The Stovebolt Site Forums The Shop Area Engine Shop 235 block differences

I need some help guys. I had a '55 235 in my '53 Chev 3/4 ton. Removed it and took a few photos before removal, but apparently not enough. Then bought a 235 out of a '61 Biscayne. There are some differences and now I'm trying to figure out where all the tubing lines go. Unfortunately, the newer motor was a bare motor with no oil filter, manifolds or anything else. Can someone describe where the oil filter hoses should connect and how they differ on 235's by year please? On the driver's side of the motor I have 3 threaded holes in a triangle shape toward the front of the motor. Same on both sides and I know these were for the front motor mounts because this was a car motor. Moving back on the driver's side of the block, there are 3 more threaded holes. One is slightly beneath the linkage for the clutch (I believe that's what it is) and the other two are at the bottom of the block and side by side about 3" apart. At the back is one more threaded hole, but that is the block water drain. I'm thinking the hole near the linkage is for one of the hoses to the oil filter, but I'm not sure. Can anyone help me out here? THanks.
Rick

.You are correct on the oil line port at that location.The other one is further toward the front of the blockby about 8 inches or so.I will have to look again at mine to see which one goes to the top of the filter and which to the bottom.Someone else might have a quicher answer,I will look as soon as I can.

http://home.nycap.rr.com/lederman/images/blockoil.jpg

If you have an AC canister filter, the inlet/outlet ports are labelled. Different types of canisters had the inlet/outlet ports at different locations.

The following AC filter has inlet on the side of the canister and outlet at the bottom. The filter drains when the engine stops. The inlet fitting has an adapter for the oil pressure gauge.

http://home.nycap.rr.com/lederman/images/54oilfilter.jpg

Tim

Mechainiac, I checked my block again and I have no other threaded hole forward on my block, other than the 3 holes I mentioned for the motor mounts. Bear in mind, this is a 235 block that came out of a car, so the front motor mounts were on the sides. You said I was correct on the one oil line port. Which one are you referring to? And Tclederman, my canister type does have the side inlet and the bottom outlet on the filter canister. Where I'm having trouble is trying to figure out which of the threaded ports on the block are for the filter. Someone out there must have 235 block set up like mine. Again, it is a '60 or '61 235 that came out of a '61 Biscayne. If it helps, the block casting number is 3769716. That is a Chev 58-62 235 block. Any help would sure be appreciated. Thanks.

Rick, Jen's is a '62, and is probably from a car. The triangle at the front, before the exhaust, has a threaded hole just to the rear of the triangle, with a fitting and a hose running up to the bottom of the cannister. The other fitting from the cannister, runs down to the bottom of the block, on the opposite side of the exhaust. I don't know if that was the right way to run an add-on filter, but that's the way this one is. Hope that helps...

This should be the way it is connected(the bolts he has in the pic are just to keep crud out).
[img]http://home.nycap.rr.com/lederman/images/blockoil.jpg[/img]

.Thanks to tcledermanfor the pic

Mechainiac, the photo helps. Looking at your, I have a threaded hole where you show the inlet line going. Then below, I have 2 threaded holes between your inlet line and the water drain cock, about 3" apart. Both follow along the ridge below the inlet line and one is almost straight below the inlet, the 2nd is 3" toward the rear. I would assume that either of those could work for the outlet line, but I'm curious as to what the second threaded hole is for. I wonder if one of the two was for the oil pressure gauge? You would think these would be pretty much the same on all 235's of that era. It obviously is set up for a by-pass filter. Thanks guys, and if anyone else has any input, let me know. If I can locate a digital camera, and if I can figure out how to post photos, I'll show you my setup.

.There is usually a "T" coming off the upper "To oil-filter outlet.It will "T" off for the oil line going to the oil guage.
.I take it from what you have said that your engine does not have the other return from filter port that is lower and forward on the block.
.The ridge that has the port for the "to oil-filter" is an oil galley drilled the lenght of the block.The lower ports sholud drain back into the block.
.I would talk to Oly or Joy and see if they would be willing to help you with posting the pic.

OK, here is a picture of Ricks engine. His discription was very good indeed. He sure has an "extra hole here.-LOL Ricks engine

Forward of the #1 hole shown there is a plug.That should be the drain back into the oilpan.The #1 hole should be for the feed to the oil filter.
I would check with other people to make sure about the other hole and it`s purpose.

This could be a full pressure oil system as it is a later engine!!!

