Hello everybody! Somebody added a remote spin in filter to the 235 in my recently acquired '60 Chevy. They just ran 3/8" fuel line from the fittings on the block to the filter and back to the block. I have read about people converting the bypass system to full flow, and that they usually use 3/8" line rather than the 1/4" like the bypass system. Since I am not familiar with these engines I dont know how to tell if this modification was done, or if the PO did a botched job of installing a filter (other than the obvious). I can only seem to find threads talking about the pros and cons, but I haven't actually seen an article on how to do it so I can tell if that's what they did... At any rate, I want to replace the poorly routed fuel line with steel line, and I want to know if I should use 1/4" or 3/8", and weather or not I need to install a restrictor. I am also uncertain of weather or not the restrictor goes before or after the filter... Thanks in advance!!!
My guess is, someone installed a filter on an engine that didn't have one, or replaced the cannister filter with a spin on. They did not know the difference between a bypass and full flow, they just used an off the shelf remote filter adapter. But, that is only a guess. Careful examination should tell the tale. If the 3/8 lines are adapted to the stock fittings in the block my guess is probably correct. If so, you would be better off with the bypass filter. The full flow is too coarse and will not do as good a job of filtering. There are Frantz filters and others, that do an excellent job using a roll of toilet tissue as a filter. I think there are other brands made Down Under, that you can buy locally. Later...... Found this. Don't know anything about them, they turned up in a web search. They sell Australian made bypass filters for cars and trucks. http://jackmasteroilfilters.com.au/index.html Still later..... Mistook the first response for the original post - I see now you are not in Australia but in Arizona. If you can't find a bypass filter there is the Frantz filter. There are others like Stilko . OEM filter used 1/4 lines and no restricter. Frantz uses 3/8 lines with a restriction hole on the inlet side. Even later...... disregard most of what I wrote above. You can buy a fine filtering bypass spin on oil filter, I found out. Two models that came up were Wix 51050 and Hastings B50. They have the restriction on the return side, the filter itself is under full pressure. So, you can use the convenient spin on filter adapter and just buy the bypass type filter for it.
Carefully trace the lines to the block. One line receives oil pressure off a large rib paralell to the oil pan - the main oil galley. You should also see the oil pressure sending unit tapped into it. The second line (return) is tapped into the block just above the oil pan. If BOTH lines come off the rib, you have full-flow filtration, but I think that is unlikely - these filters were dealer installed or added by an owner at some point. I KNOW Sears (Allstate brand) and Fram sold accessory filters, along with several others, all were were mounted on the intake manifold. Send me a PM if you are interested in one - think I have an extra I can dig up. Good Luck, Tim
To make it full flow it is necessary block the oil pump from feeding the internal oil gallery with a plug, tapping into the space below the plug on the outside of the block to run a line to the external filter. A line from the filter the feeds into the engine oil gallery. I tap these for 3/8" pipe fittings. The filter then has the bypass if wanted. I am not exactly familiar with the 235 as I am with the GMC but all work is done when the engine is bare block. I normally do this using -10 AN fittings and drill out the 3/8" as large as possible without loosing strength. These are racing engines but 90% of the GMC's in the Inliners International do this on every engine and I am sure there are provisions to do the same thing on a 235. Good luck
Contrary to popular opinion the bypass filter is just as good as the full flow as far as engine life goes. The full flow is a must only on engines with hydraulic lifters. So if you have the bypass filter keep it, just be sure to use the correct filter.
Many of those 235s have hydraulic lifters and they are still going so I don't buy that "must have" deal.
If you read about the screw on filter you use, you can see that many of them have an inturnal bypass. Oil pumps have them too so over time all the oil will go thru your filter. The old Frantz toilet paper ones really kept the oil clean and it was a total bypass usually fed off the oil pressure sending unit port.
Thanks for the replies! I just got home and am waiting for my phone to charge enough to go take some pictures. It seems like it is set up like a bypass filter, but that it is just done incorrectly. . Regarding the Wix 51050, you said it has a restriction on the return side. Does this mean that I would forgo adding a restriction fitting in the block? Also, would this filter require 3/8" or 1/4" line to and from the filter? I'm thinking that if I stick with the six in this car I might like to switch to either a Frantz type filter or an OE style canister and sell the spin on set up, just for aesthetics.
