Im prepping my block for reassembly. I had the block hot tanked and the shop removed all the freeze plugs and oil galley plugs. I have a freeze plug kit coming, but I need two threaded oil plugs for the back of the block for the cam/lifter galley ends. What size are they and should they be internal wrenched for clearance?? I dont know what came out of holes but see they are threaded.
Im sure I can get it anywhere, but I wanted to confirm size. Is it 3/8 NPT and is it suggested it be internal wreched for clearance rather than a plug that sticks out of the block. I dont know which was in there.
You need THREE plugs for the rear! One for the main gallery and one each for the left and right lifter galleries.....The NPT plug for the right side is 'hidden' behind a freeze plug/welch plug. Too easy to miss that one for those not familiar with Nailheads! Leave that out and you starve half your lifters of oil. And yes, they are 3/8" NPT, internal 5/16" square drive, 3/8" to 7/16" long. This looks like the correct Dorman, pn 090-019: http://www.dormanproducts.com/p-26544-090-019.aspx?origin=keyword You can opt for threaded plugs for the front of the block too. Holes need to be tapped for threads, and the plug must be thin enough to not block internal passages to the cam bearing. My shop used some thin Ford plugs they had on hand.
Which of these rear plugs is known to start leaking over time and cause one to think they have a rear main seal leak? Steve
any of those plugs,,, if leaking,,, should be a massive oil leak,,,because they are under pressure from the pump.... The center, rear plug is threaded, the left side is threaded,,, the ''hidden'' plug is on the right side, inside the engine block.... the only way I can imagine one leaking is if one of the screw in plugs was not tightened after removing and replacing it... the ''hidden'' one would leak inside the engine... the other 2 would leak outside ... but ,,, I would say that if you have a leak at the rear of the engine,,, and the oil is engine oil and not red colored trans oil,,, you probably have a leaking rear main seal...
It's definitely engine oil, but after reading posts about the other possibility I'd thought I better check there too while I have to opportunity. It's the original engine with 118,000 on the clock. Wondering which seal would work better in this situation; the neopreme or the rope seal. Steve
Neoprene,,,, there was a reason all the engine manufacturers went to the neo's.... it was a better system....
Convert to the screw in plugs all around, I do it on all of my Nail builds-cheap insurance. Neo seals are the only way to go. Install the rear seal about 1/8-1/4in rotated in either direction. The idea is to not have the real lips line up the main cap mating surface. Also, don't forget silicon where the seal ends meet and around the back of the front seal.
