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Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 1030078 times)

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Offline Koncretekid

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #870 on: September 11, 2012, 06:40:58 PM »
Bo,
That's one clean looking motor.  I haven't taken mine apart yet, but don't expect it to be that clean. One small piece of white metal on the sump screen, and some small specks in the drained oil seem to indicate a rebuild would be a wise move.
Tom
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Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #871 on: September 12, 2012, 01:03:12 AM »
Yea, Tom.  It is better to take it apart yourself than have it disassemble itself during the race.

The headers on Matt's bike show the typical megaphone system.  The upstream end of the meg is at the third harmonic point.  The headers for my bike are on the kitchen table.  The cross-over tube is at the third harmonic.  These "H" systems work well for vertical twins whose pistons rise and fall together and fire on alternate strokes.  The next few posts show how I use Pipe Max to design one for the big motor. 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #872 on: September 12, 2012, 11:50:56 PM »
My tuning philosophy is extremely simple.  I try to wind up the engine as tight as I can without blowing it apart.  This motor is reliable at 7,500 rpm and it will hold together to the 8,400 rpm red line.  I use 7,500 rpm as my target for setting the gearing.  This is the rpm I want to be at through the mile.  Why is this?  The high engine speed allows me to use a numerically high gear ratio that gives the engine good leverage on the track.  The bike runs fastest when the peak horsepower occurs at 7,500 rpm, too.  Exhaust and intake tuning can be used to shift the peak horsepower to exactly where I want it.

The 2011 dyno runs for the jetting are shown.  The Arrow "midrange" pipes were on the bike.  The engine reached peak horsepower at too low rpm.  The 2012 jetting curves are shown.  The OEM headers and glass paks were used.  The horsepower peak is at too high rpm.

The 2012 runs were to be the last for the mid size engine.  The standard Triumph headers and the glass paks were intentionally used as the first step to design the exhaust system for the big motor.  The big mill will use a variation of this "H" system.     


Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #873 on: September 12, 2012, 11:52:12 PM »
The graphs.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #874 on: September 13, 2012, 11:20:47 PM »
The next step is to model the existing engine in Pipe Max.  The engine data is entered along with the actual peak power rpm, 8000.  The option to calculate torque and horsepower is selected.  The volumetric efficiency is adjusted until the average horsepower is around 93.3.  This is what I estimate the engine dyno power to be.  It is 1.1 times the 84.8 chassis dyno power.  The engine is modeled.

 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #875 on: September 13, 2012, 11:24:04 PM »
The option in Pipe Max to calculate pipe specs is chosen.  The existing system and the proposed will be tuned to the third harmonic.  This is 22.5 inches for the existing engine.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #876 on: September 15, 2012, 01:33:55 PM »
Peak power that happens about halfway between the Arrow and OEM header tunes should work good based on on-the-salt experience.  This is a little bit lower rpm than my 7,500 target.  Now I enter all of the engine data for the 994 cc engine with a 7,300 rpm power peak.  The 865 cc engine torque when it is tuned to produce peak hp at 7,300 rpm is estimated to be 61.6 lbs-ft.  The 994 cc kit will increase this 10% with no other changes, according to Matt.  The 994cc engine torque converted to engine dyno numbers is 74.6 lbs-ft.  The volumetric efficiency is adjusted in Pipe Max until it is close to this number.  It is 105%.  This is realistic.  The cams, valves, etc are all the same as in the 865cc mill.  The 994cc motor is modeled in Pipe Max.

The 3rd harmonic tuned length differs 2.8 inches between the 865cc engine as it is tuned now and the future 994cc motor.  A set of headers is ordered with the cross-over tube moved 2.8 inches back.  Right now I am working a bunch of overtime so I have money and no time.  No time to do this and I am a lousy welder at best.  The trained professionals at Alldens Exhaust in Horncastle, England, are making these pipes.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #877 on: September 18, 2012, 12:22:56 AM »
The Pipe Max run for the 994cc engine says the header pipe diameter should be 1.431 to 1.556 inches OD (1.306 to 1.431 inches ID).  The OEM headers have a 1.4 inch ID.  Pipe Max was developed using data collected at near sea level in Louisiana.  Everywhere there is not very high up.  This indicates the pipe diameter should be correct for Lake Gairdner in AUS.  It is at a little over 1,000 foot elevation.

The elevation at Bonneville is just over 4,000 feet and the air is thinner.  My assumption is the air is 0.86 times as dense as at sea level.  The 994cc displacement is multiplied by 0.86 to get 855cc.  This motor has a 89.5mm bore, or 3.520 inches.  The smaller bore is entered into the Pipe Max data.  This pseudomotor sucks and blows amounts of gas similar to the 994cc one at Bonneville altitude.  The recommended header diameter range is 1.316 to 1.441 inches OD (1.191 to 1.316 inches ID).  The standard OEM headers are a little bit big for that altitude.

