Tappet guide hold downs and 'freeze out plug' replacements

Evening You All,
Today I installed the tappet guide hold downs and sweated it the whole time.  I't a pretty important up grade IMHO that can save an engine.  One weak spot in the head design was that the tappet guides could come loose over time/overheating and start working their way up, when they do the cam starts hitting them and if not caught quickly destroy the cams and damage the head.  Not a good situation for sure.  There are several ways to make sure this never happens and one way is to install hold down plates, pretty simple but does require drilling and tapping holes for the bolts that are required.  It's a bit nerve wracking but it turned out OK.

Here's the plate at the top of the two tappet guides, I'll need to drill two hole perpendicular to that surface then tap the hole with threads for the necessary bolts.

Holes are drilled on the exhaust side, started with a pilot hole then went to the correct bit for the 1/4" 18TPI threaded bolt

Drill bit, Tap and bolts

Carefully tapping the drilled hole (3/16 bit)

Plate installed, bolts coated with sealant and torqued to 60 in/lbs.  Sealant was necessary IMO since the holes do enter the water passage below.

 Ok, on to the next task,  There had been some coolant leakage from this freeze out plug* so it was time to remove the old one, clean out the opening and replace with a new one.  The new one is a friction fit concave disk that you install with JB weld then Hit the dome of the concave dick which then fits pretty tight (I hope ;-)

Since I was replacing the one freeze out plug I thought it wise to get rid of the rest of the old ones.  The ones on the block are, on a 4.2, little cups that have to be driven in after coating the mating surface with JB Weld.  The openings have to be pretty clean before this is done so it's a little PITA to get it prepared then using a large socket and a BFH they are driven into place.

Freeze out plugs on the exhaust side where we had the most evidence of leakage.

Well that's it for this week. Waiting for the head gasket and flywheel to be resurfaced/balanced.

Cheers,

Lynn

*technically  they are casting plugs but somewhere along the way they got the name in the US of 'freeze out plugs'.

6 hrs