Crankshaft experiment

stew79 · Post by **stew79** » Wed Apr 25, 2018 8:51 am

yes jack, i did read that (and all of this very interesting project) but i am trying to think of a way around the "out of ratio" problem that becomes worse the faster it runs. swash plate fuel pumps can have an adjustable stroke which could be used to compensate at higher speeds ? perhaps the "proportional" approach to set the fueling, always has the same basic problem, but if you start from the top end and work down, it works well enough. (thats setting the max fueling first with way over the amount that you think the engine can burn, which must give a good safety margin as well) then reducing that max amount, so if the slower part, or initial pick up is just too rich. end result, top end strong, cool, safe, pick up to mid point a bit rich but the ignition is strong enough to cope.
stew

Jack Gifford · Post by **Jack Gifford** » Thu Apr 26, 2018 5:24 am

You've stated the usual approach very well. If I had chosen parts of a "normal" nature (say a little Weiand 170 c.i. blower) I'd probably be well on my way to having it sorted out by now. But... this project is mostly about things I wanted to investigate (thread title: Crankshaft experiment). I really want to learn how much heating of the intake mixture can be avoided by turning a very large (511 c.i.) blower quite slowly. If my estimate of this blower's efficiency (using it in this manner) hadn't been so far off, there would not have been these setbacks to report.
Not quite apart yet- still hoping the repairs won't be too bad.

Post by **minetymenace** » Thu Apr 26, 2018 9:59 am

Jack Gifford wrote:I really want to learn how much heating of the intake mixture can be avoided by turning a very large (511 c.i.) blower quite slowly.

I would hope that most of the heating of the mixture could be predicted by Boyles Law, assuming an adiabatic process. If anything the, compression of the mixture will heat the blower more than the inefficiency of the blower causing the mixture temp to rise. As your small(ish) motor no doubt produces a lot of heat, I'm sure the blower is well insulated from the head. Do you measure the temperature and pressure either side of the blower?

stew79 · Post by **stew79** » Thu Apr 26, 2018 10:20 am

hi minety, as i see it there will be very little heat generated from the engine, and with so much fuel going through the blower with the air i doubt it goes over 50 deg c. i think methanol really is a wonder fuel and one day i will have a play myself.
stew

Jack Gifford · Post by **Jack Gifford** » Fri Apr 27, 2018 7:00 am

Roots blowers are notorious for heating the mixture, well beyond the fundamental Boyle's law contribution. Most is due to fluid friction- mixture moving at high velocity through "leaks" (rotor-to-rotor, and rotor-to-case). Some is due to mechanical friction- Teflon strips under high centrifugal loading actually touching the case and other rotor. I've never measured temperature of my compressed mixture- just watched for symptoms, such as sensitivity to small increases in spark lead, signs of highly heated plug electrodes, etc. [For this to be the learning experience I intended, I'll probably eventually add a sensor for compressed mixture temperature]
Yes, vaporization of the methanol does accomplish much mixture cooling (my V8 would frost up the blower case when idling with no load). But this cooling is limited by the fact that my engine (and most others) put the majority of alcohol into individual port nozzles, just a couple of inches from the intake valves. This is done to allow adjustment of fuel/air ratio to individual cylinders- GMC-style Roots blowers tend to push more air to the front cylinders.

stew79 · Post by **stew79** » Fri Apr 27, 2018 9:06 am

jack, i assumed the fuel was injected into the blower, not at the valves. i have often wondered about the small helix angle of the blower rotors, having an influence on local pressure, after all the type with the much greater angle are almost axial flow. the more i read and see the more i want to play
stew

Jack Gifford · Post by **Jack Gifford** » Sat Apr 28, 2018 5:56 am

With head now off, damage assessment is a mixed bag. A small torched spot in the chamber of #3 by the exhaust valve appears quite repairable. But #2 & #3 sleeves are damaged. If they were typical cast iron sleeves, I wouldn't be too surprised that they appear to be cracked at the approximate spot their top rings sat when the detonation occurred. But I specifically turn my sleeves from DOM steel tubing, to not suffer the cracking that cast iron does when shock-loaded. So until I can get it completely torn down and those sleeves pressed out, I won't know exactly what the failure amounts to.

