Performance Boats Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
122 Posts
Discussion Starter #1
what is a good starting point for ignition timing at idle?
stock 460 ford, 1974 southwind 18ft jet.
its a stock distributor, with pertronics electronic conversion.
its mechanical advance only, no vac adv.
i don't have a dial-back light.

thanks...

also, whats it mean if the boat has a tendancy to blow off one of the exhaust flappers?
 

·
Registered
Joined
·
132 Posts
I believe what Schiada 21 is saying is blowing off the flappers could be due to engine running lean.

6-8 degrees at idle is good starting point but best method is to time based full or total advance on the distributer. About 32-34 degrees at around 3,000 rpm is good place to start. The exact number is a function of fuel, cam, heads, etc. You need to experiment to find the maximum advance that gives best performance without detonation at speeds or kick back when starting.
 

·
Registered
Joined
·
122 Posts
Discussion Starter #5
I believe what Schiada 21 is saying is blowing off the flappers could be due to engine running lean.

6-8 degrees at idle is good starting point but best method is to time based full or total advance on the distributer. About 32-34 degrees at around 3,000 rpm is good place to start. The exact number is a function of fuel, cam, heads, etc. You need to experiment to find the maximum advance that gives best performance without detonation at speeds or kick back when starting.
kick back eh?
it does occasionally back fire when starting...
can i check total adv. at 3k with a standard light? probably don't want to do that on the trailer tho:)
 

·
Registered
Joined
·
273 Posts
kick back eh?
it does occasionally back fire when starting...
can i check total adv. at 3k with a standard light? probably don't want to do that on the trailer tho:)
Yea you can do it with a standard light. Use a little whitout on the fly wheel to mark the 34 degrees to make it easy. Is it a Prestolite disty?
 

·
Registered
Joined
·
3,878 Posts
Timing! Go get a degree tape (stick on installed the right way) And set at 36 degrees and give it a shot. Fords like timing and fuel! Or you could do it the old school way and time by ear! I will admit it takes an educated ear to do so but works in a pinch, with the right ear. M
 

·
Registered
Joined
·
122 Posts
Discussion Starter #8
Timing! Go get a degree tape (stick on installed the right way) And set at 36 degrees and give it a shot. Fords like timing and fuel! Or you could do it the old school way and time by ear! I will admit it takes an educated ear to do so but works in a pinch, with the right ear. M
that's the way it is set now, by ear/feel...
runs good, gps'd on sat at 59mph at 4k rpm, i'm maybe looking for a little more revs.
 

·
Registered
Joined
·
3,878 Posts
that's the way it is set now, by ear/feel...
runs good, gps'd on sat at 59mph at 4k rpm, i'm maybe looking for a little more revs.
I don't blame you. Without knowing the condition of the pump, what loader, and valve spring condition that boat should see 4800 rpm. 59mph at 4000 rpm is not bad but the tach could be lying to you! M
 

·
Boat 502
Joined
·
1,298 Posts
Timing! Go get a degree tape (stick on installed the right way) And set at 36 degrees and give it a shot. Fords like timing and fuel! Or you could do it the old school way and time by ear! I will admit it takes an educated ear to do so but works in a pinch, with the right ear. M
Fords do like fuel....but NEGATIVE on the timing ! Your wasting your time and putting extra strain on parts if you put more then 34* in it.... 36* won't burn it down, but you will see zero gains. Any Ford guy will tell you that. Just my 2 cents...
 

·
Registered
Joined
·
122 Posts
Discussion Starter #11 (Edited)
lost another flapper again last night, someone told me its from running too hot, is this why running lean would cause flappers to flop off?
anyone have experience putting a thermostat kit in a BBF?
the reason i ask is cause it runs really hot in the marina in the 5 zone and really cool opened up. like 210 at idle and 165 or so opened up.
i hear you've got to modify the intake to accept a stat then drill the stat and plumb in the exhaust return lines...
if so, then what kind of stat cover do i use to plumb in the two hoses that go to the risers?

oh and for springs, they're stock, untouched, the tach could be lying but i don't think so, it doesn't sound like its working that hard, it really sounds like its just chugging along at WOT, not really singing.
 

·
Registered
Joined
·
44 Posts
your dist has about 20 advance so i would start at around 12 if it feels doggie on the bottom bump it up a couple. As far as the flap did it spit it of running it out of the water?
 

·
Registered
Joined
·
122 Posts
Discussion Starter #13
your dist has about 20 advance so i would start at around 12 if it feels doggie on the bottom bump it up a couple. As far as the flap did it spit it of running it out of the water?
yeah it did spit it out on the lake. the driver side this time, pass. side last time. they were new last season with just a couple runs last year and several hours this season.
 

·
Registered
Joined
·
43 Posts
I purchased my themostat set up from Tom at Jet boat performance. Came with everything needed and was a simple install. Boat warms up fast and stays at 195 all day long with no valves to play with.

Same 460 ford-now if I could only stop the breather from spitting oil after running hard I would be happy!
 

·
Registered
Joined
·
672 Posts
Set the timing to 32 or 34 total at 2500- 3000 fpm. The initial will be what it is after the all in total advance. Because all dist maybe different because o spring wear and weights the all in total will give you the initial of the dist you are using.
 

·
tintingsandiego
Joined
·
1,063 Posts
What type of exhaust are you running? I have logs and have my gate wide open, runs 140-160 with spikes up to 180 or so after a cruise back to idle.
 

·
Glendale Arizona
Joined
·
2,368 Posts
Now if I could only stop the breather from spitting oil after running hard I would be happy!
Two words

Catch can
or
Puke tank

Works wonders. Relatively inexpensive and one of the best things I ever did to my BBF.

Also agree with the guys that are saying 32-34 total advance. At least mine doesn't like any more timing than that. I'm running 10 BTDC static and the MSD is bushed for 21 degrees mechanical advance for a total of 31 degrees. Running it with the lightest set of springs so all in by 2100-2200 rpm. Works good on mine. Tried it with more timing and it didn't agree with it.
 

·
Registered
Joined
·
122 Posts
Discussion Starter #18
I purchased my themostat set up from Tom at Jet boat performance. Came with everything needed and was a simple install. Boat warms up fast and stays at 195 all day long with no valves to play with.

Same 460 ford-now if I could only stop the breather from spitting oil after running hard I would be happy!
nice. i like the no-valve idea.
hows your PCV valve?
 
1 - 18 of 18 Posts
Top