i have a bbc 454 with a dual carb tunnel ram set up. i have a nieghbor who is a car mechanic so he has a timming light. is there much difference, if any, from setting the timming in a car or a jet boat? any suggestions on the best way to do this. and what should my total timing be.:idea:
Depending on the fuel you run and your ignition, lock out all the advance (vacuum and mech.)and start out at 36* and if you run good gas you can take it up to 40* 2* at a time. This all depends on whatelse is in your engine more info would be helpful
the guy i got the engine from said it was pretty much stock on the inside. I've just ran 91 octane in it.
Just a guess here. If you say your engine is pretty much stock I will guess the timeing is maybe at 32. Run higher octane 100/110 advance the timeing and you will get more snap out of the whole.
Depending on the fuel you run and your ignition, lock out all the advance (vacuum and mech.)and start out at 36* and if you run good gas you can take it up to 40* 2* at a time. This all depends on whatelse is in your engine more info would be helpful
I dont think you want to lock the timing on a n/a deal. Thats more for the blown deal like you have where you need to keep a low total timing # when your up on boost with no retard box. By locking the timing out on a stocker n/a engine I dont thing it would have enough nut on the bottom end like a blown engine plus I would think starting would really lag with a base of 40 degrees without a starter retard. I would run the boat up to 3 grand, set it at 36 degrees total and then check it at idle to see where your at. If you have 25 degrees of curve in the distributor with a base of 11 that would give you 36 degrees. You will probably be safe running up to 16 degrees of base at idle and still be able to start it but you dont want too much total where you start to pre detonate 9ping). 36 degrees of total timing at around 3000 rpm is usually a nice safe # for pump gas. Hope that helps.
F.J.
Setti8ng the timing is no different, but a jet boat can use a far faster advance than a car/truck since there is really no mid-RPM load. Get all the timing in by 3-grand (2,800 is just fine too), I run a base of 10* with a 25* advance by 2800, starting about 1300.
I can't think of a good reason to lock the timing 40*, and to me, 40* seems awfully aggressively risky on the pump-gas.
No one mentioned yet, but you should have the boat in the water when doing the test. There have been volumes written on this forum about running jets out of the water.
J
On an engine like that, I'd stay at about 34* total timing, coming in early just like stated above. Anything above that in a jet boat is just hammering the bearings and crankshaft with an extra load.
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