10 :1 vs 12:1 c/r ???

[76miller]

How much of a hp increase will you actually see w/ 2pts. of compression ? If the motor is done making power @ 6400 rpm how big of a role will the added compression play. Torque will not be a problem because it will be a stroker, but the big question is, is the gained hp of 12:1 c/r worth the cost of fuel ?

[IMPATIENT 1]

could be as little as 40hp gain, could add alot more. worth it imo, just run a less aggresive timing curve when you need to run pump gas;)

[wannabe]

Depends what you are doing with the boat. I have ran high octane in another boat and an old Bronco and I am F'ing done with that $hit. For me up in Washington it was a complete pain, I even have a station within a few miles of my house. I carried extra barrells and always ran out. Let's say you want to stay a few extra days when your out boating...sorry no fuel for you, not to mention the crazy costs!!
If you don't already have it throw a shot of N2O on it, you will be happier with that than the pain of FINDING high octane when you need it...oh and by the way don't plan on using octane boost.
Also be careful trying to back timing down, it may bnot work with the combo that you have or if you do it will run like crap!!! Been there :(

[Sleeper CP]

How much of a hp increase will you actually see w/ 2pts. of compression ? If the motor is done making power @ 6400 rpm how big of a role will the added compression play. Torque will not be a problem because it will be a stroker, but the big question is, is the gained hp of 12:1 c/r worth the cost of fuel ?
All else being equal assume an 8% increase(that's 4% per point)
Example: if the engine is making 600Hp w/10:1 it will add approx 48 HP with the compression bump.
Keep in mind you may be able to gain an equal amount with a very good set of heads (that's flow,port shape and combustion chamber) without having to go the 12:1 route. If you can stay under 11:1 and with the right cam and timing you can make good (very good) power with 92 octane and not detonate. The Ford combustion chamber and flat top or dished piston you will run to get to 11:1 is a big advantage that you will have to keep the detonation down. ( just my .02)
Oh, could run the "old" 565 (855 hp engine) w/10.8:1 on pump gas at 32* timing with out a problem. We didn't do it much but a couple of times to get back to camp.
Sleeper CP
Big Inch Ford Lover:D

[cfm]

All else being equal assume an 8% increase(that's 4% per point)
Example: if the engine is making 600Hp w/10:1 it will add approx 48 HP with the compression bump.
Sleeper CP
Big Inch Ford Lover:D
If motor is already optimized for 10:1, 12:1 will need a cam swap and add another say 40-60hp on top of that 40hp from compression alone.
So, yeh, many motors going from 10:1 to 12:1 and making appropriate other changes, big power is realistic.

[Sleeper CP]

CFM,
Exactly, as far as optimizing the engine that won't happen unless he makes a cam change. That's why I stated "all else being equal" If I re-call correctly I don't think 76 Miller ( Wayne) runs a roller cam in that engine.
If he is going to build a stroker and put 12:1 compression in it with the correct cam he can make some big power. But he may not want a high maintenance engine.
Sleeper CP
Big Inch Ford Lover:D

[cfm]

Yup.
I quoted you to add to what you said, not differ. :)
10:1 big cube engines can really make decent power. Most definately.
Also, if you don't change anything else adding more compression will usually reduce max hp rpms. IE: lower the powerband's rpms.
==========================
Is there a detailed list of the engine as it sits now ? Or planned build up ?

