The dyno's here?

[GT6Steve]

Hi Carter, Thanx for that.

 

I was introduced to Dataq a couple of years ago in my job.  Major disruptions forced it out but I agree that it is the affordable way forward.

 

 

 

Just now my big puzzle is getting the GT6 headers/extractors into the dyno for back to back tests.  These things are built for V8s with the headers going around but our cars have the pipes going thru the middle.  Big hurdle so far,....

[GT6Steve]

Started from scratch this afternoon fitting the engine to the dyno.  After some fettling and removing the old tat I came up with this:

 

 

I've got to cut the black support plate to allow the collector to pass thru

 

 

Then I have to rotate the entire water brake assembly by 45 degrees in the supports so the water lines will clear the exhaust.

 

The entire point of this excercise is to quantify induction variations.  Not much good if I have to use a stock exhaust system??

 

 

Whatdya think of that propshaft alignment?  At 8500 RPM???  There's a heavy guard that goes over it but it seems a bit scary to me.  But then, I see a million monster pickup trucks with worse.  Opinions??

[Royboy66]

opinions?

 

stand behind the house with a cold beer! ;D

 

 

looking good though buddy!   proper boytoy

[GT6Steve]

I have a 1/2" thick piece of Lexan I'm thinking should go over that window and operate from the office...

[the other tim]

There is a dyno forum on Land & Sea (your side of the pond!) much of it covers their own electronics and dynos but there is a section for us mere mortals on a shoestring  

 

Looks like there is a decent looking guard around the cardin shaft

[GT6Steve]

Progress is being made!  Started the mule motor this morning and it actually ran pretty sweetly for having sat a lot of years.  I was able to run up oil pressure with a starter motor built into the dyno.  Nice touch.

 

The biggest problem remaining is plumbing with a lot of 3/4" hose and fittings needed to get it all sorted.  Also need some 1 1/4" fittings for the engine cooling.  Nothing cubic dollars can't sort :'(

 

On a seperate note, the mule has gotten me interested in finishing the Spitsix body transfer.  I pulled it out of the old Spitsix body and can put it back into the new one for a major step forward. ;D

[GT6Steve]

Been stewing on building the control panel and it just occurred to me to do it on wheels as all the other bits.    Maybe a roll around desk sort of thing.  More thought required...

[GT6Steve]

Well Mates, the dynoes running as we speak.  The mule is perfectly content to run forever on the heat exchanger that is part of the system.  It's not yet established equilibrium but it's maintaining between 170 and 190 dependant upon RPM.

 

There are some issues.  The Water brake requires an adequate water supply to retard the motor.  My well pump garden hose supply is inadequate.  I can't stall the engine at all. let alone at 6000 RPM.  With this things ratings I should be able to., I think.

 

I've got about six crude number sets to calculate and see if they are linear, lot's to learn.  I guess I should go turn off the Spitsix motor but it sounds so nice burbling away outside the office window....

 

Edit,  Uncorrected calcs come in at roughly 46 HP at 4200 RPM and 58 FT'Lbs of torque and down to 2 HP at idle.  I haven't graphed it or corrected for atmospheres but still interesting.

 

Next trick will be to throttle the discharge water (wide open) to raise pressure across the brake.  More gauges and plumbing required;-))

[GT6Steve]

second set of tests with the discharge restricted produced a better load control with the two flow valves provided.  I was better able to control engine RPM.  

 

Mind you, this is not yet correct.  I have a screwdriver stuck in the carb linkage providing a steady throttle.  Not WOT.

 

This test produced similar numbers to last time with torque overall higher.  Best was 3000 RPM and 96 FT/Lbs of torque for 54 HP.  Uncorrected.

 

There's still a lot of work to do before it is scientific but at least we have something.

 

BTW, this mule motor is a totally stock 2000 Liter with dual 1.5 Strombergs.  Crappy extractors with no collector.  These numbers may well be in the ballpark.

 

I wonder what the corrections will produce? 8)

 

Edit.  Corrections say HP x .98.

 

Does 50 HP at 3000 RPM seem real world?  Yuk

[Nick Jones]

second set of tests with the discharge restricted produced a better load control with the two flow valves provided.  I was better able to control engine RPM.  

 

Mind you, this is not yet correct.  I have a screwdriver stuck in the carb linkage providing a steady throttle.  Not WOT.

 

This test produced similar numbers to last time with torque overall higher.  Best was 3000 RPM and 96 FT/Lbs of torque for 54 HP.  Uncorrected.

 

There's still a lot of work to do before it is scientific but at least we have something.

