Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 1438182 times)

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Offline 4-barrel Mike

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1815 on: September 02, 2014, 01:30:36 AM »
Bravo, Rose!  I got my Boy Scout Mile Swim Badge at Camp Meriwether as a young, in shape teenager.  It was hard.  I might have been able to do it in my early twenties but as a thirty-something (or older!)  :-D  impossible!

Again,  BRAVO!

Mike

 
Mike Kelly - PROUD owner of the V4F that powered the #1931 VGC to a 82.803 mph record in 2008!

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1816 on: September 03, 2014, 01:42:33 AM »
The freeway we were on coming home on from the swim meet was closed cause some nut was shooting at the cars.  We were caught in the mother of all traffic jams.  They routed all of the Interstate 84 traffic off of the freeway at one exit.  That is three lanes of traffic going down a one lane ramp.  Racing at Bonneville, Rose swimming across the river, and the traffic jam.  It is good to be home.

Mike, the injectors are inside those carbs.  There is a lot of room in them the that is not used.  They are perfect places to hide small things.


Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1818 on: September 04, 2014, 12:50:57 AM »
This is the time of year when I plan what to do for the next one.  The chassis including suspension and streamlining is about as good as I can get it.  The motor needs a few horsepower so I can go 150 mph.  Consultation with Matt Capri reveals I am 10 to 15 horsepower short of where I should be.  I need more compression, much bigger valves, and another set of cams.

The cylinder head flow data are below.  The intake flow is most critical and it is what I look at.  These figures represent the flow through the head with valves, manifold, carb, bellmouth, and air filter attached.

The cams in the bike now have 0.388 inches lift.  The new cams will have more than 0.425  Note the flow in CCFM is 209.5 at 0.375 lift and only a very small slightly better with 211.1 CCFM at 0.450 lift.  This shows me the higher lift cams will do me no good unless I put in bigger valves.

I cannot afford the valve work so the cams are not feasible.  The only option I have left is to raise the compression and to use the cams and valves I have now.  Matt says 12.5 to 1 will work and it is about as high as I want to go.  I will need to use race gas after this change.

     

   

 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1819 on: September 05, 2014, 01:40:25 AM »
The next step is to figure out how much more horsepower the added compression will give.  Two methods will be used.  One is to look at the handy chart on Page 69 in David Vizard's "How to Build Horsepower."  It says that increasing the compression ratio from 10.5 to 1 upward to 12.5 to 1 will give me 2.65% more horsepower.  This is 87.2 x 0.0265 = 2.31 HP.  Not much of an increase.  Tomorrow I will use PipeMax.

Offline Koncretekid

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1820 on: September 05, 2014, 07:09:56 PM »
Bo,
2.31 hp might not seem like much, but you've still got long pipes and mufflers - - which might be good for a wide torque curve, but not for maximum hp.  I think that if you shorten the pipes and possibly lengthen the intakes along with that increase in CR, you'll see a big difference.
Tom
We get too soon oldt, and too late schmart!
Life's uncertain - eat dessert first!

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1821 on: September 05, 2014, 09:38:39 PM »
Tom, the Arrow 2 into 2 mufflers and headers I used a few years ago were long and exactly what you say was true.  The effective length of the pipes on it now ends right under the front of the engine where the cross-over pipe is.  It connects the two headers.  This short tuned length uses the third harmonic to make a big increase in power.  A bunch of dyno time went into the inlet tract length and shape.  They are right where they need to be for these cams.  They are a lot longer than it appears from the outside.  Tom, tell me what you know about ceramic coatings.  I can order the pistons with them.

The PipeMax printout for this year's motor is attached.  The 7,300 Peak HP RPM is from an average of three dyno runs with optimum spark advance curve and jetting.  The measured rear wheel HP was 87.2.  The engine HP is estimated to be 1.1 X 87.2 = 95.9 HP.  The volumetric efficiency entry in PipeMax was changed incrementally until the Peak Horsepower from an Average engine is close to this.  The VE is 108 percent.  This is typical of the most VE I am able to get from these motors.       