[76miller]

All else being equal assume an 8% increase(that's 4% per point)
Example: if the engine is making 600Hp w/10:1 it will add approx 48 HP with the compression bump.
Keep in mind you may be able to gain an equal amount with a very good set of heads (that's flow,port shape and combustion chamber) without having to go the 12:1 route. If you can stay under 11:1 and with the right cam and timing you can make good (very good) power with 92 octane and not detonate. The Ford combustion chamber and flat top or dished piston you will run to get to 11:1 is a big advantage that you will have to keep the detonation down. ( just my .02)
Oh, could run the "old" 565 (855 hp engine) w/10.8:1 on pump gas at 32* timing with out a problem. We didn't do it much but a couple of times to get back to camp.
Sleeper CP
Big Inch Ford Lover:D
Sleeper-
I would rather go pump gas, but I'm just not sure. If 12:1 is going to have the hp # to reach my goal than so be it ! I don't mind checking springs, and valve lash, but the cost of race fuel doesn't seem to inviting w/ a tunnel ram deal. Check your pm's:idea:

[76miller]

Yup.
I quoted you to add to what you said, not differ. :)
10:1 big cube engines can really make decent power. Most definately.
Also, if you don't change anything else adding more compression will usually reduce max hp rpms. IE: lower the powerband's rpms.
==========================
Is there a detailed list of the engine as it sits now ? Or planned build up ?
CFM
I'm not bumping c/r on a current motor. I did run a motor on 10.5:1, but now I'm doing a new build and just don't know what c/r to run.

[BrendellaJet]

CFM
I'm not bumping c/r on a current motor. I did run a motor on 10.5:1, but now I'm doing a new build and just don't know what c/r to run.
Wayne, ask your builder this question. Better yet, tell him you want NA, X amount of horsepower, on pump gas. He knows the drill. Also, youd be surprised to see just how close to 12:1 he is with pump gas.:idea:
if you want to see what one of his motors can do let me know and Ill take you for a ride. My boat is a 21 footer and it gets up and moves pretty well. When I had it in my 18 is was just sickening how hard it pulled.

[The Doctor]

How much of a hp increase will you actually see w/ 2pts. of compression ? If the motor is done making power @ 6400 rpm how big of a role will the added compression play. Torque will not be a problem because it will be a stroker, but the big question is, is the gained hp of 12:1 c/r worth the cost of fuel ?
There's way too much information missing to make a truly informed decision. From what you have said here the only real answer is a 3/4 race cam. LOL
The entire engine package has to be custom fit (blueprinted) to your application from the ground up to match the components appropriately. There are even some situations where more compression could take you backwards-especially when speaking of fuel to be used. Give us more info and your answers will get better and better.

[bubbletop409]

Yup.
I quoted you to add to what you said, not differ. :)
10:1 big cube engines can really make decent power.
==========================
Is there a detailed list of the engine as it sits now ? Or planned build up ?
I am currently in discussion with Sunset Racecraft in Lubbock, TX about a pump gas 565 for my Cole. They currently offer a 565 designed to run on pump gas making 750 HP @ 6200, and 730 TQ @ 4800. Engine includes Comp Cams hyd. roller cam and roller rockers, Manley rods, Callies crank, JE pistons, Brodix 3X oval port heads and so on. Plus they build some killer full race motors.

[Nucking futs]

I just built a 540 800 hp @ 6200 740 ft lbs @ 5150 with 10.2/1 comp on pump gas. twin domis with afr 325 heads and a matched cam for the heads and induction and I was real impressed with it.
What is your power goal and what are you going to do with the boat?

[76miller]

I just built a 540 800 hp @ 6200 740 ft lbs @ 5150 with 10.2/1 comp on pump gas. twin domis with afr 325 heads and a matched cam for the heads and induction and I was real impressed with it.
What is your power goal and what are you going to do with the boat?
Futs-
My power goal is as much as I can make.....w/ my budget ! I pretty much just plan on going out to the river and making a bunch of noise, and being able to run hard at night. I would really be happy to make your #'s , @ 6200 rpm ! That sounds like a good time w/ an "A" or "AB" impeller. Chris Straub do your cam ? I just might have to call him up. Pump gas is what I want, but I will pay for the better fuel if its gonna make it that much more fun when my foots in it ! :) This is one of those things where every builder has a different opinion, as far as final power results.

