Road NC30 to track NC30 in 100 million years and counting

[superlite]

Erm, it's back in now!

Although, I did admire my shiney carb porn before I put them back together!

It's a pretty basic mod to do, but obviously it aint easy to drill very small cylindrical objects where you want to. But as brass is reasonably soft, you should be able to punch it easily before drilling. Otherwise get one of those bolt lockwire jigs or make one out of a nut.

@Stickshift: I noticed that there was a set of original HRC emulsion tubes missing from the kit! Either the marsupial mice have found them, or you've knocked them off!

[Cammo]

@Stickshift: I noticed that there was a set of original HRC emulsion tubes missing from the kit! Either the marsupial mice have found them, or you've knocked them off!

Yep, must be the darn marsupial mice, or maybe the flaming galahs that knocked them off....

[Martin]

That's great Mr Laidlaw, much appreciated I have my stupidly small drill bits on order as we speak.

[Martin]

Right then. One head finished to the best of my abilities and tools. Inlet ports both knife edged. Inlet bowls opened to 21mm, area behind the valve guide opened to 22mm and throats 30mm. Outlets bowls opened to 19.5mm, area behind valve guide to 20mm and throats to 33mm. All valve guides chamfered by 0.5mm and all valves lapped in.





Only one more to go although I was a lot quicker on the second cylinder than the first (first took about 6 hours whereas the second took about 4) so hopefully it shouldn't take too long. Then I can put it all back together, check clearances and fingers crossed it'll start and run better

[CMSMJ1]

Totally wicked man. Great pics too. Looking forwards to the finished results.

Are you going to replace the valve guides?

Removing the quietening gears too?

[Martin]

Cheers Mark .Replace the valve guides?!?! No they're fine and sealing properly, no scores and well within limits mate, I thought about replacing the valve guide seals but at a fiver a go (you need 16!) I'll chance it as they still make a nice pop when you put the valve back in so i guess they're sealing properly. I've taken the back lash gears off the cams but left the ones on the cam drive gears as I can't see how you'd remove them without getting busy with an angle grinder and getting all medieval on them.

[Variablevalves suck]

Hi Mart,
Nice post and even better build. Wanted to ask if the HRC carb slides are available to buy and is the rubber diaphram removeable from the plastic body? I ask as having a lathe in the garage i think an alloy rep could be made so long as the rubber diapham could be used.
Chris.

[Cammo]

Wanted to ask if the HRC carb slides are available to buy and is the rubber diaphram removeable from the plastic body? I ask as having a lathe in the garage i think an alloy rep could be made so long as the rubber diapham could be used.

The hrc slides are the same as some nc21/24 slides. There are a couple of minor variations between the rounded slides of these models but they're pretty much identical.

The slide and rubber is one piece, I imagine it would be pretty difficult to take the rubber off and get them to seal properly on a knocked up metal slide. Good thought though.

[Variablevalves suck]

Shame as the body of the slide would be very simple to make in alloy.

[Martin]

Didn't do a huge amount over the weekend. I've modded the emulsion tubes so they've now got the extra holes, a very easy mod to do, thanks for the pics and info guys. I also put all the valves back in the finished head and took the rear heah off to start work on that. These pics illustrate very well why I'm doing it I think.





A bit grim eh?