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1822 on: September 05, 2014, 10:12:26 PM »
It is assumed the same 108 percent VE will happen with the higher compression motor.  The compression ratio entry in PipeMax is changed from 10.5 to 12.5.  The horsepower reading goes up to 99.4.  In terms of an increase in rear wheel HP:  (99.4 - 95.5) / 1.1 = 3.5 HP.  Not much of an increase and for all practical purposes a result similar to Vizard's prediction.

Look at octane requirements!  10.5 to 1 needs around 96 octane and 12.5 to 1 needs around 109.  A huge increase.

The flow this engine will need at 28 inches is 178.5 to 188 CCFM intake and 125.8 to 140.4 exhaust.  The head as it is now will provide plenty of flow as per the attachments to a recent post.

The goal is to exceed 150 mph with a NA motor and nothing more.  I will investigate use of ceramics with the compression increase.  This should give me what I want which is five or so more HP.

The next step is forced induction and the existing cams, displacement, and valve sizes are what I plan to use.  The ceramics will be a big help, too.  My goal is to get a 150 medal and go to blow without tossing out a lot of expensive parts.   

Offline Sporty Dan

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1823 on: September 06, 2014, 12:30:22 AM »
Wobbly, ceramic coatings on pistons are a good thing. I have a heat barrier on the top and a slippery coating on the piston skirts. They seem to work well. Have you looked at ceramic bearings for your wheels? They are pricey, but from what I've heard they make a big difference. One other thing I just thought of, if this is going to end up as a race only bike you can get rid of the charging system. That would get rid of drag and rotating mass.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1824 on: September 06, 2014, 02:14:58 AM »
Thanks for the advice, Dan.  Ceramic wheel bearings will go on this year along with a heat barrier.

This is a lot of work for a few HP using gasoline.  Why not raise the compression ratio much further and run on dope?  The FIM class I am in allows it and I have done a lot of mods to use fuel.  That engine is very strong, structurally. 

Offline Sporty Dan

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1825 on: September 06, 2014, 08:36:14 PM »
Wobbly, are you talking about alcohol or tipping the can? (Nitromethane)  :evil:

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1826 on: September 07, 2014, 04:58:34 PM »
Thermal management will be a big issue with this air cooled engine and forced induction.  A few years ago I was helping Lars with his supercharged flat head Indian.  He used alcohol and this kept the combustion temps at a reasonable level.  This is when I learned about this concept.

VP makes an alcohol blend that is easier to deal with than straight methanol.  There is also E85.  Right now I am thinking of running high compression with NA and alky or a alky based blend so I can get familiarity with the fuel.  Basically, I am kinda cheap and lazy so this will influence the ultimate choice.  I do not know Jack about any of these fuels so my mind is open to good advice.

Nitromethane sure is tempting.

Offline Peter Jack

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1827 on: September 07, 2014, 06:24:10 PM »
Nitromethane sure is tempting.

Not if you're cheap!  :-D :-D :-D

Pete

Offline manta22

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1828 on: September 07, 2014, 06:50:01 PM »
Thermal management will be a big issue with this air cooled engine and forced induction.  A few years ago I was helping Lars with his supercharged flat head Indian.  He used alcohol and this kept the combustion temps at a reasonable level.  This is when I learned about this concept.

VP makes an alcohol blend that is easier to deal with than straight methanol.  There is also E85.  Right now I am thinking of running high compression with NA and alky or a alky based blend so I can get familiarity with the fuel.  Basically, I am kinda cheap and lazy so this will influence the ultimate choice.  I do not know Jack about any of these fuels so my mind is open to good advice.

Nitromethane sure is tempting.

I remember reading something to the effect that in air-cooled aircraft engines, the maximum power output is limited by its allowable cylinder head temperature.

Regards, Neil  Tucson, AZ
Regards, Neil  Tucson, AZ

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #1829 on: September 07, 2014, 11:30:30 PM »
The bike would be a fuel tank with wheels if it carried enough nitromethane for a down and back run.

Neil, you are right.  On this engine the cylinder head can get hot enough so the aluminum between the valve seats or between the valve seats and the spark plugs permanently deforms.  The metal cracks when the cylinder head contracts as it cools.  There is a lot of money tied up in a cyl head on one of these bikes and this is a big concern.

The big Harley Valerie Thompson rode a few years ago ran on E85.  Maybe I can find out who built it.