I check out other things on both Pipe Max data sheets like valve choke.  Everything seems to be OK at either altitude.  The exception is the maximum effort cam lift.  This is less than the lift provided by the standard Triumph cams.  This Pipe Max data is suspect.

A set of modified OEM headers should work just fine, diameterwise.  There is no need to go bigger.  This will save me some money. 

 

 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #878 on: September 18, 2012, 11:23:52 PM »
This last exhaust tuning post will be on temperature.  The pressure waves bounce back and forth in the exhaust at the speed of sound.  This velocity varies with temperature as shown on the graph.  As a general rule, cooling the exhaust gases slows them down.  This has the same effect as increasing the tuned length.

The power characteristics of the engine were tested on a dyno in summer 2012.  An electric fan blew a gentle breeze across the engine and exhaust.  It did not cool them too much.  The air movement behind the old fairing was similar.  It was subdued.  The power curves observed on the dyno resembled the power that was felt on the salt.

The power should have been strong in 2012 at the highest rpm based on the dyno runs.  It did not feel that way.  It felt like the torque was falling off at higher rpm.  The fairing has a larger opening and the headers were in a very strong breeze.  My suspicions are this cooled the exhaust sufficiently to slow down the speed of sound in the gasses.  This increased the tuned length of the headers.  The peak power rpm dropped as a consequence.

This year I will wrap the front of the headers where they are in the breeze.  Next year, when I have more time, I will close the hole in the front of the faring a little bit.  This will help aero and keep the pipes warmer.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #879 on: September 19, 2012, 01:59:18 PM »
A few years ago I took the motor apart after ten runs down the salt and lots of street miles.  This was the original engine assembled by Triumph in Hinckley.  There were dark stains around the connecting rod big ends from oxidized oil.  Parts were getting too hot.  Usual practice on these motors is to fit the white coded big end bearing shells.  They fit looser and increase the amount of oil flowing between the rod bearings and the crank journals.  This worked.  There was no sign of big end overheating on this teardown.

Gall marks showed that the small end bearing on one rod seized to the gudgeon pin and freed itself.  This was with the original Triumph built engine.  I had no idea if the initial clearance was too tight and this might have caused the problem.  I did note that the gudgeon pin and the hole for it in the small end were both steel.  Steel on steel is not always a good idea for a little end bearing in a race motor.  My solution was to install a set of Carillo rods.  They are in the engine in the photo.  The little end bearing is phosphor bronze.  This is a much better combination to go with the steel gudgeon pin.  Racers recommend these rods.

A lot of piston and bore wear was seen on the recent teardown.  The standard Triumph connecting rod is shown in a photo.  It has a hole to squirt oil up onto the piston and little ends.  The Carillo rods do not have this.  Lack of oil might be causing some wear.

The serious racers rev these engines up to 9,000 and 10,000 rpm.  Most of their engines are race motors, only.  It is easy to see why they prefer and recommend the Carillo rods.  My target rpm is 7,500 and the rev limiter is set for 8,400.  The standard rods are plenty strong for me and I am concerned about piston and bore life.  This is my street bike, too.

There are two types of Triumph connecting rods for these engines.  One is designated as the "short stroke" rod.  It has more metal around the little end bearing than the other type.  I ordered a set from Triumph.  The plan is to have phosphor bronze bushings installed in the little ends and to get them honed to fit the 994cc kit gudgeon pins.  I might have the rods polished and shot peened, too.

Who has a good reputation for doing this rod work?  Quality and doing the work on time are more important considerations to me than cost.

Offline Koncretekid

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #880 on: September 20, 2012, 09:58:55 AM »
Bo,
I'm running a Carillo rod and I had the same reservations about oiling the piston. I thought about trying to drill a hole in the top of the bottom end of the rod, but ended up with an oil squirter instead.  I've seen 8800 rpms on occasion, and the motor saw more than that when the primary chain broke.  Piston still looks ok, but may be a little loose for street use (.007" clearance after two years land speed racing).
Tom
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Life's uncertain - eat dessert first!

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #881 on: September 20, 2012, 01:19:12 PM »
That is something I might do and will consider.  There are two oil pumps on these bikes.  The rear one is very important.  It is connected to the oil pressure bleed off valve, oil pressure idiot light, crank, rods, squirters, and cam bearings.  The front pump sends lube to the tranny shafts and it circulates lube to the oil cooling system passages.  I can tap into the front pump and cause no pressure drop in the most vital rear pump system. 

The pistons were set up with 0.004 clearances.  The piston diameter is 3.54 inches and that is not unreasonable.  These short and fat pistons confuse me.  It seems some clearance is needed for the wide guys to expand when they get hot, and at the same time, they need tight skirt clearances to keep from rocking.  The rocking was at TDC.  The outlines of the piston skirts were visible on one side of the bores.  All of this did not help the ring sealing and it might be one reason of several for this year's slowness.

