OK, I have researched the hell out of this and I have looked at a bunch of setups and I still don't have a certain idea of how to route the oiling for my 1960 235. Here's what's up right now: Oil comes out of the pressure port on the rear, lower, driver's side of the block. It feeds through 1/4" line to the bypass (factory) oil filter housing. It goes into the top side of the housing, and has a T on entry with the oil pressure gauge sender. From the bottom of the oil filter housing, another 1/4" line runs to the passenger side of the head, in the middle, to a nipple that feeds the rocker oilers. Car runs fine, but has about 30psi cold of oil pressure and 5psi at hot idle. At cruise, it sits around 20psi for the most part. Never drops below that at 1000rpm or more. This is with 15/40 oil. Does this sound right? I just picked up another 235 and it had a pet-cock style adjustable valve just before the line entered the head, I assume this was to regulate pressure to the rockers, but I am not sure. Thanks
My 235 years ago was nowhere like that. The rocker oiling came from inside the engine. I had a 1/8" pipe plug centered on the passenger side of the head or block. That is probably where your line from the filter is going. I would probably look on www.stovebolt.com for more answers. I don't believe your oiling system is correct. BTW: I had to get one of those weird head bolts that allowed oil to reach the rockers from the inside of the engine.
Well, my oil from the filter does go to the passenger side of the head. I have verified that this oils the rockers (though I understand that some engines also had the slotted bolt that fed oil up from the bottom) The engine was plumbed like this when I got it. It runs great and seems happy, with no excess valvetrain clatter and clean oil. I just think the oil pressure is lower than it should be and I wonder if the oil routing is wrong or if I am missing some kind of restrictor in the line. I've put over 800 miles on it since I got it, with no issue, but I want to be sure.
running the oil line over to the side of the head is a band-aid solution to not getting enough oil to the rockers. Usually because of a problem with the oil passage between the block and head becoming slugged up. Some people put them on whether they needed to or not because they didn't know any better. Removing it will improve your oil pressure. I doubt it needs the line anyway. You could put a valve on it and experiment.... Make sure you have '58-62 rocker arms on a '58-62 engine, otherwise it will not oil properly.
Originally the line you now have going to the head was plumbed to the block. That return line need,s some restriction as it may cause loss in oil pressure. I used to flatten the metal lines that where used with the old overhead oiler kits that where installed on almost every Y block ford back in the day. You seen them on chev and ford sixes also. Some 235,s used a special head bolt & some had a metal tube located in the lifter galley. If the rockers have been run dry and you get oil going to them again its likely that thay are worn and will cause oil pressure reduction. OldWolf
the oil line under the side cover was removed starting in 1958. The drilled head bolt was a factory solution to shops trying to put '53-57 rockers on a '58-62 block. With the redesign of the block in 1958, the flow control of oil to the rockers moved from the block to the rockers themselves. That's why if you put the earlier rockers onto the later engines you will end up with too much oil at the top end. To solve this, then came up with the drilled head bolt which controlled the oil flow. It also required plugging the original passage at the top of the block, otherwise you would have nothing to force the oil through the bolt. The changes to the internal oiling system are well documented in any '58-62 factory shop manual.
Thanks for the info guys. Is there a HAMB-Friendly source for a factory manual or is Amazon or Ebay my best bet? I'll try a valve today. I folded the rubber line off that went to the head and zip tied it last night for a quick test and the oil pressure seemed to pick up a bit with no rocker noise. I'll pull the valve cover and see how the oiling looks with the line plugged.
Remove the small pipe plug on the middle right of a 58-62 head and you'll see the drilled restriction hole inside.It's .062,by the way,the same as the rocker oil feed restriction on GMC inline 6's So somewhere you need to restrict the rocker oiling.The slotted factory head bolt is a bullshit fable.Old time hacks who didn't understand 235 rocker oiling slotted the bolt thinking it would help .
swapmeets, ebay, any place that sells parts for old Chevies, etc... will have shop manuals.... just to clarify, the change to the oil restriction occurred in the block, not the head. All '53-62 heads are the same except for chamber volume, and the size of the hole for the temp sender.
Found this info a minute ago. Pictures are helpful. I am gonna block the line going to head off this afternoon and if all is well, I'll re-route the drain back into the block. http://chevy.oldcarmanualproject.com/miscellaneous/oilcanister.htm
I will continue to disagree and maybe in the end I will be wrong as usual But.....I just checked a 58-62 261 block sitting on my engine stand.I'm thinking the 261 oiling is identical to the 235 of same years.The oil feed for the rockers extend down from the center right head bolt hole into the oil galley that is drilled from front to back to supply oil to the lifters.I used a length of .125 electrical wire that went in very easily.The oil galley is feed from front and rear cam bearings,no restriction to be seen. The 848 head on the stock 58 block in my 50 truck for sure has a .062 restriction under the plug in the center of the head...