[76miller]

Wayne, ask your builder this question. Better yet, tell him you want NA, X amount of horsepower, on pump gas. He knows the drill. Also, youd be surprised to see just how close to 12:1 he is with pump gas.:idea:
if you want to see what one of his motors can do let me know and Ill take you for a ride. My boat is a 21 footer and it gets up and moves pretty well. When I had it in my 18 is was just sickening how hard it pulled.
12:1 on pump gas ? Talk about running on the raged edge ! I might have to take you up on that offer for a boat ride, its going to suck this winter not being able to make some passes w/ a sweatshirt and beenie on in Jan. I love that $hit, no wake boarders, only pissed off fisherman.:jawdrop:

[Nucking futs]

Futs-
My power goal is as much as I can make.....w/ my budget ! I pretty much just plan on going out to the river and making a bunch of noise, and being able to run hard at night. I would really be happy to make your #'s , @ 6200 rpm ! That sounds like a good time w/ an "A" or "AB" impeller. Chris Straub do your cam ? I just might have to call him up. Pump gas is what I want, but I will pay for the better fuel if its gonna make it that much more fun when my foots in it ! :) This is one of those things where every builder has a different opinion, as far as final power results.
Well like I told my brother when he was builing his 496, figure out your program,what you want to do and what your goal is and stick to it. Its real easy to get half way through gathering your parts and then want to change one area of the build. That could kill the whole thing. He wanted 700 hp,and he got 710 @6200 and is real happy with the engine. My goal was 800 and we barly made it there. I left alot on the table as far as head work and should see an increase in power if i decide to go that way later on. I wanted a pump gas 800 hp engine that would support a 200hp hit of the funnygas and its ready for it. Like it was mentioned earlier in the thread,find a builder that you like and talk to him about options.
DNE does awsome work and has some bitchen combos that are proven,but I couldnt afford one of is engines and I have built alot of engine for myself and felt I could do this one as well.I delt with Chris Straub and we talked about what i wanted and what my specs were being I has all my parts and knew compression ratio rod length induction and he supplied me with the cam lifters and advised me on the heads that would suite the build and it hit dead on.Chris knows his chit forsure and he did my brothers cam and lifters as well. Defantly call him and talk about what you want and im sure he can help you out.

[76miller]

Futs- Ya, the cost difference in a 600 hp motor to an 800 hp motor is huge !! Thanks for the reply, I'm going to give Straub a call and pick his brain.

[IMPATIENT 1]

I just built a 540 800 hp @ 6200 740 ft lbs @ 5150 with 10.2/1 comp on pump gas. twin domis with afr 325 heads and a matched cam for the heads and induction and I was real impressed with it.
What is your power goal and what are you going to do with the boat?
why the twin dominators futs? wouldn't a single dominator on a good intake done the same numbers with possibly more tq?:confused:
i agree, figure out what you wanna make, build that and stick to it. i've been second guessin my build for months but i finally said to hell with it, what i planned from the beginnin was right.

[Nucking futs]

why the twin dominators futs? wouldn't a single dominator on a good intake done the same numbers with possibly more tq?:confused:
Not sure about that, but my domis are only 750 cfm.I got a killer deal on them so thats what I ran. After talking to Chris and steve at westech,I would of left alot on the table with just a single.I might want to go that route later on, but then i would need to change the cam. The cam was designed for the "WHOLE" package I had. I was initially going tunnel ram injection,but that changed....:D My engine ran 33 hp less without the vacuum pump.

[IMPATIENT 1]

ya know, i'd like to see a dyno sheet ran with dual doms up to 6500, then switch to a single and run that up to 6500, see the difference. i'm runnin a 1150cfm dom and i was hope'n it was all i needed.picked my block up today and gonna start file fitting fri. nite:mad: see if i can't have a long block built by sat evening.

[IMPATIENT 1]

ya know, i'd like to see a dyno sheet ran with dual doms up to 6500, then switch to a single and run that up to 6500, see the difference. i'm runnin a 1150cfm dom and i was hope'n it was all i needed.picked my block up today and gonna start file fitting fri. nite:mad: see if i can't have a long block built by sat evening.

