timing

[mikey-jones]

how far advanced are all of you running your timing on your jet boats? should it be the same as if the motor was in a car or does it make a big difference on a boat?

[RandyH]

mikey-jones:
how far advanced are all of you running your timing on your jet boats? should it be the same as if the motor was in a car or does it make a big difference on a boat?36 Degrees Locked at full advance. Don't know all the reasons for 36 , but the locked advance is working well. I still can't believe the thing starts and it does everytime. I hope things don't change as my batteries get older. Its a Big Block Chevy.

[squirts]

I run at 35 degrees. Its also a BBC

[HighRoller]

RandyH,I have a tip for you that my buddy turned me on to.If you run a non-computer engine on a jet turn the water inlet valve all the way open.Running your engine that cold does nothing to harm your performance,as a matter of fact once you find out what temp this runs your engine at you can rejet leaner to compensate,therefore more fuel mileage and power.Also you never have hot start problems,which is critical in your case with locked advance.I'm more conservative but my buddy runs an adjust a jet at the equivalent of a low to mid 60 jet(Holley)while I run low 70.He gets almost 4mpg with a big block/jet!

[77charger]

38 total with a bbf 11-1 motor on nos.

[Infomaniac]

mikey-jones:
how far advanced are all of you running your timing on your jet boats? should it be the same as if the motor was in a car or does it make a big difference on a boat?What gas and compression? That will determine how much TOTAL timing you can get away with.

[mikey-jones]

comp is 10.1 on 91 oct. pump gas

[RandyH]

HighRoller,
Thanks for the tip. My new Ultra/jet had no valve on the water inlet so I put one in. I leave it wide open for now and have been running about 130 degrees water temp. mostly. Its also been very easy to start, especially warm. I may be alittle rich now by looking at the plugs.
I have the 6M2 MSD ignition and I wonder if it retards the timing at low RPM? I have read that some do if you turn on that feature but this Marine model has no setup switches.
thanks again,
Randy
[ September 22, 2002, 08:25 PM: Message edited by: RandyH ]

[Infomaniac]

Depending on the operating temp as previously mentioned, I think 36 might be pushing it.
Personally I would set it at 32 degrees TOTAL. Try advancing it 2 degrees TOTAL from there. If you do not get any more RPM's or speed after advancing. Put it back to 32. If you do get some increase, leave it there. Better safe than sorry.
Try and set up your ignition system to advance as fast as possible. wink wink wink wink

[homeblt86jet]

running to cold does cause dammage,.....dont know why but if you run a motor to cold it causes your motor to wear out faster....best temp is around 190...for best life....just a thought...

[LVjetboy]

My BBC set to 28 for NOS. So not ideal. But I'd still be conservative even without the juice.
Couple reasons.
First, dock gas quality varies...at least where I boat. Calville's ok, but Temple Bar only has 89. And State Line Marina on Lake Powell...87!! Hard to imagine for such a big lake. I pulled in almost on E and found that one out :( They said, "oh, but we got additive." Well you can take your additive and stick it. My experience with additives is that most don't work as advertised. Used to run a high compression Pontiac on 98. When octanes dropped I tried all kind of additives. Some with limited success, but none kept the pings away like a good load of quality fuel. And my boating day usually includes at least one filling at the dock.
Second, for my jet and probably others, it's hard if not impossible to hear detonation before too late...unlike a car. So if you're running the edge and get a bad load, how you gonna know before damage is done? Unless you check plugs every time you fill it?
So although the factors that drive ideal timing are the same as a car, being a little conservative may be a good thing in the long run.
jer