[Steve Johnson]

Rectangular port 188's on a 454. The heads are on the block. I'm concerned about crud and maybe a some metal shavings where they might end up (I am using a true thread chaser kit, not a tap, but I still think some metal may be cut out with the chaser). I see that some of the holes have passages past the threads. I can use grease on the thread chaser but wonder if I'm doing more harm than good. So should I chase the threads in the head or leave them be?

 

[gnicholson]

if they need cleaned up go ahead.use a small nozzle on a vacuum cleaner to remove the chips.some of the holes break slightly into the water jackets.as long as you mask the engine off good you could also use compressed air

 

[Bluegoose1970]

Which thread chaser kit? I could see with the ARP kit, you could get carried away with it.
Other ones you could make one with a bolt, and cut grooves on the threads.
They are made not to undercut the threads and give the crud a place to go, and straighten slight imperfections in the threads.
Oil it like a tap, blow the hole out first, run it in, just do not twist the hell out of it. Back it in and out like a tap if needed. The blow the hole out again. And continue.
You can use a bottoming tap, as long as you are careful.
ARP set is basically a dull bottoming tap.


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[Steve Johnson]

The kit is made by Evertough from oreilys.

 

[Bluegoose1970]

use light oil, and keep it clean, should be fine. How bad are you holes? Crud or rust, rust I would soak first, and what comes out is going to come out.

 

[Bluegoose1970]

I actually have a cheap set I only use during assembly for putting lube in the holes, like ARP moly paste and sealant, with the slots and being undersize it coats pretty even. add some on the bolt and good to go.
Also you find holes you missed, like that ever happens to me.
Good Luck!

 

[Steve Johnson]

crud

 

[sschevellefan]

I use to have to chase threads on Harley engines and transmissions when I was a Harley tech and several times there was a risk of metal or whatever getting into the engine or transmission. I would dip the tap or chaser in grease and the shavings would stick to the grease and come out with the tap.

 

[Steve Johnson]

Got all the thread sealer out. Time to Gasgacinch the gaskets. As always I appreciate the help. As another member mentioned in his thread "Team Chevelle is the best tool in his toolbox" and I agree :yes: