I always like a happy ending. I’m glad you got it working and hope you have a great time on the run your goin on. Sent from my iPhone using H.A.M.B.
Yes in high HP stick cars the block flexes and out comes the best flat disc. I have had it happen a few times. My last 2 blocks were bored out for BBC cup plugs and my leaking has stopped - my radiator cap is zero pressure cap because of the copper head gaskets so the plugs never see any water pressure - just block flex.
I've never looked but is there not enough material to thread block for screw in plugs? Sent from my SM-G973U using Tapatalk
Keep in mind that a water pump also adds pressure to the block. A crankshaft driven water pump creates higher block pressure with higher engine speed - one more reason why the original plugs tend to "pop" when racing. Of course it's different if running an electric water pump. If the electric pump is off, it is obviously not adding to block pressure.
I know this is an older thread, but I have a little add. Studebaker has the same style and most of my lip is gone, I have an engine builder friend who bores out the holes to accept a SBC cup style plug......this is what I'm planning for the future.
I realize this is an older thread but I have one of these leaking. The Hot Head styleI tried to tighten but can feel the crossbar turning and it's leaking worse. If the cross bar is wider than the hole, how does one get these out to replace it? Or do you just push it to one side then back to the middle? Argggggg I got to drain my antifreze now
It's kind of what you're thinking, one side at a time. You have to loosen it up just about as far as it will go without the cross bar coming off to sneak it out. Just go slow and loosen it up a little at a time, trying to weasel it out each time, then loosening a bit more until it can be freed. Too far and the bar drops into the block and then that's where it lives. ironandsteele.com
Glad this post was here along with the pictures of how the strong back goes. The one I took out was flipped around backwards. If I had to guess....I'd say the are all backwards. I don't know if I should remove the rest and check them? I tried to loosed the next one and the screw backs out but the disc won't pull out of the recess. I suppose I should check them all. The ones behind the motor mounts are gona be a bitch. I'm getting ready for a first run, cam break in and I pressurized the radiator/cooling system and found a few leaks. Glad I found them now and not on the break-in run. Thank you for your reply on this!
My 392 kept puking out core plugs, so I made my own. Very similar. I measured each hole, and they were all different, so I made each plug the exact size of the hole so they would seal perfectly and not leak. It's a little hard to see in the photos, but mine have three steps instead of two like HH's. The O-ring is 100% captured and can't move at all in any direction. I put a little Permatex Ultra-Black around the O-rings as I installed them. It's been at least 5 years and I haven't leaked a drop out of any of them.
Nice Job....whats the purpose of the 3rd step? Rigidity? I work for a company that has a full machine shop....CNC, Scanners....lots of high end stuff. My machinists can make anything I ask for so I'll keep this in mind. When you say your motor was puking out plugs, were the HH Plugs? Wondering if I'm setting myself up for trouble. Thank you for your reply
No, I didn't buy the HH core plugs. I'm too cheap, so I made my own. The inner most step is the exact same size as the core hole. The middle step is the same size as the land in the core hole, and the O-ring is on that step. The outer land is the largest, and acts as a cap that completely covers the core hole. Here is a photo of them installed:
They look good. My immediate need is to run / break in the motor. The real purpose is to make sure there are no issues. Its in the frame right now. Once I verify /break it in, the motor is coming out of the frame and I'm going to either paint it or send it out for powder coat. I can change out these plugs, or check that the other strong backs are flipped the right way and lockem in. when the frame is done the motor will go back in and I'll get ready to mount the grill, cab & bed. Thanks again for your help. My motor
I have the same intake manifold on my engine. It has excellent street manners for a tunnel ram, and I like it a lot. I have 112,000 miles on the engine since I built it. Best wishes for a smooth project.
I have them in 2 392s. I provided a set to a well respected SoCal engine builder (now deceased) when he was building a motor for me. He insisted on using the original style, as …”they were more reliable.” , so he did, and two started leaking while on the break-in stand. I replaced all with the Hot-heads plugs and have had no problems in the last 15 years.
Thank you! 112K That's awesome! What motor you running? Carb? Cam Specs, Bored?....if a 331 Mines a 331, I was instructed to go with a single 4 barrel so changed the 2x4 plate......I have a Holley Street Warrior 600. I'm .060 over with a 270 Isky Mega Grind 221/221 465/465 lift 111 Cam, 10 to 1, Stenke Roller Rockers. Hot Heads Heads & Intake. I didn't build it and not a motor guy. Hope it runs strong.....
Hey, coop46; IIRC, when HR & I discussed these, at least one, if not 2, of them was a bear to do, since there was almost no room for the-back-bracket, so it had to be real thin. HR might remember the thickness he got away with. If he doesn't, just measure carefully. Marcus...
I think I would stick with the old school plugs, more surface area to seal against rough surfaces, just my .2 cents
For Desoto291. The plugs stayed in from the factory because were in a stock motor that more than likely were on an automatic trans with perhaps 180 hp. they worked fine, but when you double the hp like we all do the stock plugs do not like that, and pop out. Mostly the center plug on the passenger side, especially with a chevy waterpump. Ask me how i know.
If these were the cup style plugs i would agree, but these disk type plugsin a hemi can be a real pain in the ass. My engine builder put in the stock plugs and we hadnothing but problems. after two failures, we took all the plugs out and insralled new ones with JB weld to seal them. Guess what, those popped out too. Now we have the Hot Heads plugs in and no problems. We have another Hemi in the works and will either use the Ho Heads plugs or have the holes in the block machined to accept the later cup plugs.
Mine is a 392. There are two quads on the tunnel ram, but I'm only running on one (watch and see what THAT stirs up!). The second carb is just "window dressing" and has a thin copper plate under it to block off air flow. If you look at your tunnel ram, you'll see the plenum is nearly large enough to stick your whole forearm into. Never had any issues with it running lean, and my spark plugs last 8 years or more. I rescued the engine from a tractor puller in MN. It had been badly beaten, and needed to be bored .040 to clean it up. It's been 24 years since I built it, and my memory isn't what it used to be... I think the cam is a 280/224 with just slightly above stock lift? Can't remember the name of the place I got it from... Parts Warehouse in CA? They had a separate Hemi parts catalog, and I got a lot of my parts from them. It has stock hydraulic lifters, stock push rods, stock rods, and Egge 10:1 cast pistons with chrome/moly rings. I built it to be a 100,000 mile engine, so I win on that front. It has been in 25 states under it's own power. My T is Fad style and not traditional.
Yes, it was "Performance Automotive Warehouse" or PAW. Here's a thread about it. https://www.jalopyjournal.com/forum/threads/what-ever-happened-to-paw.1184966/
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