| Author |
Message |
    
red grimsley
New member
Username: redg2005
Post Number: 2
Registered: 01-2007
| | Posted on Wednesday, November 04, 2009 - 05:30 pm: | 
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I am building a pair of 360's and wondering if I change distributors,could I use vacuum advance type and high output ?
redgrimsley@aol.com |
Freshwater Fred
Advanced Member
Username: fred70
Post Number: 200
Registered: 01-2009
| | Posted on Thursday, November 05, 2009 - 08:43 am: |
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I don't think that ANY of the vacuum advance type are marine approved.
#2 I'm not sure if the vacuum type will allow enough centrifugal advance.
Fred 156-M |
Ricardo E.
Advanced Member
Username: ricardomarine_vp
Post Number: 741
Registered: 03-2009
| | Posted on Thursday, November 05, 2009 - 11:16 am: |
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Vacuum advance is both an emmissions control device and off-throttle device for automotive engines..... not only is it unnecessary, but is not marine approved.
The advance curve and limit will also be incorrect for marine application and usage.
You must have the correct advance curve and limit (spelled TA) for a marine gasser! No exceptions!
. |
Dan Finnelly
Member
Username: tolly_family
Post Number: 88
Registered: 07-2006
| | Posted on Thursday, November 05, 2009 - 06:02 pm: |
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Not true about emission device, it's for mileage and improved throttle response. The vac advance on a carbed car is hooked up to ported vacuum ond only operates at part throttle. Look at advance maps and you will see 32-38 degrees at full throttle and 40-50 degrees at part throttle cruise. No it won't work or is it needed on a maring engine as the load is always the same and the maniflod vacuum constant at a specific RPM. Marine distributors besides being ignition protected have completely different advance curves than automotive units. I have run my 84 Mustang with a bad vacuum advance diaphram and the miles on a tank of gas went from 250 to 160. Most hot rodders disconnect it and while not affecting wide open power it kills their gas mileage. We know that EFI motors make the same or slightly less power than carbed engines but get much better mileage because the computer is controlling the timing. Hook up a digital timimg light to a EFI car and check the timing at 3000 rpm and you will see 50+ degrees.
Dan
Dan |
