Brazos River Rat ( Billy's ) Update

[73 Sanger Flat]

Billy I think it is good your going back to reset the timing.  You always want to set the timing at 2000-2500 RPMs.  Back in the day we did this to get total advance with the weighted springs in the distributor.  I don't think your has these but that could be part of why the jumping around and why you need to do it at a higher rpm.  It could also be the lope of the idle. 
7.5 fuel pressure is fine as that is the max you want to run anything more and you will flood the carbs as the floats/needles/seats won't hald back the pressure when the bowls are full.  Holley especially performance carbs will hold 7.5 just fine.  My old Carter and the new Edelbrock carbs won't hold much over 6.5.  Everyone is right on the fuel that volume is more important than pressure as long as you are flowing enough fuel to keep up with what is draining out of the carb into the engine.  I also don't think that is your problem right now. 
I wish you luck on the next outing and hope it runs well.  You are at a performance level that every little thing can make a huge difference.

Come on Tim , spit it out ..

 

[Carnivalride]

Billy

One thing that I believe you said was, "It's still pulling".
The runs that I remember you making were not even close to 1/4 runs and appeared much shorter, by a lot.
Others may remember longer, but I don't.

If it's still pulling, you haven't reached the boats potential.
If your boat doesn't seem to hesitate coming out of the hole, you can pull the 32 gears, but if you want it to accelerate quicker, I believe lower gears will do that.

If you are willing to turn the motor 7300-7400 the 25's will be very close.
27's should get you around 7200.
I know you have a fairly long stroke and don't need the high rpm of a smaller motor, but V-drive's do like rpm.  So, it depends on the quality of your parts.
I think you've actually got some very good parts.
    :smile17:

Billy I was just going to tag on to what Jim said here, "you said it was still pulling". That's good and a properly set up v-drive should keep pulling and creeping speed up. When your under geared like I am right now you can feel it nose over up top when it runs out of gear or cam. That's fine if you're trying to be as quick as you can as long as it's after the race is over. lol

With that 4.5" stroke I'm not sure how hard I would rev that thing, it might die off like miine with 25s or it could keep going. But if there's not much difference it might live longer at 7k vs 7400.

Have fun and be safe!  :smile30:

 

[jimsplace]

Jim- I think the 32's are a little too high to get it to run out the top end like it should in a 1/4 or less .. I need to air it out and just see what she will do . But dam that water is going by fast even at 110 mph .. I just need me a long stretch of water so I can just stand on it for 12-15 seconds and just see what it will do .. Most likely I will step down to 27 and keep the RPM around 7200 max . That is what I wanted it to top out at on RPM .. Yes the engine can handle a lot more , but why stress it if I do not need to .. I am not a pro racer , just a weekend speed junkie..  What I am trying to do it to get the max out of this set up to see what it will do before I change gears. then i will change gears later if I am not happy .. This sucker is pulling pretty hard on all the passes just like it is , just the MPH is off some ..  --------+++++
Jim are you going out this weekend  ??

I would think the 27's would be a good place to be, it won't be far off regardless.

Why would you run it for 12-15 seconds?  That would seem to be putting a lot of stress on everything unnecessarily.
It's seldom you'll run it a 1/4 mile at the river and probably more like 1000 feet.
Even if you run it 1/4 mile, it should be maxed out speed wise, and with your set-up,  you'd better not even be at 11 seconds or something needs to changed.
Honestly, I don't think you're going to run it 12-15 seconds, it wouldn't feel right.
I doubt you're going to use your watch to time the 12-15 seconds.

I haven't thought about this week-end.
I saw you were thinking about going, do you know when?

 

[Disturbed]

Actually, a ten second boat will be on the throttle for approximately 13 seconds.  At the track.........

 

[Carnivalride]

Actually, a ten second boat will be on the throttle for approximately 13 seconds.  At the track.........

Ditto, between the flash, pull down and getting moving that first 125' burns some time.  hurry.gif

 

[jimsplace]

Actually, a ten second boat will be on the throttle for approximately 13 seconds.  At the track.........

Ditto, between the flash, pull down and getting moving that first 125' burns some time.  hurry.gif

I don't think so.

Correct me if there is a flaw in my thinking.
Many drivers click in gear at 6 or 7 on the countdown timer.
Each number represents about a tenth of a second.

Therefore, at something less than 6 or 7 tenths of a second, plus the ET would be the time a driver is on the gas for 1/4 mile plus 125 feet.
So, it would be 10 seconds, plus something less than 6 or 7 tenths.  I assume it goes into gear a fraction of a second before the throttle is pushed.
I also assume you get off the throttle as soon as the finish line is reached.