Jack Gifford · Post by **Jack Gifford** » Tue May 08, 2018 4:15 am

Air pressure check of coolant jacket shows that integrity of sleeves is fine. What appeared to be damage is actually addition of metal to some places on sleeves' surfaces. I'm guessing the detonation "slammed" the top rings forcefully enough to deposit bits of ring material onto sleeve walls. I'm hoping that's good news- assuming the walls can be honed true again.

Jack Gifford · Post by **Jack Gifford** » Fri Jul 20, 2018 6:35 am

beat wrote: ... I will have my nose in to the methanol metering...

I see that AutoMeter does offer air/fuel-ratio meters that will work with methanol fuel. But before I buy one, I'll follow up on an offer from a fellow racer to borrow his 4-band metering system, which would be great to have for the next dyno session, since it could create a data log. In any case, I've welded bungs into all four exhaust stacks for the oxygen sensors.

Repairs are made and engine is going back together, just awaiting a custom copper head gasket. With any luck I'll be back on the dyno in August.

beat · Post by **beat** » Fri Jul 20, 2018 8:02 pm

hi Jack

my nose did not get far by this surch....

anyway, when I started mit my one, I was getting quickly good information for the A/F R.
in the beginning I was continuing the plug reading and had the Meter just along.
and I learned as the plug reading is not wrong, - no, - it is just to rough.
the Meter is much more sensitive about trottle position and it shows faster and easyer how much a change in jet Nr. it will need.

beat

Jack Gifford · Post by **Jack Gifford** » Wed Aug 22, 2018 6:20 am

Engine is ready to test-run, just waiting for the borrowed air/fuel-ratio metering system to arrive here. But then I'll need to sweet talk my honey into the loan of her laptop to log the data.

beat · Post by **beat** » Thu Aug 23, 2018 8:32 pm

this engine looks a bit " loud " to me.

just hope the laptop survives....

loging the datas needs to go in synchron to the " trottle " position to say something exactly

what is your sensor for trottle or flap position ?

beat

Jack Gifford · Post by **Jack Gifford** » Fri Aug 24, 2018 6:18 am

Thanks for pointing out the usefulness of logging throttle position. I don't have that, so I'll think about how to add such a sensor.

Post by **minetymenace** » Sat Aug 25, 2018 11:23 pm

Four white paint marks on the twist grip...

Jack Gifford · Post by **Jack Gifford** » Sun Aug 26, 2018 6:50 am

minetymenace wrote:Four white paint marks on the twist grip...

Fine- if I can log ten of them per second...

Jack Gifford · Post by **Jack Gifford** » Sun Sep 30, 2018 5:45 am

I built sensors for throttle position and fuel valve angle; they work fine.
Battling to understand the logger software is going less than fine. An 8 or 9 year old kid would probably do better...

Jack Gifford · Post by **Jack Gifford** » Sun Sep 30, 2018 5:49 am

beat wrote: ... just hope the laptop survives...

I was forewarned by the owner of the logger to use a laptop with a solid-state "hard drive", as acoustic vibration from engine exhaust would wreak havoc with a spinning disc drive.

beat · Post by **beat** » Sun Sep 30, 2018 6:20 pm

hi Jack,

I guess the logging the all mesuring is the real challenge.

so much easier when A/F Reader is continuously on the bike and after a change in jetting setup you can just go out on the road and observe the result....

beat

Jack Gifford · Post by **Jack Gifford** » Mon Oct 01, 2018 6:09 am

Beat- Besides the logging, I do intend to make good use of live displays during test running- air/fuel ratios, EGTs, RPM, time, throttle & fuel valve positions, and boost pressure.
I'm getting less uncomfortable with the logger software. Enough to fire up the engine for a test run, as soon as I can coordinate a session with my two sons.

