Project KH500 triple resto....

[Gosling1]

lookin good mate

[h.b.bear]

Hangabout? I thought he should have had it finished by know Looking fantastic Dave

[ProblemChild]

sweeet.

[kawadave]

Ta all....
Striped the carb's down today... a lot simpler than the Z1R carbys that's for sure.
Have them soaking in white vinegar...man doesn't that stuff work a treat.

[jacobb]

Show us some photos of the carbs Dave! I am cleaning a set of 34mm CVs with an ultrasonic cleaner - it would be good to have a comparison...

[kawadave]

Will do tomorrow Jake...just off to watch the ARL gf.....

[kawadave]

Here's a before and after shot of one of the carbs that was left to soak in white vinegar for about 3 hours then scrubbed using a toof brush.
The grime literally fell off.





Also I'm pretty sure?...that both the inlet and outlet ports have been ported and polished at some stage.

Although difficult to see in these pics...the ports are super shinny.

[s man]

Nice work, very nice!!!

[ProblemChild]

amazing stuff that vinegar. lookin great.

[kawadave]

amazing stuff that vinegar. lookin great.

$1.10 for 2 litres at Aldi....

I've been advised...
" It is better if you roughed up the intake and port with 150 grit and polished is for dry flow".

Any advise on this appreciated.

[Gosling1]

....I've been advised...
" It is better if you roughed up the intake and port with 150 grit and polished is for dry flow".

Any advise on this appreciated.......

mate I would just leave those intakes as they are. Someone has definitely cleaned them up and matched the liner to the barrel at some point in the past - you would need to measure the port dimensions from the top of the barrel down to the top of the inlet ports (and the transfers and exhaust) to work out if any porting mods have been done though......polishing stock ports was fairly common back in the day.

It is better for the exhaust port to be polished as this helps reduce carbon build-up on the port walls. it's not about flow - the shape of the port determines the flow. Intake ports......you will hear all sorts of different things. The advice about roughing up the intake ports is based on the theory that rough walls help atomise the mixture better - smooth walls don't. Maybe if you are chasing 10ths at the drag strip this would make a difference - but for a street bike ?? You won't notice any real difference at all. I don't bother polishing the inlet ports on any of my 2T motors though. Better to spend the time on the exhausts if you really want to put some hours into it.

Those carbies came up well !! Good old vinegar - old school is still cheaper and works better than all the new-fangled stuff

[kawadave]

you would need to measure the port dimensions from the top of the barrel down to the top of the inlet ports (and the transfers and exhaust) to work out if any porting mods have been done though......

Excuse my ignorance Gos....measure what from where? do I need dimensions from a stock barrel to confirm any porting mods?

[Gosling1]

stand by - I will post up a *port map* which will make it easy. I have the stock port dimensions for a H1 down in the library....

Basically - you measure the distance from the top edge of the barrel down to the very top edge of each port, to the bottom edge of each port and also the widths of the ports. There are stock dimensions so it is easy to compare and see if your motor has been ported. 2T barrels can be ported, or polished - or both.

I'll get a port map so you can see how it works.

[Gosling1]

OK here is a port map from some Italian 2T motor - doesn't really matter which.

You can see how there are specific dimensions in 'height' of all the ports - exhaust (closest to top) - transfers (in the middle) and the inlet (lowest port).



In this picture - the inlet ports are on the left, the exhaust port is the big one, and the transfer ports are either side of the exhaust. This is a pretty standard-looking port map. The only thing of any note is that the inlet port is split. In your H1 - it is one port.

When a 2T motor gets *ported* - then these dimensions are modified. Typically, the exhaust port is lifted at the top (so the measured distance is shorter than stock) - often widened a bit - the inlet port is also enlarged - often widened - and sometimes lifted a bit as well. Transfer port heights can be varied by using thin spacers under the base gaskets (which also varies the other 2 ports but these can be bought back to stock positions easily.) - It is much harder to modify transfer ports than it is to do the exhaust or inlet.

This is just for piston-port motors. Rotary-valve 2T motors are heaps better for lots of reasons.

I will dig up the stock port map for a H1 and if you can accurately measure the port heights of your barrels, it will be easy to determine if the porting has been modded. My guess is not, this is a real science and tuners who know their shit do porting mods using a flow bench for best results. I reckon that your barrels have just had the casting imperfections removed and the ports tidied up. The casting imperfections can be significant on old 2T motors, cleaning these up is pretty easy and does make a difference to motor response......

[kawadave]

I will dig up the stock port map for a H1 and if you can accurately measure the port heights of your barrels, it will be easy to determine if the porting has been modded. My guess is not, this is a real science and tuners who know their shit do porting mods using a flow bench for best results. I reckon that your barrels have just had the casting imperfections removed and the ports tidied up. The casting imperfections can be significant on old 2T motors, cleaning these up is pretty easy and does make a difference to motor response......

Thanks Gos...my guess is as you mentioned.."I reckon that your barrels have just had the casting imperfections removed and the ports tidied up".

But would like to see the stock port map for a H1 and measure the port heights for my own curiosity.