Torque Specs On Heads W/ Arp's?

12sec67

Active Member
Oct 6, 2003
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San Diego, Ca
i did a search... i found 1 thread close, but it confused me.

it said long one's 80 lbs and short one's 70 lbs... is this correct for ARP 7/16 x 14 head bolts with motor oil.

i never heard using different specs for shorties vs long's? :shrug:

i also heard 70-75 using oil... who is right?

thanks for your help :cheers:

Rich
 
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ARP makes headbolts for $40 bucks for the 302 that I used on my AFR 165’s with the part # being ARP-154-3601. I would get some ARP thread sealer as well for the bottom bolts that go through coolant passages so that it can seal off any kind of liquid getting out of the head bolt holes. Cover the threads well and completely on the bottom bolts. Here is the part number for the ARP Thread Sealer - ARP-100-9904. Put oil or moly lube (suggested) on the top bolt threads to help with the torque reading accuracy. Put antiseize underneath the washers supplied with the ARP bolts so they don’t rust to the head. When you actually go to put the heads on make sure that they “drop” on the dowel pins on the block so they heads will be held in place while you bolt them down.

Use the proper torque sequence for the heads when installing them.
If your looking down at the top of the head here is the torque sequence order:

Inside of the head (intake side)

9 5 1 3 7
10 6 2 4 8

Spark plug side

This is the tightening procedure I used on my AFR’s –

Top bolts: 30lbs, 50lbs, 70lbs, 80lbs
Bottom bolts: 30lbs, 50lbs, 70lbs, 75lbs

I used those head bolts for 165cc emission legal heads. (stud mounted).

I'm pretty sure the higher torque rating for the longer bolts is for one or two reasons in my mind. The longer ones being torqued harder on top is to hold the heads on a bit tighter with the intake bolted to it when it wants to "lift" under compression? Or better yet, where the longer bolts go thru they have more meat to be torqued against compared to the shorter bolts that don't have as much meat???
 
According to my ARP bolt instructions (7/16" bolts) if you use the ARP moly lube on threads/washers - the torque spec on aluminum heads is 60 ft-lbs top and bottom.

For cast iron heads lubed with oil - 85 ft-lbs. For cast iron heads lubed with ARP moly lube - 70 ft-lbs.