I have a blown 392 Hemi & have a question. A couple of header bolts on passenger side- (cast iron heads) are seeping water after driving it. Do any of those threads run into water jackets? I assumed they were blind if they did. I have to pull the front end off for access & wondered if anyone has the scoop on those bolts.
If memory serves me correctly some are oil and the others are water. So yes it could be water. Wrap them with teflon tape and reinstall should be fine. I installed studs in mine with the teflon tape and never had an issue. Also the top three hole for the valve covers are also water.
Makes sense. Some are oily too. My 1st hemi & I'm in my mid 60's! Got a lot to learn. Can someone recommend some books?
yes, you need to use some type of thread sealant or teflon as stated above. i could have had a 392 for cheap when a guy found water in his exhaust of his freshly rebuilt 392 that he fired on a test stand. he replaced the head gasket on that side but he still had water. dummy me told him about the exhaust studs going into the water passage. he was thinking he had a cracked head.
This was the reason for Chrysler using studs in these early heads while new. They used them into the '70's also on all there engines. Harry Hunter
The top exhaust header bolts go into the head oil return and the lower bolts go into the water jacket. Use high temp thread sealer like permatex copper or arp pipe thread sealer will work. Chrysler used studs for exhaust and valve covers for that reason. I used the permatex copper high temp on my 392 on the header and valve cover bolts and it sealed them. just don't put it on where it can get into the water jacket, threads only would be enough.
Put "Hemi Tech Index" in search & start reading! The Index Thread will provide hours of reading! Valve covers: top should have studs because of water, botton uses bolts
Ok, so when you decide to take them out Drain the coolant first or you'll have a mess squirting off to the side of your ride. 100% on using studs, Sealant of your choice should be a brush able Teflon paste. ARP stuff is great. I also slightly foul the thread on the center of the stud not the end. That usually ensures the stud stays put until I want to move it. You can't really use sealer and lock tight on the same stud. Any time those come loose you get a leak, anytime you want to fix a leak you need to drain the systems .
I had a lot of antifreeze coming through my valve covers during test stand startup of my 392. I had early Hot Heads heads. Studs stopped the leaks. Their newer heads do not have the water jacket problem.
No studs anywhere on the valve covers or the headers. Just bolts. Looks like they've been leaking a long time. Freeze plugs leak too- nearly every one of them. They have a bolt in the middle of them. Tricks to sealing them up too? This motor sat a very long time after build. Can't have more than 1200 miles on it. Just leaks like a sieve everywhere! Griffin X flow radiator installed low- a lot lower than the water neck on cross over. Hose has a fill in line & I'm sure the cap is junk. Pukes water out overflow hose (no catch can) too. This motor is in that chopped 41 Willys I posted about in another thread. I picked this car up for the right price. New aluminum heads are on my short list. These are cast iron.
No shit. The harder I look, the more I find it needs. This car build started out as a B gas car. The build stalled & was finished up for the street instead. Well, sorta finished. I have to finish it now. I'm kinda excited about it to tell the truth. I have the money to finish the car, unless things escalate to stupid. Hope you guys don't mind the stupid newbie Hemi questions. I'm not opposed to pulling the motor out & going through it just to be sure. Just some FYI- I pulled the dipstick & oil is like new. No signs of water. Oh and BTW- who's the dumb fuck who though to stick the oil fill in the rear of the finned valley cover instead of the front? It's under my 871 BDS blower! Lots of access in front. I believe the manifold & cover are Hot Heads. Another item for the short list.
The bolt might tighten them up. If leaking around the edge...an application of JB Weld will seal it, but will make them hard to remove later. Alloy heads have a large loss of heat(power) from the better conductivity of aluminum. You need 1 point higher C/R to offset that. That's strange, never thought about if they can be put on backward, or was it made that way? Sounds like a PITA. Get to reading the Tech Index.
To start off with I would put studs in for the exhaust and use 12 sided nuts it is a lot easier to get the wrench in to tighten if using headers. If using bolts in the tops of the valve covers I would replace them with studs also. I would remove the freeze plugs and put some silicone sealer and reinstall.
I do not recommend silicone sealer on the freeze plugs. AFAIK, I was the first to make a front fill aluminum valley cover, but still will not clear with a low blower. The Hot Heads intake sits fairly high. The valley cover only fits one way. Good aluminum heads will make the same power as iron, without a 1 point compression increase. If you cant find studs, let me know. I stock replacement valve cover studs and ARP exhaust studs.
Oh and BTW- who's the dumb fuck who though to stick the oil fill in the rear of the finned valley cover instead of the front? It's under my 871 BDS blower! Lots of access in front. I believe the manifold & cover are Hot Heads. Another item for the short list.[/QUOTE] I hear ya on that Steve... I use a set Of Donovan water fills on each side of the Valve cover(If you have room)...and use them to oil fill. Just a suggestion.
You know I've never thought of it that way. I see it as the aluminum heads let you run more compression before heat related problems set in. The way you state this is that an aluminum head swap will net a loss in power if no compression change is made & an aluminum head swap needs bumped compression to net same power. Maybe I'm misunderstanding you ? Maybe my thoughts are wrong ? So where's the benefits with aluminum heads in your ideas or are there none ? Now in Steve's 32 case he could theoretically run more boost with aluminum heads. An increase in boost will certainly get more power out it.
In my case because of how tight the motor is in my car I was not able to use studs (wish I could!) the bottom row of header bolts go into the water jacket and the top row go into the rocker valley. Also the valve covers, the top row go into the water jacket, I used Teflon thread sealant on my bolts with good luck. The only freeze plugs I have had luck with on a blown motor is Hot Heads stainless steel o-ring bolt in plugs, noticed I said blown. Blown motors blow out the other freeze plugs, I know I didn't believe it at first but its true. You can read several storys about it right here in the HAMB, mine blew first time I stressed my motor in the car.
The usual benifits of alloy heads(on the typical V8 from Ford, GM, Chr) is lighter weight(for sure on a Hemi) and usually better port design/size, valve size, ect, than OEM heads from most of the OEMs. In the case of the Hemi the 55-56 heads are hard to beat. In generic terms lets say ACME makes 2 identical sets of heads that are identical except one is alloy & one is iron, the iron one will make more power do to less heat conductivity. If you would run 9:1 on a wedge you can run 10:1 with a hemi w/o having to increase your octane level because of the better chamber design. An increase to 12:1 would be needed to offset the conductivity, don't know if that would require an octane increase or not. It's a case of needing to run higher than allowing higher C/R.
So you are saying a 10:1 iron head engine making 400 hp would need to be 12:1 if using aluminum heads? No. You are wrong.
I hear you on the rear oil fill. I have that valley cover my self and I welded a fill tube to the front with a breather and used the rear fill cover for a pcv valve port. I don't know if this would work for you with the blower but here is a pic of where I added the fill tube to the front of mine.
no, what I was saying is...if everything else is equal you would need 11:1 in an alloy head to equal 10:1 out of the exact same head made of Iron. The 10 vs 12 was speculation about octane required, your supposed to be able run a hemi 1 point higher C/R on the same octane as a wedge, and the extra cooling of the alloy head would reduce detonation level a bit also.
Good idea but won't work for me. It would hit front of blower & snout. Just an O-ringed cap in front would be perfect.
I hear ya on that Steve... I use a set Of Donovan water fills on each side of the Valve cover(If you have room)...and use them to oil fill. Just a suggestion.[/QUOTE] I have plenty of room for one of those!!!! Link? I've been reading those tech threads- great work putting that together!
Not a big deal Steve...drill and tap, or if you have tin covers.. just some nice fasteners and use the gaskets that come with them.
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