Page 1 of 2 1 2 LastLast
Results 1 to 15 of 24

Thread: Waking up a 351 with cam and heads

  1. #1
    Join Date
    Jul 2010
    Posts
    79
    Rep Power
    0

    Waking up a 351 with cam and heads

    I have had my 17' Champ for about 8 years now and am thinking it is time to increase my horsepower some. This is due to needing to service my intermediate bearings which will be having me pull the motor.
    I am currently running the 1:9 six cylinder gears in my volvo 280 outdrive, turning a 15x23 solas titan prop. I tried last year to change to a 270 outdrive with 1:61's and got everything hooked up only to find that the pivots were seized on the newer outdrive so I switched it back just so I could run it another season.
    This year may be different. Mattyboy mentioned at one time by switching gears that I would not be able to turn the prop I am currently running without adding some more power to the motor.
    Here is my question and without spending big money and I want to change the cam and add a newer set of heads to my 351 to wake it up. I am thinking of getting a set of gt40p heads or possibly some Winsdor jr.'s if it is in my budget. What cams and specs may be be a good choice for this motor and would you go roller.
    Any thoughts?

  2. #2
    Join Date
    Mar 2005
    Posts
    3,244
    Rep Power
    16
    If you want to run the Solas 23 with a 1:61 ratio out drive you will need about 400 hp and at least as much torque.

    I had 440 hp and 495 ft lbs of torque turning the Solas 23 on a 1:61 Volvo 290. Could spin it to 5300 at 65, on a Donzi 16.
    “Oh right, because you walked into strippers discount warehouse and said ‘Help me showcase my intellect.’” - Archer

    Bill
    Grand Rapids, Michigan
    1985 Donzi Criterion SS
    1967 Donzi 16 Ski Sporter, C16-409, Has a new home!
    38' Carver Aft Cabin
    1968 Sea Ray SRV 180 w/1975 70 hp Evinrude
    10" RIB w/15 hp 1984 Evinrude

  3. #3
    Join Date
    Jul 2004
    Posts
    2,904
    Rep Power
    17
    Sorry, can't help you in regards to your main question, but when it comes to cams always go roller if you can. It's just a better, more reliable setup.
    Why is faster never fast enough.

  4. #4
    Join Date
    May 2001
    Posts
    10,197
    Rep Power
    27
    again with the ford exhaust is going to be an issue going to a hotter cam may lead to a Hi Po exhaust. $$$$$


    here are two benchmark/guidelines I used when redoing my ford note the 302 at 310 hp doesn't need a hi po exhaust the 351 at 350 does. just a reference from the shop that re-did my 302 . I have the cam specs on the 69 Holman Moody 351 which was rated at 290 ish hp that used standard glemwood log exhausts

    302

    Ford 302 CI Small Block Marine 310HP 360FT/LBS TQ
    Block
    Bored and honed with torque plate
    1pc seal design non roller
    Premium core max .040 bore. No repairs. No sleeves

    Cylinder Heads
    World 180 CC cast heads 1.94/1.60 58cc
    New Head Bolts
    3 angle competition valve job

    Valve Train
    Comp cam 218/218 456/456 110
    High Intensity lifters
    Cloyes True Double Roller timing chain
    Scorpion Aluminum Roller Rockers 1.6 ratio
    Screw in studs and Hardened guide plates
    Manley .080 wall pushrods
    7 deg hardened locks and retainers
    1.94 int 1.60 exh Stainless valves
    Performance springs

    Rotating Assembly
    Speed Pro Coated Hypereutectic pistons 9.7:1 CR
    OE rods w ARP rod bolts
    OE 2MAE crank 10/10
    Balanced rotating assembly within 1 Gram
    Speed Pro File Fit Moly Rings
    50oz Balance

    Intake and Tinware
    Professional Products Dual plane Manifold
    Professional Products Damper 50oz
    New OEM Front sump Pan
    Tall Chrome Valve Covers
    New Aluminum universal timing cover
    New OE 50oz Flywheel

    351

    Ford 351 CI Windsor Marine 350HP 400FT/LBS TQ
    Block
    Bored and honed with torque plate
    1pc seal design non roller
    Premium core max .040 bore. No repairs. No sleeves

    Cylinder Heads
    World 200 CC cast heads 2.02/1.60 60cc
    ARP Head Bolts
    3 angle competition valve job

    Valve Train
    Comp cam 226/234 512/531 111 requires performance exhaust
    High Intensity lifters
    Cloyes True Double Roller timing chain
    Scorpion Aluminum Roller Rockers 1.6 ratio
    Screw in studs and Hardened guide plates
    Manley .080 wall pushrods
    7 deg hardened locks and retainers
    2.02 int 1.60 exh Stainless valves
    Performance springs

    Rotating Assembly
    Speed Pro Coated Hypereutectic pistons 9.0:1 CR
    OE rods w ARP rod bolts
    OE crank 10/10
    Balanced rotating assembly within 1 Gram
    Speed Pro File Fit Moly Rings
    28oz Balance

    Intake and Tinware
    Professional Products Dual plane Manifold
    Professional Products Damper 28oz
    New OEM Front sump Pan
    Tall Chrome Valve Covers
    New Aluminum universal timing cover
    New OE Flywheel
    When the sky is grey,look out to sea.
    When the waves are high and the light is dying,
    well raise a glass and think of me...
    When I'm home again,
    boys, I'll be buying!

    My Ride

    Come Join Us on The Queen Of American Lakes



    Contact Us

    www.lgdonziclassic.com

  5. #5
    Join Date
    May 2001
    Posts
    10,197
    Rep Power
    27
    may be more economical to drop to a 21
    When the sky is grey,look out to sea.
    When the waves are high and the light is dying,
    well raise a glass and think of me...
    When I'm home again,
    boys, I'll be buying!

