Adventures with oil pressure

I think the Triumph is trying to make me crazy. After closing on Sat., I was running it to check on the fuel system and the loss of oil pressure. Adding the extra discharge hole in the carb and enlarging the existing one helped, but it wasn’t anywhere near enough.

The oil pressure was again at 50 psi, enough for the crank to live but not enough for running with a load. I opened up the accelerator pump orifice and rechecked the running….better but still not enough. A couple of ignition timing changes didn’t seem to make a difference either. The oil pressure was a couple of pounds lower.

I thought this might be a good time to check the blower belt tension and since the motor was warm, I made certain the tension was on the snug side of spec by tightening it up slightly. I ran the motor again and damned if it didn’t start leaking out of the back of the primary, near the sprocket shaft.

I drained down the primary to the level plug and loosened the blower belt and after cleaning it all off ran it again and it quit leaking. All I can figure is that the tighter belt deflected the crank and caused the seal to not keep oil and/or crankcase pressure in the motor, although the outer crank seal didn’t leak (Japanese seal?).

At this point I checked the flow into the pump through the line and then removed the screen over the inlet of the line. No improvement. I took out the pressure relief valve and increased the tension on the spring, but no help there. At that point I took off the timing cover and re-evaluated the oil pump.

The pistons looked a bit more scored than I remembered them and there was a fiber in the check ball area of the pressure side of the pump. I went to the box of parts from the other motor and compared the pumps. The old parts box pump looked better and after cleaning, I installed it.

After start-up I watched the gauge go to 105 psi, and then the pressure relief popped off and the pressure stabilized at 90psi. At this point, the throttle response seemed the best it had been yet. So now we are going to enlarge the original discharge hole, add another, and watch the blower belt life at the reduced tension to in turn reduce crank deflection.

Why oil pressure and running may or may not be related makes as much sense as blower belt tension and a clutch shaft oil leak. Ya gotta love it! I think I will move the tank up to right below the pipes and carefully heat shield it to increase the head of potential pressure at the oil pump, and special care will be needed to deal with the cap at that point.

Cheers!

Bill

Driveway Test

The driveway test didn’t go as planned.

The transmission doesn’t work. The oil pressure is low. It won’t take full throttle.

Still, you have to admit she looks pretty good out in the daylight.

–Sam

Progress on the Supercharged 1966 TR6 as of 1/5/09

After seeing the Discovery Channel’s show on Bonneville last night it got us revved up enough to provide a long overdue update on the Bonneville projects.

First, there hasn’t been any progress on the Ducati.  The realization that there is a desperate need for electronic fuel injection became apparent after the trip to Byron Dragway, but the comprehension of and the loading of tuning parameters into the Microsquirt has thus eluded us.  If you know anyone who has used one of these nifty little units on a 90 degree twin, please let us know as we can sure use some help with it!!!!  The high fuel consumption of a mechanical fuel injection system would cause too great a late-run weight imbalance (inducing wheelspin) to allow that to be used, thus relegating us to electronic fuel injection or blow-through carburetion (an equally mysterious but in my mind roulette-wheel type of tuning).  Once again, the electronic devotees out there…..Help!!!!

Well, things have continued to be a challenge on the blown Triumph front as it seems this bike is insisting on being dragged, kicking and screaming, to the starting line.  The decision to use a conventional front end to keep in the “retro” motif has caused the bike needing to be raised 2 inches to maintain a relative balance and some weight bias adjustability.  This necessitated a lower triple tree made by Guy Bartz to be used to keep the hike in height to just 2 inches.  It also allowed the use of the beautiful aluminum unit in place of the stock SV-650 cast steel unit (what were they thinking?).  The rear end also needed to have the axle blocks flipped over as well.  The initial design of the chassis was also allowing for the 190mm tire to be the shortest tire, as all the drag racing slicks tended to be taller, causing the initial location to be the lowest possible.  The Ducati, on the other hand was never intended to be at the dragstrip so the 200 rear tire was expected to be the tallest.  Go figure.  An upside-down front fork would solve this problem, but we also have kept the right side shift on this project as well, keeping the schizophrenic nature of the beast intact.

