Tuning Terminology

Ok, I hear a lot of terms with regards to engine tuning but i'm not exactly sure what the process involved or the benefits. Obviously the main benefit is more HP, but i'm more interested in why - Could someone enlighten me! Not that i'm looking to do any of this stuff - I'm just curious

Ported Heads?
Gas Flowed Heads?
Timed Cams?

Can't think of anymore off the top of my head, but I'li add them if I do

Thanks
Luke

[rictus01]

Originally Posted by lukemillar

Ok, I hear a lot of terms with regards to engine tuning but i'm not exactly sure what the process involved or the benefits. Obviously the main benefit is more HP, but i'm more interested in why - Could someone enlighten me! Not that i'm looking to do any of this stuff - I'm just curious

Ported Heads?
Gas Flowed Heads?
Timed Cams?

Can't think of anymore off the top of my head, but I'li add them if I do

Thanks
Luke

Morning Luke (or whatever time it is there).

Ported heads = behind both the exhaust and inlet valves are tracks and a small area to either mix (as in swirl around) on the inlet or allow free exhaust flow/ back pressure on the exhaust side, porting is when these have been altered in some way, be it reprofiled to maximise fuel/air delivery or smoothed to reduce turbulance (can also be used to reduce valve heat buildup).

Gas flowed = this is where the head has the full gas track both into and out of the combustion chamber tested to show any problem areas and then those are sorted out ( both porting & gas flowing are often done together)


Timed Cams = these are Custom designed once again to optimize both the lift and duration of the valve, but also have a degree of adjustment on the cam sprocket as well for fine tuning.

HTH.

Cheers Mark.

Extra torque is generally more useful than extra BHP.

Generally if you can get more waste gasses out, you can put more fresh air and fuel in, allowing for better combustion.

Heads and Cam work both often require you to make a compromise. You might be able to make mild improvements to either, by improving the standard design or by removing casting glitches in the head.

But to make a big improvement you generally have to sacrifice low end power for top end power, this makes the car / bike less drivable but obviously faster if you spend your life at the top of the rev range.

Wild cams are going to give a lumpy bottom end, and if you open the head ports too much then you're going to reduce the air speed which will reduce torque and low end power.

Manufacturers design engines with a load of parimeters in mind, economy, cost of manufactuer, target power output, target power / torque curves, smoothness and emissions.

So any changes are going to alter the above.

Google it, you'll find everything you want to know, and a bloody lot more.

You forgot 'Skimming' ... this is the single greatest power improver ...

Originally Posted by Blue_SV650S

You forgot 'Skimming' ... this is the single greatest power improver ...

Is that when the head is machined or material skimmed off to increase cylinder compression?

Originally Posted by lukemillar

Is that when the head is machined or material skimmed off to increase cylinder compression?

Yes, its where you shave a bit off the head (i.e. the surface where it mates with the head gasket gets a slither taken off it). Increasing compression

Rule of thumb is the higher the compression, the more power!! (but you need to take measures not to cause pre-ignition).

[rictus01]

Originally Posted by lukemillar

Is that when the head is machined or material skimmed off to increase cylinder compression?

indeed it is although in the first instant much of this can be achieved by thinning or removing the base gasket, bike dependent of course.

Cheers Mark.

nah lower the compression and add a turbo

Originally Posted by Miles

Extra torque is generally more useful than extra BHP.

Only one thing Torque is directly related to BHP, to get more torque you must get more power...

Power (BHP) = Torque x revs (ft-lb) / 5252.

e.g. my bike 70ft-lb x 7000 / 5252 = 93.29BHP @ 7000RPM...

Originally Posted by Miles

Generally if you can get more waste gasses out, you can put more fresh air and fuel in, allowing for better combustion.

Heads and Cam work both often require you to make a compromise. You might be able to make mild improvements to either, by improving the standard design or by removing casting glitches in the head.

But to make a big improvement you generally have to sacrifice low end power for top end power, this makes the car / bike less drivable but obviously faster if you spend your life at the top of the rev range.

Wild cams are going to give a lumpy bottom end, and if you open the head ports too much then you're going to reduce the air speed which will reduce torque and low end power.

Manufacturers design engines with a load of parimeters in mind, economy, cost of manufactuer, target power output, target power / torque curves, smoothness and emissions.

So any changes are going to alter the above.

Google it, you'll find everything you want to know, and a bloody lot more.

All this is right.

TL1000 vs SV 1000 is a good example the SV creates more power/Torque till about 8000RPM then the TL with its bigger 40mm intake valves and other bits (SV has 36mm) takes over to create more peak power. Which makes the better road engine... Ill guess the SV since you spend more time at <8K RPM on the road.

Originally Posted by Razor

nah lower the compression and add a turbo

Difficult on a twin... youd have to have both Exhausts together and to do that you have to go a long way which means MASSIVE turbo lag. Super charger it...

http://www.youtube.com/watch?v=k-Etbtej7z8

Onboard at end...