What about the center valve that was mentioned? Someone said it can be left out because it just diverts flow to the in block cooler passages?

Leave the center out. I use a Canton Racine block adapter works way better that the stock one.

I see adapters offered a few different ways. Spin on and bolt on. The bolt on ones seem to either use a large bolt in the center or to small ones. What is the difference in the adapter styles?

ttt

bump

If you use the center bolt style on a Gen VI, it would plug the center oil bypass. The screw on style uses the thread from the center bolt that houses the bypass to screw on to. You have to have the large threaded adaptor in the block already for the screw on type.

This is a old quesion but here is the answer. The bolt on ones use two bolts, the threads are already on the pad.

ok so i am bringing this forum back to life, i have a gen 5 with stock oil system and need to upgrade. I want to block the bypass in the block filter adapter. Do i have to drill out the holes where the oil lines connect so i can run larger lines? or can i buy a whole new adaptor so i dont have to mess with it? im new and slightly confused about the cleanest/easiest way to perform this modifaction. Any help would be great. Ive read the thread twice but still need some help

All oil systems are application dependant, the Mercruiser BBC has a half decent set up if you stay with stock power, but if not, it needs some help, especially with the Gen V.

The Gen V can use an adaptor or sandwich plate as described earlier. They can come with either 3/8" or 1/2" NPT thread holes. I use a Canton adaptor with the 1/2" holes and run AN-12 hoses in and out, to and from my oil cooler and filter. So long as you have the 1/2" inlet and outlet at the filter and adaptor, you'll never have any flow issues and you won't have to do any drilling. I don't think the Gen V has the same filter pad area as the Gen VI but I think you still have to upgrade or block the bypass (up from a 15lb to a 30lb or plug with a 20mm freeze plug). Others would know far better than I do!

Anyway, the oil system is the sum of it's parts as I'm sure you've read. If your lines and adaptors are all the right (AN-12 to 1/2") size at the pad adaptor, cooler inlet and outlet, filter in and out, you won't have any drama's. Just make sure you've got a HV pump like the Melling 10778 or the 10778c (I think I have the numbers right???) that's up to the task of maintaining the pressure through the larger diameter / volume hoses or you're srewed!

Good Luck.

Ghostrider is correct, I have done the same thing. Get the Canton Racing Products block adaptor for Gen V (I think V & VI are the same). Use 12 an fittings and lines, get a larger aftermarket oil cooler. I use a EMI 3" combo ps/oil cooler, if you are running huge power use the 4". Make sure you remove the center valve and replace the one on the pad with a 30psi valve. I modified the filter housing with a rorory tool, smoothed out the radius and enlarged the openings. Or you could purchace a new aftermarket one. Filter the oil first the cool it.