 

BTW, this mule motor is a totally stock 2000 Liter with dual 1.5 Strombergs.  Crappy extractors with no collector.  These numbers may well be in the ballpark.

 

I wonder what the corrections will produce? 8)

 

Edit.  Corrections say HP x .98.

 

Does 50 HP at 3000 RPM seem real world?  Yuk

 

 

If it's not at WOT then figures don't mean alot..... in fact factory figures give 117lb/ft at around 3000 rpm, so it's some way off the pace.  Should try it with the standard cast manifold maybe for a bone stock baseline?

 

Nick

[GT6Steve]

If factory says 117 FT/lbs at 3000 and I measured 96 thah maybe we're in the real world.  I have to rig a throttle controller before any more playing.

 

Just added an inline flowmeter to the cooling tower so I can get real water pump flow numbers.  Should be interesting.

 

Again, let me be clear.  Yesterdays numbers were NOT scientific.  Just what I noted while testing the dyno.  On top of that disclaimer there may be a stuck ring in there somewhere as I noticed a puddle of oil on the floor after that was apparently forced out of the dipstick pipe.  The engine was a fairly fresh rebuild but sat for a long time.

[GT6Steve]

Any plans to make a bomb-proof bunker in case it goes 3-mile island....

 

Boys, when Bruce speaks I'm going to be listening from now on!

 

I had a seriously frightening experience this afternoon that could easily have been fatal.

 

The dyno has a driveshaft connecting the engine to the water brake absorption unit.  Big heavy sucker with giant flanges and U-Joints,

 

Spinning the engine up this afternoon for another set of trials I had the engine at WOT and enough load on it to drag it down to 2000 RPM.  I was at the back of it recording numbers when there was a loud bang and I was out the door like a shot.  Behind me I hear the engine roaring to max RPM so I know we've lost the brake somehow.  I run back in thru the office and come around the front of the engine to jerk the coil wire out.  I can see sparks flying and about then the driveshaft breaks out of the protective enclosure.  I don't see that as I'm focussed on the coil wire but apparently it flew out and hit the wheel of the Yellow racer.  Not real clear on the chronology there cuz I was kinda busy.

 

Turns out the eight bolts adapting the driveshaft to the dyno unit sheared allowing the driveshaft to flop around at 5000+ RPM's  It may have ended there but I didn't have all the bolts in the containment unit so it was able to escape.  Will not make that mistake again, THANK THE LORD I had the containment unit on!!!!

 

Lessons learnt?

 

1.  Keep the guard on and secure all the bolts

2.  I wisely avoid standing in the area of the flywheel and engine where centrifugal bits could fly.  Not just here but at work as well.

3.  I need some kind of kill system attached to my body so if I run it'll shutdown.  Have top think about that one.

 

I'll admit it put a serious fright into me that I'm not yet over.  I'm used to being around big rotating equipment and I've seen my fair share of faults but the potential of this one has my attention.  

 

 

 

 

[GT6 Nick]

Bloody Hell Steve! That had the potential to take your head off, good on you for getting the hell out so quickly. Maybe you need kill switches outside the room? I doubt the torque was too much for the dyno if it was built for V8s - were the UJs operating at extreme angles? Or maybe they were just old.

 

You forgot to mention steps 4 & 5, changing pants and drinking beer to calm the shakes. The order of these is optional.

[lordleonusa]

Glad to hear you are safe, remember that which doesn't kill us, only makes us stronger!

 

L

[Nick Jones]

Glad you are alive to report.......

 

Small chassis Triumph sixes are used to killing their transmissions - bit surprised you managed to break that though!  Presumably the broken UJ is a consequence of the initial failure rather than the cause?

 

Nick

[GT6Steve]

It seems the root cause was shearing the six (of eight) 1/4-28 bolts that adapt the unit to the flange of the water brake.  Desinged that way not bodged.  two of the bolts were already broken and left that way.  That's a bodge.

 

Root cause seems to be the driveshaft angle, there's about 15 degrees difference between the engine flange and the dyno flange.  It may have been binding at some point?

 

I'll take the driveshaft in today and get that fixed and look at mounting the engine differently.

 

As well as put ALL the bolts into the containment shroud this time

[willcolumbine]

Blimey - that's some carnage!  

 

Glad you're still around to tell the tale!

[Mother Teresa]

Boys, when Bruce speaks I'm going to be listening from now on!

(yes)

 

All joking aside- a lesson learnt. Glad you're still around to let us know.

Kill system? how about a Co2 discharge in area of intake? that would give you time to effect a more permanant electrical isolation there-after. It wont run without oxygen!