Jack Gifford · Post by **Jack Gifford** » Mon Oct 08, 2018 4:55 am

Test run completed- no glitches!

Great throttle response- quick jabs showed about 6,000 RPM (up to 6,400 per the log). No leaks (fuel/oil/coolant) nor strange noises. Log shows air/fuel ratios about where expected- safely "fat" as planned. All data got logged except boost pressure (hardware? software?), but analog gauge showed about 10 PSI on throttle stabs- at least in the ballpark of my goal.
Now I can schedule another dyno session.

beat · Post by **beat** » Mon Oct 08, 2018 7:54 pm

Jack Gifford wrote: Log shows air/fuel ratios about where expected- safely "fat" as planned.

this is giving you safety and dos encourage you for going further in process....

any Values of fuel type and A/F you can tell ?
if they are secret, maybe by private message ?

beat

Jack Gifford · Post by **Jack Gifford** » Tue Oct 09, 2018 5:03 am

No secrets. Methanol fuel. Fuel/air ratio, as I understand, should be about 5:1 under full throttle maximum load. With no load other than engine acceleration (as throttle was "hammered") was about in the range of 3:1 to 4.5:1 during the test run.

I'm mystified by the lack of logging of manifold pressure. I hooked up the laptop today and double-checked the static live test of the sensor. At atmospheric pressure the live data shows about 0 psig, and at 15 psig it shows about 14.9 psig. I have no idea why it didn't log anything but zero.

Post by **minetymenace** » Tue Oct 09, 2018 8:40 am

Jack Gifford wrote:I have no idea why it didn't log anything but zero

What sort of sensor? Possibly overcome by vibration or electrical noise....

Jack Gifford · Post by **Jack Gifford** » Sat Oct 13, 2018 6:58 am

Yes, vibration and RFI are possibilities. I used twisted pairs for all sensor leads, but who knows what interference from a high tension magneto can do.

Jack Gifford · Post by **Jack Gifford** » Sat Oct 20, 2018 6:08 am

Dyno scheduled for 8AM Friday the 26th.
I'll be using the dyno shop's boost pressure sensor and logging, which I know works okay. So the main thing I'll be logging (and watching) on the laptop will be air/fuel ratios.

beat · Post by **beat** » Sat Oct 20, 2018 7:15 pm

hi Jack

not only how much it is, - how much it rises and falls is important.
and of cause: by wich trottle position it is reaching the extremes.
it was taking me weeks to get it in to a narrow band of 1 Gramm of air.

beat

Jack Gifford · Post by **Jack Gifford** » Thu Nov 01, 2018 4:51 am

I did get to observe live data of air/fuel ratios on the dyno, but the laptop had an "SD card error" so no logs were created. I don't yet have copies of the dyno's logs, so I can't yet comment on the engine's performance. We did manage to tweak port nozzle sizes to even out the four cylinders (EGTs and air/fuel ratios). The engine got quite a lot of run time over the first three days (would you believe 13 gallons of methanol?) and I thought it might come home with no damage. But today #3 cylinder died with a head gasket leak. So.... one more time it's got to come all apart.

Jack Gifford · Post by **Jack Gifford** » Wed Nov 07, 2018 6:34 am

Engine is going back together now. You could say it was merely a head gasket failure, but it was due to something I missed during the last teardown. I had concentrated on repairing the torched spots in cylinders 2 & 3, and didn't notice that the detonation had "lifted" the middle of the head. Yesterday I had to cut the head .0125" to get it flat again.

beat · Post by **beat** » Wed Nov 07, 2018 7:21 pm

Jack Gifford wrote: the detonation had "lifted" the middle of the head.

this is why I do use only ONE cylinder

by 2, 3 ore evan 4 brothers - you never know what they are doing .....

Jack Gifford · Post by **Jack Gifford** » Thu May 16, 2019 5:18 am

After some more test-runningl last month, it's time to start fitting the engine into the lakester. Proceeding with baby-steps...

beat · Post by **beat** » Thu May 16, 2019 9:56 pm

good luck, - and don't miss anything please....

