Just one question, why? Because I don't know. You said the inside of the block is coated with glyptal. Wouldn't this interfere with heat transfer? As far as the plugs that fill the holes in the block go, I've never had a problem with steel, or brass, plugs with Permatex #2. But to each there own. -Dave
I do understand now. These plugs were used for initial clean out after the casting process. So they are actually irrelevant as to protecting a block from freeze damage. This makes sense now that I recall an old 6cylinder chevy block I had cracked between two core plugs. Neither plug was disturbed, seems rust held them in place! Here in Louisiana of all places. Thanks for the clarification.
This is what I use for core plugs and installing sleeves. Just smear it where the plug meets the block https://shop.advanceautoparts.com/p...ks&gclid=CO6jgPDZ-ecCFVyPxQIdVzIO-A&gclsrc=ds
I am not sure everyone is familiar with the Mopar disc type Plug ( be it either freeze, core, sand removal or some other name I am sure they have been called). These damn things are for sure and for certain a huge pain in the*****. They do not install anything like a more common cup type plug, because of this they are prone to fall out under pressure. Once you get the hang of the correct way to install them they can be just fine ( at least that is my experience with them) but no matter they are I think a poor design from a user point of view. For me personally I use JB Weld to install these, once it sets up I am pretty sure it would take a small explosion to blow one of them out of the hole. Pictures: Cup type Mopar Disc type plug Correctly installed Mopar disc plug, you "MUST" expand these by hitting them in the center and forming that dimple.
Hombre, That looks like a 440 block,,,I have never seen plugs like that in a 440 ? Were they very common ? Tommy
If you are still trying to get them in without the backside turning, and if you aren't worried about appearance, and if you don't mind "ruining" some nice plugs, (I use the "whatever works" approach), you could drill and tap about a 3/16" hole in it and put a screw in it long enough for the tab to catch. Maybe a nut on the back.
Core support hole plug..The hole is the result of the core "supports" that maintain the distance between inside and outside cores where the casting material will build up when pored in forming the block, not originally designed for clean out. If block could be cast with out they would, but it does help with clean out of the core sand but also later when the ancient engines are resurrected. Lucky the engine in pic has side plates instead of plugs..
Maybe the inside threaded bar is bottoming out on the plug before it can get a grip because the block is thinner at that particular hole. Maybe could put little bends near the ends of the bars to make up for lack of material..
Any style plug can come out. Mopar racers be it drag or nascar would drill and tap the block for a strap across the plug. A high hp engine will flex allowing the plugs to fall out. Ask me how I know.
Sorry Hombre, The best I could see the pic threw me off. I saw the reinforcement ribs on the side and immediately thought 440,,,,sorry . I should know better ,,,LoL. Tommy
For what its worth I never use steel plugs........nice non rusting brass plugs last forever........andyd
This is a very good point but I would think that the thickness of the block wouldn’t allow for that. Is there a shoulder on the bolt that may possibly be bottoming out? It seems that the torque that’s needed to lock the plug is. Properly would be much less than the effort to turn the tap inside the block. Did you try the never seize as mentioned earlier? There’s been other treads with people using these with no problems. Sent from my iPhone using H.A.M.B.
The purpose of the holes is to hold the water jacket sand core in position during the casting process. In a perfect world they would not be there. They serve no good purpose in a running engine. Radiator caps vent steam pressure, when water freezes in an engine, it expands everywhere and cracks the iron. The plugs serve no purpose there either. Other manufacturers machine the holes with long sides so a welch plug can be 'glued' in securely. Chrysler machined shallow grooves with a landing so a cupped shaped disk sits in the pocket. the idea is to then hammer the cup flat, expanding the OD and forcing an interference it seal. It worked the beginning but over time I guess the machined rim of the hole gets enlarged and the disks no longer fit. That happened to my 331 rebuild and the disk blew out twice. The replacement plugs I used in the post above is made in two cupped pieces of copper with a thru bolt. Then the unit is placed in the hole in the block and the bolt is cinched down, the two copper cups expand a lot and give a strong mechanical seal. Add a film of gasket sealer for a good seal.
Thanks for all the advice guys, I used to have the brass/copper other plug that Hot Heads offered but it had a small drip of antifreeze all from after firing up the motor for the first few times (I purchased the motor from another person who stated it was built by an out of state shop, these were already in it) I tried to replaced it myself with the exact part from a nearby Advance Auto parts but it did not expand to seal in the block so I lost my patience & bought these O ringed ones. The motor is in a jammed tight in 1930 model A roadster and I really want to avoid engine removal for now, the frame is real close to the hole so the ball hammer can’t make it in there for discs.. So here in the end is what I did, it seated good & tight now, adding fluid now & fingers crossed! It’s gotta drive to Cleveland Piston Power show in 10 days or bust!!
shaunez, Man not a damn thing wrong with that. The idea is to get the set screw tight, looks like that ought to work just fine. I am not going to go back and read all of the post on this thread but if I remember correctly I think someone mentioned something like this might work. Good luck at the show, don't worry about it it's a Hemi it will do just fine!
" The motor is in a jammed tight in 1930 model A roadster and I really want to avoid engine removal for now, the frame is real close to the hole so the ball hammer can’t make it in there for discs.." I wrote a chapter in that book!!! This is just one small inconvenience for the distinct privilege of owning the best engine ever made by man.
Don't forget Murphy. He says, "Tighten the bolts or they will leak.". Guaranteed! Admiral 'Shallow Water' Murphy
Yeah, well I put it in last night & its leaking already..so many set backs on this build.. I think in my haste I put the inside beveled edge on that "T piece" in wrong.. if you look closely it can be turned around. Ill try that tonight after getting baptized in coolant once again
Under the internals were covered with glyptal by the previous owener, as was but it appeared as some may have seeped into other areas because the previous leaky plug here had glyptal bonded behind it
I think upon closer inspection I might have the inner piece on backwards, I believed the beveled area was to allow for block thickness, maybe I am the reason none of this is working! GGRRRR!
Good idea welding that bar on the end of the "T". I can see these being a real****** to remove down the road after things corrode a bit and that allen head bolt attaches itself to the T-bar.
I said a prayer, threw some holy water on it & removed the plug. Yup, I Turned around the “T” on the back & pressurized the system & I am leak free (fingers crossed!) So if anybody ever searches this in the future, look at this picture. If you look to the far right this is how they came in a flat sealed package without room to move around, and****embled... so that is how I put them in.. but due to the counter sink on the block, or just the center hole on MY 392 block it didn’t seal.
The good thing is all the pieces are stainless steel, even the part we welded on too. There is a large O ring on the plug, but also a very small O ring on the Allen head set screw and a recessed area in the plug body for it, it looks very professional
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