Hey Oly, thanks for posting the photo for me. I appreciate it. I have a little more information about this, but I'm still stumped. This is a '60 235. I checked the photos of the motor when I first looked at it at the junk yard. At that time, it still had the fly wheel and the manifolds, carb and air cleaner on it. But no oil filter is present in the photos. From the threaded hole that I marked on my photo as "oil filter intake" there was an oil line with a t-connect. This line went around behind the motor and above the fly wheel. It attached to a threaded hole at the top of the motor just forward of the coil. Looks like it was intended to feed oil to the other side of the motor. From what you guys have said, it sounds like the oil pressure gauge would connect at the t-connect threaded hole that was left, which leaves no room for this to be to the oil filter intake. Am I right so far, or would the t-connect be for the filter and the pressure gauge connect elsewhere? I'm now starting to wonder if this motor ever had a by-pass filter. Is that possible and have it be original for a '60? If I'm right about the t-connect being for the oil pressure gauge then that only leaves threaded holes #1 and #2 for the filter. Mechainiac, the plug you mention forward of hole #1 was already inserted and tight, so when the motor was taken to the junk yard, there was no filter hose connecting there. Also, looking at the old photos I took at the junk yard, the air cleaner was mounted forward of the carb on the manifold, so the only place there would be room for an oil filter mounted on the manifold would be to the rear of the carb, which puts it above the two threaded holes 1 and 2. I'm still stumped. What did you mean that this could be a full pressure oil system? What would that mean? No filter? Unfortunately, when I bought the motor, the wrecking yard owner had already removed the air cleaner, carb, manifolds and fly wheel. Glad I took the photos before I bought it or I wouldn't even have this much information.

Here is some info on the full pressure engines Full pressure

Yes, I had seen the article before. But it appears that even with a full flow system (if that's what I have), there should be an oil filter. I'm still trying to figure it out. Thanks.

Line running to other side of engine was probly to head and fed rocker's as orig path may have been blocked. We discussed this on old thread somewhere here. Aftermarket kits used outside line to get oil to the rockers. You run a pressure/pump test with drill to chck for oil feed to top?
I'm thinking that both those lower holes are returns to pan. Upper one is in the oil gallery that feeds to all engine prts.
Those side holes should be "Engine Mounts" not "Motor mounts". This is an engine, motors are electric!
One other thing.....Engine won't run/start with all that tape over the intake holes! :p

Regarding the full-flow oil filter system on '58-'62 truck engines:

1. Was the full-flow oil filter system available on the 235 engine? I understand it was only available on the '58-'62 261 engine sold as on option on USA trucks (not the 261 in Canada).

2. It is my understanding that an oil filter was still an option on the '58-'62 261 truck engines. As I recall, when adding an oil filter to one of these engines, a bypass in the block had to be changed (it might have been mentioned in the 261 article posted above).

3. I was told (by Patrick's, after buying a beehive filter) that a canister-style oil filter could not be installed on a full-flow engine (I know for certain that one would not work on my 1960 261).

4. The '58-'62 261 block's holes for the oil filter lines are much larger diameter than the holes for the by-pass filter (1/2" NPT ? - approximately a 7/8" hole, as I recall). I will post a picture tonight or tomorrow.

Hope this is correct and that it helps eliminate some "possibilities".

Tim

1) Early 50's "Powerglide" 235 and later car engines were full-flow high pressure engines but never had full-flow remote oil filtration. That was for 261 only.

2) Correct, factory made the filter unit optional because of fleet requirements. There is a dowel in the block that must be punched in to block the filter in & out connections, forcing oil out to the filter. If frozen in place, it can be risky trying to move this dowel.

3) Beehive filter just replaces the cannister - line size is too small for the big 261 lines.

The best way to be certain on the filter lines is to pull the pan and follow the oil pump path to the main oil galley. This path will be under oil pressure and will have a threaded hole for a pipe fitting out to the filter. Check the 2 lower holes and at least one should go all the way through the block into the crank case. This is the return path. Use the most convenient one and plug the other. Or (my preference) plug all holes, forget the bypass filter and change your oil frequently.

Hey GL, I wondered where you've been. So you're thinking that line may have been aftermarker, huh? Makes some sense. I had the ENGINE back together, but had already decided to pull the oil pan one more time and put in a new pump, so I'll check a few things while I have the pan off again. If both of the lower holes are returns to the pan as you said, one of those should work for the filter output and I guess I would plug the other. The upper one (marked oil filter intake on my photo) would be for the intake as thought. Right? It is in the oil gallery. I ran a bore brush through the gallery and it's pretty clean. Couldn't get the plug out on the other side of the engine to check that one, but it's probably okay. Haven't been able to run a pressure test yet, but will once I get the new pump in and get ready to put the engine back in. So, if I have this right, I could remove the outside line, cap the hole on the spark plu side where the line went into the head, put a t-connect in at the one marked oil filter intake on my photo, run a line from there to the intake on the filter and use the other part of the t-connect for the oil pressure gauge, and use either of the two holes below for the oil filter outlet and plug the remaining one. Or if it turns out those two don't go into the pan, I could probably take the plug out of the one further forward by the side engine mount holes and use that for the return to the pan. If I have this all right, what I need is a line from the oil gallery to the filter intake and a line from the filter outlet to the oil pan. And it won't affect the oil pressure gauge if the intake to the filter and the connect to the pressure gauge are on the same t connect. Is that the way this should work? And Sixpack, if I'm following you, the main oil gallery threaded hole should be the oil filter intake. When I ran the bore brush through the oil gallery at that location, I got a little bit of carbon type material out and some came out through the threaded hole, so I know this one is threaded into the gallery like you said. I'm getting there, guys. Just have never seen a set-up like this one. Thanks and let me know if I'm on the right track.

