Forum Replies Created
-
Bundyroy wrote:
Quote:I’m pretty sure I understand what you’re trying to do but have a couple of questions.1) By shave the head I assume you mean machining down the flat mating surface on the head so that the compression goes up due to reduced volume at the top of the stroke. Correct
2) By shaping I assume you mean that the domed part inside the head is machined away (as well as mating surfaces) to a better shape to allow for better fuel burn.Correct
3) None of this will effect the distance that the spark plug screws into the head, so is the distance between the end of the spark plug and the piston the limiting factor or is there changes that can be made here too. Yes may have to pack the the spark plug out a couple of mm
4) How much extra compression can the materials etc handle before life expectancy is reduced in exchange for performance gain.Because I am putting in two extra base gaskets to get the top of piston aligned with the bottom of exhaust port at BDC the compression will not be much different to what I already have. Approx 175PSI give or take a few PSI.
5) I have a 2T but I’m guessing this can increase performance on 4T as well.
Most certainly but 4T usually have fairly high compression ratio to begin with ie 12.5 – 13.5 to one. Their performance gains can be done in many different ways like cams valves timing dome shape etc
Hope this helps
Diddel wrote:
Quote:Ollie wrote:Quote:Thanks Diddel how much coin did it cost for the head work?Ollie
$130.
I noticed a nice difference in power.Happy with that,
I will also give greg ball a call
Ollie
jack maybe photies to follow
Sorry Jak, :laugh:
when the piston comes up to TDC the area between the piston dome and the head is called the Squish band. By reducing the band down to approx 1mm this will have the effect of raising the Compression ratio.
To check this squish band we need to get some lead solder wire and place it on the dome of the piston.The head is replaced and the engine is slowly turned over using the kick starter. The piston will compress the solder and this is then measured using a vernier. The engineering shop can then use this to determine how much material is removed from the head.
Hope this helps :unsure:
Ollie
yep thanks Bruce,head needs to be shaved and reshaped. I could do the shaving at work,but would be a lot more comfortable if the pro’s did it. I will look up NP on the other forum
cheers Ollie
crash wrote:
Quote:A few weeks ago someone wrote something about Greg Ball closing down. I was speaking with Batman from Battyes Bikes today, and he said that it’s not true. He is expanding into the Unit next door and therefore is not doing as much work at the moment. Also, his other son is joining the business, so I guess that means he’ll be pumping out top class work for years to come!!Crash
Cool, that was me Crash,Madmac wanted to get a sump plug hole repaired but was told he was shutting shop. I want to get my gassers head machined so he probably would be the perfect choice to give it to. Lets hope he is indeed expanding as his work is excellent and price is good
Ollie
Trailboss wrote:
Quote:mal5.1 wrote:Quote:TB – Medogrockets flat was before he put goo in the tyres. It was part of his 10min work period on the start of day 2.:blush: Oh dear my bad :laugh:
TB
I was going to say it would of had to have been a pretty serious hole or tear for the goo to fail. I run fairly low pressures and havnt had flat yet. Not to say I never will but i do have a lot more confidence now
ollie
Moto wrote:
Quote:Ollie wrote:Quote:Trailboss wrote:Quote:Your 450 Moto?I heard the 300 is sold?
Ollie
It is. To me
Oh good :laugh:
