Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 1438419 times)

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Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #165 on: June 08, 2010, 01:32:34 AM »
This morning I pulled the noise baffles out and the Arrow pipes are straight through glass packs.  Nothing in the exhaust path.  The bike runs very good.  It is break in time so I shut down at 5,500 rpm.  It was pulling hard.  Lots of power and no stumbling.  It is quite loud so I am trying different baffle shapes.  It was reversion.

Hours, days, and years I work on the inert Triumph.  Lots of futile paths and wasted tiime and money.  Fleetingly and without warning, the monster awakes, and my fiendish dreams come true.     

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #166 on: June 09, 2010, 01:10:24 AM »
Geez, I read about reversion and a lot of my bikes had problems with this.  We said the "pipes and cams were fighting each other" in our backcountry talk.  It seems to affect cammed engines the most and back pressure and reflected pressure waves are the major causes.

The mufflers are straight through glass packs and the baffles fit in the ends.  It came with eight 10 mm diameter circular holes per baffle.  I drilled another eight in each one and I enlarged every other hole to 12 mm.  This reduces back pressure.

The baffle end was flat and it was perpendicular to the flow direction.  A source of reflected waves.  I made some pointy ends out of rod stock and bolted them to the baffles.  Hopefully the points will not reflect pressure waves directly back to the valves.

Right before the test ride the rain started.  This is Oregon.  Tomorrow I will see if these work.   

Offline fredvance

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #167 on: June 09, 2010, 10:10:45 AM »
Why dont you just remove the baffle??
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Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #168 on: June 11, 2010, 02:08:04 AM »
Fred, the baffle is only for street and road riding.

The rocket nose cone things helped a lot.  This showed me that a reflected wave was the source of most of my trouble.  The cones reflected the waves to the muffler core sides rather than straight back to the exhaust valve.  Now I tried something different.  I drilled 1/2 inch holes in the baffle ends.  This change also reduced the reflected wave and it lessened the back pressure, too.  This modification helped a lot.

Next, I pulled out the carb slides and replaced them with a set of slides that I drilled.  The air hole shown is drilled out from 2.5 mm to 3 mm using a #32 drill bit.  This trick I learned from the Jenks Bolts carb tuning pamphlet mentioned in a previous post.  The bike ran even better in the reversion zone.

The engine ran better, but it was not smooth in the 3,000 to 4,000 rpm zone, especially at 1/4 to 1/3 throttle.  These Bonnevilles wear out their jet needles and needle jets and they run rich at lower throttle openings when this happens.  My bike has 20,000 miles on it and it is overdue for a set of needles and jets.  I had a set of new jets and I installed them.  This made the bike run really well.  The reversion problem is fixed.

 

 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #169 on: June 12, 2010, 01:21:33 AM »
Dyno work costs a lot of money and I pay by the hour.  The best situation is a short jetting session that accomplishes what I want.  This is what I am doing, or have done during the last few years, to prepare.

1)  I sort out the mickey mouse problems as best as I can, such as the reversion.
2)  I check and set the float levels and replace worn carb parts as needed.  The new needle jets are examples.
3)  The pilot jets are covered by aluminum plugs.  I drill them out and remove them.  Now the pilot jets can be easily changed.
4)  The cheezy soft phillips screws on the float bowls and carb tops are replaced with stanless steel allen bolts.
5)  I fill the bike with clean fresh unleaded non-etanol premium before the test.
6)  I bring a selection of jets in the sizes that I might need.

Now the mechanic can strip and rejet the carbs without taking them off of the bike or removing the seat and gas tank.  This saves me a lot of $$.


Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #170 on: June 15, 2010, 01:52:14 AM »
The rod small big end bearings should be checked annually on a highly modified Triumph that is raced hard.  This is a big job with standard connecting rods.  The connecting rod bolt heads are on the bottom of the rods, and bearing inspection or renewal requires that the engine be removed from the frame and the cases be split.

The connecting rod bolt heads are on the top of the Carrillo rods.  The head, cylinders, and rods can be removed while the engine is in the frame.  These top loading rods save a lot of work.  The bearing inspection process is tricky and South Bay Triumph gave me some help.  I could not figure this out on my own.  It will take two posts to show the procedure.

First, I wash a ratchet strap so it is clean.  The strap I use held a Hinckley Triumph in its packing crate.  Usually the Triumph shop will give these away if asked.  I thread the strap under the crankshaft rod journal.