I totally missed that the return from the oil filter on this engine goes to the port on the passenger side of the head. From what I've read this is wrong for my head, casting number is 3836848. I cant read the block casting number because the motor mount is in the way, but the date code is July 9th, 1958. (side question: I understand that this would make it a 1959 model year engine, having been cast in '58. Is this correct? Would this indicate it is not the original engine, or would they have been using these blocks still in 1960?) It seems like this motor/head combo should be internally oiled, and the port on the head should be plugged. I also see that I should verify that the correct rocker assembly is installed, but I'm not sure how to tell... any advice here? I still haven't got pics because its too dark, but I'll try to snap a few before I leave for work in the morning..
Up until '58 or '59, there was a 1/8 supply line to feed the rockers from the rear cam bearing. It didn't take much crud to plug the line, shut off oil to the rockers. The easy fix was to feed the rockers with an external line. Along that time period, the block was drilled from the center cam bearing to the head, eliminating the line - that passage could also be plugged. Nothing wrong with an external feed, as long as the rockers are oiling. I'd pull the push rod cover, see if you have the line. Clean it with brake or carb spray, along with the passages in the head and upper block. The internal passage is tougher to unplug - soaking with a solvent might help maybe - hard to access without pulling the rocker assembly (or maybe the head) at least to stick a wire through. Do what you can for cleaning now, short of a tear-down - you have the external line to fall back on! Good Luck, Tim
I bought a 57 pickup with a 235 that was an old Air Force truck, blue with black numbers stenciled on the hood, and it had a long 56/57 car style full flow canister filter on the lower left side of the block. This is a picture of the after market full flow kit; not as nice as the AF one.
Thanks for the help, man! Is there anything I should check for with the rockers? I read the 53-57 rockers are different than the '58-62 in how much oil they flow, but I'm not sure how you tell without disassembling them, or weather or not that is even important in my case. Will it be obvious if they are oiling properly? I haven't opened it up yet, but I plan to tomorrow morning or afternoon.
Got the valve cover off today but haven't started the car with it off yet. I looks like there are at least two different types of rockers in no particular order. Looking in my service manual I know there are right and left hand intake and exhaust but this doesn't seem to correspond to which ones are ribbed and not. My plan of action I suppose is just going to be firing the engine with the line connected and then firing it with it plugged and checking to see that there is a dribble of oil coming out of each rocker, and not a spray or no oil. This is what I have gleaned from reading related threads, anyways.. Ill post my findings later thus afternoon! Here you can see the two different casting types for the rockers.. Are these early and late rockers mixed on the same shaft or what? In this next picture you can see the fuel line they used. This is the return for the oil filter.
Well, fired it up as is and oil was DUMPING out the rockers like crazy. Not a spray, but a LOT of volume. It couldn't drain back fast enough and almost immediately overflowed the head. I disconnected the oil lines and installed pipe plugs, fired it up, and I get a trickle of oil from the rockers now. It did take about a minute to get oil to the front three rockers. The rear shaft got oil immediately, and then the front rockers got oil one at a time. From videos I've seen, etc, a small trickle is ideal, but I'm not sure 100% what is correct.. Thanks again for the help and advice guys!! Now I just have to get the valve cover back on and get to cruising!
Ok, one more question for you guys.... While waiting for my valve cover gasket to get to the parts store I was reading about crimped vs uncrimped overflow tubes on the rockers.... I do notice that mine flows quite a high volume of oil back into the head. Would I be helping or hurting if I crimoed this to get more pressure to the rockers? I'm not really sure what benefit it is having LESS pressure to the rockers the way the overflow is set up from factory....
If ther rockers are dripping oil off the with some coming out of the top hole you have enough oil up top. The best way on one of these engines is to remove the distributor and get about a 12" screw drive blade in a 1/2" drill and run it. You can watch all the oil flow and you don't need any special top seal like SBC. If some one can crank it over at the same all the better..
So before I installed the valve cover I did crimp the return line because while there was oil coming out of the rocker holes, there wasn't a lot dripping from them. I used my best judgement and crimped the tube AFTER the small hole at the top of the arch, so some oil still comes out of that hole while pressure to the rockers is increased enough to get a good amount of oil from them. I still havent hooked up a pressure gauge (need to pick up some fittings) but it does run smooth and quite, and at least has enough pressure to keep the dummy light off.
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