Removing CYL Head...

[Genpac]

Got the head removed from my RB20 due to three snapped exhaust manifold studs. I attempted to extract one of the stud ends and failed so...



Off to the machine shop it goes... In the trunk of my 350. I knew the hatch would be useful someday.



Anyone else have issues with breaking the mani studs off in the head? Is this common for RB motors?

Thanks.

[Sil240]

Yup I believe its common I know I had 2 or 3 snapped in my head.
I posted up a Lawson part # for the studs if you search in my threads.

[l0nestar]

I had two studs recessed inside their bores in my head. I was able to remove them without removing the head from the block. A decent machine shop should be able to remove them with no troubles. Now be sure to replace all of your studs and anti-seize them before installation.

[d356bud]

I had four snap but I was able to get all of them out

[240z4u]

I had 3-4 break off as well. Common.

[RustspecS13]

Ive had lots of my nissan's break exhaust studs.

NO NEED FOR A MACHINE SHOP!! Just weld a new bolt onto the snapped stud, there couldn't possibly be a better or easier way. I just used my trusty little mig welder and tack welded a 12mm bolt to the stud and backed it off with a wrench.

Since the head is aluminum and the bolt is steel, the weld will only stick to the steel. And the heat of the welding will break loose any galvanic corrosion that's holding the steel stud into place. Best of all no drilling, re tapping, helicoils, etc etc.

~Alex

[Genpac]

Just dropped the head off at the machine shop. Hopefully removing the broken studs will be a simple task for them. The top stud on cyl #1 and the top studs on cyls# 5 and 6 were sheared even with the surface. They did a quick check for straightness on the head and there was some slight warping (couple thousandths) between cyls# 4 and 5.
I have new studs on order, as well as a full gasket kit. I did find another problem during teardown, the upper to lower intake plenum bolts were not all there... 5 of 11 were missing. So, i'll be searching for replacement bolts as well. >.<

[Genpac]

Ive had lots of my nissan's break exhaust studs.

NO NEED FOR A MACHINE SHOP!! Just weld a new bolt onto the snapped stud, there couldn't possibly be a better or easier way. I just used my trusty little mig welder and tack welded a 12mm bolt to the stud and backed it off with a wrench.

Since the head is aluminum and the bolt is steel, the weld will only stick to the steel. And the heat of the welding will break loose any galvanic corrosion that's holding the steel stud into place. Best of all no drilling, re tapping, helicoils, etc etc.

~Alex

I had seen several videos on youtube of the same thing (welding a nut or stud to the broken end) but unfortunately, I do not own a welder.
I attempted to remove one of the broken ends myself but probably made it far worse and it will more than likely have to be helicoiled.

[SullivanRacing06]

ive had one break off in a old 20, went ahead and installed the arp exhaust manifold stud kit on my 26