Brazos River Rat ( Billy's ) Update

[Patchman]

:smile23: :smile14:

 

[Carnivalride]

Thanks Loren , was you able to watch the two videos? The side is cleaning up pretty good with the adjustments .. I am not sure what you are referring to "]a longer arm where the rod connects."  Can you post a pic for me .. I am not sure how much actually down movement i have on the plates .. I measured them one time and not sure how much .. I have to slide the boat back about a foot or more to get the plates cleared to move down .. If I added longer eye levers would that help get more down on the plates .. Teach me PLEASE ..

Sorry I don't has a pic here so I'll try and explain it better. On my pedal assembly I only have a down pedal, on that down pedal is a piece that sticks up that the rod attaches to that goes from there to the arm on the cavitation rod on the transom. Any way that piece coming off the downpedal is about 2-1/4" long from the down pedal shaft to the center of the hole which is about another 1/2" longer than my old one. My center plate with 1-3/4" long eyelevers has over 1-3/8" of down in fact I think it's a solid 1-1/2" if I remember correctly.

The easy way at home is just disconnet the turnbuckles on the outer plates and just measure the center plate travel.

 

[73 Sanger Flat]

OK-- I got it know .. Longer rod off of the down pedal that will make it throw more .. I understand on disconnecting the outside plated to get the movement on the inside plate also .. Thanks --

 

[Knotty Girl]

I think that boat is entirely too fast, no need to drive that fast on the water.  :smile30:

It is OK Henry , it is a Flat- bottom V-drive  and not a Hydro -- I can turn it  .. It is getting pretty fast and I know I must respect the boat at all time , no matter what speeds it is going .. It can hurt you quick ..

I was just messing. Your boat looked real good!  clap.gif

 

[whitetrash148]

One does what one must do to make it run the number.  Remember this is bracket racing, most can run just a little faster than the class their in requires. Being the fastest boat in the class will not win the race, the one that runs closest to the number and the driver with best reaction time will normally win. Red lights will kill you! Look at it this way, a red lite costs approx. $1000.00.

 

[fenceman]

Secret to rope racing? Make a lot of laps and have some luck here and there. Pretty simple huh?

 

[Knotty Girl]

I have heard it is easy and all you have to do is leave on your number.  crazy.gif

 

[73 Sanger Flat]

It is  racing the clock and not racing the boat next to you is what is going to be hard to do .. Red light = 1000.00 .. I have to remember that one .. That is an expensive ticket there ..

 

[73 Sanger Flat]

OK - I started thinking yesterday and I know that can be dangerous..I can not keep thinking that this new engine making about 110 more HP should run faster than the old engine .. The old engine would run 108-110 and new engine is running 110 every pass ..So pretty close to the same on the MPH .. I know I changed props and that will affect it  .. So I am thinking that something that is different on the boat than on the Dyno may be causing the lack of RPM .. These are my four scenarios.. 1: Flame arrestor ? None on Dyno---I only have two coils on the flame arrestor now .. going to remove all coils and try it . May be restricting air ?? That is what I think it may be .. Lack of air .. be the cheapest to try also .. 2: Fuel Pump --- Dyno had two electric pumps . I have one huge mechanical-----I will put the video camera on the gauge next outing and check for pressure ----3: MSD box I believe was the same ??----4: Timing on Dyno was 33* and I have it at 32* .. Will change next outing . That will help perk the engine up --
I have checked the throttle cable for WOT and it looks good to me .. The boat is beginning to free up some and that may help some ..
I attached both the old and new dyno sheet .. What is weird I am pulling to about 6700 RPM with both engine in the boat , so that is what makes me think it could be an air restriction .. Hell I don't know .. I know the boat is fast enough already , but it should run 8-10 mph faster in my calculations ..

 

[Chevy2184]

If you are running the aluminum style flame arrestor? No way that thing can flow enough cfm...


