Torque & HP Open Discussion

kapla wrote: ALan what info you need to desktop dyno my upcoming engine setup? sebastian

Get me your specs from the cam card, I have the head data and can give a pretty good guess at the CR and everything else.

Luchog wrote: Alan, I think Kapla's setup will end up very much like graph C on page 1 of this thread.

Very close but he's running different cam and rocker ratio. Compression ration is a guess too so I'll start with stock CR and refigure based on the smaller CC's of the gt40p heads.

Might be a few days as the PC this program was on lost a hard drive last week and I haven't loaded it back up yet.

Tim what do you mean by RR?
cam specs are lift 490int/exh duration @ .50 218 int 222 exh.
Dish piston .30 over bore....

this is the info on the pistons...
now that i see them they are for 1977-89 351w engines...should this worry me?

piston measures

60 hp UMMM almost 25% gain over the stock not bad at all....
This equals more ballast I�ll be able to handle equals more wake size equals massive air equals reduced knee and engine life

alan they are stock replacement....

I sure hope somebody is gonna make those "Fastest Boat at Green Lake 2009" plaques.........

Alan, that sounds great!!

Alan that sounds great . It is obvious you have done your homework . I hope she pulls to atleast 57.3. Whats next ?

Hey, what about a rookie of the year award..



I would hate to beat somebody at GL09.

Glad to hear the changes have you smiling Alan, we never had any doubt she would be a flyer. About time someone put a good running engine in that generation hull;-). It will be cool to see some air fuel ratio data. Your all ready into test and tune season and I have nothing attached to my engine block but the crank, main bearings, and caps...

Interesting tuning trip yesterday, first thing I learned is it's almost impossible to use a laptop computer in the bright sunlight!!! Impossible to see the screen so I just made some passes and logged data ti view later.

I did get the idle mixture perfect and the boat is running very good but the logs show it is very rich at 4000 rpm and higher, richer is better than a lean condition but it may be holding the engine back so I'm going to add a secondary metering block so I can change the jetting. You can really see when the power valve is opening as the engine goes from 13:1 to 10.6:1, I'm not feeling a bog but it goes rich and stays rich, I "may" drop the PV so it comes in later

Now for prop info I did put on my OJ 13x13 and here's what I found. I was hoping the motor would slow down to 5400 and it did drop to 5300 but I lost 1 MPH. (I'm not embarrassed to have the boat running 55mph with the stock prop though but I was hoping to go the other way) The holeshot is ofcourse not as violent as the 540 either BUT the oj is a better choice for general use as the bow lift at throttle up is much less than the 540 and the boat has a more comfortable feel to it. I think I'm going to send the 540 out and have as much cup as they can added to it. The 540 makes the boat racey and the throttle response with it is incredible but again the oj might make a smoother skiing prop where as the 540 would definately be a better choice for boarding as the nose runs high at those speeds.

I may eventually add another data logging module to the setup so I can record engine vacuum and rpm. Sort of tricky right now driving with a laptop, vacuum gauge and a stop watch in my hands.

Brktracer wrote: Alan, Pick up an LMA-3 for your LM-1. LMA-3 has the MAP built in. All you will need to do is connect a hose to manifold vacuum. It also has an accelerometer included so it can measure g force as well. It uses power from the LM-1 and the only wiring connections are the communication cable to the LM-1 and a tach signal wire. Calibrate the accelerometer and configure the channels and you're ready to run! I have one in the race car and it's really neat! I'll try to post a log later. It has 5 channels total so you can log things like voltage, fuel pressure, oil pressure, etc. Also, it has a 5V output and ground connections for each channel to avoid ground differentials.

That's the unit I thinking of adding, although I don't have an LM-1, I went with the LC-1 and a DB gauge thinking I would use the laptop for logging. Turns out the laptop is a PITA and the small handheld would have been easier to use and download. The Lm-3 will still hook right up to my setup and is in the future somewhere. The LM-3 is pretty cool,I was wondering how many g's you could pull in a powerturn!!!

Wait til Jbear reads this crap eh?

TRBenj wrote: On the Acme I had cup added to I didnt notice a penalty on the holeshot either- double bonus.

Because Cup is supposed to start affecting performance over 2000rpms.

So what you gain with a smaller/cupped prop is the holeshot of the lower pitch prop and the top end of a higher pitch prop.

81nautique wrote: Wait til Jbear reads this crap eh?

Are you guys kidding.....I know exactly what you're talking about....

HW..pass me another Beam huh?

john

Mucqb - Have you checked your foam & stringers for water saturation? Maybe the boat is just too heavy.