Australia and New Zealand team build anyone?

[hi speed scrap]

M6 x 0.75 sounds good for the plug thread, I have those taps for the thread in the head.
I have 7xxx series Ali blocks or centrifugally cast, cast iron to choose from
for the heads and valve blocks.
Stainless or silversteel for valves, I would prefer silversteel, easier to machine
in smaller dia's.
Brass for the valve seats?
Also, I am confused about the transfer port, drawing doesnt show drilling detail
to match valve seat retainers, not to mention exhaust and inlet ports.
Maybe its an age thing, or I am a page short of the book

Dave

 

[tel]

I was thinking more of the M6 x 1 standard thread Dave - would that be a problem? Otherwise I will have to buy a die in.

 

[hi speed scrap]

M6 x 1 is ok, have those as well.

Dave

 

[tel]

Pinion blanks (steel) roughed out - now I gotta find something to do the big gear blanks, probably cast iron unless I have a lump of bronze I don't know about.

 

[Herbiev]

Looking good Tel. Just wondering are we building 6 or 7 engines?

 

[tel]

Six as far as I'm aware mate, but I always make a spare on runs like that - that way you never bugger one up and need a spare!

 

[Herbiev]

Good thinking. In my case I'll make two extras just to make sure

 

[hi speed scrap]

I have profiled an ali block to the head shape, it is long enough for 8 heads
so will probably make 8, barring stuffups!
Similiar with transfer ports.
Dam small arent they,

 

[tel]

Yes, it is a small engine - smaller than the first look through the drawings seemed to indicate.

I got two (only) blanks for the big gear (in steel BTW) cut yesterdasy before I got interrupted.

 

[warranator]

Hi guys. There seems to be a few dimensions missing on the crank shaft drawing (diameters), does anyone have any idea what they are? One dimension cannot be read also (distance of offset). Do we just match up where they go? Is there a tolerance?
How does the conrod connect to the cam shaft?

Also how does the cam lock onto the shaft it runs on?

 

[tel]

You might have to pick those dims up off the bearing and connecting rod drawings?

As far as the cams go, the attachment of the gears does not show eityher - I plane to put an M3 grubscrew in the bosses to hold 'em. Might do thou likewise with the cams.

 

[Herbiev]

Hi all. Does anyone have hole sizes and position measurements for the base plate ?

 

[tel]

Can't see 'em - might be another case of picking them off the various components.

Moving right along - there's been a bit of a change in the game plan, as I turned up a bit of more suitable stuff for the 'big' gears.

 

[Herbiev]

Picking off the components only tells me the mounting holes for the "supports" are 30mm apart. I cant seem to find a way of finding where on the base plate these mounting holes are drilled. Is it possible for someone that is familiar with computer CAD stuff to shed any light on this. Without measurements on the plans it has got me stumped

 

[tel]

Can't help much there I'm afraid - the more I look at these plans the more stuff I see missing

 

[hi speed scrap]

then there is the valve porting issue, if one looks closely, the
valves are 6.4mm dia, and the port they open into is only
6mm dia.
there is no drilling detail shown for inlet/ex gases, nor anywhere
to bolt on a carby.

Also there is a huge amount of potential compression lost in the
large porting volume, my calcs suggest with the piston up against
the head a max comp ratio of only 3.4 - 1 is achievable.
Someone will need to check my calcs tho!

Has anyone seen a working model from these drawings?

Google reveals some interesting information about the
designer.

In the meantime, my chipmaking has ceased.

Dave

 

[Herbiev]

I have managed to contact the designer and he seems happy to answer questions so I shall post the above queries to him. I shall also ask if there are any construction notes and if we can see a working model

 

[hi speed scrap]

well done!

Maybe there is a completed set of drawings available,

free ??

Dave

 

[Herbiev]

Thats what I'm hoping for. He seems genuinely interested and said "thanks for building this engine" so I gave him the web site address and invited him to join and follow our progress.

 

[tel]

Damn, damn, damn. damn, damn, damn, damn. damn, damn, damn, damn. damn, damn, damn, damn. damn, damn, damn, damn. damn, damn, damn, damn. damn, damn.

Made an extra pinion blank, as you all know, and then proceeded to roon TWO!!!!!! So back to making some more blanks - +2 this time!

The good news is the 'big' gear cutting went without a hitch - got 8 of them on hand now.