Sent from my shop setting in my boat making motor noises

 

[73 Sanger Flat]

This is what I am running 10 x 3 inch with only two rounds of the screen on it only .. It should flow pretty good with just two rounds of screen on it , but  am going to take them off and try it . I have to use the frame of the arrestor to hold the scoop on , but I can remove all the screen and do that

 

[Patchman]

Wouldn't the prop and the gear box dictate top mph? I mean you can have 500 hp or a 1000 hp in a car, and with a 4:56 gear it will go the same mph. I would think top speed is a direct correlation with crankshaft rpm. So at 6700 rpm with same setup should equal same speed. More power should require a gear or prop change to get maximum benefit I would think. You mite be hitting that 110 mph quicker with your current power. I don't know, just thinking about your statement. think.gif

 

[Disturbed]

Wouldn't the prop and the gear box dictate top mph? I mean you can have 500 hp or a 1000 hp in a car, and with a 4:56 gear it will go the same mph. I would think top speed is a direct correlation with crankshaft rpm. So at 6700 rpm with same setup should equal same speed. More power should require a gear or prop change to get maximum benefit I would think. You mite be hitting that 110 mph quicker with your current power. I don't know, just thinking about your statement. think.gif

^^^^^  He's learning Vdrives!  clap.gif clap.gif clap.gif clap.gif 

Billy, you're maximum horsepower is at 6700 RPM.  You're not going to turn the prop any faster very quickly.  If you want to go faster MPH, you're gonna have to change gears or a prop.  My $.02

 

[73 Sanger Flat]

I would think if i could turn the same gears and prop to 6700 with last engine , this new engine  should go ahead and spin on up past there ..Hell the new engine  made more HP at 7400 RPM than the old motor made at at 6600 at 843 HP ..So why wont it pull the RPM to 7400 at 887 Hp like the old engine did ..  I understand the new engine made max HP at 6700 but that does not mean that the engine should not go ahead pull the rpm's up past that .. Hell If I put a set of 18's in it , it should go to 7800 RPM's , it would  be quick like that .. Even if I use the TQ number , it still should spin to 7200 RPM with the new engine to match the TQ that the old engine had ..

 

[73 Sanger Flat]

Wouldn't the prop and the gear box dictate top mph? I mean you can have 500 hp or a 1000 hp in a car, and with a 4:56 gear it will go the same mph. I would think top speed is a direct correlation with crankshaft rpm. So at 6700 rpm with same setup should equal same speed. More power should require a gear or prop change to get maximum benefit I would think. You mite be hitting that 110 mph quicker with your current power. I don't know, just thinking about your statement. think.gif

I would think if the 1000 Hp engine would turn more RPM with the 4:56 gears , wouldn't it go faster turning more RPM  ?? Unless something is restricting the RPM on the 1000 Hp engine and not letting it spin up ..

 

[73 Sanger Flat]

GW that races a Cole TR-4 at the SDBA races is running a 598 high compression engine with a set of 12's in it and turning the engine to 7800- 8000 and running about 125 in the quarter .. It all about the prop speed , not the actual engine RPM .. The high engine RPM will get you there quicker ..
Hell i don't know , teach me guys .. I need a good crew chief ..

 

[Disturbed]

My suggestion is this, try whatever you think might get you where you want to be.  I've tried to up my RPMs by going with 18s.  I found that it would only turn 6600-6700 RPM with 22s or 18s.  It didn't matter.  I took off my flame arrestors, etc.  Not saying that's what yours will do, just saying that was my experience on mine.

 

[Patchman]

Just because you have more hp doesn't mean it will turn more rpm. If you spin it to 7k horsepower doesn't matter, it's still turning 7k. More power just means you spin it to 7k easier. I would think that the prop may have an effective rpm range. So maybe if you spin it faster, don't necessarily mean it pushes the boat faster. I'm just guessing here, seems to be my experience that more power doesn't always mean faster. There are always other limiting factors like props and gears. Maybe your spark arrestor is restricting the motor. Side note, seat of your pants data isn't the most accurate. If you had time slips, you would know what the real benefit of your new power is.

 

[73 Sanger Flat]

Thanks Guys -- Just trying to wrap my head around all of this .. That what we did on the old engine , we went from 22's pulling 6900 RPM at 102 mph  and changed it to 32's and went  110 mph .. The old big engine liked to be under a load .. I think it is geared to high myself right now .. It is still pulling hard when i let off of it Saturday .
Most are telling me to drop down to 25's and let the RPM come up faster and it would help the set also , but then RPM should come up at the same time .. I understand that some engine just have a max RPM they are going to turn no matter what , but on the Dyno this dam thing pulled way past the 6700 RPM and started dropping HP of course higher it went ..
I am going to try a few things and see if it help , it wont cost anything and if by chance it works , I will be super happy
Thanks again for the input -- I always like to hear other people thoughts on stuff like this .. I am always trying to learn how to make a boat faster .. ..

 

[73 Sanger Flat]

Yeah only thing I have to help me is my GPS and the Tach to tell me if something is better or worse .. The track would be nice .. But I don't want to be having to change stuff at the track .. I would  prefer to have it dialed in by then .