Small Threaded Plugs

[MingOK]

What are these and where do they go? They were in the box of small parts the machine shop removed when I had my block worked.

 

[JMOR]

 

[MingOK]

Thanks,

I guess the front cover is coming off again

 

[showcrop]

I would guess oil gallery plugs. Machine shops prefer allen head plugs which they can tighten much better, and they are probably stainless steel so they will look better too! At least this is the case with every block that I have had cleaned.

 

[Btzj02]

JMOR is probably right. Hard to tell the diameter from the picture. I have a couple 1/8 inch plugs at the base of the distributor. Originally I also had what looked like small 1/4 inch frost plugs at each of the cam bearing, (may not be the correct terminology), locations. The machinist removed those frost plugs, threaded the holes and installed new NPT plugs. Oops. Those plugs were on my 172 Ci engine not the flat head so it may not apply to your situation.

 

[Jim L WA]

Thanks,

I guess the front cover is coming off again

Ming, call the machine shop first, and ask if they replaced those plugs before you remove the front cover.

 

[MingOK]

Ming, call the machine shop first, and ask if they replaced those plugs before you remove the front cover.

One plug fit in the rear opening, so I'm guessing they didn't. Cam has to come out as well. Dang. Never too old to learn stuff I guess.

 

[MingOK]

So, for posterity or any other ignorant newbies; The rear plug was no problem as I have the motor on a stand. I had the motor pretty much assembled. Head on, oil pan on, exhaust manifold on. To install the front plug I had to remove the front cover, then rotate the engine on its side and remove the valve cover plates. Then I removed the valve guide retainers and pull the lifters up as much as I could to clear the cam lobes. Mark the cam and crank gears to make sure to get timing back correctly, then pull the cam out enough to access the oil gallery hole and install the plug. It went back the way it came off. Not sure if that's how its done but that's how I did it.

 

[wore out]

So, for posterity or any other ignorant newbies; The rear plug was no problem as I have the motor on a stand. I had the motor pretty much assembled. Head on, oil pan on, exhaust manifold on. To install the front plug I had to remove the front cover, then rotate the engine on its side and remove the valve cover plates. Then I removed the valve guide retainers and pull the lifters up as much as I could to clear the cam lobes. Mark the cam and crank gears to make sure to get timing back correctly, then pull the cam out enough to access the oil gallery hole and install the plug. It went back the way it came off. Not sure if that's how its done but that's how I did it.

LUCKY you caught that before final assembly and startup!