Thursday, October 30, 2014

"Project Bantam" - Arts and Crafts

I've finally amassed all the parts required for the Briggs&Stratton 14FB engine overhaul.  The main bearings look good, and the piston ring gaps are within spec using new standard size rings.  One of the exhaust valve keepers was rattling around in the tappet chamber when I opened the tappet cover last month.  The exhaust valve seat was rather rusted and required significant lapping to get down to good metal.  A quick grind on the valve stems put it back within gap specification.

exhaust = 0.015"
intake = 0.008"

The gudgeon pin is still tight and the piston looks good as well.  It can be put back in with the new standard size rings.


I went with a two-tone paint job on the block.  The fins were rather rusted, so I wanted to make sure they got painted and stayed painted.  So they got a 1200'F rated exhaust paint in silver.  The crankcase got a 500'F rated engine paint in black.  The exhaust elbow was rusted fast, but the threaded adapter to the exhaust pipe still had good threads, so that's staying.  I just need to obtain a new mating nut and olive for the exhaust.  It looks like an electrical fitting.

I had my son help with the arts and crafts.  Making measurements and cutting gaskets is a tedious task, but still enjoyable.  I started with some relatively thick gasket material for the tappet cover, point cover, and oil pan.  The bearing housings require some adjustment based on axial float of the crankshaft.  I made them out of thin material as templates.  I can go back and duplicate these easily when I get the crank set in, if the float needs increased to meet spec in the manual.

On closer inspection there are marks on the inside of the timing gears.  It looks like someone has had this engine apart before, since the cam gear has a awl scratch on it pointing to the correct place between the timing teeth.  The manual says to set the timing based on the outside of the gears, which is presently obstructed by the main bearing.  Timing will have to be set by the inside viewing through the bottom of the crankcase.


Sunday, September 14, 2014

"Project Bantam" - Fuel Tank

The steering shaft and new gear went on without any trouble.  The ends of the shaft were a little mushroomed, but nothing a quick turn on the lathe couldn't fix.

The fuel tank was new from Mr. Shaffer.  I decided to powder coat it for extra durability. It came out looking great for a part that is not seen.  The original sediment bowl was lost, so a new Briggs-Stratton model 690612 was easily obtained.


The support straps were made from some spare stainless that I had lying about in the scrap bin.  To keep the neck from banging up the hole in the hood, I stripped some wire and used the insulation to protect the hole, by splitting it with a razor blade and fit that to the edge of the hole.  Using some silicone lubricant, the neck slid nicely into the hole.  Some inner tube rubber made a nice cushion for the fuel tank.
It looks more crooked in the picture than it actually is, because of the odd angle I had to take the photograph from.  (Don't mind my finger in the photo.)  Notice the nuts holding on the bolts onto the hood, since the original holes no longer had sufficient threads to hold the bolts to my satisfaction.
The body is looking rather finished at this point.  Considering how poor the tractor looked when it rolled into the workshop, its a ten-footer overall.  Not a show winner, but a restoration staying within a reasonable budget.

Hopefully the next post will involve some progress with the engine.

Tuesday, September 2, 2014

"Project Bantam" - assembly mockup

Since most of the sub assemblies were already prepared (except for the engine). I was able to set the pieces together to make sure everything fit right.  In retrospect, this should have been done before I painted.  I would not have thought that there would be a problem with the fit of the new fenders.  The build tolerances are not the most precise, so it should not have surprised me that there was a problem.

  
From the picture you can see that the right fender does not fit down against the running board.  Its too late now, a spacer will have to be fabricated.

The original input shaft stud mount bearing was completely shot.  This consequently wore down the shaft, which had to be repaired with welding in more material, and then machined down again.  Otherwise, the input shaft fit right back in place.

Otherwise parts fit back in position as they were originally. Its starting to look more like just a collection of parts now.



Sunday, August 24, 2014

"Project Bantam" - Orange

All the de-rusting, blasting, bodyfiller, and sanding has culminated in this weekend of painting.  A six-pack of Kubota Orange tractor/implement paint has transformed the pile of tractor parts.  Only the hood has too many imperfections for my liking.  It will have to be sanded down again and re-sprayed.  They body looks good enough, as do the grill and fenders.

  
The basketball hoop in the driveway served as a great location to paint the body.

The only part which hasn't been painted now, is the engine.  I still need to come up with a plan for the exhaust and muffler.


 
The front wheel assembly went back together easily. The new design for the wheel bearings should be much more reliable.  I can't wait to mount the rear wheels and pillowblock bearings I bought to replace the rear axle bushings (which looked rather sorry and worn).

For now the paint must dry and I can drink a beer with a sense of accomplishment.  After getting everything painted, I'll need to purchase a set of new fasteners.  Tractor Supply sells fasteners by weight, so I'll have to compile a shopping list soon.

Thursday, June 12, 2014

"Project Bantam" - I was rebuilding a tractor wasn't I?

