I have a 1953 331 Chrysler hemi, and I am to the point where I am ready to install my Hot Heads oil bypass plug, as I will be using a spin on oil filter. I read the directions, and it states that in there should be "what looks like a ring" that should be "loosened with a screwdriver". Well, all I see is a solid-looking thing that might be a plug? I have read that the very early 331's were already "full flow oiling", and might have a "cast plug" where the valve is supposed to be. Has anyone seen one of these "cast plugs", or do I have a valve, and just don't know what I'm looking at. I didn't think mine was early enough for full flow oiling, being a 1953. I tried sticking a rod down the oil pressure port, and it seems like it hits something pretty solid at the bottom. If this is the plug, I should not need to install a different oil bypass plug then, correct? I don't see anything from the bottom in there that looks like a ring at all. Does anyone have a pic of what the bottom of a bypass valve should look like? Any experienced hemi advice would be much appreciated!!
A number of them have been reported that wern't drilled all the way through, effectivly & literally blocking the passage. If it was drilled there would be a round sleeve/cage like thing that has a narrowed spot to hold the ball bearing check valve. It should be obvious i'd think if you can see down the hole.
I may be wrong here. But as I remember the early long bellhousing Chryslers had the relief in the filter adapter. I know the pad for the filter mount is different on the early motor and I believe you can not use a remote oil filter adapter made for the later motor. I don't remember a anti drain back check valve in the early block. If you are running soild lifters in your engine look to see where the oil passage comes from that runs to the lifters. You do have the rear main cap off, right?
Yes, I have the rear main cap off. The filter assembly was HUGE, so maybe it was in that. I still have it somewhere. I am going to use the adapter that mounts to the engine, with the filter in an upright position. What are the differences in adapters? I bought it from Hot Heads also. It is a long-bellhouse block. Thanks for the help, any more info is also appreciated!
Take a piece of solid rod and smack it with a hammer. Most of the time the factory plugs are stuck in place and need some persuasion in order to come out. This is what you will find is stuck in there and this is what the bypass plug from Hot Heads replaces.
Which part in that pic is at the bottom where you can see from under the rear cap? Do you have a pic looking at it from under the rear cap?
As I understand it, yhat thing is to keep oil from running back from the hydrlic lifters on shut down. So they don't clatter on fire up. The plug is just to cut off oil to the lifters since if you have put in a solid lifter cam you don't need it and the oil would be better used on the mains and rods. If you still have hydrailics you can't plug the passage or your lifters will never pump up. In the old days we just used a plug to pound in the hole. Didn't buy a pretty blue thing.
Also, if you look at a long bell filter mount pad you will see a hole for oil that is bypassed by the pressure relief to return to the pan. I believe that the later short blocks have the pressure relief built into the pump. So if you use an oil filter mount or bypass ment for the later block on an earlier block you will have mucho oil pressure because you have no pressure relief. Or no pressure since it will all go in that extra hole. Check with Hot Heads on this.
The oil comes up from the pump & the plug/check valve directs it to the filter. The oil comes back in above the check valve/block. The check valve is designed to open if the filter clogs up. There wasn't detergent oil back then & precautions were taken in case people didn't change oil filters. If you leave the block out the oil goes unfiltered, preventing drain back may play a role but main thing is oil will bypass the filter. If there is no check valve there, just solid metal, you might leave it alone where the solvents can come into the block from top & bottom anyway.
I had a 392 in my Vega for a while. I could be wrong but as I remember all the oil from the pump came out the lower hole on the filter mount pad. At that point I tapped my block and ran a hose to a remote filter. The return from the filter went into the upper hole and from there to the oil gallerys. Because I had pounder a plug into the place the chack valve had been no oil went to the lifter oil gallerys. But with or with out the stock oil filter and plug all the oil that wasn't bypassed by the pressure relief went through the filter. As I remember.
I have a 1952 331 chrysler hemi. I went into a panic after we had the motor all together and didn't use the by pass valve. I contacted Hot Heads and felt pretty comfortable that I could go forward without changing the valve. Speak with Mr. Walker and give him the details about your engine. I don't think the early extended bell engines need the bypass as far as I recall from my conversation. An earlier post mentioned the reason for the bypass being a clogged filter. I don't think that should be an issue in today's day due to the detergents in the oil. Make sure you use a quality filter. To give you some comfort, contact Hot Heads.
Oil to lifter galley. The check valve remains closed except when the pressure of pushing oil through the filter gets above a trigger point. Under normal conditions it remains closed, in theory, all the time. The only way oil would be cut off from where it would normally go was if the plug ended up somewhere beside between the lower & upper passages.
Do you have a Chrysler to look at? Oil from the pump runs out the lower hole to the filter. Oil out of the filter runs in the upper hole to the oil gallerys and oil pressure port. If there is no oil passing through the filter this check valve aint doing dick because no oil is getting to it. The plugged filter valve is either in the filter adapter or more likely built into the filter it self. Get a Motor Manual or something and trace the oil passages and tell me how that anti drain back has anything to do with a plugged filter.
4 331s. No oil getting to the check valve? That's the 1st thing the oil encounters leaving the pump. When closed it directs the oil out to the filter instead of going on up in the block. If you plugged off the oil filter passages the oil goes through the check valve & the engine oils, just with unfiltered oil. Where we have detergent oil & do regular oil changes the check valve becomes unnessesary & is replaced by a solid block between the upper & lower passage There is some thought that the spin on filter may have a higher flow resistance that might cause the check valve to open as another reason to replace it.
Now that you mention it, I do have a 3rd hole where the filter adapter bolts on. If I use an aftermerket adapter, it will block off this 3rd hole, as far as I can tell. Is this going to create a problem? Also I opened up my adapter, and it has a flat gasket to go behind it, should I be using this or o-rings around the oil in/out passages? I am leaning toward the flat gasket, since that will seal up that 3rd hole off to the side.
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