Marine Remote oil filter question

[LouC]

Ok I’ve been wanting to install a remote oil filter set up on my 1988 marine GM 4.3 V6. This would allow me to change the oil & filter without having to remove half of the rear seat. I got a nice remote filter kit for this engine from Michigan Motorz. What I have heard from a few engine experts is it is recommended to change the bypass valve in the oil filter mount pad on the engine from the standard 11 psi one to a 30 lb one. The explanation given is that the oil lines add extra resistance to flow which might cause the bypass to open and allow unfiltered oil to bypass the filter. The guys at Michigan Motorz sell a lot of turn key engines with these remote oil filter set ups so I think if there were problems they would have changed how they set them up.
BTW, sone oil filters have a bypass & sone don’t. The Wix filter that came with the kit I bought does have an 11 lb bypass so even if you had the 30 lb bypass on the block the one in the filter could still open.
Thoughts?

 

[ZeeOSix]

What I have heard from a few engine experts is it is recommended to change the bypass valve in the oil filter mount pad on the engine from the standard 11 psi one to a 30 lb one. The explanation given is that the oil lines add extra resistance to flow which might cause the bypass to open and allow unfiltered oil to bypass the filter.

If the filter bypass valve is in the block that the filters mount to, then it's only operating on the pressure difference (dP) across the filter block. so it doesn't matter how long the oil lines are. A bunch of long oil lines to a remote filter setup would have more effect on the oil pump pressure relief valve, not on the filter bypass valve in the filter mount block.

 

[nate379]

Size the lines properly.

 

[fantastic]

I'd say go with the 30 and use a filter w/built in bypass. It's ok that the filter has a psi range so a specific psi isn't all that important other than staying below 30 which will be easy since most filters are not that high.

 

[LouC]

I did some research on how the OEMs set these up. Mercruiser sells accessory kits for engines that didn’t come with the remote filter set up & they don’t provide a different bypass valve vs what’s already in the engine. I also looked at Crusader engines catalog & for engines that only have the remote filter; the bypass isn’t changed. However if they also have an external oil cooler in addition to the remote oil filter then they do replace the standard 8-11 psi by pass with a 20 psi bypass.
The lines that came with the kit are 1/2”. The spin on filter is about double the size of a standard Merc/Quicksilver or Sierra filter for the 4.3.

 

[ZeeOSix]

I did some research on how the OEMs set these up. Mercruiser sells accessory kits for engines that didn’t come with the remote filter set up & they don’t provide a different bypass valve vs what’s already in the engine. I also looked at Crusader engines catalog & for engines that only have the remote filter; the bypass isn’t changed. However if they also have an external oil cooler in addition to the remote oil filter then they do replace the standard 8-11 psi by pass with a 20 psi bypass.
The lines that came with the kit are 1/2”. The spin on filter is about double the size of a standard Merc/Quicksilver or Sierra filter for the 4.3.

So the engine has the filter bypass valve in the block? If so, then is the original setup (without a remote filter setup) specifying an oil filter without a bypass valve?

 

[LouC]

Yep I actually had the standard filter off today and there is a bypass in the filter mount area.
The standard filters for these engines (Chevy small block V6 and V8) usually don’t have a bypass in the filter because it’s always been in the block. I looked up a bunch of Wix filters for Chevy small blocks and none of them had bypass valves.
However after reading the specs on the Wix filter that Michigan Motorz sent with the kit I found that it also has a bypass. I didn’t wind up installing the kit this time because I couldn’t get good enough access to make sure I didn’t cross thread the fittings for the oil lines with the exhaust manifold in the way. At the end of next season I’ll probably take the exhaust off to inspect (& probably replace) the elbows so I’ll pull the manifolds too & then will have better access to install the remote filter.