My A4 adventures

[ndutton]

Not a video but you might find this interesting. Here is a picture from a few years ago of Don posing with a new block A4 being tested on the original dynomometer Universal used. Load is applied by a water brake attached to the output coupler.

And FYI, I don't think a shop will technically dyno individual parts.

[Dave Neptune]

We all have our DYNO

I have run many an engine on water brake dyno's and they work great. I had one blow up when doing a bunch of "Offy's" for team Rahal before he got into the Indy class. We had one engine that we destroyed because of troubles with that particular engine. The engine was testing about 7~10 Hp below the rest, we set it aside and finished the rest of the engines then mounted the cantankerous one. I was on the gages and the boss was fiddling with the engine. We got so entranced with the engine we did not pay proper attention to the water tank. Well we were under full load when the engine "revved" without resistance. The dyno impeller came apart before the engine and we thanked our lucky stars that we were not destroyed too. The dyno came apart after running out of water (around 10500+RPM's) and destroyed the roof and walls of a cinder brick building. When the dust settled we looked completely covered in dust. There was daylight where there was none before and we still had all our parts Luckily neither of us were in radial alignment with the impeller housing thus no harm to us. The Offy had no valvetrain left, the pistons were destroyed as well as the block. Lucky to of survived!!! The problem was that the #3 cam lobes were a few degrees off of centerline thus the HP discrepancy. We shipped 13 engine not the 14 ordered. The fourteenth was shipped after the building was fixed and the dyno replaced.

On OB engines we had what were called "test wheels" which were kinda a prop with no real thrust only resistance. These test wheels were specific to a particular engine, and reaching a specific RPM while in the test tank was only confirmation of HP. Perhaps one of these could be adapted to the A-4 for testing but the prop would be removed and replaced after testing. A not so good procedure..

Now we all have props on our boats but many different ones. The load from the water is a "dyno" of sorts. By measuring our RPM's vs load "when the prop and bottom" are clean is the same thing but without the HP rating that a dyno will give. This load vs RPM is how to tune "your" engine by making the constants of resistance of the clean prop and hull your dyno and higher RPM's being a gain and visa versa.

Dave Neptune

[Ando]

I really appreciate the comments, tips, pics and stories, guys. I'll post more pics from now on

Last night I dismantled what was once my "doner" carb and rebuilt it this morning using the parts from my recently acquired (late model) rebuild kit, all the parts of which were in the carb that has the air leak.

I pray to Netuno (the Italian God of the Sea) it works just as good as Neil's does as I haven't installed it yet. But not before putting in a 3"-3.5" partially threaded bolt and Permatex'd nut in that aft fuel pump bracket as I just might have one (hopefully two) laying around.

Thanks again guys.

P.S. re testing the integrity of the almost totally disassembled early model: I called it "Dyno" testing but was really just referring to testing the integrity of the block. The machine shop's website has a pic of a machine called "Superflow" on it...so I figured that was the machine they use to "Dyno" test. Here's the link: http://www.valleyhead.com/tour.html scroll all the way down and you'll see a pic of the machine I am referring to. I saw it and just assumed it was the same thing.

[Dave Neptune]

Ando, that's a "flow bench" which is for testing how much air you can get through the "ports". After a few hours of grinding, cutting and scraping the ports so they are a bit larger and especially "smoothed" out for air flow. Then back to the bench to check for improvement hopefully. I have observed some flow benches that actually rotate the hole engine at various RPM's with the carb or FI attached just to measure how well the engine "pumps" air at various settings. No fuel used in this testing. Basically they measure air volume whereas a dyno measures HP at various RPM's and throttle settings.

Looks like a good "ole boys" shop. Thatch would enjoy those toys.

Dave Neptune

[Ando]

That’s so much easier to deal with. Thank you ronstory 👍🏼👏🏼

[Ando]

[YOUTUBE]https://youtu.be/XBIw-YZVU04[/YOUTUBE]

I installed the rebuilt doner carb and she’s running ��

[ronstory]

Glad to help, I did it twice the hard way before I learned.

... and CONGRATS on the running part. Woo-hoo!!

[ndutton]

Ando, thinking back to when you started this quest, how is your confidence level now?

[Ando]

Ha! It's flying pretty high right now yet I know still have a lot to learn and that makes me happy too. So ya, I'm pretty stoked

[ronstory]

Woo-hoo!

[Ando]

Woo-hoo!

Thx ronstory...it's def a nice feeling of a milestone. Reflecting on how it all slowly unfolded, the stories, the people met, the things learned, the places discovered, and the friends I met on the way (you guys) and looking forward to the future really puts a grin on my face.

And on that note, on to the next task (ie resolving the fuel delivery issue). Maybe it resolved itself? Ha!

[Dave Neptune]

Excellent.

Dave Neptune

[Ando]

04/10/20 update:

Hi All, I worked on the fuel delivery issue today.

Since the external fuel tank was connected to the efp and the engine ran and ran, I knew the efi and the carb are both working.

Therefore, I connected this bulb at the end of the fuel line (ie I connected this bulb where the internal fuel line meets the efp.

And began pumping. And fuel came out (into a clear container). I figured "might as well see if there's any water/fuel separation while I'm at it.”

Then the internal fuel line was connected to the efp. I got the go ahead to “fire it up” from ndutton.

It was running and running good. I then went to open the thru hull valve and, to my dismay, it was already open 🤦🏻*♂️ And the exhaust pipe was smoking like crazy, which worried me a lot. So I turned the A4 off to cool it down and it did not restart. Based on nudtton’s suggestion, I checked for fuel in the carb and there was about a shot glass of fuel.

He then had me reconnect the auxiliary tank and try to start. Aux tank connected...Wasnt starting...realized engine was warm and so I closed the choke and it started. Maybe the open choke is the reason it didn't start again when the main fuel line was connected? Bingo! That was it! The engine was warm and wouldn’t restart bc the choke was closed. Learned that a warm engine doesn’t need choke when it’s warm from Mr. ndutton awhile back and I’m just glad I remembered it.

I guess the short story is that fuel delivery issue did actually resolve itself!!

As a bonus:
The forward and reverse actually work!! (I didn't know for sure if they would bc I didn't test that prior to the purchase of this new old engine)

She threatened a stall when I first eased her into forward. Reverse was fine. Upon a third attempt at forward, she didn’t threaten a stall at all...ok maybe a bit but not too bad. I’ll take it. Who’s up for a test drive?

[Ando]

Here’s some media[YOUTUBE] https://youtu.be/YKEmqehVyXw[/YOUTUBE] This mist scared me at first but it dissipated
[YOUTUBE] https://youtu.be/H23Byumu3rs[/YOUTUBE] this resolved itself. I assume it was from the thru hull being open for a few days.fuel pic...no separation whatsoever

[Ando]

I hadn't installed the OPSS correctly the first time I put it in not very long ago. The plug wires weren't in all the way and I figured that out because I took them apart to resolve the fuel delivery issue, and when I separated the wires and connected them to the actual plugs that go into the OPSS, the engine refused to start. So I took the wires out of the plugs and saw they the wires were not properly secured to the plugs. I saw that when I removed the yellow protector covering (plastic) the actual plug (metal). Once the metal plug was separated from the yellow plastic, I placed the the entire wire through the yellow plastic covering. Then I clamped the wire to the metal plug and the slid the yellow covering over the wire and the metal connection. Then simply plugged each into their proper spots on the OPSS. I’m sorry for the lack of pictures. I’m horrible at taking pictures in the heat of the job. The connections are now in properly and i know bc the A4 is again working!!