L98 Head Bolts & Washers?
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 1,234
Likes: 5
From: Herriman UT
L98 Head Bolts & Washers?
The stock head bolts on my 86 alum. heads have washers. The new set of Manley head bolts are shoulder bolts with no washers. Should I add washers or not? No washers = affect on torque readings?
Le Mans Master
Joined: Jul 2001
Posts: 8,184
Likes: 3
From: Santa Maria, CA
Defintely use washers so as not to gall the Al head with the bolts as they get torqued down.
btw, for anyone reading, don't re-use factory head bolts as they are torque to yield. They've stretched.
ARP
btw, for anyone reading, don't re-use factory head bolts as they are torque to yield. They've stretched.
ARP
Last edited by pablocruise; Jan 11, 2005 at 04:00 PM. Reason: spelling
Racer
Joined: Aug 2002
Posts: 386
Likes: 0
From: Lancaster Lancashire
Originally Posted by CFI-EFI
On an '86???
RACE ON!!!
RACE ON!!!
However, on Aluminum heads as far as I am concerned, you need to use washers on the bolts to prevent the harder steel bolt galling (cutting into for want of a better description) the softer aluminum head when tightening/torquing down.
Check the application list for your new bolts, if they dont have washers, they may be meant for cast iron heads only.
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Melting Slicks
Joined: Oct 2000
Posts: 3,426
Likes: 4
From: Heidelberg PA
Cruise-In V Veteran
Originally Posted by geezel
"Shoulder" bolt is the wrong term. They have a flange that is formed as part of the hex head which may act as the washer.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by Davemc1963-87conv
I think CFI-EFI means that on an 86 the bolts if original would not have been torque to yield fasteners and can be reused.
Even with a flange headed bolt, I would use a washer if the bolts are long enough.
RACE ON!!!
Le Mans Master
Joined: May 2004
Posts: 5,866
Likes: 60
From: Hellinois
Finalist 2020 C4 of the Year - Modified
I have built my own engines since I was 17 years old but had never came across "torque to yield" head bolts before my 85 L98. I knew the small block torque spec and sequence by heart so I just went ahead and started tightening the head bolts down. As luck would have it I snapped off the last one to be tightened. I was highly miffed so I went and bought a whole new set, this is when I learned about "torque to yield". Sure wish I had new it a couple hours earlier. Anyway, do NOT re-use any headbolts and I agree with CFI-EFI, use washers if length permits. The shoulder of the bolt is still going to gall the aluminum.