The motor, being a 1966 vintage also has the delights of Whitworth, British Standard, and OBA threads.  In case you didn’t know, the British are the only people that came up with a more disparate and eccentric manner of bolting things together than the U.S.  In many instances the threads are 26 threads per inch which doesn’t coincide with anything.  Even the wrenches have issues as they are designated by the size of the bolt threads they are to fit, not the size of the bolt head. You need the British tool set, the U.S. and Metric wrenches out all at once to expect to get things done this century.  It is trying Fred’s patience, I can tell.

Reversing the cylinder head to allow the rider to sit down in the bike also requires a different set of cam timing specs.  Luckily about 26 years ago, a former employee Allen Jelle, did a reversed-head Triumph while he was here.  He was gracious enough to sell us the bottom end, and help with the intuitively conflicting cam timing.  AJ’s front-engined blown Desoto-powered dragster is a thing of beauty, so he also has a vested interest in this project.  A certain restraint is needed to keep from blowing everything to pieces via blower overdrive and/or nitro percentage in both the Desoto and our bike.

The design and manufacture of the blower/fuel pump and ignition drives is started, and will hopefully be done in the next two to three weeks.

There is a general shaking of heads when this project is viewed by the rest of the world it seems, but just watch the Discovery Channel program on Bonneville or pull out your trusty copy of “The World’s Fastest Indian” and you’ll understand.

Until the next “milestone” (millstone?).

Cheers!!

A quick jot about the trip to Byron Dragway.

Testing of the driveability of the Ducati Turbo was done at Byron Dragway on October 19, 2008.  Even after making a new countershaft sprocket and putting on the biggest rear sprocket that wouldn’t require modifying the 160 link chain on the bike now, first gear was still over 100 mph.  Not a great way to get down the quarter mile.

Driveability still was awful with the motor either in a full bog or going mental at 22 psi of boost and spinning the rear tire at half track in 2nd and through the lights in third.

Ergonomics are still literally a sore point and will give us additional things to work on through the winter.  Now the serious adaptation of fuel injection is shown to be the only way to be productive for the assault on the salt in October of 2009.  A couple of trips around the block again and a few more trips to the dragstrip should help iron out running and riding issues.

Stay tuned!

World Finals 2008 cancelled

It seems that, due to flooding of the course, the World Finals event at Bonneville has been cancelled for this year.

Update from 9/10/08

This is the latest in the installation of the TR-6 motor in the frame.  The cylinder and head are upstairs having the pistons fitted, valve guides installed and the decision being made whether bigger exhaust seats are needed for the considerably larger inconel valves.  The delicate balancing act between how much power is needed versus how much can be produced before the head splits and/or the cylinders are knocked off the engine cases comes into play.

This bit of mental math usually causes Jim’s (the owner) eyes to roll back in his head.  Keeping the engine heat manageable is part of the reason for the big exhaust valves.  The effect of the big exhaust valves upon driveability (that is surprisingly important at Bonneville) is somewhat mitigated by the ability to change blower drive speed, and percentage of nitro.  The engine heat buildup will also be more of a factor with the reversed head.

I will need to take a page from the Britten design book that made use of conduits and ducting to manage heat and feed air in the engine bay of the legendary V-Twin roadracer.  If we have opportunity to do a billet head, the stability at elevated temperatures is so much better, the only heat consideration at that point will be the under-seat temperatures (aka “nut roaster”).

Some attention to the design issues of the early iron Hemis is needed to try and avoid certain flaws in the valve train longevity choices as the run-time of this combination will ultimately be much longer than a quarter mile, and while the valve train survived three miles at 8,000 rpm the first time, the pressure loading on the intake side and the heat loading on the exhaust side will be considerably higher, and survivability is a must.

The assembly of the first real bottom end will begin next week and we hope to have the frame out of the jig and fitting the wheels and forks in time to show it at the Slimey Crud Run Ocober 5 here in Madison.  An intergrated oil tank/rear bulkhead along with the fuel, battery and varuous ancillary devices are yet to be done, so stay tuned as the work continues.

