409 oil gallery plug

Don Jacks

Well Seasoned Member
Supporting Member 3
No on the restriction,yes on the oil pump.The pump needs a weaker by pass spring.As to keeping metal out use grease on the tap you're using,then use your priming tool and push any metal out of the holes.Do one by tapping,prime the engine to blow anything out,install the screw in plug,proceed to the next one.I'd put a little blue Loc Tight if it were up to me.
 

nana1962409

Well Known Member
Supporting Member 2
Sometimes when I have to drill and tap things and I want to make sure I don’t want to get metal in the project I use the grease on the tap and also put a magnet with a hole in it around the hole to help draw out any metal from the process that the grease might not have caught. Maybe I’m just overly cautious. I think one of my magnets came from a small speaker I took apart.
 

benchseat4speed

Well Known Member
Supporting Member 7
Use grease on the tap and clean and reapply often, then use a magnet and run a priming tool to flush.
If one fell out you may want to think about doing the rest of them.

No on the restriction,yes on the oil pump.The pump needs a weaker by pass spring.As to keeping metal out use grease on the tap you're using,then use your priming tool and push any metal out of the holes.Do one by tapping,prime the engine to blow anything out,install the screw in plug,proceed to the next one.I'd put a little blue Loc Tight if it were up to me.

Man that is some GREAT info^^^ good call. never had to do this thankfully but, now I know:think
 

Ishiftem

Well Known Member
Supporting Member 2
Don't prime the engine to flush out shavings. Use a long magnet from the front plug in the block to clear out the entire passage. By running the pump you are just as likely to push metal towards the bearings as you are to flush them out of the hole.
 

benchseat4speed

Well Known Member
Supporting Member 7
I dig what you're saying, but it seems like a greased tap and hitting the primer once would be safe. Chips are gonna follow the path of no resistance, straight out and all over the garage floor:brow
 

Ishiftem

Well Known Member
Supporting Member 2
The holes are in the side of the block because that’s where the drill the passage that connects the main feed along the pan rail to the main and rod bearings. Now think of that area as a four way intersection. Oil coming down one street can either make a left and go out the block, turn right and go to the main and cam bearing, or go straight where it encounters more oil passages to the mains and cam. Could you say with any certainty that the oil and any chip will ONLY make the left turn? I couldn’t. And I wouldn’t want to take that risk on something I spent that much money on.
 

63impalass409

Well Known Member
Supporting Member 2
I bought a telescoping magnet that fits through the bigger front gallery hole that I'm going to shove to each hole I'm working on and go from there and if I feel like I didn't get everything out motor will come apart as at the most it will cost me is time and a gasket set and it's a back up motor so I'm in no hurry and I put them together myself so no labor cost. In the future though I will do like Paul has done since his plugs blew out tapping every hole while at the machine shop.
 

63impalass409

Well Known Member
Supporting Member 2
Ok update time!!! So motor had the melling hv pump so I changed it to the standard flow pump and talked to my machinist and he said he would not take a chance tapping oil gallery plugs while motor is together and told me to bring the motor to him with the new factory style gallery plugs and that he would steak them to keep them in place so I did this day before yesterday and got it fired up again today with 60# oil pressure cold and about 50 hot and I am tickled pink that I have no issues now.. Just a fyi he streaked all of the plugs so they ate not coming out on their own.
 

61BUBBLE348

Well Known Member
Supporting Member 11
On one of my builds I used a HV pump, way too much pressure, I pulled the pump and put standard pressure spring in, back to what I considered normal levels.
With those small gallery plugs, I run a 5/16 UNF tap through them, use a short bolt with a copper or aluminium washer with a bit of Stag sealant on both sides of the washer and lock it up FT, I also put the bolt in the lathe and square off and flatten the underside of the bolt head.
 
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