FE ARP head bolt torque?

[pbf777]

I call ARP, earlier today and they do not recommend any more than 100 lb of torque on the 155-3601 bolts, period. That surprised me since both Edel & TFS recommend 110.

        I wouldn't expect the "Guy" on the phone to "recommend" anything other than that which the company outlined, after all, it's not his name on the marquee out front!   

        I also would have to agree with the idea that is the responsibility of the fastener maker to determine and present a "fastener torque recommendation", not the retained component part manufacturer; unless they were advising you that their components were 'sensitive' to the potential clam-load that might be imparted and particularly if this might lead to a failure of in this case the castings.   

        But of coarse this doesn't mean one shouldn't at least listen to recommendations from others, particularly any that might be considered experienced or privy to feedback from those utilizing their product with testimony of what "works".  I will add that the staggered fastener torquing procedures, taking the fasteners to the 90% range of it's intention has been in practice for quite some time, and I have spoken to some of the engineers at ARP in the past where they have acknowledged this practice as suitable.  But also that you just might want to retire them earlier in the number of torquing schedules than one would have otherwise!   

        Scott.

 

[frnkeore]

In this case, since aluminum expands at 3 time the rate of cast iron and ARP uses the same tq for CI, the increased elongation via the aluminum heads would make me want to be conservative.

I even asked the guy about using 100 lb on the long bolts and 90 on the short, he said NO, 100 on all!

I need to call TFS and find out what gives, regarding their recommendation.

There is another option though. You could use good quality Allen Bolts for the long bolts, they have a higher tinsel strength than 180k. 

[blykins]

Or.....you could just use ARP bolts and torque them at 100 lbft......which has worked in every cast iron block/cast iron head/aluminum head combination that I've done in the past 20 years.  Works for Windsors, Clevelands, FE's, everything with a 1/2" head bolt. 

The only time I've ever had any issues with torquing head fasteners was when I received a batch of aftermarket aluminum heads that had been heat treated incorrectly.  When I went to re-torque them on the engine stand, they would not hold torque. The washers were sinking down into the aluminum.  Not a good time.

[Rory428]

Since the ARP instructions call for 100 ft/lbsm I assume that is the number I used when I first installed the aluminum TFS heads over a year ago. Since I am using the same heads, and bolts, on the same block, and that the head gaskets looked fine when I removed them, I elected to go with 100 on all 20 bolts again. I also have a new set of ARP head studs, but I will save those in case a more serious engine happens sometime down the road. As for "calling ARP or TFS", I would imagine that anybody you are able to talk to on the phone will most likely be a sales person, who would just be reading the same information on the website, catalog, or instruction sheet, rather than an engineer, or anybody involved with the manufacturing process.

[blykins]

Since the ARP instructions call for 100 ft/lbsm I assume that is the number I used when I first installed the aluminum TFS heads over a year ago. Since I am using the same heads, and bolts, on the same block, and that the head gaskets looked fine when I removed them, I elected to go with 100 on all 20 bolts again. I also have a new set of ARP head studs, but I will save those in case a more serious engine happens sometime down the road. As for "calling ARP or TFS", I would imagine that anybody you are able to talk to on the phone will most likely be a sales person, who would just be reading the same information on the website, catalog, or instruction sheet, rather than an engineer, or anybody involved with the manufacturing process.

Typically, when you call ARP for an "engineering" type question like that, they pipe you over to the manufacturing plant and let you talk to someone in manufacturing. 

I just received a set of Callies rods for a build and the rod bolts had markings on them that I had never seen.  Because of issues I have had with ARP L19 bolts in the past, I called them to ask exactly which fastener was used in that rod.  They gave me another phone number for the manufacturing side so we could talk about alloys.  It was in fact an L19 style fastener, so I was able to talk to the guy about another option. 

[frnkeore]

I called TFS and talked to a tech guy, named Jeff.

I explained the issue to him and he seemed surprised to hear about it and had no explanation for it, just assumptions, like everyone else. He also said that he hadn't heard of any failures, one way or the other.

But, he was very concerned and is going to get with the engineers to get a answer then,  Email me the results.