Head Mod... Few Q's

[Quadrider10]

ok so im facing a new top end rebuld, and so i figured i would do a few of my mods that i want to do while i wait for the new parts in the mail and such. im doing a +4 timing mod, and head mod.

for the head mod, what i wanted to do was lay some sand paper down on a perfectly flat surface (ima tape some paper on my kitchen counter) and i was gonna shave the head down a little to raise compression. im not going crazy with this, i just want it to have a little more compression. so now my question is, how should i go about doing this? what sand papers should i use, and should i wet sand it or what?

or should i put the head in a vise or something, and tape sand paper on a flat peice of wood, and do it that way?

 

[89blaster89]

i might be interested in doing this also, what are the pros and cons of doing this mod?

 

[Quadrider10]

i might be interested in doing this also, what are the pros and cons of doing this mod?

pros = is higher compression more power and HP
cons= if u do it too much, u need to run race gas with higher octane im pretty sure at least

 

[Xero]

Well, aslong as its smooth all the way round and even, i dont think it really matters, mine survived SAND BLASTING! and came out with 165psi the other end! I:I

 

[Triplecrown421]

you have the right idea use a flat surface and lay paper on that you can wet sand it if u like and just make sure you have that head perfectly flat to that paper.

imo shaving a stock head is probably just gonna make detonation and ruin your new top end, a +4 timing adv with that shaved stock head is gonna make EVEN MORE detonation and really F@ck shoot up.

my advice a REchambered head is the only way to goo.

some guys will disagree with this but i know what spark knock sounds like and maybe they dont. with a good chambered head it will improve the burn eliminating chances of knock

 

[Quadrider10]

Well, aslong as its smooth all the way round and even, i dont think it really matters, mine survived SAND BLASTING! and came out with 165psi the other end! I:I

damn! nice! !

 

[Quadrider10]

you have the right idea use a flat surface and lay paper on that you can wet sand it if u like and just make sure you have that head perfectly flat to that paper.

imo shaving a stock head is probably just gonna make detonation and ruin your new top end, a +4 timing adv with that shaved stock head is gonna make EVEN MORE detonation and really F@ck shoot up.

my advice a REchambered head is the only way to goo.

some guys will disagree with this but i know what spark knock sounds like and maybe they dont. with a good chambered head it will improve the burn eliminating chances of knock

what do u mean +4 and shaved will make detonation? and im planning on shaving it a little. not going crazy with it.

 

[89blaster89]

what do u mean +4 and shaved will make detonation? and im planning on shaving it a little. not going crazy with it.

i could see the +4 being a problem but i think if your only doing the shaved head a little i think it would be fine, but i dont know if it would even be worth it to only do a little...

 

[Quadrider10]

let me take a pic.......

 

[Quadrider10]

ok so i want to shave it to the point where i can still use pump gas. higher octane is ok with me, but i dont want to be running race gas. so im only gonna shave it a little. where that lip is from the dome to the top of the gasket mating surface is probs the most farthest im gonna go. and if i do that, would thta be better then a +4 or would +4 be better? or can i do both?

 

[89blaster89]

i would think you can do both your going to be getting detonation, but idk

 

[Quadrider10]

someone explain quickly what detonation is. im getting confused lol

 

[Triplecrown421]

i had tryed it i shaved like .30" off the stock head and it did help the torque and seemed better but under load and at WOT i could head a pinning or ticking sound. you could feel it aswell everytime it knocked the bike would shot down power.... not good.
i didnt want that so we sent the head to the machine shop and got it shaped.

 

[Quadrider10]

i had tryed it i shaved like .30" off the stock head and it did help the torque and seemed better but under load and at WOT i could head a pinning or ticking sound. you could feel it aswell everytime it knocked the bike would shot down power.... not good.
i didnt want that so we sent the head to the machine shop and got it shaped.

i was planning a little less. ima ask ken when he calls me back if i should do it.

 

[Triplecrown421]

detination from what i know is the fuel in the combustin chamber is "lighting" prematurely and forcing agenst the piston. it can come from different problems but in the blastys case its from a poorly designed head. This is why surpreme fuel and race fuel are needed to add octain and eliminate detinaton for motor compression or performance motors

just from what ive picked up someone else should chime in

 

[Quadrider10]

detination from what i know is the fuel in the combustin chamber is "lighting" prematurely and forcing agenst the piston. it can come from different problems but in the blastys case its from a poorly designed head. This is why surpreme fuel and race fuel are needed to add octain and eliminate detinaton for motor compression or performance motors

just from what ive picked up someone else should chime in

how would a higher octate help that? if it were that, a timing retard would be needed. higher octane i thought is needed because of higher compression, the gas cant cumbust as eaisly cause of how much it is compressed. so a higher octane fuel is more exploseive, so it inginates eaiser. idk if thats rite, but that wht i think it is.....

 

[slickerthanyou]

If you don't send it out and have it done right, As I really don't think that the method you are going to use will do hardly anything.
My head is rechambered and shaved flat, Is awesome, however i'm not running any advanced timing.

I understand your wanting to try a few things yourself, and that is awesome! I Just believe this is a Builders Job, whoever you choose! Now if I had a lathe, I'd try it! I'm not trusting just a machine shop, someone that works on these is your best bet!

Wanna cut a head, go to Ken's open house next year!

 

[Quadrider10]

If you don't send it out and have it done right, As I really don't think that the method you are going to use will do hardly anything.
My head is rechambered and shaved flat, Is awesome, however i'm not running any advanced timing.

I understand your wanting to try a few things yourself, and that is awesome! I Just believe this is a Builders Job, whoever you choose! Now if I had a lathe, I'd try it! I'm not trusting just a machine shop, someone that works on these is your best bet!

Wanna cut a head, go to Ken's open house next year!

i get ya..... i have a lathe, but its not mine, andthere is no way in hell my brother would let me use it. maybe ill just leave the timing, and let ken rechamber it. idk if i will have enough money to do it tho. if it is rechambered, will i have to run race gas?

 

[Quadrider10]

alright it comes down to this.....

ken is 65$ which is a good price, but no way i can offord that rite now with new piston, and hone on its way. so should i shave it my self a little, or just have ken od it in the winter? im not planning doing it a lot like i said, i just want to raise compression a tiny bit? heres a quick question? new wesico piston, stock head, how much compression am i looking at taken out of all the varibles.

 

[Quadrider10]

cause if i shave it, i can do it now lol. and im bored and have nothing to do