What's the first thing you would do to a motor...
#21
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I also have an oval port torkerII manifold for you cheap if you are interested. I was going to install it but never got to. I will get some pics later. Chris
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I did Imco exhaust, an Edelbrock Performer intake, and a mild Comp Cams cam swap and gained about 300rpm on a 300HP/7.4L. That engine was in my 1989 24' Pantera and the top speed went from 62 to 65mph.
I know a source for 420HP/8.L Volvo Penta low hour test engines for around 7K. There are not close cooled though.
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Pat were you able to run a bigger prop with the changes that you made? When I had the boat I was seeing almost 4700 on the lake at 312ft elevation M+23 prop. I think the stock motor is closer to 5000 at sea level, Hopefully Dude can chime in on that.
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here is one in your town, too bad it is the 375 and not the 425 allthough it says HO. I am confused.
http://www.offshoreonly.com/esvon/page-14022.html
and here is the 375 to 425 upgrade, I am not entirely sure that it is all you would need but it sounds good http://www.offshoreonly.com/esvon/page-13794.html
http://www.offshoreonly.com/esvon/page-14022.html
and here is the 375 to 425 upgrade, I am not entirely sure that it is all you would need but it sounds good http://www.offshoreonly.com/esvon/page-13794.html
Last edited by IRONMAN; 01-05-2007 at 09:47 AM.
#26
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The engine topped out at about 4400rpm with thru prop exhaust.
After speaking with JO about many possible upgrades, I ran the exhaust thru the transom and gained about 100rpm.
Then I did the engine mods.
With the same 23p Turbo the engine would spin 4800rpm. With a 23p Mirage + about 50rpm less. and with a 22p Bravo 1 about 4900rpm.
Top speed when I bought the boat was about 60 and when I sold her, 65...
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Yup, right on or a tick over 5,000 with the Mirage 23 plus.
I haven't picked up a GPS yet, so I don't know how fast, but in 3' - 5's at 15 seconds you get one wild ride!
Oh, and that's a great find on the 496, but my wife would shoot me out of a cannon if I went out and bought a new motor for the boat right now!
I haven't picked up a GPS yet, so I don't know how fast, but in 3' - 5's at 15 seconds you get one wild ride!
Oh, and that's a great find on the 496, but my wife would shoot me out of a cannon if I went out and bought a new motor for the boat right now!
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I don't know what kind of shape you motor is currently in but if all is well such as not needing the crank turned , & the cylnders are in good shape ect.. it is worth spending a few thousand on ( including the exhaust ) I spent around 3k on mine when I pulled the motor out of my 24 ( 330/TRS )
& that was including the new exhaust. My boat went from running the average 61-62 on GPS to running a solid 70 on GPS & the midrange was incredibly better , it was like getting a whole new boat. Here is what I did : ( Keep in mind I did all of the labor myself including all of the engine work so that will make a differance if you have to pay for that or will be doing that yourself. I also already had the intake , cam , lifters , & springs ( roughly another $ 450.00 or so give or take.) But if you got a good buy on some used exhaust like Kirk's you will be ahead another 1k or so from what I spent.
I give around $ 1850.00 for my headers once I got them shipped.
1979 454 330 hp / stock TRS drive
new tri-metal race bearings ( Crank & rods )
Installed ARP Wave lock rod bolts in the stock rods
New Powerforged Pistons (compression ratio approx 9.4:1 )
Z gap rings
Portwork on the existing 049 ovalport heads ( mainly bowl blending , gasket match , ect but nothing to exotic. )
Reseated valves good
Harland Sharps 1.8:1 full roller rockers
Mild Hydralic Cam ( I will be glad to give you the exact specs if you want but I would have to look them up , its been a day or 2. )
Edelbrock performer 2.0 intake
Holley 750 carb
Lightning marine headers
Of course all new quality brand gaskets
& I am shure I have forgot a thing or 2 but maybee this will give you something to keep in mind.
Like I said the boat went from running the average 61-62 GPS
to a solid 70 & was alot more fun to drive !!
I would say the motor was making a solid 450-475 HP
I was spinning a 25 pitch mercury tempest prop.
& that was including the new exhaust. My boat went from running the average 61-62 on GPS to running a solid 70 on GPS & the midrange was incredibly better , it was like getting a whole new boat. Here is what I did : ( Keep in mind I did all of the labor myself including all of the engine work so that will make a differance if you have to pay for that or will be doing that yourself. I also already had the intake , cam , lifters , & springs ( roughly another $ 450.00 or so give or take.) But if you got a good buy on some used exhaust like Kirk's you will be ahead another 1k or so from what I spent.
I give around $ 1850.00 for my headers once I got them shipped.
1979 454 330 hp / stock TRS drive
new tri-metal race bearings ( Crank & rods )
Installed ARP Wave lock rod bolts in the stock rods
New Powerforged Pistons (compression ratio approx 9.4:1 )
Z gap rings
Portwork on the existing 049 ovalport heads ( mainly bowl blending , gasket match , ect but nothing to exotic. )
Reseated valves good
Harland Sharps 1.8:1 full roller rockers
Mild Hydralic Cam ( I will be glad to give you the exact specs if you want but I would have to look them up , its been a day or 2. )
Edelbrock performer 2.0 intake
Holley 750 carb
Lightning marine headers
Of course all new quality brand gaskets
& I am shure I have forgot a thing or 2 but maybee this will give you something to keep in mind.
Like I said the boat went from running the average 61-62 GPS
to a solid 70 & was alot more fun to drive !!
I would say the motor was making a solid 450-475 HP
I was spinning a 25 pitch mercury tempest prop.
#30
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Yup, right on or a tick over 5,000 with the Mirage 23 plus.
I haven't picked up a GPS yet, so I don't know how fast, but in 3' - 5's at 15 seconds you get one wild ride!
Oh, and that's a great find on the 496, but my wife would shoot me out of a cannon if I went out and bought a new motor for the boat right now!
I haven't picked up a GPS yet, so I don't know how fast, but in 3' - 5's at 15 seconds you get one wild ride!
Oh, and that's a great find on the 496, but my wife would shoot me out of a cannon if I went out and bought a new motor for the boat right now!
When I bought my 24' Super, I first powered her with a 310HP/7.4MPI. She ran faster at 4400rpm with a 26p Bravo one than spinning faster with a 24p. That engine is/was slightly different than the old carb engines though.
We all feel your pain getting approval from the wife. That's why I'm aways buying used stuff and rebuilding it...
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