screamingcub Posted August 23, 2011 Report Share Posted August 23, 2011 I've got a 421 cub that's had the ports cleaned up (internally,no mods to the port windows) and the cases have been opened up to match the cylinder. I'm curious if anyone has had the pistons intake ports widened to match the width of the cylinder intake port windows? (pro-lites) Would it be a worth while mod the next time it's apart? Quote Link to comment Share on other sites More sharing options...
Nightrider Posted August 23, 2011 Report Share Posted August 23, 2011 I tend to leave the size alone,but i usually chamfer the ports to create a smooth transition between the windows and pistons.It can be done with a few handfiles and takes about 20-30 minutes..Not sure if the gains are substantial but it should make for a better flow. here is a rough diagram,you can see how the piston ports are not opened up,they are just blended to the intake windows. Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted August 24, 2011 Report Share Posted August 24, 2011 yes....there are a few people that have done it. actually more than a few. HOWEVER.....there have been instances where the porting of the piston intake windows have cracked and shattered the pistons skirt.....causing chaos in the cases. If i had the money i would try to do both....run a motor with new pistons, and then run the same motor after opening up the windows. but since im not made of moeny.....no dice. Quote Link to comment Share on other sites More sharing options...
camatv Posted August 24, 2011 Report Share Posted August 24, 2011 some motors also run good with NO holes in the pistons.... i USED to port match intakes on ported cylinders but it just lead to cracked skirts and low cyl life. so i stopped if its ablaster piston in there its got larger windows anyways.. Quote Link to comment Share on other sites More sharing options...
AKheathen Posted August 24, 2011 Report Share Posted August 24, 2011 well, i would not do it myself, and there is allot that i take on... if you must, have a scale handy to keep track of the material you are taking of, and ballance the pistons. read allot about it, and talk to people. really, ask some builders and have it done. if they say "i wouldn't suggest it" they really mean it for a reason. someone good and experienced at it will have the best shot you are going to get at not sacrificing strength. i would suggest asking brandon at wildcard..... i just bought postons where the windows are already ported.... Quote Link to comment Share on other sites More sharing options...
camatv Posted August 24, 2011 Report Share Posted August 24, 2011 there are some theriores with velocity vs volume in there also.. if you do read about it you MAY come across a big thread about this subject if it even still exists about a dyno run with non window'd pistons, std windows and " so called ported windows" the results were pretty interesting. again for what its worth. i just leave them alone. Quote Link to comment Share on other sites More sharing options...
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