Phathead racing head?

[1999 Kx 250]

I'm thinking about getting a phathead racing head but I want to make sure it's worth the money before I get it. Anyone have any experience with the product or know if it's worth it

[William1]

Why do you want it?

[turbo dan]

Its cheaper and probably more effective to measure and correct the squish on your stock head.  They do run better with the squish set correctly.  Its worth doing one way or another.

[1999 Kx 250]

Its cheaper and probably more effective to measure and correct the squish on your stock head. They do run better with the squish set correctly. Its worth doing one way or another.

ive never heard of squish in the head what is that and how do i know if it needs corrected

Why do you want it?

because it gives you more top end power why else would I want it

[William1]

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

because it gives you more top end power why else would I want it

If it gives you more top end power and that is what you want, what is the question?

[turbo dan]

ive never heard of squish in the head what is that and how do i know if it needs corrected

because it gives you more top end power why else would I want it

 

Squish clearance is the gap between the top of the piston and the face of the cylinder head.  It is usually at least a little off from the factory.  They leave a little extra room in there to allow for wear and different combinations of tolerances.  Too large a squish band results in reduced power across the entire range and less resistance to detonation.

 

The reason I say you might be better off with the stock head is that they can only guess what kind of squish clearance your motor will have.  The only way to optimize it is to measure it and adjust it.  An aftermarket head may have a different squish area, as in a wider or narrower squish band, but this won't have as great of an effect on overall power output.  If your squish clearance is too great the squish area won't have much effect at all.

 

How much is a Phathead?  I suspect it would be cheaper to have your existing head corrected.

[1999 Kx 250]

Squish clearance is the gap between the top of the piston and the face of the cylinder head. It is usually at least a little off from the factory. They leave a little extra room in there to allow for wear and different combinations of tolerances. Too large a squish band results in reduced power across the entire range and less resistance to detonation.

The reason I say you might be better off with the stock head is that they can only guess what kind of squish clearance your motor will have. The only way to optimize it is to measure it and adjust it. An aftermarket head may have a different squish area, as in a wider or narrower squish band, but this won't have as great of an effect on overall power output. If your squish clearance is too great the squish area won't have much effect at all.

How much is a Phathead? I suspect it would be cheaper to have your existing head corrected.

its $250

[1999 Kx 250]

If it gives you more top end power and that is what you want, what is the question?

to make sure the product is worth the money and is a good product. Do you not know how this site works

[William1]

to make sure the product is worth the money and is a good product. Do you not know how this site works

I think I might have an idea how the site works.

 

My comments obviously were misunderstood by you. Sorry.

Many people buy products not because they actually need the item but because they bought into the marketing. Many are purchased because the are fancy, easy to install and are 'blingy'. All while not actually improving things for the rider.

Items like the 'phathead' have been bought by hundreds, if not thousands of TTers. Many have written about them over the years. For some, it was an improvement, for others, it made things worse. turbo dan was basically saying the same thing. One of the biggest mistakes people do is throw parts on a machine assuming that part alone will perform miracles. Unless you put the items together that match and are designed to 'play well with each other' you get the phrase 'slowed down for racing' where a person just bought parts, put them on and assumed the bike would be faster.

 

Use the search function on TT regarding this product.

Hit Google, look for articles by Kevin Cameron regarding head design on a 2S. Become educated.

[turbo dan]

Sweet Jesus.  Would cost less than half that to get your stock head done up however you want.

 

If I were you I would start with a compression test.  See where its at currently.  If its 175 or less you could use a little more.  180-190 is good for pump gas.  Over 190 and you may have trouble with detonation.  This is assuming your engine is fresh and in good condition.  If the top end is worn you won't get good results and you should freshen it up before looking into head mods.

 

So if your compression is 180-190 and the squish clearance is too large they will have to enlarge the dome to keep your compression in the acceptable range.  If your compression is on the low end they can probably just correct the squish and leave the dome alone.  Option number three is to adjust the squish band area to change what RPM the head works best at.  I wouldn't recommend that option.  The stock head uses a pretty neutral squish width that works well enough everywhere.  Whichever way you go though it won't cost anywhere near $250.

[1999 Kx 250]

I think I might have an idea how the site works.

My comments obviously were misunderstood by you. Sorry.

Many people buy products not because they actually need the item but because they bought into the marketing. Many are purchased because the are fancy, easy to install and are 'blingy'. All while not actually improving things for the rider.