Jack Gifford · Post by **Jack Gifford** » Fri May 17, 2019 6:10 am

Okay beat- I'll depend on you to tell me what's missing!

There's a lot to be done, but I've decided how to approach a few things. The longer engine/drivetrain only leaves room for a 4" ctr-to-ctr driveshaft! I'll take the most expedient solution- I'll forego the rear suspension to obviate the need for a driveshaft w/u-joints, and use just a short shaft and a greek-coupler. Fixing the rear end in place is a simple matter of replacing shock absorbers with adjustable heim-end rods- which is easily reversible if I ever want to use the suspension in the future. Of course nobody makes a greek coupler to fit the Ford 8" rearend, so making one up will mean some precision machining and welding. I've got a mental picture of front and rear engine mounts and started making patterns. Clearance for the exhaust stacks will only require modifying one frame upright. I had to cut out two frame cross-tubes which I'll need to replace with removable ones. And... on, and on, and on.....

beat · Post by **beat** » Fri May 17, 2019 9:56 pm

........ this all sounds of some little work to do......

I just hope as your testrunns will end up better than my one with the BSA Gold Star last Tuesday:
we endet upside down in a sharp corner

nothing seriously on our bodies , nor the bike is showing any cracks ore bends.
but it was teaching me to go a bit more carefully!
the story behind was, as this corner was passed until then always in the first gear. the engine revs a bit to high for my feelings...
so I fallowed the old rule of : if you are not feeling good in a corner, - try to go true by one gear higher!
the result was clearly : like a Bug on he's back... ( sorry, no pic taking )

Post by **minetymenace** » Fri May 17, 2019 11:32 pm

Gosh beat, don't wreck the combo before I've had a blast in the chair! Glad you are OK..

Jack Gifford · Post by **Jack Gifford** » Sat Jun 29, 2019 5:14 am

Accomplished lakester builders are packaging experts; I'm not. Everything is now jammed into it but the body around the engine will need to grow a good-sized "blister" to cover it all. Nevertheless it's going for a trial run Sunday- a local tenth-mile dragstrip is better than nothing. With 1.5" of ground clearance I can't even run it down my lane. With fixed gearing, it certainly won't perform like a drag machine, although I've selected quick-change gears for about a 120 mph top speed- as opposed to gearing it for 200+ mph at a landspeed venue.

Barry Creary · Post by **Barry Creary** » Sat Jun 29, 2019 1:44 pm

Work of art Jack

koncretekid · Post by **koncretekid** » Sat Jun 29, 2019 11:04 pm

Good luck with your trial run, Jack. 120 mph should be a rush in any case, especially on a 1/10th mile course! How about bringing it to Loring next month for a little extra room to go and mostly, to stop? I'll be there with some spare time, as I'm only bringing the Bridgestone, and I'm not planning on making many runs for fear of breaking the crank.
Tom

Jack Gifford · Post by **Jack Gifford** » Sun Jun 30, 2019 4:22 am

I don't expect to actually run 120 MPH in a tenth-mile!
Loring would be great, but I can't be ready. Many things are out-of-date (tires, harness, etc.) and I don't yet have a HANS device or latest-Snell helmet, nor a -15 firesuit. I know there are also some rules changes in the last decade- arm restraints, etc. Hopefully I can get it up-to-date later this summer. Besides, I've put many non-race tasks aside for six weeks, so I need to get caught up.

Jack Gifford · Post by **Jack Gifford** » Mon Jul 01, 2019 4:52 am

Inaugural outing went amazingly well. No problems, no liquids on trailer deck afterward. The only disappointment was my failure to observe ANY of the gauges, not even the tach, during those quick few seconds. Unfortunately the track's timing system failed to get an ET or MPH number. It definitely was not an embarrassingly sluggish ride- I'm guessing about 80 mph after 528'

There's a video of the run on facebook tonight- look for South Butler Nostalgia Drags.

beat · Post by **beat** » Mon Jul 01, 2019 8:20 pm

Looks like a aeroplan to me....- just wondering where are the wings.....

beat