head bolt torque

[Pappillion]

I am putting together my top end on my 06 800 ho. The book says 27 lbs but that seems low, Maybe its just me. Any help would be great. THX

 

[Modman]

I am putting together my top end on my 06 800 ho. The book says 27 lbs but that seems low, Maybe its just me. Any help would be great. THX

27 lbs/ft or 27 Nm? Either way, that is a dry torque value, do not over-torque your head bolts, aluminum strips easily.

 

[OVERKILL 19]

I am putting together my top end on my 06 800 ho. The book says 27 lbs but that seems low, Maybe its just me. Any help would be great. THX

I always go 10% above the book. And torq in steps 15ft/lbs first then 20 then 30ish. I think I torqed mine to 30

 

[HagmanMod1]

dont over torque a buddy of mine over torqued his jug bolts and wrecked the gasket causing a coolant leak and i dont remember the spec's but it was quite low

 

[Scotty]

Torque by the book. Remember to re torque after your first ride.

 

[OVERKILL 19]

Torque by the book. Remember to re torque after your first ride.

So you are saying pull the head off and re-torq the jug bolts???

I don't see the benifit of doing one without the other.IMO

 

[sumx54]

What ever you doo don't loc-tite them. I've seen that happen before and its not purdy

 

[Scotty]

So you are saying pull the head off and re-torq the jug bolts???

I don't see the benifit of doing one without the other.IMO

NO... just re torque the head bolts to spec again. When you rebuild your engine and run it for the first time everything expands and contracts due to heat and cooling etc. Just retorque without pulling anything apart Do not over torque.

 

[Scotty]

One other thing... remember that there is a torque sequence... you have to torque the head bolts in the pattern that the manufacurer recommends. Check it out for your mill.

 

[OVERKILL 19]

NO... just re torque the head bolts to spec again. When you rebuild your engine and run it for the first time everything expands and contracts due to heat and cooling etc. Just retorque without pulling anything apart Do not over torque.

Could you not say that your jug bolts would do the same?

 

[Scotty]

Could you not say that your jug bolts would do the same?

The bolts are steel.. the jugs are cast aluminum. They both expand and contract at a different rate.

 

[megatron customs]

If you over tourqe the head and jug bolds you will strech them. then the fun begins lol tourqe them to what the book says then after you fire the sled let it warm up shut it down let it cool then re tourqe

 

[maxwell]

also not a bad idea to replace your head bolts and jug bolts.

i did another motor on the weekend and after torquing the bolts to spec it held up until the first ride when things started to expand and whatnot and one of the bolts let go.

 

[OVERKILL 19]

Not to start a Chit show, but I can't wrap my head around re-torqing one set of bolts because they are steel and they expand and contract differently "granted" then why not the jug bolts they are steel?

I have put together lots of Aluminum small blocks and bolted on countless Aluminum heads on steel blocks. IMO The importance of bolting down evenly and in sequence is key to prevent leaks as well as using new bolts as stated before. My 10% over what the book says for torq is a personal preference. I was taught that from a machinist/engine builder who has put together motors for some pretty huge names in Funny car and Nascar. But you can NEVER go wrong by following the book.