351w hole identification

[RCJones]

can someone please tell me what the non threaded holes are at 9 , 11 & 1 o'clock to the cam?

[Jeff Kleiner]

9 o'clock is an oil port that coincides with a passage in the cam retainer to provide lube to the front of the cam. 11 and 1 o'clock are the end of the lifter bore passages. They get plugged with steel cups (like small freeze plugs) but good practice is to tap them for NPT screw in plugs. The cup type has been known to blow out if they are not well staked...when that happens you have virtually zero oil pressure.

Jeff

[RCJones]

Thank you...Can you provide a link or something to the NPT plug? Not sure what NPT stands for

[BobCarter]

Thank you...Can you provide a link or something to the NPT plug? Not sure what NPT stands for

NPT= National Pipe Thread. This is the standard for most common piping used for water and gas piping. You will find NPT fittings readily available at your local Lowes and Home Depot as well as any hardware store.

[RCJones]

Great...thanks...does this hold true for the big "freeze" plugs also? are there tapped ones for those too? Just saw the summit plug kits but they weren't tapped

[Boydster]

Most folks don't tap for threaded water jacket freeze plugs because the cooling system operates at lower pressures than the oil system. Screw in plugs really aren't needed. You have a cap that should relieve pressure before it gets high enough to pop those plugs out. Those oil galleys... you don't want those coming out.

Standard knock in and stake freeze plugs should be fine for the water jackets.

[RCJones]

Thanks for the info!

[CHOTIS BILL]

The Ford Racing block uses 1.25 NPT threaded freeze plugs if you did want to go that way. M-6026-B302

Bill Lomenick

[RCJones]

Thanks...just have to think about treading...

[RCJones]

So 9 & 11 are NOT threaded and 1 o'clock is. Does this mean that 9 & 11 are water and 1 is oil? Sorry to question my offers of help.

[Jeff Kleiner]

All are oil.

Jeff