230lx434

Am currently running factory style mercruiser accessory drives up front including water circulating pump. Was originally on the 350 mag mpi that came in boat (2007) with bravo 1. Replacing it with 434. Reusing accessory drives but ditching merc tstat housing for a more simple setup. Someone originally put an aftermarket oil cooler (tube style) and dis an extremely bad job or routing new water lines. Im going to a -12an with has a 3/8npt bypass port but how should i go about routing this correctly while cooling exhaust initially also. I am running a 160* tstat but can make a change or would it be better to run without a tstat given where we boat and water temp? Any help would be appreciated because motor needs to go in this week and i can not put it back in till this is decided upon. Thanks

getrdunn

iTrader: (7)

There are a ton of threads regarding such as well a debates. You'll have less headaches if you leave stock. The X over and bypass are more taylored to race engines wfo. Your X over sounds like it has a 3/8 npt which seems extremely small. Not sure what kind of X over u have however if you can drill and tap I'd try and drill and tap for 5/8" min. That the only real water source to cool your exhaust until your stat opens. With that said 160 stat seems high however I'm not familiar with what sbc uses but BBC uses typically 140-142. No matter what you end up using drill some 3/16 relief holes to let any pressure amd steam up amd out through your stat housing.

getrdunn

iTrader: (7)

That extra 3/8" fitting your talking about on your X over plumbs above t-stat so your exhaust won't run dry and burn up exhaust hose etc. lot of this is trial and error to accommodate your application which will take some patients. When it's all said and done you'll either be satisfied and all will be acceptable or you'll end up going back to stock merc set up.

SB

iTrader: (1)

"Reusing accessory drives but ditching merc tstat housing for a more simple setup"

Report back on how simple. LOL.

BUP

iTrader: (9)

Is this a stock MPI 350 ?

What ecm are you going to use for the new engine going in ?

All mercruiser EFI / MPI OEM engines comes with a 160 degree t stat and closed cooling apps alot come with a 170 degree T stat. That is not too high.

Even ALL CARB apps for Mercruiser / Volvo / OMC / Indmar in 1996.5 / 1997 all went to 160 degree T stat

Pull out the t stat on a stock cal OEM marine engine and let me know how that runs. Bet you will have alot problems with that one.

230lx434

The tstat housing is a billet hardin with 2 (-12an) fittings coming off for exhasut and 1 (3/8npt) for bypass. I am more than likely going to run the factory serpentine belt system with circulating pump and try several different tstat reducers in its place till i get the temp im after. The efi system i am running is a FuelTech so i can play around with enrichment vs coolant temp. And i will be lowering it to try and run closer to the 140* mark