1/3 Scale Ford 289 Hi-Po

[petertha]

and so all my measurements to date on the 289 have been 33% too low. The previous 4500 rpm top-end limitation turned out to actually be 6000 rpm, and my 850 rpm minimum idle was really closer to 1100 rpm.

Excellent news! Now check your online banking dashboard, maybe you still have the 'conservative mode' switch toggled & deferring some tools. LOL.
How is the adjustment made on the ignition module (from 5.0-5.4v)? is it a switch type thing or a variable pot type thing?

 

[mayhugh1]

Excellent news! Now check your online banking dashboard, maybe you still have the 'conservative mode' switch toggled & deferring some tools. LOL.
How is the adjustment made on the ignition module (from 5.0-5.4v)? is it a switch type thing or a variable pot type thing?

The on-board 'Autolite Voltage Regulator' module is a dc-dc converter that steps the 12 volt battery voltage down to a pot adjustable voltage for the 'MSD' ignition module. - Terry

 

[BanjoPlayer*]

Absolute beautiful built engine and congratulations on winning Banjoplayer

 

[BanjoPlayer*]

Again I can't say enough. I'm trying to find how and where I write my history to all the members

 

[mayhugh1]

During a multitude of 3-5 minute runs in the past several weeks I managed to run a full gallon of gas through the 289. I then took a deep breath and disassembled it so the crank, rods, pistons, liners, cam, and all bearings could be checked for signs of wear. I was interested in finding out if my decision to not use an oil pump had been a mistake because I was considering leaving an oil pump out of my next build. I was happy to find everything looking as good as when first assembled. There was some minor scuffing on several piston skirts, but all the liners were mirror smooth. All bearing surfaces looked good, and there were no abnormal clearances among the valves and their cages. A few valve springs had weakened however and were replaced.

The main reason for all the running time was that I had been chasing a pesky inconsistency in the engine's tuning that seemed to be dependent upon ambient and engine temperature and something else that took forever to pinpoint. As time went on, nearly every restart required fiddling with the needle valve to keep the engine running as it warmed up. I eventually found a Delrin spacer around the carb's needle valve to be the source of the problem. Re-making a better fitting spacer solved the problem although I still don't see why. This exact same problem has plagued my last two engines whose carburetors use a similar needle valve design, and those will be looked at as well.

Currently I'm planning a Black Widow V8 for my next build. I purchased a set of castings from Dwight Giles shortly after meeting him at the 2012 Portland Gears Model Engine Show. In a follow-up correspondence with Dwight I received what seems to be the same incomplete documentation package that others have mentioned receiving including several cam and crankshaft design iterations. At that time I decided to set the castings aside until I had a lot more engine building experience.

After finishing the 289, I felt I had the needed experience but was ambivalent about building yet another V-8. The Black Widow's blower was intriguing though, and although it's probably more cosmetic than functional it would be a new experience for me.

I noticed a poster in a current Black Widow thread mentioning that he had gathered up all the engine's known documentation and was offering a free download link to anyone interested. After contacting him through the forum he asked that I send a second request through his work email address, but he still never followed up with a link.

I considered putting the castings up for sale, but since I'll soon be desperate for a new project, I've chosen to make my own version of the engine using just the major original castings. Since its scale is similar to that of the 289, the 289's valve train, distributor, crankshaft, and roller cam should be readily adaptable to it. The addition of a custom bell housing will allow an electric starter similar to the 289's to be added. (I've really grown fond of electric starters.)

I'll likely start the actual build thread in a month or two after completing some of the major SolidWorks modeling and rough machining of the block, intake manifold, and heads. Since this will be my first encounter with sand castings, there will be that to deal with. - Terry

 

[petertha]

As time went on, nearly every restart required fiddling with the needle valve to keep the engine running as it warmed up. I eventually found a Delrin spacer around the carb's needle valve to be the source of the problem. Re-making a better fitting spacer solved the problem although I still don't see why.

I looked at your needle valve cross section post & nothing stands out to my amateur's eye. But I do know from RC experience we had a problematic carb with Delrin seal/gland nut on the end of the threaded section. At ambient temp it held the threads firm. But when the engine got hot, it expanded so NV was able to screw itself under vibration & thus mess mixture. Land the plane, mostly cool & it seemed tight. It became evident by marking original position with a felt pen. Not sure if your assembly can even vary in a similar manner, but throwing out FWIW.

 

[mayhugh1]

I looked at your needle valve cross section post & nothing stands out to my amateur's eye. But I do know from RC experience we had a problematic carb with Delrin seal/gland nut on the end of the threaded section. At ambient temp it held the threads firm. But when the engine got hot, it expanded so NV was able to screw itself under vibration & thus mess mixture. Land the plane, mostly cool & it seemed tight. It became evident by marking original position with a felt pen. Not sure if your assembly can even vary in a similar manner, but throwing out FWIW.

View attachment 164551

Peter,
Here is the spacer I was referring to:

 

[Cessnadriver]

I will be very eager to see the Black Widow build. There are a lot of us out there that purchased the castings and most are aware of the challenges around the drawings. Your abilities to produce some of the most amazing engines will be an inspiration and hopefully be the resolve to what all is lacking or incorrectly drawn. Thank you for making this your next project!

 

[Charles Lamont]

Since this will be my first encounter with sand castings, there will be that to deal with

Unless alloy castings have been heat treated, they may be very soft and gummy. I mostly use HSS tools, and the solution I found to getting a good surface finish was to use tool angles and speeds similar to what I would use for mild steel and to lubricate the cut with RTD compound. Tap Magic is probably similar.

The other issue is of course working out where best to find the finished part inside the casting. This often requires compromise, but I suppose not so much if you are reverse engineering from the castings - you can cut your suit to fit the cloth!

 

[dsage]

and there were abnormal clearances among the valves and their cages.

I presume you meant to say "there were NO abnormal clearances...."

 

[mayhugh1]

I presume you meant to say "there were NO abnormal clearances...."

Yes, thank-you! - Terry

 

[mayhugh1]

... but I suppose not so much if you are reverse engineering from the castings - you can cut your suit to fit the cloth!

That's what I'm thinking. - Terry