Crankshaft experiment

Jack Gifford · Post by **Jack Gifford** » Fri Nov 17, 2017 7:09 am

Chances aren't good that the lakester will be ready then, but there's a good chance I'll see you there.

Jack Gifford · Post by **Jack Gifford** » Mon Nov 20, 2017 6:14 am

Doesn't win any award for collector design.

But hopefully it will allow more test-running in the dry heated garage, while it's wintry outside. The main goal is to get the noxious fumes outside, but perhaps I'll also be able to listen to the engine itself, rather than just the exhaust roar.

beat · Post by **beat** » Mon Nov 20, 2017 9:50 pm

Jack Gifford · Post by **Jack Gifford** » Thu Nov 30, 2017 7:50 am

Oh well... it worked a couple of times before self-destructing...

beat · Post by **beat** » Fri Dec 01, 2017 8:33 pm

Jack Gifford wrote: self-destructing..

I am not realy surprised....

Jack Gifford · Post by **Jack Gifford** » Sat Dec 02, 2017 6:12 am

" ... not really surprised."- that it worked awhile; or that it self-destructed?

So now I'm a slave to the weather outside, to continue testing.

beat · Post by **beat** » Sat Dec 02, 2017 7:02 pm

...... it will be self destructing after awhile....

beat

Jack Gifford · Post by **Jack Gifford** » Mon Jan 22, 2018 6:49 am

Dyno time scheduled- Mar 28th.

Post by **b50root** » Fri Feb 16, 2018 5:45 am

Jack Gifford wrote:Dyno time scheduled- Mar 28th.

Lets see a video, Please.

Rickard

Jack Gifford · Post by **Jack Gifford** » Fri Feb 16, 2018 7:48 am

Hey- I'm an old-timer, barely getting comfortable taking still shots with a digital camera, let alone trying to take moving pictures...

Besides- I'll be a bundle of nerves, wondering if the engine will survive.

Jack Gifford · Post by **Jack Gifford** » Wed Feb 21, 2018 8:44 am

Awaiting March 28th... so... finding things to do in the shop...

In some free stuff was a pair of 1.250" diameter end mills in perfect condition. But they have an outside taper that I don't recognize (2.15 degree/1.075 degree per side). They do have a straight/on-center .355" bore, so I turned a mandrel to fit, with 1/2" and 9/16" diameters on the other end to fit in a chuck or 9/16" collet of my mill. To use the other one as a short end mill, I needed to grind the outside taper to a straight diameter to fit in a 7//8" collet. But lacking an appropriate machine (such as tool-post grinder on a lathe), what to do? I finally figured how to do it on just my manual mill. Clamped the mandrel in the mill vise, made a wooden "crank handle" to rotate the piece by hand as I made light passes with a grinding wheel. Not having a cup-style wheel complicated matters, as the mandrel had to be angled away from the wheel's mounting to its shaft. Had to make many small passes (.050" steps), advancing the quill an appropriate amount for each step (tangent of the arbor angle times .050"). Success- .875" straight diameter +/- .001".

Then finally, I brazed the mandrel into the other end mill.

Jack Gifford · Post by **Jack Gifford** » Wed Mar 28, 2018 5:37 am

Dyno shop postponed my session. With any luck, will get me in early next week (April 2nd, 3rd, or 4th).

beat · Post by **beat** » Wed Mar 28, 2018 8:22 pm

wish you some of it....

Jack Gifford · Post by **Jack Gifford** » Tue Apr 03, 2018 5:31 am

New date 4/9/18.

Post by **minetymenace** » Tue Apr 03, 2018 6:28 am

The fourm language is English.

AJ CCM · Post by **AJ CCM** » Tue Apr 03, 2018 9:04 am

minetymenace wrote:The fourm language is English.

you need a spell check

Post by **minetymenace** » Tue Apr 03, 2018 9:17 am

Dyslexic "Forum" and date

Canberra · Post by **Canberra** » Tue Apr 03, 2018 11:04 am

I wondered why the wait would be to 4 September 2018. I would be rather pissed.
Note "pissed" can even mean something different around the English speaking world and a spell checker wood never now.

