[Elarson]

SD cards are handy when they work right but can be temperamental. There's different speeds, different voodoo inside them that all has to be right to work.

The first data system in the Boss Bird used an SD card and it only occasionally worked right. Fortunately it got burned up in the fire and our new RPM system uses a boring reliable serial cable.

Our Replay camera uses a mini SD card and it works ok IF (and only if) you format it every time to erase old files. It won't write new video files over old ones.

Eric

[Jack Gifford]

Mike- the runs on the dyno were short, but I probably fired it up 12-15 times (I'll email you soon- don't want to take up a lot of space here). I was too busy watching air/fuel displays to even pay much attention to other stuff, but I know it didn't make a lot of power.

Trying to look on the bright side- most of the "innovations" (DOHC design, full-circle crank counterweights, separate top- and bottom-end oiling) have not yet shown any problems. The "big blower on little engine" idea is still to be proven, but progress is being made.

[Jack Gifford]

No damage other than the gasket. When I repaired a torched spot in #3 chamber last spring, I didn't realize that the "incident" had lifted the center of the head. Had to cut it .0125" today to get it flat again.

[twooldgoats]

Good news on the engine, Jack. Glad to hear it.


Jim

[mgarblik]

Well, I would say that was an overall successful dyno session if you have some usable numbers to further the tune-up development. You have now proven the oiling system, the camshaft drive and timing, the blower drive, basic fuel map and other factors. Great job!

[Jack Gifford]

I guess I should not have said "lifted" the head, since the top surface was still perfectly flat. Sort of "crushed" the deck surface in the middle of the head. Heads from 1961 weren't the strongest cast aluminum alloy. Almost all back together; just in time for my hernia surgery Thursday...

[mgarblik]

Jack, one of the little things we did with the Grocery Getter when we were running the flimsy E-heads with lots of nitrous was intentionally oversize the dowell holes in the head. Our thinking at the time was we could not clamp the head tight enough to the block to keep it from moving or crushing anyway, so we went with controlled movement. Similar to the concept of a Cometic gasket. We oversized the dowell holes slightly, .005-.010 as I remember to allow the head to grow and move more evenly rather than be constrained on the ends by the pins and hump-up in the center when it got hot. The head studs, then essentially just kept the two parts together and let them move a little independently. If you wanted to try this little experiment, you could drill the head and install a bronze bushing in the dowel holes. Then ream to the size that works best. It would take some experimentation to discover how much that head grows. Something to think about.

[Jack Gifford]

Thanks for sharing Mike.
How about if I just avoid severe detonation?

[mgarblik]

Originally Posted by Jack Gifford

Thanks for sharing Mike.
How about if I just avoid severe detonation?

Absolutely! Was your data gathering able to determine if the detonation was a fuel or timing issue, or some combination of both? Was the software able to produce any sort of map? Did you hurt the ring lands, rings or skirts? Let me know if I can help by looking at any pics or parts.

[Jack Gifford]

Mike- no detonation on the dyno this time. In the prior session (last spring) it was simply due to too much blower speed- boost was going skyward and fuel couldn't match airflow.

Through all of these mishaps only top rings, gaskets, and chamber walls have suffered damage (and minor marking of sleeves).

I'm still waiting for the dyno logs to be emailed to me. I was too busy watching live air/fuel data (on the laptop which refused to do any logging!) to pay any attention to dyno numbers.

I think you witnessed the lack of "harmony" between me and the Castner brothers, which hurt the productivity of the session. The other problem was the mismatch of a tiny engine to a huge water brake. The dyno wasn't capable of varying the load precisely enough to perform a smooth RPM-sweep- especially with the ridiculously-fat mixture they insisted on.

[mgarblik]

Yes, after seeing their dyno, I was concerned about it's ability to regulate the water at a fine enough increment to control a small peaky engine like yours. We have run some 4-cylinder engines on our SF-901 at my school. They are a bigger challenge than any others, primarily because of the vibration and the general set-up for non-standard V-8 engines. Water control was not an issue, however. Way back in 2003, we dyno'd an accurate replica of the 1903 Wright Brothers engine, right down to the aluminum block casting made right here in Dayton, OH. Lots of custom fixtures to get it on the dyno, but we were able to run and control it. It made 12.4 HP at about 100 CU Inches as I recall. That was really fun. I hope you can find another facility to run your engine at. Let me know if I can help.

[Jack Gifford]

Originally Posted by Half-Inch Stud

... A few thermal cycles to 200F and back may let the magnesium yield. Probably good idea to thermal cycle the assembly and check TQ...

I wasn't terribly concerned, since there's considerable margin-of-safety in the fastener scheme of the crank's filler segments, and it's been fine so far. However, the engine hasn't been really hot yet, so I guess it's worthwhile to learn more. I prepared a test sample of the magnesium alloy bolted to a piece of 4340 steel (same thicknesses and fasteners as on the crank), along with a "control sample" of steel-to-steel. As the wife allows me use of her oven, I'll cycle it a half dozen times to 230 degrees F for 15 minutes, then check the bolt torques. Got a couple of cycles today and hope to finish up after the holiday.

[Jack Gifford]

Completed six heat cycles. No real surprises. Steel-on-steel sample lost 25% torque, magnesium-on-steel lost an average of 33%. That's still within the safety margin, but not by a lot. Next time the pan is off I'll re-torque those fasteners.

[Darren 639]

That’s the best thanksgiving turkey ever cooked..how did the kitchen smell ? My wife hates when I put car parts in the oven..but how else can I heat up parts I ask her.

[Jack Gifford]

I've had fifty years to learn how to chemically clean stuff before it goes into the wife's oven.

[Jack Gifford]

To apply some load to the engine the next time I test-run it, I've set up a shade-tree version of a "static dyno". A 2' long torque arm on the QC box's output shaft is attached to a load cell which is in turn anchored to the engine mounting via a spring-type game scale (for quick viewing while running). The load cell is monitored by an instrument amplifier that feeds the data logger. I removed all weights (and attaching bolts) from the CrowerGlide, shooting for a full-lockup speed of about 6,000 RPM (Crower says probably about 5,500). Although limited to 1-2 second throttle bursts to not cook the clutch too badly, the ten data points per second should provide some useful data.

Don't be too alarmed- all pieces and fasteners are generously oversized, and it includes a rugged "gate" surrounding the torque arm to contain it in any event. Nevertheless nobody will be allowed to stand in the plane of rotation of the arm!

[Jack Gifford]

Ran it without killing anybody!
Time to start squeezing it into the lakester.

[johnta1]

Congrats!

[twooldgoats]

Congratulations! Where will you first try running down a track?


Jim

[mgarblik]

Originally Posted by Jack Gifford

Ran it without killing anybody!
Time to start squeezing it into the lakester.

That's great news! Tell us some more detail about the run. Dyno? Free standing? How long running? RPM's? Load ? Lots of interest here. Pics or video?