Author Topic: Motor questions for the experts....Cylinder porting...pics (Read 2725 times)

fx4pitrone · « **on:** December 21, 2013, 10:17:24 AM »

How does the porting on this look....good, bad, ugly?? Also, how about the spaces by the bottom of the sleeve.... Is that bad or common?

fx4pitrone · « **Reply #1 on:** December 21, 2013, 10:18:09 AM »

.............

F-Red · « **Reply #2 on:** December 21, 2013, 02:46:35 PM »

I'm no expert, but I have not seen a cylinder, with the sleeve separating like that one! :livid:\

DnB_Racing · « **Reply #3 on:** December 21, 2013, 05:42:10 PM »

its hard to tell and im also no expert, but from the pics it looks like there was possible too much material removed causing the sleeve and or the cylinder to have had some uneven thermo expansion... but that's just a guess... how long has it been like this?
when was it ported? has it been running fine?

fx4pitrone · « **Reply #4 on:** December 21, 2013, 10:32:05 PM »

Thanks guys... Never ran it. Bought a non running project. Cylinder previously had some porting to it... Sent it to a builder and he was going to port it.... Got this back and wanted some opinions....

Jerry Hall · « **Reply #5 on:** December 21, 2013, 11:05:42 PM »

Quote from: fx4pitrone;20373

How does the porting on this look....good, bad, ugly?? Also, how about the spaces by the bottom of the sleeve.... Is that bad or common?

I cannot see the port windows. Port window dimensions and angles need to be taken. 90% or more of the power gains are made at the port window and within 10 mm of the transfer port window.

The gains in the exhaust port are at the window and between the port window and the exhaust flange.

The porting shown in the pictures is just the cosmetic portion of the porting. (anyone can do that part of the porting shown in the pictures with a file, with sand paper on the end of your finger or a drill with a sanding cone). It takes some special tools to get into the areas that makes the real power. These areas shown that have been touched with a grinder will add little to nothing to the overall performance.