Post by **minetymenace** » Wed Apr 04, 2018 12:08 am

Jack Gifford · Post by **Jack Gifford** » Wed Apr 04, 2018 5:28 am

I had no idea I was posting in a fourm.

[Is that spelling of 'weird' your idea of proper English?]

Post by **minetymenace** » Wed Apr 04, 2018 6:59 am

In my defence:
1. Look at the time I posted.
2. Its not my fault, I was un-supervised.
It seem I will have to wait until I am crowned galactic president, no, lets make that King, before I will be able to get you unruly colonials back in line!

PS I always assumed that "Werd" was Swedish, or at the very least, some strange Scanian dialect.

beat · Post by **beat** » Wed Apr 04, 2018 7:30 pm

Jack Gifford wrote:New date 4/9/18.

Hmmmm ??

Waiting such long for the woman you love, - yes, - maybe. ( because you can not make one yourself )

Waiting for a Dino test such long, - NO.

Jack, start to make a Dino by your own, out of a Pontiac ore Buick Hydraulik Gearbox.
More entertayning than waiting ....

beat

Post by **minetymenace** » Wed Apr 04, 2018 11:47 pm

beat, 04/09/18 is American for 09/04/18, ie next week! (Well I assume it is, hence all the banter).

beat · Post by **beat** » Thu Apr 05, 2018 7:47 pm

04/09/18---09/04/18

Jack Gifford · Post by **Jack Gifford** » Fri Apr 06, 2018 6:13 am

We colonists hate to waste words...

"April 9th"
vs
"the 9th of April"

Canberra · Post by **Canberra** » Fri Apr 06, 2018 9:59 am

Sorry Jack,

we say 9th April

"the 9th of April" must be old colonial English.

Ignoring the banter - you ready for the Dyno (take 2)? Do you need to build a wall between the engine and attendants this time. We wait with bated breath.

Jack Gifford · Post by **Jack Gifford** » Sat Apr 07, 2018 6:18 am

The dyno "chamber" has substantial walls and a separate control room.

With my 182 c.i. engine, I guess I'm a "small fish in the sea"- my session keeps getting postponed until they finish with the 3,000 HP turbo-diesel that's presently on their dyno- tractor pulling season will be starting soon.

stew79 · Post by **stew79** » Mon Apr 09, 2018 9:27 pm

what about that great american film "born on the fourth of July" they got the numbers the right way round, and no one noticed !
stew

Jack Gifford · Post by **Jack Gifford** » Thu Apr 19, 2018 5:36 am

Dyno session last week was... very tedious and stressful. I had never dyno'd an engine before (actually I never built a 4-cylinder race engine before); the shop had never run such a small engine; the mounting and driveline hardware that I had prepared beforehand needed rework (they changed to a different dyno "cart" than the one I had measured); dyno computer and my crank sensor weren't "on the same page"; zoomies had to be modified to connect to the cell''s vent duct; etc.; etc.; On the first startup in the dyno cell I forgot hearing protection and was literally deaf for the next 24 hours. Adding to the stress was the hour and a half commuting to the shop each of four days, plus the cost of $85/hour/man, usually two guys working with me.

Positives: engine is still in one "lump"; dyno data for pressures (bottom end oil, top end oil, fuel) and coolant temperature were fine.

Negatives: first attempted full-throttle "sweep" (3,000-7,000 RPM, 600 RPM/sec) ended abruptly (2.256 sec, 4,786 RPM) with a bang (but not severe enough to blow the burst panel).

Manifold pressure data clearly identifies the culprit. My guess at blower drive ratio (80% of crank speed) was totally "out of the park". This billet 14-71 is WAY more efficient than I knew. I was shooting for around 30 PSI at 9,000 RPM; data log shows more than 25 PSI at 4,000!

With a fixed fuel curve, mixture was going way lean.

A quick check showed two cylinders low on compression, so it's back home to pull the head and hoping the damage is repairable.

Post by **b50root** » Thu Apr 19, 2018 11:51 am

This is soo intresting. Thanks for sharing.