[BrendellaJet]

Not sure about that, but my domis are only 750 cfm.I got a killer deal on them so thats what I ran. After talking to Chris and steve at westech,I would of left alot on the table with just a single.I might want to go that route later on, but then i would need to change the cam. The cam was designed for the "WHOLE" package I had. I was initially going tunnel ram injection,but that changed....:D My engine ran 33 hp less without the vacuum pump.
I knew I was leaving power on the table by going with a single 4(HP950). But having the manifold ported by wilson helped to get some of it. It would be interesting to see how much Im leaving on the table with my setup. I figure by switching I would probably be on the high side of 850 by going with the TR and a new cam, but this thing sips gas so Im hesitant to make the change.

[BrendellaJet]

12:1 on pump gas ? Talk about running on the raged edge ! I might have to take you up on that offer for a boat ride, its going to suck this winter not being able to make some passes w/ a sweatshirt and beenie on in Jan. I love that $hit, no wake boarders, only pissed off fisherman.:jawdrop:
I didn't say that, I said you'd be surprised to see how close...:D

[Sleeper CP]

Not sure about that, but my domis are only 750 cfm.I got a killer deal on them so thats what I ran. After talking to Chris and steve at westech,I would of left alot on the table with just a single.I might want to go that route later on, but then i would need to change the cam. The cam was designed for the "WHOLE" package I had. I was initially going tunnel ram injection,but that changed....:D My engine ran 33 hp less without the vacuum pump.
Changing the cam for the single 4 is not absolutley neccesary. Yes if you are concerned about the last few hp, but you might be surprised if the T/R cam made max power at 6,400 switching to the best single you'll probably be within couple/few 100 rpm's or so.
Thanks for the info on the Vacuum pump, what ring pack are you running? Light tention rings or a standard or zero gap?
I was thinking about changing the carb and putting on a Vacuum pump and up grading to a custom Steph's oil pan with a kick out and mesh screen on the 565" and running it this winter on the dyno to see how close it can get to 1,000 HP.
Sleeper CP
Big Inch Ford Lover:D

[Nucking futs]

Standard ring pack. Im running hell fire rings for the nitrous. Its estimated that i would lose about 25-40 hp switching to a single,but it might pick up on ET. Its a river boat so im not really concerned about a few tenths right now.Maybe after a few trips and I relize how much fuel it uses...

[Sleeper CP]

Standard ring pack. Im running hell fire rings for the nitrous. Its estimated that i would lose about 25-40 hp switching to a single,but it might pick up on ET. Its a river boat so im not really concerned about a few tenths right now.Maybe after a few trips and I relize how much fuel it uses...
Thanks for the info, forgot to ask how many inches of vacuum are you running?
I ran the C&A Hell Fire rings in the 409" 650 hP smblk Ford we built for the Engine Master's competition. They make a very good product.
Sleeper CP
Big Inch Ford Lover:D

[Nucking futs]

9"

[WETTE VETTE]

I don't have dyno numbers, but did see a gain in the boat going from a dart single plane with a Nickerson stage 5 1250 dom to a Dart TR with 2- Nickerson stage 5 1050 dom. I also went with a slightly different stick. The original was 264/270 on 114+4 with .740" lift and the TR cam is 268/272 on 112+4 with .730" lift. All told the boat picked up 200 RPM on top and 4 MPH with better mid range acceleration. Idle is just as good as the single plane. Motor is a 10:1 598 running in the 6200 - 6500 RPM range. I was really surprised how crisp the throttle response is with the two big carbs!!

[396_WAYS_TO_SPIT]

Compression=HORSEPOWER!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!
if your going to bump the comp then you might as well go to 13-1 or 13.5-1

[396_WAYS_TO_SPIT]

Compression=HORSEPOWER!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!
if your going to bump the comp then you might as well go to 13-1 or 13.5-1

[BrendellaJet]

so whats the decision ? Did you talk to Dave about it?