I've been wrong before, just not very often, so ruin my day.
    :smile17:

 

[Carnivalride]

Actually, a ten second boat will be on the throttle for approximately 13 seconds.  At the track.........

Ditto, between the flash, pull down and getting moving that first 125' burns some time.  hurry.gif

I don't think so.



Correct me if there is a flaw in my thinking.
Many drivers click in gear at 6 or 7 on the countdown timer.
Each number represents about a tenth of a second.

Therefore, at something less than 6 or 7 tenths of a second, plus the ET would be the time a driver is on the gas for 1/4 mile plus 125 feet.
So, it would be 10 seconds, plus something less than 6 or 7 tenths.  I assume it goes into gear a fraction of a second before the throttle is pushed.
I also assume you get off the throttle as soon as the finish line is reached.

I've been wrong before, just not very often, so ruin my day.
    :smile17:

Sorry Jim those are .5 second intervals so if you leave on the 6 that's 3 seconds to green.

Oh and for best ET you cross the last timing light under full power so you're not lifting until past the finish line. Like it was mentioned a true 10.0 boat will be on the gas for about 13 seconds.

 

[73 Sanger Flat]

I am going to just run it out the back door for maybe 30 seconds or longer .I going for marathon racing now .. . just kidding .. I need to see what it tops out with the gears and the RPM so I can make adjustments if I need to with the gears.. The max I want to turn is 7200 on the top end for Max RPM .. I want this mill to last .. So I am at 6750 RPM right now and if I can tweak on it and get it to spin to 7000 with these 32's I will just leave it alone .. I think it is a little slow and may not get top speed in the 1/4 mile with these 32's .. That would be the only reason I may drop down to 27 to help me get the  speed up in that 1000 foot or 1/4 .. If SDBA takes the races down to a 1000 foot , It will be horrible with  these 32's ..

I honestly think I need to run it out 12-15 seconds to get a good reading from the time I stab my foot into it ..The  next trip to Steel Creek , I am going to mark off the 1/4 with a couple of jugs so I know how far to run ..

 

[73 Sanger Flat]

Jim-- Trey and I are going to Chisholm Trail Sunday morning for a couple of test runs ..I am hoping it will pick up 200-300 rpm with the changes and then I can load it on the trailer .. I would love to see 7000 RPM Sunday morning on the river .. I need to find me a 150lb Flat Bottom driver and it would be there ..

 

[Knotty Girl]

I am going to just run it out the back door for maybe 30 seconds or longer .I going for marathon racing now .. . just kidding .. I need to see what it tops out with the gears and the RPM so I can make adjustments if I need to with the gears.. The max I want to turn is 7200 on the top end for Max RPM .. I want this mill to last .. So I am at 6750 RPM right now and if I can tweak on it and get it to spin to 7000 with these 32's I will just leave it alone .. I think it is a little slow and may not get top speed in the 1/4 mile with these 32's .. That would be the only reason I may drop down to 27 to help me get the  speed up in that 1000 foot or 1/4 .. If SDBA takes the races down to a 1000 foot , It will be horrible with  these 32's ..

I honestly think I need to run it out 12-15 seconds to get a good reading from the time I stab my foot into it ..The  next trip to Steel Creek , I am going to mark off the 1/4 with a couple of jugs so I know how far to run ..

SDBA will not go down to 1000'.  There will not be any changes from what they are doing this year.  :smile30:

 

[jimsplace]

Actually, a ten second boat will be on the throttle for approximately 13 seconds.  At the track.........

Ditto, between the flash, pull down and getting moving that first 125' burns some time.  hurry.gif

I don't think so.





Correct me if there is a flaw in my thinking.
Many drivers click in gear at 6 or 7 on the countdown timer.
Each number represents about a tenth of a second.

Therefore, at something less than 6 or 7 tenths of a second, plus the ET would be the time a driver is on the gas for 1/4 mile plus 125 feet.
So, it would be 10 seconds, plus something less than 6 or 7 tenths.  I assume it goes into gear a fraction of a second before the throttle is pushed.
I also assume you get off the throttle as soon as the finish line is reached.

I've been wrong before, just not very often, so ruin my day.
    :smile17:

Sorry Jim those are .5 second intervals so if you leave on the 6 that's 3 seconds to green.

Oh and for best ET you cross the last timing light under full power so you're not lifting until past the finish line. Like it was mentioned a true 10.0 boat will be on the gas for about 13 seconds.

    :smile19:
Damn - I hate being wrong.
Oh well, no one's perfect all the time.
Maybe no will notice.
 

 

[73 Sanger Flat]

Thanks Henry -- Good to know

We won't tell anyone Jim  , but you did ..

