sled_dog
1 ton status
I know to step torque aluminum heads but what should I torque the head bolts to? Finally getting my 383 wrapped up and it is time to throw the new aluminum heads on. I am using factory head bolts.
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Head bolt torqueing with aluminum heads?
- Thread starter sled_dog
- Start date
thats a no no if i recall not using washers under bolt heads on aluminum heads as the bolt will bind on aluminum before real tourqe is reached.
i would ask 4x4high on this for sure.
i would ask 4x4high on this for sure.
Yep, if you use the original bolts you need hardened head washers or you will not get a correct torque reading. Since you have aluminum heads why are you going to reuse the factory bolts? I highly recommend using some ARP fasteners. The ARP stuff will come with the washers as well.
I also thought that head bolts are torqued to yield so reusing them isn't really a good idea period, no matter what head is used.
X2 on the ARP stuff, I have them on my 71 K5 and 79F150.
X2 on the ARP stuff, I have them on my 71 K5 and 79F150.
Maybe the late model engines use torque to yield bolts but i'm not entirely sure of that. The older engines definately aren't torque to yield though.
sled_dog
1 ton status
This is an 89 engine. Head bolts on them are not torque to yield. I am not sure about gen II engines but I know gen III stuff is torque to yield. Of course that being the case the ARP head bolts and studs for Gen III stuff are twice as much. My other current engine project is an 02 5.3L. Yea guess I will just break down and put ARP head bolts on. I have everything else ARP except main bolts. And I actually have those in my garage just got to remove the stock ones and put in the ARPs. Even have an ARP oil pump stud, ha.
I would not suggest installing any different main bolts/studs now. Anytime a fastener is changed in either a rod or a main the bores need to be resized.
Generally, older engines don't use torque to yield head bolts and newer ones do. Definitely make sure which one your motor uses before messing with it, but 1st gen SBC's are not torque to yield and you can reuse the head bolts.
any tourqe spec that has turn xx* after tourqe is reached is a 1 time use only tourqe to yeild system and = toss it when removed.
That is not true, there are many engines with a torque value plus xx amount of degrees that aren't torque to yield bolts.
o.k. i figured you would give me the 100%
most auto motor boots can be 1 time use if tourqe to yeild is used.
most auto motor boots can be 1 time use if tourqe to yeild is used.
sled_dog
1 ton status
Went and grabbed some ARP head bolts from my one customer that hooks me up on that stuff. So ready go as far as puting stuff together. Not sure what you mean you mean by bore having to be resized with main bolt change? I had the bolts when I sent the block and rotating assembly to the shop to be clearanced and balanced, but I forgot to give him the bolts right away. By the time I got to the shop to give them to him, the engine was assembled and done. Blah...
Using a different fastener will change the main bore diameter and concentricity. For instance, lets assume that your block was align honed using the stock bolts and the dimension achieved was 2.500" now if you change the stock bolts and install some ARP bolts (which require a different torque value) then the main bore diameter may be lets say 2.502" instead of 2.500". Do you understand? The bore diameter and the crank diameter are what determine bearing clearance. So what has happened is that you now have .002" too much clearance. This will result in lower oil pressure and a shorter engine life.
sled_dog
1 ton status
I will just sell the main bolts or shelve them for a different project. I need to sit down and reread my class books from school, ha. Anyway about to shower, get a haircut and then start building 
Col_Sanders
3/4 ton status
I found out the hard way. When they say "recommend using hardened washers", you use them. It cost me a motor.
sled_dog
1 ton status
sigh started working on the engine and ran into a big issue almost immediately. I had pulled a couple rod caps a couple months back to check out the bearing surfaces on the crank(engine has been in storage as just a shortblock for 2+ years). So I had to torque those 2 rods. Looked up torque specs on ARP's site. 50ft lbs. So torque those 2 rods. Then for the hell of it I hit another rod to verify the rest were good. They weren't even close. I tried 35ft-lbs setting and it still took a little to get a click. So I freaked and started doing all the rods. Then I stopped and realize that maybe the guy who put it together went by bolt stretch and not torque spec. But I had already started so I decided to do them all. Of course the 4th rod I did, one of the ARP studs stripped!! So now I am screwed at the moment. Not sure my guy can get just one stud.
