Piston to bore clearance cast iron suzuki 185

[Stokie]

Piston skirt length on inlet side has been shortened to 67mm - measured to edge of crown.

[Rich_T]

On the 64mm pistons I run 0.08 to 0.095mm clearance that is approx 3.5 - 4 thou inch in old money.

[johnd]

OK, i've ordered my piston, long rod crank and some bearings and seals today. The cylinder is going in for a rebore as soon as the piston arrives @ 0.085mm as i'm more inclined to have an iron cylinder with more clearance. I will build up a bottom end so that i can check the port timings and post back!

[johnd]

I've been using http://www.lambretta-images.com/archive/porttiming.php to calculate possible port timings for this tune, now bearing in mind that i don't have an array of angled die grinders (or experience with port angles) so i'm planning to leave the transfer ports alone for now, do these port timings look like they add up for a pokey motor?
approx for now:
Exhaust: 177°
transfer 118.7° (1mm more raised and it would be 125°)
Inlet 160°

Please feel free to elaborate any opinion as this is a learning opportunity for me.

[tarmac tickler]

what carb u using?
what exhaust u using?
what gearboxes are at your desposal?
and what sprockets do you have?

[johnd]

5.2 Italian GP 18/47
Was thinking 26 or 28 phbh for carb.

Pipe something old school like a PM.

[johnd]

I'm just wondering if these port timings will compliment or conflict with each other before I start cutting metal. This is an experiment to see if I can tune my own cylinder, rather than I speed record attempt. Although it will probably end up as one

[tarmac tickler]

170 exhaust
leave the transfers
150/155 inlet

47/19 = 4.94 will pull that easy without pillion, you wont have to rev its tits off to get it to shift, wont be the starship enterprise but will be a nice ride up hill and down dale

nice fast road tune that,, take off too much metal and you cant put it back on but you can always fettle a bit more off it at a later date if you want,, 175 on exhaust max will make a massive difference to the ride,, not that i know owt


check out my facebook page bollox that i,m trying to get together ,, it wasn,t so long ago i was using a router to port the exhaust and inlet

[johnd]

170 exhaust
leave the transfers
150/155 inlet


nice fast road tune that,, take off too much metal and you cant put it back on but you can always fettle a bit more off it at a later date if you want,


check out my facebook page bollox that i,m trying to get together ,, it wasn,t so long ago i was using a router to port the exhaust and inlet

Good advice that! It's easy to get carried away at the imagination stage of an engine build

Got a link to your FB page?

[tarmac tickler]

http://www.facebook.com/tarmac.tickler


i did a alloy ebay 185 nasty to these port timings with a home made remote reed ,, 69.95mph at york dragway standing quarter with no third gear,, went from second to forth,, pacemaker box @ 4.99 46/17