Now copy and paste .. LOL

 

[Carnivalride]

Hey Jim why don't you ask the circle racers how long they hold it down for there kilo runs. If I remember right they take a long run and are timed over the kilo so I'd say they are WOT for over a mile. Maybe one of them will chime in and correct me.

 

[73 Sanger Flat]

Hey Jim why don't you ask the circle racers how long they hold it down for there kilo runs. If I remember right they take a long run and are timed over the kilo so I'd say they are WOT for over a mile. Maybe one of them will chime in and correct me.

Not sure how long Stacey stay in its on his circle boat .. Maybe he will let us know .. I don't see how it would hurt the engine to air it out for 3/8 of a mile ..

Timing is set again this morning .. Put more gas in it , tighten a few things down and I think we are ready for a test run in the Morning .. Sunday at 10:0 am on the Brazos if anyone is around .. Me and Trey going to make some noise .. Chisholm Trail Park

 

[jimsplace]

Hey Jim why don't you ask the circle racers how long they hold it down for there kilo runs. If I remember right they take a long run and are timed over the kilo so I'd say they are WOT for over a mile. Maybe one of them will chime in and correct me.

They run a smaller motor with a much shorter stroke.

 

[73 Sanger Flat]

Test results this morning with Trey and Dad at Steel Creek .. Water was pretty slick and got two good runs in .. Then tried a couple more and water was to rough for me and only ran it out to 107 on the 3rd run ..

1st run it ran 112 mph and 2nd run she ran 113 mph .. On the first run Dad and Trey could see 1/2 the skag and went 112 .. On the second run went 113 and they could not see any of the skag .. Not sure what or Why ???  .Maybe water to slick and boat stuck ?? . Maybe it still trying to nose over , might need to remove one nickel ???.. Engine pulled to 6900 RPM and sounded really good .. It did better coming out of the hole , not sure if the 1 degree of timing helped or the removal of the air cleaner , but it did better .. She is getting there slowly ..I need to go play the tach back again , but I think it flashed to 6500 pulled back to 5700 and then back to 6900..

One is fuel pressure run , plenty of pressure , hard to see , but pretty sure it never dropped below 6.0 lbs ..
The other is a view from the top of the scoop ..

https://www.youtube.com/watch?v=PvAskURKi2M
https://www.youtube.com/watch?v=GkMUjuALiCo

 

[jimsplace]

Billy
It sounds like you got a lot of information this morning and the results weren't to shabby.

It sounded like the run looking over your shoulder was about 13 seconds, give or take a little.
You can probably tell almost exactly when you play it back on your tach.

If the motor flashed to 6500 with the 32 gears, it should pull to about 7100 with 25 gears, maybe a little higher.
I would assume the boat would pull harder by quite a bit with 25's

I don't recall what rpm your motor made the most horsepower.
    :smile17: 

 

[73 Sanger Flat]

max HP was at 6700 rpm .. I don't think I will change gears yet .. I want to tweak on it some and I think I can get 7000 rpm out of it with these 32's and that will be 115 mph .. If I drop down I might go with 27 or 29 .. I don't want to go over 7200 rpm max .. I will consult with JJ and get him to pick the gear for me later that will gain me about 300 rpm ..Might not be worth it .. this engine likes to be under a load ..

Pretty sure that was a 1/4 mile run give or take a couple hundred feet ..

not to bad of a test run to pick up 3 mphs..

 

[jimsplace]

Yep, at 13 second, that should bee a least a 1/4 mile, if not more.

I think that I mis-calculated.  I overlooked the 6900 rpm and was basing my number on the 6500 as max.
If you go to 29's, that'll give you 7100 rpm, or close to that, 27's should give you around 7300.
I would definitely talk to JJ, he'll know.

You're getting your boat where it should be, and it sure looks pretty doing it.

:smile21:Someday, maybe I'll learn to read all of the words or numbers.

 

[73 Sanger Flat]

jump.gif    Video of playback of tachometer  .. This at is 1/3 speed ..Pretty sure it is 12-13 seconds run .. I did not time it , but it most likely a 1/4 mile or close to it ..

Flash to 6500 , pulled back to 5700 and topped out at 6900 RPM maybe more If I would have stayed in it .. My question is at the end of the run the Tachometer was bouncing from 6800-7000 RPM and I could actually feel it in the boat .. My question is what caused this .. Is the boat wanting to go ahead and run up in RPM or maybe the back of boat is lifting up causing the prop to slip more .. I do not have a good Video of the side of the boat when it did this ..

For 32's gears this engine is pulling them pretty good for a pump gas deal .. Hell I might actually learn how to drive it this year and get it dialed in .. 

Tachometer Playback 10-11-2015..

https://www.youtube.com/watch?v=TTddUtoo_4g