Scooterotica

I have some port timings, could someone interpret them into real terms please?

exhaust 192
trans 130
inlet 149

cheers

what cc/stroke ? piston ?

inlet a little low ? i would have gone with at least 165 with those other timings

red ghost wrote:I have some port timings, could someone interpret them into real terms please?

exhaust 192
trans 130
inlet 149

cheers

Billions of variables, but on the face of it, it's going to be very peaky, particularly the exhaust timing.

I:155/T:122/E:175 has always given quite a nice road tune for me.....

This is what I measured on my Mugello 192 V4 straight out of the box, I'm running a 60/110 with a 3mm packer and I'm lost on how get everything to a more useable level.

Any advice would be greatly appreciated

eden wrote:the longer stroke explains why the inlet is short and exhaust is long, if you ran it with a 58mm stroke the inlet would be longer and the exhaust would be shorter, I hope that makes sense

with a 58mm stroke you would have something like

e 187
t 122
i 153

keeping the 60mm stroke and packing the top of the barrel rather than the bottom would give something like

e 180
t 110
i 164

transfers to low like that though IMO


packing half at the top and half at the bottom would give something like this

e 186
t 118
i 158

Doesn't look like there's an easy good solution - had a similar situation with a V2 with very odd timings.

Whatever you do, you're stuck with short transfers and advanced exhaust - more involved solutions could be:

1. Go with the 58mm stroke, machine a little off the bottom to bring the exhaust timing down, have someone open up the transfers to increase their duration/timed area and add a packer to the top to get your squish back.

2. keep the 60mm as above, but again do some work to increase transfer duration/timed area.

Thanks for the replies guys, with out the packer I measure;

ex-180
trans-116
in-159

I bought this kit with the intention of just bolting it on,check the squish and go...

I'm not a happer camper

or increase the inlet to 175/180 as is at 60mm and have a rev monster, it will be good about 9500/10000 rpm
or send it back to where it came as its not really good for much without a fair bit of work to the tranfers

It's funny, well not really. But this kit is designed to run with a 60mm crank

Anyway, after a long wait to get some packing plates and head gaskets..

With no porting work either..

With 2mm packing I get;

Ex-188
T-126
I-151

With 1.86mm packing I get;

Ex-186
T-123
I-152.5

I prefer the 2nd option

Thoughts?

Bump