Now, I put a set of new bearing shells in the rod and I tighten the cap down so the bearing shells are centered.  I grease the lower shell with assembly lube and I unbolt the cap from the rod.

Finally, I slide the lower cap into position between the strap and the rod journal.

 
     

Offline Dr Goggles

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #171 on: June 15, 2010, 02:23:34 AM »
.4)  The cheezy soft phillips screws on the float bowls and carb tops are replaced with stanless steel allen bolts

...when I was working for an importer it seemed almost every Bonnie that came out of the crate( yes, the splinteriest wood ever!) had to have the fuel bowls removed to get the varnish out of them before they'd run on two...got good at it after a while, also got good at holding the pipes on start up and if the temps were different then quickly shutting it down so it wouldn't be too hot to work on( best bike to burn yourself on, witness dark spot on the outside of my right forearm where it stuck to a pipe.....I had a blister half the size of my hand there....)...anyway, I always marvelled that they'd found something even SOFTER than the stuff they made the carbies out of to make the fuel bowl screws out of...it seemed that if you imagined a screwdriver while you were standing next to the bike they would burr.......
Few understand what I'm trying to do but they vastly outnumber those who understand why...................

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Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #172 on: June 15, 2010, 10:37:10 PM »
Doc, the carbs, soft screws aside, have given me remarkably good service.  I am a carburetor tuning klutz and these things seem to work good in spite of my best efforts to mess them up.

The big end cap is positioned on the strap so the rod will be straight up when it is bolted on.  The strap is tightened using the ratchet.  The cap is tightened against the journal enough to keep it from wiggling around.

A piece of plastigage is put on the rod.  It is held on with a small dab of grease.

The rod is positioned on the cap and the bolts are tightened as per Carrillo's instructions.  The bolts are loosened and the rod is pulled off of the cap. 

The bearing clearance is measured.  It is 0.050 mm, approximately.  This is within the 0.036 to 0.066 mm Triumph standard clearance and it is well below the 0.100 mm Triumph maximum service limit.  Normally my bike would have the "red" bearings with tighter clearances.  It came with red shells from the factory.  I am installing the looser "white" bearing shells.  This will give me additional clearance for oil flow and it is a modification for racing.

The plastigage is cleaned off, the top shell half is covered with assembly lube, and the rod is reinstalled.  It is installed in the right direction.  Carrillo has some instructions about this.  The strap is removed and the rod big end side clearances are checked.  Everything is OK.  Now it is time to move on to another step.

   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #173 on: June 17, 2010, 09:21:52 PM »
The rods are in and now it is time to fit the pistons and cylinder.  On the bench I fit the inner circlips, check the ring end gaps, and fit the rings.  Now I wrap strips of white plastic around the rings and I wrap a couple of zip ties around the plastic.  The plastic is some slippery white stuff I find at the hobby shop.  "Evergreen" brand. 

Fitting the pins is the next step.  They, and the small end bushings, are covered with assembly lube.  I never use force to install or remove gudgeon pins.  Instead, I warm the pistons with a heat gun or hair dryer.  The pins slip right into the hot pistons with a squeeze from the thumb.  The pistons are supported by two wood strips.

The cylinders are washed in hot soapy water to remove the grit from inside the hone marks.  The bores are wiped with automatic transmission fluid, and the pistons, too.  The base gasket is placed and the barrels are lowered down over the pistons.  The zip ties are cut and removed along with the white plastic strips.  The job is done.

The pistons and pins are teflon coated.  This installation method does not harm the coating.

The little studs and nuts holding the cylinders to the cases on old British twins gave me trouble and bolt metal fatigue was a topic on this forum about a year ago.  I did quite a bit of research on the subject.  The cylinder studs and the eight big bolts holding the crankcases together near the crank bearings were replaced.

 

Offline grumm441

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #174 on: June 18, 2010, 01:50:00 AM »
Uuuuum

Did you check the bearing crush?
G

From Clevites Site

Bearing crush is what holds the bearing in place. The tang on the shell that fits the saddle is only for locating the bearing during assembly.This crush, as shown on a connecting rod, is critical to bearing installation.
« Last Edit: June 18, 2010, 01:52:45 AM by grumm441 »
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Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #175 on: June 18, 2010, 11:04:12 PM »
Sort of.  I centered the shells in the rods and caps and noted that a little bit of the shells stuck up past the cap and rod mating faces.  This showed me that the bearing shells would be crushed when everything was tightened.  The amount the shells stuck out resembled what I am used to seeing.  I grunted with pleasure and continued the assembly.  I should have done something more accurate than this but I do not know how to do it.  I will learn.  Are there any references that show how to do it?