    My Ride

    Come Join Us on The Queen Of American Lakes



    Contact Us

    www.lgdonziclassic.com

  6. #6
    Join Date
    Jul 2010
    Posts
    79
    Rep Power
    0
    I am using the Glenwood high performance now, so flow should not be problem. Still have the old H/M's too, but my guess is the Glenwoods are better? Trying to get around 300 hp, maybe a little more. A little less prop is o.k. too, not trying to go 65. Still have an ultra 14x22, any thoughts on that?

  7. #7
    Join Date
    Mar 2005
    Posts
    3,244
    Rep Power
    16
    300 hp with a 1:61 drive will spin an Ultra 22 nicely.
    “Oh right, because you walked into strippers discount warehouse and said ‘Help me showcase my intellect.’” - Archer

    Bill
    Grand Rapids, Michigan
    1985 Donzi Criterion SS
    1967 Donzi 16 Ski Sporter, C16-409, Has a new home!
    38' Carver Aft Cabin
    1968 Sea Ray SRV 180 w/1975 70 hp Evinrude
    10" RIB w/15 hp 1984 Evinrude

  8. #8
    Join Date
    May 2001
    Posts
    10,197
    Rep Power
    27
    +1 on what bill said
    I ran a 22 ultra until I spun the hub then a 21 Solas
    The end dump risers are ok would be better with center risers if they fit
    I will look for the specs
    When the sky is grey,look out to sea.
    When the waves are high and the light is dying,
    well raise a glass and think of me...
    When I'm home again,
    boys, I'll be buying!

    My Ride

    Come Join Us on The Queen Of American Lakes



    Contact Us

    www.lgdonziclassic.com

  9. #9
    Join Date
    May 2001
    Posts
    10,197
    Rep Power
    27
    sorry can't find the 69-70 290 hp cam specs I have the newer detuned 240 and 255 hp specs that came along in the mid 1970s on the 351
    When the sky is grey,look out to sea.
    When the waves are high and the light is dying,
    well raise a glass and think of me...
    When I'm home again,
    boys, I'll be buying!

    My Ride

    Come Join Us on The Queen Of American Lakes



    Contact Us

    www.lgdonziclassic.com

  10. #10
    Join Date
    Oct 2002
    Posts
    1,271
    Rep Power
    17
    I got these specs from the original cam grinder at H&M... 290hp


    280 ADV duration
    .470 lift
    114 degree lobe sep
    1970 18 2+3 Hull #18-355 H/M 351W Volvo 250
    07 Cayman IT IS BACK! - '13 Abarth Cabrio
    '13 Deere 5083E
    PRESERVE, DON'T RESTORE

  11. #11
    Join Date
    Aug 2005
    Posts
    7,805
    Rep Power
    21
    I like the Windsor Jr. heads. They have a smaller combustion chamber than the Windsors so you won't lose compression and the exhaust ports are the same as the Windsor. Intake ports are a little smaller. The main drawback in a boat might be that they are heavy cast iron.
    Lake St. Clair, Lake Huron, Lake Erie, Lake Oakland

  12. #12
    Join Date
    May 2001
    Posts
    10,197
    Rep Power
    27
    The biggy is lobe separation and valve overlap what works to make hp in a car doesn’t work with a wet marine exhaust reversion is a killer

    I never had any issue with my logs but I never went above the stock marine cam the logs are tough on the rear exhaust valves heat wise when you leave the stock world the longer runners of a center risers or headers are better
    When the sky is grey,look out to sea.
    When the waves are high and the light is dying,
    well raise a glass and think of me...
    When I'm home again,
    boys, I'll be buying!

    My Ride

    Come Join Us on The Queen Of American Lakes



    Contact Us

    www.lgdonziclassic.com

  13. #13
    Join Date
    Jul 2010
    Posts
    79
    Rep Power
    0
    Quote Originally Posted by Just Say N20 View Post
    If you want to run the Solas 23 with a 1:61 ratio out drive you will need about 400 hp and at least as much torque.

    I had 440 hp and 495 ft lbs of torque turning the Solas 23 on a 1:61 Volvo 290. Could spin it to 5300 at 65, on a Donzi 16.
    So what kind of make/ size motor are you running?

  14. #14
    Join Date
    Mar 2005
    Posts
    3,244
    Rep Power
    16
    Quote Originally Posted by champ View Post
    So what kind of make/ size motor are you running?
    1972 Chevy 400, 1972 ported/polisher double hump 202 angle plug heads, Edelbrock aluminum dual plane intake, Holley 750 double pumper, CMI header exhaust. Don’t remember the cam specs.
    Attached Files Attached Files
    “Oh right, because you walked into strippers discount warehouse and said ‘Help me showcase my intellect.’” - Archer

    Bill
    Grand Rapids, Michigan
    1985 Donzi Criterion SS
    1967 Donzi 16 Ski Sporter, C16-409, Has a new home!
    38' Carver Aft Cabin
    1968 Sea Ray SRV 180 w/1975 70 hp Evinrude
    10" RIB w/15 hp 1984 Evinrude

  15. #15
    Join Date
    Sep 2011
    Posts
    1,109
    Rep Power
    0
    Please post up the cam specs/performance when you get it sorted.

    I too am building a 351W (with HM logs) and looking for at least 300+HP and as much torque as I can find.
    I am considering building a stroker to boost the TQ and will be using Aluminum heads (Edelbrock Performer) to lower weight.
    Not sure if I'll be dropping large on a FI system or staying tried, true and affordable 4bbl.

    By far, the biggest concern is the cam specs.
    Sean Conroy,
    1965 Formula Jr. (hull #2) project

    1972 Greavette Sunflash IV

    "A man can accomplish anything... as long as he doesn't care who gets the credit."

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •