Engine/ horsepower/ manifold question
+ Reply to Thread
Results 1 to 14 of 14

Thread:
Engine/ horsepower/ manifold question

  1. #1
    Aquacraft Eddie's Avatar
    Join Date
    Mar 2008
    Location
    El Paso TX.
    Posts
    235

    Default Engine/ horsepower/ manifold question

    I had a question figured i would ask here, I am rebuilding a 1971 aquacraft shark v-drive, casale 12%, it originally had a 396bc, standard with a victor jr open plane manifold in it. I am no where close to fininshing the boat, but I am buying parts for the motor as i work on the boat. I picked up a 454 standard block, My QUESTION is ,,, do I build for horsepower or torque for a v-drive???? Iam not sure was thinking horsepower but then the torque thing seemed logical to, Iam not going to race this,(i dont think?) was planning on using it as a family boat, but i do want to go fast at the same time. I picked up a edelbrock airgap manifold, and didnt know if I should use this or the victor?, I am not sure of cam right now either, trying to figure out what direction i should head in? as far as open plane, dual plane, ect,,,, I am planniing on using a set of 396 heads on the 454, I do not have the casting numbers off hand but they are oval port semi closed chamber heads. I have read some other posts on here about manifolds and to be honest i still dont know for sure what is better, I leaned towards the victor, but the airgap is supposed to have the best of both worlds (ya right) according to edelbrock. sorry for the lack of more engine specs and so on, but i have a couple of more heads laying around that i need to look at that might be better, have to look, trying to save some money,,,, basically standard 454, 30 over, not sure what cam profile is good for this? (v-drive) also full roller rockers, and either airgap or victor manifold with a 750 dp holley, these are all parts that i allready have, they had come off other projects, trying to save some cash,,,thanks.....

  2. Remove Advertisements
    PerformanceBoats.com
    Advertisements
     

  3. #2
    Senior Member
    Join Date
    Dec 2007
    Location
    Newbury Park, Ca/Mohave Valley, Az
    Posts
    7,741

    Default Imo......

    IMO, torque in a v drive is less important than say, a jetboat, or a heavy cruiser. If properly set up, your boat should dry out fairly quickly and hopefully be skimming across the water on the "flat" part in the back... Also, one of the luxuries of the v drive is being able to change gears and props to "dial in" your usage to the engine's "happy spot" of the RPM curve... In reality, boat speed is based on prop speed, which is based on engine RPMs out the final drive ratio... If I were you, I would be very cautious about your cylinder head choice. All the camshaft planing in the world is useless if the heads won't flow... IMO, look around, find some used aftermarket, or factory 990s, that were designed to be used on the added cubic inches the 454 will give you, or the added flow the camshaft is designed for. That said, if your 396 crank is a steel factory unit, you might consider using it. With the larger 4.250/4.280/4.310 (+.030-.060), bore, and the short stroke 396 crank, (3.760 vs 4.000 454) you can build a cool 427/433/440 with plenty of torque to dry the boat out, and plenty of RPM potential to see some pretty scary speeds... Dual plane intakes seem to make a pleasure boat more forgiving in the "drive-ability" areas, but the open plane should RPM up top a little better if comparing apples to apples....IMO, there is a fine line between a "fun" boat, and a heavy "rump rump" cammed screamer.. Yes, you can have both, but it takes an awful lot of homework to achieve that "right outa the box".....If you really want to have a "fun" boat, design it as that when choosing engine parts, and start collecting additional stuff for another "monster" motor for the "need for speed" we all seem to have.... Enjoy your boat for a few years while you assemble a totally different engine. Remove the "sensible" engine and stick it under the bench, install the screamer, and if it fails you still have "old reliable" to fall back on and continue your "fun" on the water..... Believe me, there is nothing worse than having your boat in the shop, covered up, because the "big" motor ate up your boating budget, and then windowed the pan. Always plan for the worse case, and keep that back up complete, ready to go back in.....Good luck..
    Ray
    LOUD BOATS SAVE LIVES
    2 OPEN flatbottom APBA seasons left.....Let's RACE

  4. #3
    Senior Member jockorace's Avatar
    Join Date
    Feb 2008
    Location
    Hudson, Wisconsin
    Posts
    2,412

    Default

    Quote Originally Posted by Moneypit View Post
    IMO, torque in a v drive is less important than say, a jetboat, or a heavy cruiser. If properly set up, your boat should dry out fairly quickly and hopefully be skimming across the water on the "flat" part in the back... Also, one of the luxuries of the v drive is being able to change gears and props to "dial in" your usage to the engine's "happy spot" of the RPM curve... In reality, boat speed is based on prop speed, which is based on engine RPMs out the final drive ratio... If I were you, I would be very cautious about your cylinder head choice. All the camshaft planing in the world is useless if the heads won't flow... IMO, look around, find some used aftermarket, or factory 990s, that were designed to be used on the added cubic inches the 454 will give you, or the added flow the camshaft is designed for. That said, if your 396 crank is a steel factory unit, you might consider using it. With the larger 4.250/4.280/4.310 (+.030-.060), bore, and the short stroke 396 crank, (3.760 vs 4.000 454) you can build a cool 427/433/440 with plenty of torque to dry the boat out, and plenty of RPM potential to see some pretty scary speeds... Dual plane intakes seem to make a pleasure boat more forgiving in the "drive-ability" areas, but the open plane should RPM up top a little better if comparing apples to apples....IMO, there is a fine line between a "fun" boat, and a heavy "rump rump" cammed screamer.. Yes, you can have both, but it takes an awful lot of homework to achieve that "right outa the box".....If you really want to have a "fun" boat, design it as that when choosing engine parts, and start collecting additional stuff for another "monster" motor for the "need for speed" we all seem to have.... Enjoy your boat for a few years while you assemble a totally different engine. Remove the "sensible" engine and stick it under the bench, install the screamer, and if it fails you still have "old reliable" to fall back on and continue your "fun" on the water..... Believe me, there is nothing worse than having your boat in the shop, covered up, because the "big" motor ate up your boating budget, and then windowed the pan. Always plan for the worse case, and keep that back up complete, ready to go back in.....Good luck..
    Ray
    Well put Ray.....excellent advice!! Jocko

  5. #4
    Or Seth, either one Budweiser's Avatar
    Join Date
    Dec 2007
    Location
    Tower Park Resort, Lodi, CA
    Posts
    2,137

    Default

    Quote Originally Posted by Eddie View Post
    ...they are oval port semi closed chamber heads...
    Sounds like they may be 049 heads. If this is the case and you are set on using them, the dual plane manifold will suit well with a cam aimed at creating max hp at around 5000rpm. 049 heads flow OK in stock form but nose over at about .500" lift, so no need to go crazy with the cam. There is much to be gained with 990 (style) heads in the way of more potential rpm and flow, hence more horse power overall.

  6. #5
    New here Beer:30's Avatar
    Join Date
    Feb 2008
    Location
    Bakersfield, CA
    Posts
    4,219

    Default 427

    I am fond of 427s, myself. Drove a few as a kid and just loved the way they had plenty of TQ, but would also wind out on top.

    So, that being said, I personally would use the 396 crank in the 454 block - as mentioned - to make a 427. If you can buy rods and pistons, make it a long-rod motor for better dwell and less angle. Not mandatory to do so, though. It will run just fine with stock rods.

    The happy-medium for a V-drive boat comes with a transmission. Put a T400 or Powerglide into the mix and it gives you the best of all worlds. You can gear the the V-drive for all your motor can push on top (high gear), but still have TQ multiplication and slow/idle drivability with 1st, and 2nd gear. I am fond of the usefulness of three gears instead of two. Again, this would allow a heavy rump-rump cam (top end motor) but still have docking manners. Plus, you get reverse.
    Quote Originally Posted by gn7 View Post
    EFI is the wave of the future. There can be no denying it. Electronics have been on the leading edge of our entire lives. Not only os the magneto dead, but the standard issue CDI is wavering. Its all about total fuel, air AND spark control. Anybody that thinks its not has their head up their ass.


    2001 SleekCraft 30' Heritage SSB, open-bow mid-cuddy. 496HO / Bravo-I.

  7. #6
    Aquacraft Eddie's Avatar
    Join Date
    Mar 2008
    Location
    El Paso TX.
    Posts
    235

    Default

    Thanks for all the help!!! I really appreciate the info, I was looking for some 990 heads but have not been able to find any around here. The 427 ci is a great idea, I just have to check out some of my cranks, I have a few 396 motors, parts, not sure whats good or bad, been sitting for about 30 yrs... I was asking about the airgap, mainly because of its claim to be good down low and up high, performance wise, I have never used one so I dont know, I will probly try using both and see what works, or just go with the open plane, THANK YOU ALL FOR THE RESPONSE,,THATS WHY I POST ON THIS SITE<,,,,,,,,,

  8. #7
    New here Beer:30's Avatar
    Join Date
    Feb 2008
    Location
    Bakersfield, CA
    Posts
    4,219

    Default

    Quote Originally Posted by Eddie View Post
    Thanks for all the help!!! I really appreciate the info, I was looking for some 990 heads but have not been able to find any around here. The 427 ci is a great idea, I just have to check out some of my cranks, I have a few 396 motors, parts, not sure whats good or bad, been sitting for about 30 yrs... I was asking about the airgap, mainly because of its claim to be good down low and up high, performance wise, I have never used one so I dont know, I will probly try using both and see what works, or just go with the open plane, THANK YOU ALL FOR THE RESPONSE,,THATS WHY I POST ON THIS SITE<,,,,,,,,,
    I have a pair of 990 heads, but hanging on to them for a future build. Just put some 290 oval ports on the 427 for my '65 Impala SS, which work real well. Way more motor than I expected.

    The AirGap will treat your motor well, although it will knock down the top end a bit. Depending on how much you are going to WOT the boat, you may also consider a tunnel ram. Once again, especially if you put in a T400 trans. Regardless of boat-speed, you could keep the motor in a happy RPM powerband. Yes, you gain some weight and give up some HP to drive the trans, but personally I see the benefits out weighing all of the negatives.
    Quote Originally Posted by gn7 View Post
    EFI is the wave of the future. There can be no denying it. Electronics have been on the leading edge of our entire lives. Not only os the magneto dead, but the standard issue CDI is wavering. Its all about total fuel, air AND spark control. Anybody that thinks its not has their head up their ass.


    2001 SleekCraft 30' Heritage SSB, open-bow mid-cuddy. 496HO / Bravo-I.

  9. #8
    Aquacraft Eddie's Avatar
    Join Date
    Mar 2008
    Location
    El Paso TX.
    Posts
    235

    Default

    Thanks , I was also wondering about a single carb tunnel? vs the airgap, not sure how well the single carb tunnel would work compared to the victor jr open plane that I have?, so right now I am considering airgap, victor jr , or single tunnel ram, the tunnel ram only becuase I have a friend that has one, he may let me have it for a good price, but not sure if I should even bother with that? THANKS FOR THE HELP, when I have better info on the parts I have, I will re-post to see what you guys think might be better, but im to busy working right now to even dig my stuff out,,, HAPPY NEW YEAR,, THANKS FOR THE HELP!!!

  10. #9
    New here Beer:30's Avatar
    Join Date
    Feb 2008
    Location
    Bakersfield, CA
    Posts
    4,219

    Default

    Quote Originally Posted by Eddie View Post
    Thanks , I was also wondering about a single carb tunnel? vs the airgap, not sure how well the single carb tunnel would work compared to the victor jr open plane that I have?, so right now I am considering airgap, victor jr , or single tunnel ram, the tunnel ram only becuase I have a friend that has one, he may let me have it for a good price, but not sure if I should even bother with that? THANKS FOR THE HELP, when I have better info on the parts I have, I will re-post to see what you guys think might be better, but im to busy working right now to even dig my stuff out,,, HAPPY NEW YEAR,, THANKS FOR THE HELP!!!
    Most people here will tell you not to bother with single-carb TR. If you want to stick single-carb, go with a Victor Jr., or other well made single-plane. Single-planes are the mid-step between dual plane manifolds and tunnel rams, in essence.

    However, anyone here will also tell you that you need to cam the motor for what your END result will be. If you plan on doing a tunnel-ram, either during the build OR later on, you need to cam it for a TR. If you are gonna stick with single-plane, the cam will not be THAT much different, so they can somewhat share a cam profile. Dual plane will like a tamer cam AND will not make use of any high-rpm cam timing. So, you need to know what your combination will be AS you are assembling the short block.
    Quote Originally Posted by gn7 View Post
    EFI is the wave of the future. There can be no denying it. Electronics have been on the leading edge of our entire lives. Not only os the magneto dead, but the standard issue CDI is wavering. Its all about total fuel, air AND spark control. Anybody that thinks its not has their head up their ass.


    2001 SleekCraft 30' Heritage SSB, open-bow mid-cuddy. 496HO / Bravo-I.

  11. #10
    cfm
    cfm is offline
    Banned
    Join Date
    Jan 2008
    Posts
    1,263

    Default

    Quote Originally Posted by Beer:30 View Post
    I am fond of 427s, myself. Drove a few as a kid and just loved the way they had plenty of TQ, but would also wind out on top.
    454's (factory: steel crank, 7/16" rods/forged pistons/rect heads) that don't wind out like 427's just don't have enough camshaft.

  12. #11
    Foxwell Motorsports
    Join Date
    Dec 2007
    Location
    N/E Tennessee
    Posts
    12,323

    Default

    The difference I see between a jet and a flat is, when you mash the loud pedal, the jet basically goes to whatever peak rpm it's going to run and stays there. Because of the limitations of the pump, you're typically stuck with making as much power as possible in the 6500-7000rpm range MAX. Some ultra HP race boats will push more than that, and most weekend "performance" jets will see less than 6000rpm. This is why jets have the reputation for needing lower rpm power rather than higher rpm power and why bigger is always better in a jet. With a V drive, you can gear and prop to run whatever rpm you want so a smaller engine isn't a problem to get some rpm out of. The other difference I see is, a VDrive wants to burn the prop to get some rpm out of then hole, but unllike a jet, when the prop starts really biting it'll pull the engine down and then the engine needs to be able to recover and pull through a range of rpm. 99% of the time, both cases will benefit from the widest rpm range and broadest usable power available. A jet is a drive system that's loaded 100% right off idle and needs good power to keep accelerating the impeller. On a VDrive, once the prop is loaded, the engine will need good power to accelerate and keep accelrating. With peak power under 7000, I'd build both engines about the same. Maybe cam a little different one to the other, but not much.

    With some very basic mods, the oval port iron heads will feed the 427 or the 454 just fine up to about 650hp. You can expect about 310cfm @ .600" lift with a 2.19 intake and a good valve job and basic bowl blend, maybe 240-250cfm on the xhaust. I wouldn't waste my time with the airgap since there's very little load on these engines at lower rpm. The Vic Jr with a 750-850 will make as much toqrue and more HP than the 'gap. I also see no need for rect. port heads for either engine- even if you go aftermarket. You can run a set of 990's but the engine/cam won't be quite as user friendly and won't make a single HP more in the 6000rpm range. No matter what you choose, having accurate flow numbers will really help in deciding what direction to go with the cam. A roller will obviously have perfromance advantage over a flat tappet and personally, I wouldn't run a FT these days. Rollers are a good investment for both power and reliability.
    The thing about the 427 is, by today's standards it's just an overweight smallblock. You're going to have to turn some rpm to make some power. Not quite as much so with the 454. Unfortunately budget dictates everything, but for a "budget" 427/454 in a flat, I'd be looking at investing in a solid roller valve train, a little head work on the ovals, some decent rods and pistons (longer rods if you have the choice), as much compression as you think you can stand, and the best machinework and as much attention to detail as possible.
    Of course, there's no substitute for displacement, and a 489/496 would ba another choice.
    JMO