[GT6Steve]

Thanx Bruce,

 

Any more clairvoyence on your part give me a shout straightaway! ;D

 

I lay awake last night for most of the night thinking about this.  Ironically I have a mushroom head E-Stop button intended to go in but the electrical buss is still in the planning stages.  

 

During the night I recalled that I have an old old Autometer RPM activated switch meant to control a shift light or shift cylinder or somesuch.  It'll go on as a peak RPM kill for another such runaway.  Dial in a peak RPM setpoint just above where I'd expect to test and it'll kill the engine if it goes over.

 

Most important thing is to drill down to the root cause, WHY did the bolts shear?  Probably driveshaft alighment but LOTs more thinking is required.

 

CO2 discharge is an idea to ponder as well.  Fire suppression.  

 

 

[Royboy66]

phew !  go easy Amigo !! 8)

[GT6Steve]

Some research suggests the driveshaft (propshaft) was not what the manufacturer intended.  They wanted their dyno direct coupled thru a splined input shaft.  They provided a massive alloy adapter plate for the user to drill and adapt their bellhousing to the dyno for a direct thru the clutch connection.  

 

Total sense.  Guess where I'm going?  I'll fork out at least two hundred Dollars tomorrow to pick up the repaired propshaft but I hope it'll become a museum piece.  I don't need that kind of drama in my life these days.

 

Downside is I have to scour up a 1-23 spline input shaft from some old Ford to accept the race engine but I have old TR input shafts I can adapt for the mule.

 

An infinitely safer program once it's sorted!

[oviwan]

ehhhh, did i miss a reply here? hope i don't repeat someones answere but there is a (big) mistake in this picture...

 

 

was the propshaft aligned like this when it fails? not the angle in total, i'm talking about the alingment of the fork ends as they have to be aligned to each other (still believe that alingnment angle is too much). in that picture they are 90� to each other, that will cause massive vibrations and is most likely the main reason for the failure. moreover it is a u-joint killer. ask me how i know but that was on my  driveshafts and i thought the rear end will disintegrate at higher speeds. at the revs of the propshaft, oooommmph,  happy birthday so far....

 

its a typical mistake most professional workshops do. oe tr6 driveshafts had a missing spine so that you could only assemble them in one direction.

 

for the killswitch, what about a cable, attached to pullswitch, running above your head across the worshop, e.g. at the escape route. so its easier to grab that wire when in panic.

 

harry

[the other tim]

Wow well spotted.

  

    Steve this may be a numpty suggestion but would it be possible to cant the engine over a few degrees to get more clearance for the exhaust manifold?

  

    There was an old Froude water brake (300bhp) 8000 rpm) kicking around here and that used a cardan shaft with u/j's similar to yours. After your experience i fully understand why you're changing it. The water pump that supplied the brake was a fair size, the flow rate escapes me but i think the pressure was around 20psi.

 

 

         Tim

[GT6Steve]

ehhhh, did i miss a reply here? hope i don't repeat someones answere but there is a (big) mistake in this picture...

 

 

was the propshaft aligned like this when it fails? not the angle in total, i'm talking about the alingment of the fork ends as they have to be aligned to each other (still believe that alingnment angle is too much). in that picture they are 90� to each other, that will cause massive vibrations and is most likely the main reason for the failure. moreover it is a u-joint killer. .

 

for the killswitch, what about a cable, attached to pullswitch, running above your head across the worshop, e.g. at the escape route. so its easier to grab that wire when in panic.

 

harry

 

Heeeyyy, GOOD CATCH!  The manufacturers rep said it was likely a vibration issue.

 

I'll be picking up the repaired driveshaft in a couple of hours.  I'll ask...

 

It's that kind of thing, over and over, that makes this the best forum out there... ;D

 

 

EDIT:  Tim, I've now milled a passage thru the black plate and put nineties on the water fittings to extend the exhaust out thru and under the brake.  That may need some more work with the bellhousing moving the engine further to the rear?

 

 

EDIT2:  Just got the shaft back and they reassembled it just as Oviwan has observed.  I'd have never even noticed the discrepancy because we (I) just take it for granted.  Now I'm of two minds as to whether to use it again or not...

[Nick Jones]

Interesting comment on the UJ alignment.  Not sure what you had was that bad as the UJ trunion axes are in line (more or less at least), just their trunions rotated 90º from ideal.  The real bad news is if they are at odd angles to each other due to being 1 spline out.

 

You could swap it for a CV shaft (well, I would say that  ), but seriously, you could easily adapt a driveshaft from something like a big BMW with a lobro joint on each end or even use something from a conventional FWD - you might even find one with a 1" x 23 spline!  Either way the rotation mass will be considerably reduced and much more tolerant of odd angles.

 

Nick