Items like the 'phathead' have been bought by hundreds, if not thousands of TTers. Many have written about them over the years. For some, it was an improvement, for others, it made things worse. turbo dan was basically saying the same thing. One of the biggest mistakes people do is throw parts on a machine assuming that part alone will perform miracles. Unless you put the items together that match and are designed to 'play well with each other' you get the phrase 'slowed down for racing' where a person just bought parts, put them on and assumed the bike would be faster.

Use the search function on TT regarding this product.

Hit Google, look for articles by Kevin Cameron regarding head design on a 2S. Become educated.

i want this product because trying to keep up with one of my dads racing friend is hard on my bike I'm good at riding flowing trails but when we stop and I shut the bike off it'll sit there and smoke for lie 5 min out the exhaust it's being pushed so hard so if I put more power into it won't struggle at least that's what I think

[turbo dan]

I think I might have an idea how the site works.

 

My comments obviously were misunderstood by you. Sorry.

Many people buy products not because they actually need the item but because they bought into the marketing. Many are purchased because the are fancy, easy to install and are 'blingy'. All while not actually improving things for the rider.

Items like the 'phathead' have been bought by hundreds, if not thousands of TTers. Many have written about them over the years. For some, it was an improvement, for others, it made things worse. turbo dan was basically saying the same thing. One of the biggest mistakes people do is throw parts on a machine assuming that part alone will perform miracles. Unless you put the items together that match and are designed to 'play well with each other' you get the phrase 'slowed down for racing' where a person just bought parts, put them on and assumed the bike would be faster.

 

Use the search function on TT regarding this product.

Hit Google, look for articles by Kevin Cameron regarding head design on a 2S. Become educated.

 

That's pretty much spot on.  Before spending $250 one should understand what they hope to gain from it.  These motors don't really need higher compression.  Stock is pretty high as it is.  Squish may need adjustment but you can't expect to bolt on an aftermarket head and have a better combination of parts than it came with from the factory.

 

I would save my money and fix the stocker.  Mine just needed the head decked.  This increased the compression but not above what is acceptable for pump gas.  I was able to do this myself at no cost other than labor.  The result I achieved was at least equal to if not better than what i would have if I had spend $250 on a Phathead. 

[1999 Kx 250]

Sweet Jesus. Would cost less than half that to get your stock head done up however you want.

If I were you I would start with a compression test. See where its at currently. If its 175 or less you could use a little more. 180-190 is good for pump gas. Over 190 and you may have trouble with detonation. This is assuming your engine is fresh and in good condition. If the top end is worn you won't get good results and you should freshen it up before looking into head mods.

So if your compression is 180-190 and the squish clearance is too large they will have to enlarge the dome to keep your compression in the acceptable range. If your compression is on the low end they can probably just correct the squish and leave the dome alone. Option number three is to adjust the squish band area to change what RPM the head works best at. I wouldn't recommend that option. The stock head uses a pretty neutral squish width that works well enough everywhere. Whichever way you go though it won't cost anywhere near $250.

oh oh that sounds better than $250 but how do I go about measuring my squish ho do you know it its to large or to small

[turbo dan]

i want this product because trying to keep up with one of my dads racing friend is hard on my bike I'm good at riding flowing trails but when we stop and I shut the bike off it'll sit there and smoke for lie 5 min out the exhaust it's being pushed so hard so if I put more power into it won't struggle at least that's what I think

 

Your exhaust is smoking because the silencer packing is saturated with oil from riding too slow.  It should be getting that hot on a regular basis. 

 

Don't worry about hurting the bike riding it hard.  It is made to be ridden hard.  Work on riding the bike better so you don't have to flog it as much to keep up with your buddy.

[turbo dan]

oh oh that sounds better than $250 but how do I go about measuring my squish ho do you know it its to large or to small

 

The conventional method is to insert a piece of soft lead solder in through the spark plug bent at an angle to reach into the squish area.  Then you turn the motor over which crushes the solder to the thickness of the squish.

 

You can also pull the head off and measure the deck height, head gasket thickness and depth of the squish band in the head.  Then you add up the measurements and you have a pretty close figure.  In the case of my motor which is also a 99 the squish was about .020" too large.  Correcting this provided a definite boost in power.

[shrubitup]

Correct squish band and how to measure write up here

http://www.rb-designs.com/rb_designs_llc_005.htm

Typically a bike that smokes that long after shut off is running hot from being too lean with its jetting.

[1999 Kx 250]

Correct squish band and how to measure write up here

http://www.rb-designs.com/rb_designs_llc_005.htm

Typically a bike that smokes that long after shut off is running hot from being too lean with its jetting.

i don't think it was literally that long it was probably for only a minute and plus I've already put the correct jets in it