Small Port Vs Mid Port Vs Big Port ???

[CALE12]

need input ....the small port give more low end power but flat lines at high revs and big port high end power but lower bottom end speed !!

 

this is for a 3k engine only running 2nd gear...2,000 rpm to 7,800 i know it all about the cam range but want from anyone ???

[SLO-030]

If your running it up to 7,800, you'd be chasing something that performs well in the top end.

[CALE12]

If your running it up to 7,800, you'd be chasing something that performs well in the top end.

its from 3,000 -7,800 abut not for long

[altezzaclub]

How important are the last 1000revs?

 

I imaging it won't be hard to get a motor to do 2000-6000 with small or medium porting, it will be harder to get the 6000-7000 working quickly and keep the bottom end, and most difficult to get that last 1000rpm.

 

I'm sure you'll need big ports up around 7500rpm, but more important will be the choice of cam.

 

Which end can you chop off easiest?? or how much can you lighten the crank & flywheel & clutch??

[skidsharpe]

How important are the last 1000revs?

 

I imaging it won't be hard to get a motor to do 2000-6000 with small or medium porting, it will be harder to get the 6000-7000 working quickly and keep the bottom end, and most difficult to get that last 1000rpm.

 

I'm sure you'll need big ports up around 7500rpm, but more important will be the choice of cam.

 

Which end can you chop off easiest?? or how much can you lighten the crank & flywheel & clutch??

Hey mate we are not aloud to lighten or balance anything

[corolla_nut]

I take it you are racing? how do they manage to scrutineer flywheel weight or engine balancing???

 

Depending on what you are doing, find out what camshaft everybody else uses and go something a little bit less "wild" than that, especially if you are allowed limited mods, you might find it will go quicker when you race it....... everybody always goes for something too "wild" and loses drivability and midrange meaning slower times....

 

Its all trial and error though when you are building something like that :S

 

Robert.

[philbey]

Hmm, if you can't balance it, you're not going to be getting much out of your top end anyway, I'd look for more power in the midrange.

[altezzaclub]

Stock cars?? Round and round in second?

[skidsharpe]

Stock cars?? Round and round in second?

We are aloud to bore the blocks. Do minor head work, cam of your choice. every part we use must be from that make and model. We change diff and gearbox ratios to try and alter the rev range as well as different cams. Some of the datsun boys who race sunnys are reving up to 8200-8800. Most corollas are reving between 7500 and 8000.

Edited January 8, 2010 by skidsharpe