I have a 235 that is supposively a 57 that I had to grind a slot through the threads of the head bolt to get oil to the rockers,what did I do wrong when I assembled the motor to stop the oil flow.
Bolt is most likely too long in my opinion.Looking at a bare block, the "by pass" for the rocker feed is about an 1-1/2 inches below the block deck.
OK, here is what I found. The port on the head appears to not have any sort of restriction. I've Removed the feed from the oil filter and I still have rocker oil, just fine. Oil pressure is now 35 at idle, so that is cool. I just removed the whole bypass filter since its ugly and apparently not all that effective. 1500 mile oil changes are no problem. The head is an 848, FWIW
So the return line from the filter needs a restriction,I know it does not have one on my 235 since I just bought some flexible lines that would work from a local parts store. I thought my motor should have more oil pressure then what it shows on the gauge and will have to look into that.
junkyardjeff, that's exactly whats been bugging me since I started driving the car. I've been going round and round on it. Going for a drive now to see how she does with warm oil
After I figured the rockers were not getting any oil I was told to grind a slot through the threads and it started to oil on the top,I picked up another head bolt that had been drilled and enlarged the holes some and seems to be getting enough oil. I dont think these motors are supposed to get alot of oil like the late models but was wanting it to get oil a little quicker after fired up,on mine it has to run a couple minutes before any oil started to drip out of the rockers which I thought was too long but might be the norm.
at least your right about the 261 oiling the same as a 235... Please look at a 1959 truck shop manual.... under the pushrod cover there is a 1/8"NPT plug in the middle of the block. Behind that is the orifice that controls oil flow up to the head. '58 is 1/16" diameter. In '59 it changed to 11/32". In conjunction with this change, they made the grooves inside the rocker shafts smaller and offset them a 1/4". It's all in the manual.... once the oil gets to the top of the block, it sidesteps over to the gap around the head bolt via the triangular hole in the head gasket. It travels upward around the outside of that head bolt till it gets to the horizontal hole that is drilled in the head from the outside (which is why there is a 1/8"NPT plug on the outside of the head), and then it goes up that funky piece in the middle of the rocker assembly and then to all of the rockers.... The earlier engines do not have the oil passage coming up from the lifter galley as shown in the pictures. Instead they have an oil line that takes oil from the rear cam bearing and brings it to the middle where that orifice is. This orifice controls the amount of oil getting to the top of the earlier engines. To prevent this from getting plugged up with crap, they opened up the orifice to 11/32" and made the oil control at the rockers instead for the later engines.
Take the oil canister apart and look at the post in the middle. There is a small hole drilled in the side of it. That's what controls oil flow with one of these filters, not the lines or fittings.
Well fuck a duck,I'm wrong once again Thanks for taking the time to find the description in the service manual.Man,I rebuilt two 235's and two 261's over the last 12 years and they all ran excellent.And they were all a mismatch of parts for different years.
Yes, sometimes it can take awhile to get the juices flowing in these. especially if it's a tired engine with thick oil on a cold day... Put in "normal" parts and then take a look after it's warmed up. If it's fine after warmed up, you shouldn't need to worry about it.
Apparently not as mismatched as you thought! Time to play the lottery.... some of this stuff can be put together wrong, and the engine will still run, just not like it should....
Rebuilt with less then 10,000 miles,I use straight 30 weight oil and after warmed up there is plenty of oil flowing out the return tube on the rocker connector or what ever that part is called. I have seen on the 58 and newer 235s the return tube on the connector part was pinched off from the factory and thinking about getting one so all the oil goes in the rockers.
yeah, just flatten the one you have. No need to replace it if you don't have to... BTW, Chevies are even tougher without ford stuff......
Not this Chevy,I have to add Ford parts to keep it going. The 235 has a noise which is most likely piston slap in the cylinder that was sleeved so if it gets yanked its time for some good Ford power. I never had a good sbc and it looks like this ones not that great too so time for a motor that I am more familiar with,cracked cylinder and a cam with bad lobes should have told me to stay away after the two terrible 350s I had in a 67 C20 plus the bad 250 that originally came in it.
This thread is pretty old I know but I'm wondering if you guys can help me out. I just picked up 1960 848 head with no rocker assembly that I'm planning on matching up to a 54 block. I have a 53 235 rocker assembly lying around the shop can i use it on the 60 head as long as I put a drilled head bolt in with it to restrict oil flow? Sent from my SM-G935V using The H.A.M.B. mobile app
I think you should be ok,there is a problem with putting later heads on the earlier blocks which I think will cause a lack of oil to the rockers that a drilled head bolt should solve.
I think what I've read is that with the late head on the early blocks there is to much oil at the rockers and it squires everywhere and doesn't just dribble out like it's supposed to Sent from my SM-G935V using The H.A.M.B. mobile app
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