    ETA: An Edelbrock Street TR (oval port) and a pair of 650/750's on it would be way cool on either the 427 or 454 with the ovals .
    Last edited by steelcomp; 01-05-2012 at 05:15 PM.
    FOXWELL MOTORSPORTS
    STRAUB TECHNOLOGIES
    Performance Cylinder Head Specialties
    Custom Cams
    Complete Engines
    Retail/Wholesale Parts sales




    In the madness of this world, know the Peace of God.

  13. #12
    Junior Member SoldHondaBoughtHondo's Avatar
    Join Date
    Oct 2009
    Location
    Lake Havasu az.
    Posts
    4,255

    Default

    If you are thinking about that 3.76 x 4.250 combo check around for pistons first...seems like availability is kinda limited. And pay attention to the open/closed chamber deal. 396/427 heads should be closed chamber...put them on a 454 short block and the pistons might hit. As long as you have the time it might be a good idea to wait for a deal on 454 stuff to come long. Nothing really the matter with the smaller motors...they seem to work better in lighter boats
    and you need to spin them harder to get the most out of them.
    And these days with engine oil the way it is, lifters with wheels
    are a good investment. Have a flat tappet cam go flat and by the time you tear down and clean all the metal out of the motor, buy another cam/lifters/gaskets you didn't save any money. I swapped a dart/1050 for a t/r and 660's on my deal and i like it much better.
    "A liberal paradise would be a place where everybody has
    guaranteed employment, free comprehensive healthcare, free
    education, free food, free housing, free clothing, free
    utilities, and only law enforcement has guns. And believe it or
    not, such a place does, indeed, exist: It's called prison."

    Sheriff Joe Arpaio
    Maricopa County Sheriff's Office

  14. #13
    Aquacraft Eddie's Avatar
    Join Date
    Mar 2008
    Location
    El Paso TX.
    Posts
    235

    Default

    Thanks for all the info, I did decide to go with the victor jr intake, its a very early version, very old, will need alot of clean up and inspection. I found a set of my 396 heads, (still looking for the other ones) the casting numbers are #3856206 should be 1965-1966 closed chamber 97.2cc chambers. I have to find the other set to see what they are, I am a chevy guy, but I do like some fords, I have a 1971 mach 1 with a 351 cleveland ( i love those motors) it has the quench heads (4v) the intake is 2.19 big heads, they look like my 396 heads!! anyways I rebuilt the motor about 10yrs ago, I went with a flat tappet cam, now I wish I would have gone with a roller, I was trying to save money, and I did not know that they were going to stop putting zinc in the oil!!!!!!!! F@##@#$k plus that motor was known for wearing cams down because of the valve angle,, but at that time i did not know this, So If i can find a good deal on a roller cam set up for the chevy I will do it!!! I was originally going to save the 396 for the street, and put the 454 in the boat, I have to get the casting numbers off the 454 to see what heads they are, its a 1984 block so im not sure, hope its not peanut port.. THANKS FOR THE HELP,,

  15. #14
    Aquacraft Eddie's Avatar
    Join Date
    Mar 2008
    Location
    El Paso TX.
    Posts
    235

    Default

    I found a hurricane intake for $200.00 bucks, they say they recomend a 800cfm or bigger carb, I have a 750 dp I dont think this would be a problem if I went with this? but then again I have the victor jr, also I wanted to ask, I found a set of pro-comp heads for about $800.00 bucks complete, oval port, I have to get the casting numbers, but my question is are these heads good? I have never used them before so just wondering ? also here is a pic of the ford!
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	0518091325a.jpg 
Views:	23 
Size:	88.3 KB 
ID:	144774  

+ Reply to Thread

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Tags for this Thread

Digg This Thread

Posting Permissions

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

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91