Cheers!

Bill

Latest Triumph photos

Here are the latest photos of the Triumph.

The image above (posted last time) shows the bottom ends intact on the frame jig.

Here they are broken down and ready to start procuring the needed parts for freshening and reassembly.

This is what is left when a 29 pound block (from this post)  is machined to make the blower manifold.

These photos show the blower, manifold and head set together to verify that they do in fact fit as an assembly.

Second Bonneville Project Officially Underway

Having run the 1967 Triumph T-120 Bonneville on the salt last fall and run afoul of a cosmetic technicality, the suggestion was made by the tech officials to return and compete in a less-constrained class.  Being the free-spirited types we are, the decision was made to go back with a similar bike in class to the Ducati we ran last year and are returning with this October.

The first question was “what”, then “how” and then “why?”   Jim Haraughty was the principal of the project, so he elected to stay with the 650cc pushrod format.  The logical choice was to stay with the Triumph 650cc pushrod platform.  This answered the “what”.

The record he opted for was the A (special chassis construction) Pushrod Blown Fuel.  This will involve a chassis built by guess who (the “how”).  The Blown part caught my attention as I had just found a cute little 2-lobe Roots-Type supercharger and didn’t want no stinking mufflers or exhaust restrictions (turbos) on this one.

I haven’t built a blower bike in many years and the thought of blown Methanol with a whisper of Nitro sounded sort of fun.  Poor Jim’s eyes got about as big as pie plates when the mention of Nitro came up and a visit to Arnie Heller’s shop on a billet aluminum buying spree didn’t help.  Arnie is my frame of reference on turbo/gas/nitrous used on the Ducati project but he has always had an aversion to Nitro as being unpredictable and destructive (coming from a guy who replaced cases and cranks every two races with the gas/juice combination that made enough hp to go 219 mph).  Discussing his current project and his exposure to Nitro got Jim going, but at the end Arnie did admit that “there isn’t anything like it”.

Workin’ for the week’s end…

Knowing the weather was doubtful for any activity on the salt at all, everyone was up and in the truck before daylight.  It was still dark as we rolled out to the pits across the salt, but a faint glimmer of the beauty to come could be seen to the east.

We pretty much had our pick of the pits as there were only a quarter at most of the entries there on Thursday.

While unloading we were greeted by a photographer who called himself “Porkpie”.  He was an engineer for Porsche living in Germany but coming to the salt for the SCTA Speedweek and the BUB events as well as the World Finals each year.  He said he had adopted the name from the British slang for “second chance” as he had been a streamliner pilot and crashed hard a number of years ago.  Realizing he had been given a second chance at living, he made it a point to return and enjoy the racing he loved and not “wait until there was enough time”.  Using the backdrop of a spectacular sunrise (see the last photo in the gallery) he took photos of both bikes and the crew.  We are waiting for him to send the CD of the shots at this time.

Following much the same routine as the previous two days we went to the starting with a jet change to make the first run of the day.  The bike’s performance was sluggish again, even though the same jets that had yielded the one good run the day before were in it.  The exhaust gas temperature stayed at a sluggish 1400 degrees indicated and the power just wasn’t there.  I turned off after the first mile and we went back to try and figure out what to do next.

Thursday’s Child

Returning to the salt on Thursday morning we all were looking forward to the day.  Jim needed to prove the bike capable of accomplishing the mph goal and I hoped to get a chance at the next license level.

Jim’s first run was a success as he was able to run 107.813 mph on a 97.320 record.  It was a big lift to everyone and we looked forward to the next one for him until he mentioned that the run had been done in third gear rather than fourth as it wouldn’t shift.  The entire 2nd mile was run at 8,000 rpm.  While those of you used to Japanese bikes may not see the significance, the British twins owners and Harley riders know what a mile at those rpms can do.   On his next run, even though the bike did shift into 4th gear, the valve train showed its unhappiness with a rather lot of noise and the bike was parked, but not until having run 10 mph over the existing record.

The Ducati began the show with a missed call on the jetting and an early termination to make the needed changes.