     

Offline grumm441

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #176 on: June 19, 2010, 12:10:51 AM »
Sort of.  I centered the shells in the rods and caps and noted that a little bit of the shells stuck up past the cap and rod mating faces.  This showed me that the bearing shells would be crushed when everything was tightened.  The amount the shells stuck out resembled what I am used to seeing.  I grunted with pleasure and continued the assembly. 

Sounds good to me
I generally put the bearings in the rod while very carefully holding it in a soft jawed vice
Torque both bolts up, check the rod bolt stretch, then undo one of the bolts about one or so turns and measure the gap with a feeler gauge.
But I like your method as well, however I am more recently finding  problems with the calibration of my eyes. In  fact I am having problems reading the numbers on the feeler gauges.

the only even half decent thing i could find online was this on ACL's site
http://www.acl.com.au/web/acl00056.nsf/a7d23b8ace0d7e31ca2560d3001fb663/b90f8e875ec620b44a25669d0014af37?OpenDocument
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Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #177 on: June 19, 2010, 12:58:18 PM »
Thanks for the info.  This will be handy on the next build.  My eyes are a problem, too.  Bifocals and a magnifying glass help.  My wife uses reading glasses for up close things.  We will need to work on bigger engines with bigger parts when we get older.

The cam is a bumpy thing that opens and closed the valves.  The ramps on the cam flanks bring some civility to the process.  They raise and lower the valves from their seats with gentle actions.  Everything works well if the valve springs are strong enough to keep the rocker arm, cam follower, etc in contact with the cam when the valve closes.  The follower will not be in contact with the cam flank if there is a weak spring.  The cam lobe will rotate out from under the follower and the valve will be slammed shut by the spring, alone.  There will be a power loss and the valve head can break off of the stem when this happens.  Experience has shown my wallet and me the consequences of weak valve springs.

A minimum valve spring free length is listed in most of our shop manuals and I measure the springs against that specification.  I always do strength tests for racing engines.  This is how I did it for this build.  It will take two posts to show this, one today and one tomorrow.

Some asking around tell me that standard Triumph springs are adequate for my hot street cam and the engine speeds allowed by the rev limiter.  There are no spring strength specs in my manuals.  I buy two new springs.  Their strengths will give me a basis for decisions.

I take one of the handles off of my drill press and screw off the knob.  This gives me a threaded rod.  A nylock nut goes on top of the rod and and then the valve spring and a couple of washers go onto the rod.  The agglomeration is hung through a hole on the drill press table and a screw eye is threaded on the rod.  Two hooks are hung from the eye.  A dial indicator is placed above the hanger and the tip rests on the rod top.

I hunt around for a weight that will compress the spring 1/8 to 1/4 or so of the distance to coil bind.  A 25 # weight does the trick.  I mark it.  It is the preloading weight and it is always hung first. 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #178 on: June 21, 2010, 01:02:39 AM »
The dial indicator reading is recorded for the preload weight.  Now all of the rest are put on for 85# total.  The dial indicator is read and recorded a second time.  This is done for all eight valve springs.  I am getting tired ... I fell like I have been lifting weights.  I am glad I do not have a 32 valve V-8.

The difference in dial indicator readings is the distance the spring compressed under load.  All springs are OK.  I replace the weakest old spring with the strongest new spring.  The spring strength records are put in the notebook.  The tests will be done again during the next tear down to see if there are any changes. 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #179 on: June 22, 2010, 11:47:23 PM »
The Triumph is at the end of the break in period.  Overall, the new motor did not meet my expectations.  The power at low to moderate rpm was less or equal to the old build and the baffles made things worse.  My tuning during the last few weeks made the situation better, but still for street use, I did not gain anything.

This evening, after work, I took it on a 50 mile test loop of back roads in the Cascade mountains and foothills.  No baffles this time.  There is this two lane road.  I crest a hill and I can see for miles across the wheat fields and the road stretches out straight before me.  Policemens are never there.  No hiding places.  No deer or other critters.  I checked the mirrors and no one was following, then I turned the Triumph loose.  Not much happened.  Then, suddenly, this horrible howl came out of the intakes and I was gone.  The road got narrow really quick and I had to shift fast to keep up with the engine.  It was scary.  The power is there.  It is hiding up high in the rev range where I need it for B-ville.  Mission accomplished.  The #813 cam is responsible for this madness and the next few posts will address basic cam setup.