GDB Inline 4 Cylinder OHV I.C.

[eccentric]

Bob,

I am working on my main bearing caps and have been studing your methods. Yours are beautiful, here is a picture:



I noticed you have not machined the o-ring notch in the main bearing cap or the cylinder block.  Was this a conscious decision?

Thanks, Greg

[90LX_Notch]

Greg-

Yes it was a conscious decision.  I plan to machine the o-ring groove with the cap and block assembled.

-Bob

[90LX_Notch]

Breather assembly-

Unfortunately, I did not take many pictures.  The tube was made from a solid piece of 3/16 aluminum.  The bar was bent while still solid.  A vee-block was set up in the four jaw chuck in the Atlas 618.  The bar was then drilled and bored. 

 The flange was done on the rotary table from a turned part.  The cap was a simple turning job.  The insert for the cap was turned, then milled with a ball endmill.  The bolts were turned from a piece of steel that was milled into a hex with the Spin indexer.  A 1-72 die was used for the threads.

-Bob

[steamer]

Nice progress Bob!    I see the Atlas!....Where's the Rivett?!!   

Hope things are well my friend...

Dave

[90LX_Notch]

Thanks Dave.  All is well.  It’s winter, so my machining progress slows to a crawl.  We’ve been getting a lot of small winter events that we still have to go out for.  I’ve been called out the last seven weekends, we were out both Christmas Eve and New Years Eve.  It’s just one of those winters.  Thankfully I made it to Cabin Fever this year.  I was out the next day plowing.

The Rivett is still here.  I had to make a set of gears for the carriage feed.  I use the Atlas much more because I can leave it full of chips.  Whenever I use the Rivett, I meticulously clean and oil it.  The Atlas is a  “winter beater car” and the Rivett is a classic high end automobile.

-Bob

[steamer]

Thanks Dave.  All is well.  It’s winter, so my machining progress slows to a crawl.  We’ve been getting a lot of small winter events that we still have to go out for.  I’ve been called out the last seven weekends, we were out both Christmas Eve and New Years Eve.  It’s just one of those winters.  Thankfully I made it to Cabin Fever this year.  I was out the next day plowing.

The Rivett is still here.  I had to make a set of gears for the carriage feed.  I use the Atlas much more because I can leave it full of chips.  Whenever I use the Rivett, I meticulously clean and oil it.  The Atlas is a  “winter beater car” and the Rivett is a classic high end automobile.

-Bob

 

[90LX_Notch]

I haven’t updated in awhile.  I made all the 0-80 socket head cap screws for the timing cover, side cover and oil pan. It took awhile to develop the tooling and process, but I am happy with the results. 

I’m currently planning on returning to the head.  I am going to try and salvage the head that I had started on.

-Bob

[Admiral_dk]

Oh man they are tiny - did you make them from stock or modify a bigger screw ?   

Per

[90LX_Notch]

They are made from bar stock Per.  The threads are die cut.  The recessed hex is .050 (1.27mm) across the flats. 

-Bob

[Admiral_dk]

OK and the recessed hex is where it get tricky or did you have a tool for this too 

[90LX_Notch]

Per-

I used shop made tooling.  The hex was created by center drilling .045 (1.143) deep with a .032(.812) diameter tipped center drill.  Then a .043 (1.092) shop made single lip endmill was used as a boring bar to bore the hole to .046 (1.168) diameter.  This produced a “flat” bottomed hole .045 (1.143) deep.  Next a shop made broach was used to make the hex.

The broach was guided through a sleeve ensuring that it was centered to the screw which was screwed into a lower section.  An arbor press was used to push the broach into the screw.

-Bob

[Kim]

Wow! That is quite the elaborate process to make your own SHC Screws!  That must have taken some time to do that!  I'm very impressed!

And then you blackened them? They look very good, whatever you did!

Were you unable to source 0-80 SCHS? Or did you just want the challenge?   That is just amazing work!

Kim

[RReid]

I'm very impressed, not least because they are so tiny. I just love posts like this that show what can be done with relatively simple, and shop made, tooling.

[Admiral_dk]

Like RReid and Kim - I am more than duly impressed     

I knew it could be done, but these are the smallest of it's kind I've seen so far     

Per

[90LX_Notch]

Thank you Kim, Ron and Per for the compliments.

I did it for the challenge and to see if it could be done.  I now have the capability to produce any kind of fastener, based on any combination of features.  Also, I want be able to say that the engine is entirely built from scratch; except, for five screws that hold the top plate down.  The screws were blackened  by heating them and dipping them in virgin olive oil.

When it is all said and done, they are very expensive screws. 

-Bob