Re: Auto vs. Marine motor assemblies?
I know that this topic has been visited in a variety of ways, but I hope to generate more specific answers to a troubling question.
Other than the obvious external parts, like starter, alternator, distributor cap, power steering pump and exhaust system...what are the key cost differences associated with the engineering and or production of a marinized engine versus a standard truck engine? Is it perhaps industrial grade bearings, rods, cams, pistons and rings? Stronger valve springs? More precise porting of the heads? Gold filled lifters and diamond encrusted water jackets? I'm trying to understand why a marine small block Chevy is so much more expensive than its automotive equivalent. Could it be simple supply and demand, or is the issue more academic than that? I look forward to your answers, both serious and silly.
My own experience I have replaced a few SBC marine engines none ever having anything special in them except, diff cam ,brass core plugs and windage tray internally other wise on the outside used all the marine equipment that was in the boat getting the different engine and all this was confirmed by a marine racer,and engine builder for the first few swaps.
No balanced engines, common rods, bearings, pistons, lifters,timing chains ,valves, seats and even gaskets when used in fresh water,very few even had 4 bolt mains, all this marine hipe I heard over the years is just that,
HIPE
If you have your wife and a couple kids on a holiday at the cottage for a couple weeks out of a whole year and the boat dies the majority of people not being able to repair it themselves will pay whatever they have to to have that boat working ,and as a marina selling parts to do so sell marine branded equipment only, then availability,and a couple more middle men, pays 12 months wages to employees from a couple months busy season and covers the legal issues by using marine equipment (law suits) and the guy has a happy family.
When I do an engine swap I use whatever is available and swap
ALL MARINE RELATED PARTS POSSIBLE internally and externally now I have a marine engine
and have never had one back because I used a car engine from the local wrecker yet. I also try and come close to the compression ratio as what I am replacing which isn't usually a problem as most of the ones I have done are about 8.5:1 which is far better for an engine under load almost all the time.
I am running one of these conversions in my own boat, 228 Mercruiser(305 chevy) replaced with a 350 from a 1975 chev car in a 20ft.Crestliner with a cuddy other than what I previously stated the only other thing that had to be changed was the prop
