Formula 311 Values ?????
05-07-2008, 09:23 PM
#81
Hey Michael,
Thirdbird does have some very valid facts on the running characteristics of a 311 with or without trs drives.
For example there are 3 of us with 1988 311s with all three engine and drive combinations available in 1988. At one point all three were bone stock . Mine has 330s w/bravos ... the most efficient but the slowest. Kris has 365s w/bravos fastest , middle as far as efficiency and Ted had 420s w/trs the worst efficiency and slightly faster than me.
Ted's boat lifted in the rear far better and ran cleaner in the water than the other two. The transmissions sucked up alot of horsepower which in turn cost him in cruising speed and efficiency. He always had to run approx 500 to 700 more rpm to cruise with us.
That being said he upgraded his power to 585hp a side and put on 26 pitch Bravo 4 props ....... totaly different boat now .... the runs the fastest hands down and is running alot less rpms than we are at whatever cruising speed we pick.
With the bigger hps and the bigger wheels he is turning this boat runs flat in the water with no azz end sink and little to no tabs ....
Just my 2 cents for what it's worth .....
Jeff
Thirdbird does have some very valid facts on the running characteristics of a 311 with or without trs drives.
For example there are 3 of us with 1988 311s with all three engine and drive combinations available in 1988. At one point all three were bone stock . Mine has 330s w/bravos ... the most efficient but the slowest. Kris has 365s w/bravos fastest , middle as far as efficiency and Ted had 420s w/trs the worst efficiency and slightly faster than me.
Ted's boat lifted in the rear far better and ran cleaner in the water than the other two. The transmissions sucked up alot of horsepower which in turn cost him in cruising speed and efficiency. He always had to run approx 500 to 700 more rpm to cruise with us.
That being said he upgraded his power to 585hp a side and put on 26 pitch Bravo 4 props ....... totaly different boat now .... the runs the fastest hands down and is running alot less rpms than we are at whatever cruising speed we pick.
With the bigger hps and the bigger wheels he is turning this boat runs flat in the water with no azz end sink and little to no tabs ....
Just my 2 cents for what it's worth .....
Jeff
05-08-2008, 01:43 PM
#82
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Were all three of those 311s turning the same props? I'm pretty sure, even with all the different combos, that the original props would be the same, 23p Mirages. If so, at least that confirms what I thought: a 454MAG/Bravo is a tad faster than a 420/TRS.
05-08-2008, 09:14 PM
#83
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I don't debate that there's a difference, just the reason for the difference. In my opinion, it's more than just a change in CG.
Were all three of those 311s turning the same props? I'm pretty sure, even with all the different combos, that the original props would be the same, 23p Mirages. If so, at least that confirms what I thought: a 454MAG/Bravo is a tad faster than a 420/TRS.
Were all three of those 311s turning the same props? I'm pretty sure, even with all the different combos, that the original props would be the same, 23p Mirages. If so, at least that confirms what I thought: a 454MAG/Bravo is a tad faster than a 420/TRS.
Oddly enough though mine has labbed 23p Mirage props (330s w/bravos) don't know if it makes any difference at all I don't know anyone with the same engine / drive package as me. The norm is the 365mag with bravos.
Jeff
05-09-2008, 08:43 AM
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05-09-2008, 11:55 AM
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Very interesting....turns out according to BAM's website, the 370 and 454MAG share the same carb, intake, cam and heads. Rocker arms were different, valves were different. Really makes me wonder about crank vs prop HP numbers.
05-09-2008, 01:40 PM
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Even though this was a 2005 thread, how 'bout we get back to the topic:
http://detroit.craigslist.org/boa/673541883.html
http://nashville.craigslist.org/boa/670180860.html
http://cgi.ebay.com/1988-FORMULA-SR1...QQcmdZViewItem
http://detroit.craigslist.org/boa/673541883.html
http://nashville.craigslist.org/boa/670180860.html
http://cgi.ebay.com/1988-FORMULA-SR1...QQcmdZViewItem
05-11-2008, 02:41 PM
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I agree with Jaybird... I have TRS drives on my 311. I wouldn't be so scared of them- mine work great!
Thirdbird is right though, 311's with Bravos have a lot more room in the engine bay.
Good luck with your decision
Thirdbird is right though, 311's with Bravos have a lot more room in the engine bay.
Good luck with your decision
05-11-2008, 09:39 PM
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Hey Handfulz, what's the full address of the BAM site you mention?
05-11-2008, 10:57 PM
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www.mercruiserparts.com
Then click on the link towards the upper left...that gets you to the parts lists & pics. FWIW, in order the compare the 370 vs MAG, I had to go back and forth between "High performance and racing" for the TRS stuff and "...Sterndrives..." whatever for the regular MAG info.
Then click on the link towards the upper left...that gets you to the parts lists & pics. FWIW, in order the compare the 370 vs MAG, I had to go back and forth between "High performance and racing" for the TRS stuff and "...Sterndrives..." whatever for the regular MAG info.
