some of the nuts turned again. Not all but about 75% of them. Let it sit over night and reTQed again. Some more nuts turned..... this went on for about 5 days untill none of them required anymore reTQes. So I can only imagine when a engine builder TQ's the head studs down and then sends the engine out, to what the head TQ actually is by the time you go to fire it up. I would suspect about 20-25FT/LBS less than what you had. Also have your engine go through a few heat cycles, pull the valve covers and re-TQ the nuts one last time.

 

I am a little confused on this but then again that tends to happen to me more and more. Anytime I have built a 2v or 4v 4.6 or 5.4 I have used our service method of torquing. That is 45nm in sequence then 90 deg in sequence and then 90 deg again in sequence. The important thing to remember is that when using new bolts they have to be stretched first. I usually install the new bolts then go thru the torque sequence, loosen them all and then go thru the entire procedure the second and final time. This is the same process that is used during assembly on the line but is performed by robots. The production method is also performed with torque to yield and recorded. I have not experienced any problems with the bolts loosening up and I have built at least 500-600 of these engines. I have only used the production head gaskets though. From my experience the current production head gasket is much much better than the old Ishikawa head gaskets and we very rarely if ever get any of the current engines back from dealers with head gasket leaks. Just my thoughts. Thanks

 

DYNOTECh - Per Neal's post, the ARP studs require prestressing cycles unlike the oem TTY bolts. Check here- -http://www.arp-bolts.com/Tech/Tech.html

 

Thanks ONELOWF. I was misinterpreting what he was doing. In my job all we use is OEM parts. Not familiar with the stud installation. I am also used to talking with dealerships regarding the 4.6, that call head bolts- studs, bolts- screws, Lash adjusters-lifters, Cam covers-rocker covers. You get the picture. I thought that is what was going on here. Thanks again.

 

Neal, you hit the nail on the head with this one . While just beginning to put some miles on the new VT Engines motor that Mike had built for me, he noticed a problem. And sure enough some of the head studs had lost about 20 FT /LBS of TQ. He also said he was going to do 3 or more retorqes on the heads after each warm up. I just wonder why VT Engines did not tell him about this happening with the gaskets. I didn't find anything on the Cometic website saying to retorque their gaskets multiple times. This gasket problem has now basically cost me another month of waiting to get my truck back, which is now allready at 7 months and counting. Seems like the more you shell out for a motor the more problems you have with it. Thanks for the info, and I think I need to call Mike tomorrow.

 

HI!... It's not just the COMETIC MLS head gaskets. I find this same problem with ALL MLS head gaskets on the modulars when used with ARP or any other head studs.

 

Thats good to know.