The saga gets stranger. I pulled the oil pan and replaced the oil pump today. The only hole that goes through into the inside and would drain to the pan is the one I previously described that had a plug in it. The two threaded holes marked 1 and 2 on my photo do not go through into the oil gallery or into the interior of the block. To make matters stranger, I removed the rocker assemblies and checked the hole there for the oiler. It goes down about 2 inches and ends, so the only way I can see for oil to ever have gotten into the rockers is through the line that went around behind the engine and threaded into the hole near the coil on the opposite side of the head. Strangely, this threaded hole is drilled through to run right into a head bolt that sits inside the cylinder head. I tried shining light through to see if any gets past the bolt to the oiler hole and nope. Nothing there. I'm going to take a few more photos and send them to Oly in hopes he will post them so you can see what I'm dealing with. At this point, I can't see any way that there ever was an oil filter on this engine. The intake location at the gallery would have to have been for the intake on the filter, the exterior line that goes to the threaded hole on the other side forward of the coil and the oil pressure gauge. Can it be that a '60 235 for a car would not have had an oil filter even as original? Very strange indeed.

Rick, Look at this link in tech tips. I think this may be what has been done on your block. Look at your picture and the ones in the tech tip. Sure looks like it may be it. If you think so just e-mail me and I will get you set up right. Tech Tip

Hi Oly. I've looked at that tech tip several times and that's not what I've got. I'm starting to think the only way I can get this to work without drilling is to leave the oil filter off. I can then leave that bottom hole plugged and run the line back around as before. The only thing is, I can't figure out how the heck it gets oil to the rockers unless it can get past the inside head bolt I was talking about before. I'm going to put the oil pan on loosely and flip the engine back right side up. Then I can take a couple of photos to send you. Maybe you can figure it out. I have a Motors manual for several different years, but haven't found anything that shows this setup for oiling. Guess I need a shop manual for a '61 Biscayne. Then maybe I can see what the original looked like. Sure is frustrating! I haven't pulled the cam or the crankshaft and will put it back together before I do that. If the cam was out, maybe I could see underneath whether there is a hole through that oil galley. Can't feel up in there and can't see it with a light. Strange!

My '57 235 truck block feeds oil to the rockers through the head bolt like you describe. The bolt has a flat spot milled into it for that purpose. There is an oil line in the block that runs from under that bolt behind the side cover back and down to the lifter oil passage.

Hey 4onthefloor, that's encouraging. Maybe we have the same setup. Does your engine have a line that runs externally from the driver's side and screw into the head near the bolt you describe? Also, does your motor have an oil filter? If so, how is it set up?

The oil line 4onthefloor is talking about is located under the engine side-cover.It is not visible with the cover in place.
.I am still wondering about the two threaded holes that are toward the rear of your engine, are they blind holes for mounting something?

Yes, they only go in to the block itself and not through, so they were used to mount something. Just not sure what it would have been. I'm trying to find a '61 Chev passenger car shop manual so I can try to locate a photo of the 235 that went in the cars that year. I'm hoping that might give me a clue as to what would have been mounted there and where, if anywhere, the oil filter might have been connected. I have the side cover off, so I've seen the oil gallery under there and it has a plug in it that I suppose might be used to clean out a portion of the oil gallery. From what I can tell, this gallery comes up from the lifter gallery and is supposed to feed oil up to the rockers. The gallery comes up behind the head bolt to the rocker oiler. The threaded hole that enters on that side is drilled directly into the head bolt location. It could be that there is enough clearance for oil to get around the bolt, but it couldn't be much. I sent Oly some more photos to look at and possibly post that shows exactly what I'm talking about. I haven't seen them yet and haven't heard back from him, so he must be away for a day or two. I suppose the two back threaded holes could have been used to mount the oil filter, but seems a little low to me. By the way, for those of you who are reading this, maybe you can answer a question about the pressure gauge. If I can figure out a way to run a connection fitting to the main oil gallery, can I connect the oil line that runs around behind the engine, the pressure gauge and an oil filter inlet hose at that one plug without screwing anything up like the oil pressure? If it's a pressurized system, seems like this might work. Just have to find a connect that will allow for that many things. I don't want to drill a new hole into the main gallery. Afraid I might screw it up. And in spite of what several have said about not running a filter, I'd still like to have one.

I have my '60/'61 Factory Light Truck Manual and the oiling for the rockers feed off of the front and rear cam bearings. through a galley right at the bottom of the side cover, then up to the bottom of the headbolt hole and through a 1/16" orfice to the adjacent rocker oill feed on early models or a 11/32" hole on '59 and later engines. The rocker feed hole appears to be a blind hole, but the orfice is in the side toward the rear of the engine. You should be able to find it with a piece if small wire bent 90 degrees to put down the hole and see if you can hook into the side orfice. Make sure the wire is less than 1/16". This is all in the block. The oil path in the head should be clear through the head.

I also have a picture of the Full Flow oil filter on the 261. Its connections are like nothing I have seen on a 235, and they also have the note that "If oil filter lines are removed, connect a jumper between the fittings on the cylinder block. Do notplug fittings in cylinder block as this will cut off oil circulation". This is on Page 8-5 of the 1960 Chevrolet Truck Shop Manual