Stretch bolts

[GAMAYBERRY]

I am rebuilding my Mercruiser 4.3 V6 and will be putting the heads back on this weekend. I have installed stretch bolts before and have always "eyeballed" the extra xx? stretch. Without purchasing a torque wrench that has the degree feature on it, is there a more exact way to get the extra 20? stretch? (or whatever the specs say, they are at home and I am at work)

 

[Bondo]

Re: Stretch bolts

I am rebuilding my Mercruiser 4.3 V6 and will be putting the heads back on this weekend. I have installed stretch bolts before and have always "eyeballed" the extra xx? stretch. Without purchasing a torque wrench that has the degree feature on it, is there a more exact way to get the extra 20? stretch? (or whatever the specs say, they are at home and I am at work)

Ayuh,.... Chevy head bolts are Torque to Spec,...

Not Torque to Yield bolts,...

You can Not properly install a chevy head without a torque wrench,...

 

[GAMAYBERRY]

Re: Stretch bolts

You are absolutely correct. I am torqueing to spec, however on the head bolts (being stretch bolts) they require a torque of 22 ft lbs, then an extra 55?, which is the stretch (and there are 3 different length bolts, which require different degrees). I am obviously using a torque wrench, however there are, *much higher priced*, torque wrenches that will measure the degree stretch as well. I dont have that, just a standard. I am asking if there is a more exact way to measure the extra stretch, without going to spend around $450 for that wrench tomorrow. I have asked around, and no one that I know has one to borrow.

 

[RogersJetboat454]

Re: Stretch bolts

I think this is what you're looking for;
https://www.google.com/search?q=bol...69,d.eWU&fp=e3c630419a7f1357&biw=1366&bih=618

 

[GAMAYBERRY]

Re: Stretch bolts

Thats exactly what I need! I didnt know there was a seperate piece I could buy. $12.99 at Advance is ALOT better than the other option!

 

[Howard Sterndrive]

Re: Stretch bolts

you don't need any special tools
a hex bolt has 6 points - each point is 60 degrees apart.
so, you torque to spec, then mark one point of the bolt with white out, and mark the block at the next point, turn until the points line up - voila 60 degrees

and the real pros also put a white line on the outside of their socket so they don't have to keep lifting and looking

that said- I'm with Bondo - since when does Chevrolet use anything but torque on 4.3 fasteners?