The Stovebolt Site Forums The Shop Area Engine Shop question about tech tip 235/261 Pressure Oiling

I've got my motor completely apart at my brother's shop and I thought, hey - since its apart maybe I could add this full pressure oil filter I read about. However, when he read it - and looked at my block - he said he can't figure out how the mains will get any oil if you plug the passage to the mains as described in step one. He asked if there was another passage he's not seeing because it looks to him that if he plugs that, its not going to get any oil. Are we missing something, or is this even something that I should be trying (or need to)? I just thought since it was apart I'd try it, but if I don't even need to, maybe its not worth the trouble? Any ideas?

Do you have the splash version of the 1953 235? If so, you can't do the conversion as stated.

sorry, I guess I should have said: We're working on a 235 from a 1956 car (had a hydromatic behind it). Its a full pressure.

First let me state that my opinion on this topic is the complete opposite of conventional wisdom and my suggestion is don't do it. I researched pretty thoroughly and concluded that the decision on whether the oil is filtered or not is done by a spring and disc inside the filter. Anytime the pressure differential between the in and out side of the filter exceeds around 15 PSI (depending on manufacturer) the oil is let on by without any filtering. During cold starts, hard acceleration, dirty filter, etc. no oil is filtered. This made sense to me as I can find no example where an engine failed due to a clogged filter as oil to the bearings takes priority over cleanliness. I believe a modern, high effiency bypass filter will do a better job of keeping the oil clean and as such I run an Amsoil bypass filter with an effiency rating of 98% at 2 microns absolute and think my oil would beat any full flow setup in a lab analysis comparison. Spend your block machining money on zero decking and a modern one pc. rear seal conversion.

(flame proof suit on)

hey Curt B., thanks for the info. By high efficency bypass fiter do you mean using a good cartridge filter (you said "Amsoil") in the canister that's on the engine already (the one attached to the intake/exhaust manifold)? Also, what do you mean when you say spend your block machining money on "zero decking and a modern one pc. rear seal conversion"? I'm not sure what "zero decking and a modern one pc. rear seal conversion" is, but since my brother is having all this work done for me, if I ask him to do it he will, if I don't - he won't - but I have to know what it is I'm asking for! Thanks,

Sorry for rambling and I will elaborate.

This is what I am describing for filtering:

http://s176.photobucket.com/albums/w186/curt160/filters/?action=view&current=Picture002.jpg

And this is what I am referring to regarding the rear seal:

http://www.enginebuildermag.com/Article/1766/old_iron_sealing_stovebolt_chevy_engines.aspx

Zero decking involves assembling the bottom end, determining how far the pistons are below the deck and then disassembling and removing that value from the deck surface to increase compression but retain valve train geometry.

Get your bro to read this article too:

http://www.selectric.org/55chevy/soup.html

INtersting, I was just talking to an AMsoil rep about their product the other day. They were marketing it to all the Dodge/Mercedes Diesel Sprinter vans that everyone in the vintage motorbike scene here seems to have. He was telling me he put one in his wife's suburban (modern) and when he went to change the oil it looked spotless, after 5K miles!
I think a bypass filter is a great idea, especially for diesels as particulates, kill the oil pretty quickly. I'll go with both (a pressure filter and a bypass filter) on my 261 build.

Jeremy

Did we ever answer the question in the original post by Paul's53chevy? If one does want to convert to a full flow filter, follow the steps in this Tech Tip. The hole that is drilled and tapped in steps 2-4 will intercept the main discharge passage from the oil pump before the plug that is installed in step one.

When I started my most recent engine build in 2005 I decided to add the full-flow filter to my 1954 261 engine, and followed the instructions in the link above and in the Inliners' Tech Tips . The statement that "The next hole you will drill from scratch and may be a little scary for the first timer." is an understatement. I was terrified, so I set up the block on my small milling machine to drill and tap the holes for the 3/8" NPT fittings. Using a tapered reamer after drilling the holes also helps. The installation worked out ok.

Subsequently, after conducting some real research, I have come to the same conclusion as Curt B, Jerry, and others, that a good bypass filter may be a better solution. The lubrication handbooks I located also recommend using both a full flow and a bypass filter for optimum filtering, with a differential pressure measurement across the full-flow flow filter so that you know when it may be in its own bypass mode. I believe that Jerry and others have said that they have seen this used.

Hoyt

thanks so much hoyt, I was kind of hoping someone would answer it for me. I'll email this to my brother and see what he thinks. Thanks