Years ago I ran forged pistons in another motor.  A guy told be to count up from "one alligator" to "20 alligators" before I took off on a cold engine.  This warms the pistons so they expand, he said.  He also said to take it easy for the first mile.  It no problem on the street and a challenge to do during a race.

The 865cc barrels and pistons were sent south a week or two ago for triumph performance to look at before they set the clearances for the 994cc jugs and slugs.  A asked for "street clearances."  To make this tight clearance work with no seizing I am accepting some self imposed limitations.  Modified Triumph rods with oil squirters will be used.  The 7,500 rpm target rpm and 8,400 rpm red line will be unchanged.  I will run the cooler burning 110 octane leaded on the salt rather than the 100 octane unleaded.  I will stay with the relatively mild #813 cams for now.

This is the big long term plan.  It is major work to pull the engine.  The head and cyls come off relatively easy.  This is an DOHC setup and all of the go fast stuff is on top.  The Carillo rods are top loaders and I will see if the Triumph rods can be changed to this configuration.  This allows me to check and renew the critical rod big end shells with the engine in the frame.

The 994cc engine will be the race top end that has the mongo cams, monster valves, loose race clearances, and the Carillo Rods.  The street top end will have the standard 790cc pistons, cams, the ported head with 2mm larger intake valves, and the tighter clearances.

The big issue now is finding an expert to mutilate a set of Triumph rods into some mild duty racing ones.

 

 

 

Offline Old Scrambler

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #882 on: September 21, 2012, 08:50:30 PM »
Bo........I just got my 45-year old used and abused (sat in a water-logged motor) rod back from Alpha Bearing in the UK. They reconditioned the rod, made up a new roller-bearing on a new crank-pin, and also rebored the small end and inserted a new bronze bushing for a larger diameter pin, all for the price of NOS parts from various vendors that I have found in the US and the UK. Alpha even shot-peened the rod so its looks better than new and is very smooth along all edges.

If you don't find someone to do your rods, send me a PM and I will ask my builder, Dave, if he wants to help you out. 
2011 AMA Record - 250cc M-PG TRIUMPH Tiger Cub - 82.5 mph
2013 AMA Record - 250cc MPS-PG TRIUMPH Tiger Cub - 88.7 mph
2018 AMA Record - 750cc M-CG HONDA CB750 sohc - 136.6 mph
2018 AMA Record - 750cc MPS-CG HONDA CB750 sohc - 143.005 mph
2018 AMA Record - 750cc M-CF HONDA CB750 sohc - 139.85 mph
2018 AMA Record - 750cc MPS-CF HONDA CB750 sohc - 144.2025 mph

Chassis Builder / Tuner: Dave Murre

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #883 on: September 22, 2012, 12:58:46 AM »
It looks like there are three things I can do. 

Tom, the oil squirters need to be mounted on the front of the crankcase to squirt the backs of the cylinder bores.  It can be done.

Dennis, Alpha Bearings brings back memories from my Matchless days.  I forgot about them and I will contact them.

Carrillo does not recommend drilling oil holes in the rods I have.  They make rods for this bike with oil squirters at a reasonable price.

Given my experiences in the homemade windshield fiasco, the solution that requires the least participation or intervention on my part will work best. 

 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #884 on: September 22, 2012, 12:45:51 PM »
All three options are looked at.  The oil squirters need to shoot the lube exactly where I need it if they will work.  It is about a 4-inch long distance.  There is a lot of wind inside an operating engine and I need to see what is happening inside, while it is running, to aim them correctly.  Not much of a chance to do that.  No oil squirters.

My first racing and engine building was done while I was living with my parents.  My father gave me advice.  Usually it started with "What the ...?"  One thing he said "You know what broke.  Replacing or upgrading it is easy to figure out.  It won't do much good.  Take the time and put in the effort to figure out why it broke.  Fix those problems, too."  Looking at rod failures over the years showed me that steel connecting rods in good condition rarely fail from tension or compression on mildly to moderately tuned NA motors.  Almost always a bearing failure or sometimes a piston problem is the culprit.

The Triumph and Carrillo little ends are shown.  The Triumph setup has the usual oil holes at the top.  The Carrillos have the holes at the bottom.  The channels in the "H" section on the rods catch oil and route them to the holes.  The Carrillo little ends and the gudgeon pins had almost no wear.  The Carrillo little end lubrication setup is better.

The big ends run hot when the standard tight clearance shells are installed.  Racers run the looser white coded shells.  It is hard to see in the pictures, but the wear is less and more evenly distributed on the tight shells.  It is greater and less distributed on the loose shells.  I was told this would happen and was advised to check the white shells often and to plan on renewing them more frequently.

The bolts on the Triumph rods have the nuts on the bottom and the engine needs to be taken out of the frame and completely disassembled to check and renew the shells.  The Carrillos can be ordered with bolts heads on the top and no nuts.  There is no need to take everything apart to attend to the shells.

The decision is to have some Carrillos made with oil squirters.  Although it is a lot of money, it will cost much less than a mickey mouse solution and the resulting engine blow up.