How good are 'typical' cylinder heads from the factory?
Discussion
What do the experts think about this?
http://mototuneusa.com/homework.htm
http://mototuneusa.com/the_2007_superbike.htm
http://mototuneusa.com/homework.htm
http://mototuneusa.com/the_2007_superbike.htm
Hiya
I have used various fillers and hard weld for 27 years. Weld is difficult to get where you want it and fillers do not last forever, very harsh environment! We have only used the technique for race engines. Good effect if needed but very time comsuming and probably too costly for commercially modded road heads. Our current favourite filler is Quiksteel Xtreme which we also use to smooth over where we have welded faults/cracks in heads/ports. Usually it is best to improve what the manufacturer set out to do. fettle the poor coring/casting faults and pay attention to the valve throats, valves and seats. Quite often castings are built up in the throats to give a better percentage chance fit for the valve seat inserts. Don't expect massive gains on most 4 valve per cylinder heads. Big bulk airflow already so often just get icing on cake.
Peter
I have used various fillers and hard weld for 27 years. Weld is difficult to get where you want it and fillers do not last forever, very harsh environment! We have only used the technique for race engines. Good effect if needed but very time comsuming and probably too costly for commercially modded road heads. Our current favourite filler is Quiksteel Xtreme which we also use to smooth over where we have welded faults/cracks in heads/ports. Usually it is best to improve what the manufacturer set out to do. fettle the poor coring/casting faults and pay attention to the valve throats, valves and seats. Quite often castings are built up in the throats to give a better percentage chance fit for the valve seat inserts. Don't expect massive gains on most 4 valve per cylinder heads. Big bulk airflow already so often just get icing on cake.
Peter
delcbr said:
What do the experts think about this?
http://mototuneusa.com/homework.htm
http://mototuneusa.com/the_2007_superbike.htm
Ive used this method for 10 years on bike engines , mostly on 450 4 valve singles and all i can say is yes it works. Its a bit strange not putting any oil on the ring pack or the cylinder walls and even worse when you get the newly built motor warm then spank it thourgh the gears up and down for 30 mins.http://mototuneusa.com/homework.htm
http://mototuneusa.com/the_2007_superbike.htm
The last one i did i had the piston skirt coated so then this should help with skirt wear as the JE pistons on my bike only would last 6-8k this inc off road and road miles before oil was being used.
Pumaracing said:
stevesingo said:
Dave,
I'm guessing that if I have to add say 2% fuel to maintain the previous Lambda, I will have gained 2% power at that point?
One would certainly suspect so.I'm guessing that if I have to add say 2% fuel to maintain the previous Lambda, I will have gained 2% power at that point?
3000= +3.8%
3500= +5.7%
4000= +1.8%
4500= +4.5%
5000= +7.3%
5500= +2.3%
6000= +2.5%
6500= +1.9%
7000= +1.8%
7500= -3.5%
The intake temps were close enough, although I have no idea on the atmospheric pressure, so not exactly scientific, but it seems to be an improvement.
I'll have to book a dyno run to confirm.
What do you think Dave?
Steve
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