Rickard

stew79 · Post by **stew79** » Thu Apr 19, 2018 2:22 pm

jack, if the blower was running at 80% of crank speed, it would have a bigger pulley than the crank. in the picture the crank pulley is bigger ?

beat · Post by **beat** » Thu Apr 19, 2018 8:44 pm

Jack Gifford wrote: mixture was going way lean.

Hmmmmm

Jack Gifford · Post by **Jack Gifford** » Fri Apr 20, 2018 5:48 am

stew- yes, in pictures from a year ago, it had the blower overdriven. But then in my ultimate wisdom, I decided to be on the safe side (ha ha) and swapped the pulleys.

beat- the fuel system is old-school constant-flow mechanical injection. The air/fuel ratio (at least at full-throttle/full-load) is based on the simple premise that the camshaft-driven fuel pump's output will be (roughly) proportional to engine speed, as will air flow. Nominal fuel rate is adjusted by changing an orifice (pill) in a bypass circuit back to the tank- but is still nominally proportional to engine speed, regardless of pill size.

Based on prior experience, the engine builder tries to "size" parts (fuel pump, injector nozzles and venturi sizes, cylinder head flow, and supercharger) appropriately to give the desired air/fuel ratio (about 6:1 for methanol), using typical size ranges of bypass pills (~.075"-.120").

The log shows that both air flow and fuel flow were quite linear functions of engine speed (prior to the bang), but air flow was a MUCH steeper slope than I had anticipated. Thus, at about 4,300 RPM the mixture was going rapidly too lean.

beat · Post by **beat** » Fri Apr 20, 2018 9:04 pm

sorry jack, but for such experiments A/F Ratio should be monitored continually .

the change in A/F ratio is much more quickly as expected and parts are so expensive......

the experience you will made with a A/F reading system you can always taking with you to a next engine.

beat

Jack Gifford · Post by **Jack Gifford** » Sat Apr 21, 2018 5:51 am

I have a wide-band A/F ratio meter that has been invaluable on gasoline engines. But the fact that the dyno shop doesn't have A/F ratio measuring capability makes me think that maybe air/methanol ratio in a race engine might not be easy to measure? I don't really know, but I will try to learn more. Thanks.

beat · Post by **beat** » Sat Apr 21, 2018 8:53 pm

hi Jack,
I will have my nose in to the methanol metering as well.
no experiance from my side at the moment.
but maybe some statements of others ?

stew79 · Post by **stew79** » Sun Apr 22, 2018 5:04 pm

jack, i like the simple mechanical approach to the fueling, but surely as speed increases, valve timing efficiency etc gets better ? (moving more air) shouldn't the throttle link to the fuel valve be made to give a non linear opening ? (progressively opening faster for more fuel, and automatically not going too rich at half throttle)
stew

Jack Gifford · Post by **Jack Gifford** » Tue Apr 24, 2018 4:24 am

stew- you're absolutely correct, that barrel valves are typically not linear. They are the subject of much development, but only if part-throttle operation is of importance, In may case, only full-throttle and somewhat-of-an-idle are important. Initially (and perhaps always) I'll run pavement LSR (1 and 1 1/2 mile), where I doubt that full-throttle will break the tires loose (very tall gear ratio, no shifting). In any case, I'm using a barrel valve shape that I know will allow a bit of slacking off from full-throttle if necessary.

stew79 · Post by **stew79** » Tue Apr 24, 2018 9:50 am

jack, i meant the link between the throttle and the fuel valve, to try and compensate for the non linear rise in fuel requirement. the more i think about this the more i am intrigued. or do you need a fuel pump that can pump proportionally more fuel the higher it revolves ? like some thing from jet engine?
or a separate injector for speeds from 4000 rpm upwards?
stew

Jack Gifford · Post by **Jack Gifford** » Wed Apr 25, 2018 5:50 am

Jack Gifford wrote: ... old-school constant-flow mechanical injection. The air/fuel ratio (at least at full-throttle/full-load) is based on the simple premise that the camshaft-driven fuel pump's output will be (roughly) proportional to engine speed, as will air flow...

In this earlier post, I tried to describe the principle of constant-flow injection.