There have been delays in the progress.  I had to use someone else's sand blaster to strip the frame, since my compressor couldn't muster the pressure needed.  It all turned out rather well.  I had to fix some structural items and prime it immediately to prevent surface rust.  It turned out rather well, but still needs some more structural work before continuing the body work.



Just to remember how bad it was, it sat under this tree for YEARS.


The structural welding is done, and the body work is complete.



The next step is to start applying the final paint coats.  I'm going with the Kubota color in enamel.  Its not as pleasing to me as the Allis Chalmers orange, but the Kubota color is closer to the original as far as I can see.  Reassembly of the body is just around the corner.

In other news, the front tire went on the rim easily.  I also had to re-design the front wheel bearings.  I used sealed bearings in the center, a set of spacers, and some flanged bearings on the outside with another set of spacers.  To keep the spacers from falling out, the whole assembly will need to be arranged with a dummy-shaft, and then the axle bolt inserted once placed in the steering yolk.

(Poor little guy just woke up from his nap)



Friday, May 23, 2014

Rootes Radio Console - Auxiliary Input

Having a car with an antenna, but no radio under the dash, was a situation I needed to remedy.  However locating a good radio and console for a British car from the 1960's proved to be a challenging and expensive task.  Having one that worked was a bonus.  When I finally found one worthy of my Series 3 Alpine, I set out to modify it so that it was useful for more than just AM broadcast radio.

The radio I managed to obtain was a Rootes-labeled Motorola 515T, which came out of a Series 2 Alpine.  The brightwork looked reasonably good, and all the parts were there.
 

 

 

Wisely, I didn't believe the label that read that the radio was set up for positive ground, because someone had already made the negative ground modification.  It was wired for sound, and when the switch was turned on, it sounded beautiful.  I cleaned up the mechanisms and put some fresh grease on the moving parts.
 

Now the challenge was to identify where the amplifier input was.  The easiest thing to do is to look for the leads going to the volume control.  This particular model is delightfully simple and almost elegant.  The power supply and amp section is a separate section at the back of the radio.  The volume control leads go under the RF/IF section and simply solder to the amplifier board.  Here's the challenge with that.  The common of the amplifier is tied to +12v rather than the chassis of the radio.  That means if I want to power my MP3 player off the car electrical system, I'll need a method of isolation since the audio common of the MP3 player sits at chassis potential.

To insert the signal to the amplifier before the volume control, I had to grind off the board trace between the CW lead of the volume control and the radio's preamp output circuit.  The idea was to install a switch to go between AM audio and Auxiliary audio.  To make this seamless the switch would be internal to the radio, and actuate at the far end of the tuning band.  This proved very simple with the addition of a microswitch and a small bracket.


The orange wire on the far left of the board trace is where I ground off the board to reach the CW terminal of the volume control.  This went to the NC terminal of the microswitch.  The volume control CW terminal was wired to the black wire which went to the Common terminal of the microswitch.  The final wire was a grey wire that I connected to the NO terminal of the microswitch and out the back of the radio, along with a wire attached to the CCW terminal of the volume control.  When the microswitch closes at the far end of the tuning band, the signal input for the volume control is taken from the leads going out the back of the radio.

The ground potential problem of the audio signal was solved with an isolation transformer.  I rummaged 'round in the junk box for a small transformer with about 500ohms impedance on the output winding, and a 200ohm impedance on the input leads.  This arrangement worked fairly well and yielded acceptable sound quality, as long as I didn't try to connect up both stereo channels.  I'll just modify the MP3 player decoder chip for Monoaural output.

The console enclosure was painted with a satin finish, and the components were re-assembled.  It cleaned up nicely with just some mild hand soap and a toothbrush.  All bright surfaces were then treated with a wax to protect them from corrosion.


The next challenge was to install the radio in the car, without any of the original brackets.  I did have some heavy flat stock available to make brackets to suspend the radio from the underside of the dash.  There are two rails that go from the dash back to the firewall.  These do have many holes already available for attachment.  The console was propped into position using shim wedges against the transmission hump to bring it up to the correct height, center it to the gear lever, and level it.  Using a cardboard template, the brackets were sized in-position, then the flat stock could be drilled accurately and formed to fit.  


The MP3 player sits under the dash and out of sight.  It can be controlled by IR remote if needed.  The Series 3 is now wired for sound.





Sunday, April 20, 2014

Sunbeam S7 spit as polish

The brightwork on KYL95 certainly has lots of patina. I thought perhaps too much. Some of the rust on the handlebars is just surface rust. Yes there is pitting, but its not bad. The headlight surround is also ugly, but not really bad.

I was searching for methods of chrome cleaning that won't marr the surface and came across some discussions involving aluminum foil and water. It sounded reasonable. The aluminum is soft and won't scratch steel or chrome. The water provides slight Aluminum Oxide to build up, which provides the slight chemical reaction and mild abrasive action.

Mothers polish is just too abrasive.

I tried it on an inconspicuous spot and was pleased with the results. Working upside-down the water tended to run off, so I spit on it. That worked even better than water.


The photo doesn't do it justice, but it looks so much better maintaining a level of patina without the rust layer.