Road NC30 to track NC30 in 100 million years and counting

[CMSMJ1]

You'll be right Martin. take all the casting flash off for starters and see how it goes. I did this using an air powered mini dremel doofer and some finger work with wet'n'dry. Lappedthe valves in, removed all the quietening gears and when I put it back together it still worked!

woohoo

[Cammo]

I managed to pick up a set of carbs this week that had some very strange things done to them. 160f and 162r, standard slides, pilots and needles but they did have these little gems attatched to them

Martin, if you need some pointers on where to start as a jetting baseline for these carbs give me shout.

Your carb setup is the same is my racebike, I can get you further in the ballpark (160+ is way too big!), but I'd still recommend a dyno run!

Me + Your bike =

[Martin]

Cheers Cam. Any help is always appreciated. I've stuck the stacks on my HRC'd carbs so the spec is as follows.

HRC stacks
HRC slides
MJ 150f 152r
PJ 40
PS 1.5 turns out
FI needles on the lowest clip so they're the same length as 8ZF needles
1 0.5 shim under the front needles and 2 under the rear
float heights set to standard

It starts and runs but I'm sure it'll need work.

[Cammo]

Cheers Cam. Any help is always appreciated. I've stuck the stacks on my HRC'd carbs so the spec is as follows.

HRC stacks
HRC slides
MJ 150f 152r
PJ 40
PS 1.5 turns out
FI needles on the lowest clip so they're the same length as 8ZF needles
1 0.5 shim under the front needles and 2 under the rear
float heights set to standard

Mine runs pretty similar settings.

Do you have the hrc emulsion tubes? If not, Rick might be able to put you right on a set of repros, they're fairly critical I would recommend them (if you're very careful you can probably mod standard ones...).

I run these and 142 mains all round. Edit: You'll be safe to start off on the midrange that hrc offered in the f3 manual (145's?), these bikes had a shed load of head porting and raised camshaft lift so probably got a lot more air in! Become the F3 manual.....

Don't worry too much about the needle settings this is least important of all the carb settings for sure. I run 8ZK's, can't remember what washer heights, as long as it goes well!

I've also had to adjust my PS to 1.25 turns out, you'll know what's right if it doesn't pick up off idle crisply, or if it idles too high (mine!).

Love this build, keep it coming!

[Martin]

Took the front head off yesterday, The carbon build up on the exhaust valve seats was minging and the build up on the faces of all the valves was about 1.5mm thick!!! I guess the engine's never been de-coked then. I made a start on the porting also. The guy on quality control when my heads were cast was either drunk or on a promise as he managed to be satisfied with this!



This is how far I've got, still some finishing to be done and now I know what I'm doing as far as Dremel skills and where to start first it should roll along a little quicker although I'm in no rush, I really don't want to fark this up (I may already have but it couldn't be any less flowing than it must have been what with inlet and exhust ports resembling something more like the surface of Death Valley!).

[Martin]

I think I have 145's and 147.5's in my little box of brass trinkets, I'll try them and see what happens. I need to order new head gaskets and a few other bits from Rick, I'll ask about the emulsion tubes aswell. I do have more than one set of emulsion tuibes that i could have a go at modding. Have you got a pick of the HRC ones that you could post up so I can see whether I'd be able to bodge a set please?

[Cammo]

That head work (job? ) looks really good Martin!

I'll get a pic up of the emulsion tubes in a couple of days, am away from home at the moment.

[CMSMJ1]

That looks great. Impressed

[superlite]

Very nice job! It can't be easy getting a Dremmel in there.

Here's a pic of an HRC emulsion tube:



The one pictured is a rear (5 hole). Basically, they're identical to stock items, but have 4 extra holes per emulsion tube - 2 on each side. The same goes for the front (4 hole). So each HRC rear emulsion tube has a total of 14 holes and each HRC front has 12. Hope that makes sense!? The additional holes are the same size as the standard holes. Basically you need these to get the fuel through when you're running big jets in an HRC set-up. Should be pretty easy to mod some standard ones - I don't think that hole placement would be overly critical.

[Cammo]

That explains it superbly....

I don't think that hole placement would be overly critical.

Nope, you can line them up with the first 2 std holes by eye and drill them easily. Just remember that brass is very soft, go slow with a sharp bit (I have no experience here, may need a specialty bit?!).

You WILL need these for the hrc carb mods to work properly.


@ Superlite: What the hell is that thing doing out of your carbs?? Get cracking, get racing!!