Categories
- All Categories
- 15 Non-Rinker Boats
- 2.9K General Boating Discussions
- 294 Rinker Custom Projects
- 136 Trailer & Trailering Discussions
- 473 Generator Discussions
- 172 Rinker Photo Gallery
- 364 Rinker Sport Boat Forum
- 3.9K Rinker Express Cruisers Forum
- 1.2K Engine Discussions
- 1.2K Electrical Discussions
- 662 Rinker Support Q&A
- 595 Rinker Marketplace & Classifieds
- 67 Rinker News & Updates
- 102 RBO Forum Archives
- 175 Region-Specific Questions
- 31 Canada
- 136 United States
Comments
Dream 'Inn III -- 2008 400 Express
i could SO see a hairline in the exhaust water jacket causing this. it makes sense.
we were looking at fuel charge and suspecting the charge wasn't right. we figured you were running lean because of something with the fuel system- either faulty injectors, faulty pressure, or an obstruction. but the system checked out.
i kept talking about un-metered air, such as a vacuum leak or valve seals or valve timing. i kept going back to timing of valve train/crank position as it will impact both the dynamic compression of the engine as well as have a direct impact on the ignition timing map. but that checked out.
a hairline crack in the exhaust water jackets makes perfect sense in retrospect. it 'steams' as it enters the passage- and that pressure is greater than the exhaust pulse's. it would flow with it to a point, but when it reaches a certain point it would create a barrier the exhaust pulse is unable to breech. the steam entering the cylinder past an open exhaust valve is introducing more o2 into the cylinder, which throws your air:fuel ratio lean- hence orange plugs. when the pressure is beyond that the engine's exhaust pulse can breech, it would behave precisely like an obstructed exhaust pipe- a catalytic converter clogged on a vehicle- an exhaust flap stuck in the passage not allowing but some pressure/volume past- and the engine won't rev beyond that limit.
so the question now is the condition of your valves and seats, pushrods and springs. excessive back pressure, which is what this amounts to (in addition to extra o2 from the steam) will tulip valves, bend push rods, weaken valve springs, make a mockery of valve seats, and wear on seals.
do you have dry or wet joint manifolds? wet have more opportunity for dripping into the cylinders. dry has to defeat gravity first.
the elbow in the picture is on the riser on dry joint... it's missing on the wet joint manifolds pictured below.
the crack or leak is internal to the manifold and it isn't going to care about joints. the crack, if high on the plenum, can impact all the cylinders not just one such as if it's cracked low on a particular runner...
PC BYC, Holland, MI
note to those installing manifolds- use as thin and strong a gasket as you can find while getting a good clean seal/seat, dry threads while torquing them, and afterwards pay particular attention to area around cylinders one and two. before i windowed the block of a 305 bored to 314 i had a leak there- the cylinder ingested a good amount of water, and blew apart a wrist joint and journal- with the the rod seeking (and finding) daylight with reckless abandon. those walls were thin i admit- i wouldn't rec anyone bore a hapless 305 out that far and expect life (i didn't for the record) especially when 350 cores are everywhere just as cheap... but if i hadn't ignored the leak or recognized it for what it was i'd still be running that engine.
never would i have thought that situation and this one were related.
when that engine was losing it's life, it would lock on starter right after shut down (trying to restart), but a few seconds later it would turn fine. water evaporated... with a cool rested engine, it would do the same, but i could coax it to turn by pulling the coil wire (no threat of truly starting) and pushing it out.. meaning, not much water... until there was... and when that finally happened? it sounded like a rock concert in some perverse foreign tongue i'm unfamiliar with. all it took was that once. i should have fixed it, but... then i wouldn't have the fire breathing 357 i'm running now (with fully closed cooling, 1.6 rockers and cam dialed in to perfection matching the card at each point, base timing advanced to 14.5* w/o a hint of ping running 98octane rec racing fuel, port matched intake and exhaust, and likely 325hp and puking torque that's going to make short work of the SEI alpha one clone dangling off its rear-end whether it's 'hardened' or not, a 55k coil on plugs indexed and gapped to 060)... it's the game we play.. well, it's the game i play anyway.
those four bolts... such oversight in my humble opinion... at least use hardened studs, right?
My engineering seminar for the evening. lol
PC BYC, Holland, MI
my personal failure was considering the mighty remflex gasket and using them. they are 'fantastical' for road engines- headers in particular, that don't weigh a lot and are further supported by junctions at the collector. remflex's are magic, especially with headers that aren't perfectly flat. they are thick and pliable at first, but harden after use. you actually squeeze them into the shape required to seal the marriage. after several heating cycles they're hard as brick. you gotta get them right the first time. in addition to remflex, i also use STAGE eight bolts for clamping power... those are some great tools for the purpose of exhaust clamping. check them out if you're not familiar with them. they can't be used on marine manifolds- far too short.
but to your comment, yup- the right fastener is everything...
The above statement must be wrong.
Energy in equals energy out. It matters nothing what motors you have or what is wrong with them. They cannot cheat the laws of thermodynamics. If the energy is going into that starboard engine, it is coming out somehow. If the same fuel and air are going in, the energy is either coming out as mechanical power or going down the exhaust, as unburnt fuel, or into the water as heat. I would argue this is undeniable.
I would suggest you concentrate your thoughts on:-
Is the energy really going in?
If so, where is it going?
Also, I would suggest, as all the plugs are uniform, that the fault must either be in the centreline of the engine, cam or crank, or the electrical system, as these are the only other things common to all cylinders. Possibly the connection between the them.
I am no expert on this particular engine, so feel free to call me out on any errors in my thinking.
PC BYC, Holland, MI