T/A heads
As can be seen by the pics, these heads had 1/2” OD bronze guides installed.
They were pretty worn out, so they got replaced.
As many of you probably know, stock SBM heads don’t have an abundance of spring installed height.
They also dont have a bunch of retainer to guide clearance.
The replacement guides on this set of heads had the new bronze insert sticking out above the top of the original guide boss by about .060”.
Several of the hard plastic umbrella seals were split, and the tops of the guides were shined up.
I suspect there might have been some mild contact going on there.
I spot faced the original guide boss down and replaced the bronze guides.
I made it so the top of the new guides were about .100” lower than the original boss.
With only the 1/2” guide sticking out above the spring locating step...... it makes for an easy positive seal install.
The other thing I noticed was that most of the chambers showed evidence of the combustion leaking past the gaskets.
There was a very odd pattern to the head surfacing, so I suspected I was going to find an issue with how flat the head was.
As can be seen by the pics, these heads had 1/2” OD bronze guides installed.
They were pretty worn out, so they got replaced.
As many of you probably know, stock SBM heads don’t have an abundance of spring installed height.
They also dont have a bunch of retainer to guide clearance.
The replacement guides on this set of heads had the new bronze insert sticking out above the top of the original guide boss by about .060”.
Several of the hard plastic umbrella seals were split, and the tops of the guides were shined up.
I suspect there might have been some mild contact going on there.
I spot faced the original guide boss down and replaced the bronze guides.
I made it so the top of the new guides were about .100” lower than the original boss.
With only the 1/2” guide sticking out above the spring locating step...... it makes for an easy positive seal install.
The other thing I noticed was that most of the chambers showed evidence of the combustion leaking past the gaskets.
There was a very odd pattern to the head surfacing, so I suspected I was going to find an issue with how flat the head was.