Machine Head Project

[S2central.net]

1st of the day, showing the phat new 20mm holes for the water rail from t'other nights work.

[S2central.net]

Next, shows the water rail in place, bolted down at three circles and the new holes centre punched.

[S2central.net]

Two of the three new holes drilled with a 12V battery hand drill - runs at just the right speed with a sharp HSS bit to cut thru the alloy head nicely.

[S2central.net]

ANd lastly for today - three freshly threaded holes. All fits up a treat - just need to shorten these three bolts a tad as mentioned before.

[Error404]

looking good Paul - nice gnarly finish on the intake ports, or is that just from "shaping" without smoothing or did they get different treatment to the exhaust ports all together? Are the exhaust ports getting all polished up?

[S2central.net]

The inlet ports will need something like a bead-blast treatment to sweeten them up. They look a bit too gnarly in certain light. Haven't started on the exhaust side yet - I want those to be super shiny. Will go for decoke on those ports 1st to see what I'm doing.

[SteveH]

Paul,

The M6 tap you have is a taper tap, these are intended to start a thread. To get the thread cut correctly to the bottom of your 16mm deep hole, you will need a M6 plug tap, this will cut all the way to the tip and is intended just for this purpose

5mm drill to a depth of 16mm did the trick nicely and I used an M6 x 1.0mm tap to create nice new threads. This is where I hit a small snag...

The tap I have is rather tapered towards the tip and so I wasn't able to get the full length of threads in the hole to carry the bolts. Its pretty marginal that I'll have the clamping force needed to stay watertight, so what I'll do is shorten those three bolts by approx 2mm to give me comfort zone - there is plenty of length on the bolt to get away with it. Thats my only option really, as I daren't drill any deeper (fear of damaged existing threads and / or drilling thru the water jacket).

Only other option is an M6 tap that is somewhat sawn-off to let me cut the thread deeper than what it is currently.

[S2central.net]

That figures, and I have some of these in the wrong size... I'll have to get one from somewhere - that gives me more thread coverage and is better than shortening bolts. Cheers fro the sanity check - Paul

[S2central.net]

Sourced an M6x1 plug tap and sure enough it finished the new threads off nicely - no need to go shortening bolts

Also started cutting on the exhaust side - photos to follow - but there seems to be a lot of potential for improved shaping and port enlargement. Maybe it was some added confidence or a mistake but I was able to remove as much metal from one exhaust port than two inlets so far. Granted I haven't finished by a long way.

Just hope I'm not cutting too deep - its impossible to say really.

[S2central.net]

Some pics for today then... 1st cuts on EX#1 side by side with nothing done to #2

[S2central.net]

This one you can clearly see (its EX#2 actually but they are all the same) the stepped areas on the port - I used that on #1 essentially as the guideline for shaping out to that profile.

[S2central.net]

And finally, this one showing what the first 90 mins of cartridge rolling can do to an EX port. It will need some more time and patience to impart a nice even knife-edge there in the centre and even longer to polish up the surface to blingtastis levels but I'm happy so far.

[mdm]

Paul, have you worked out how your going to mount the hall sensor?

[S2central.net]

In a word - no - but I know a man that can do that...

[terrybullwon]

Paul, have you worked out how your going to mount the hall sensor?

If you look in my project thread you will see how i mounted the hall sender on my 3B block.

Paul are you still going to beed blast your head? I heard some horror storys