Its been suggested to me by the machinest I'm considering to do my portwork to install larger valves - basically the RWR stage 3 headwork.
Who has this work done to their bike, how big is the gain over a quality port job with factory valves?
My bore is stock, going to be installing 11.2:1 pami piston, pami sport cams, 45mm flat slide. I want, need, and currently have plenty of bottom and midrange, and although more top end hp is hoped for and desired I cannot afford to lose much down low. This is why I got the sport cams. The last thing I want is for the valves to be opened up so much that I lose too much bottom.
Any recommendations? How far is too far?

 

I have 40mm intake and 34mm exhaust but have yet to start it. But I've got to tell ya there HUGE! There so big that when I look in the intake I can see the piston and both spark plugs

 

[img]i/expressions/face-icon-small-confused.gif[/img]HUH???? Am I lost?

 

you're in a DS forum. we run two plugs over here - all of us. each one has its own coil too. makes for a really clean burning motor.

 

Thats why we are faster.. 2 spark plugs [img]i/expressions/face-icon-small-smile.gif[/img]

 

HE he he, Good one!!


Hightower, from what I have seen Over-sized valves are Over-kill for a stock bore motor, but it is most likely nessassary for a bigger bore configuration. However I don't thinik it would hurt any, but if you don't plan ever going big-bore ,I would save the money. However, if that little devil on your shoulder tells you GO BIGGER BIGGER BIGGER!!! than you might aswell do it now since you have it at the machine shop.[img]i/expressions/face-icon-small-happy.gif[/img]


I am glad to see that more Bombs are getting FASTER!.........poor rappys. lol.






Biggerisbetter.

 

We are going to have add a 3rd spark plug soon!!

 

NO!!! too much wieght!!LOL.

 

i had the stage III kit befor my 760. i went from a stage I up to the stage III ( A1 cams race head) did loose some bottom end[img]i/expressions/face-icon-small-sad.gif[/img] but i did pick up great mid to top end (gear down) noticed that i needed more rpm to maintain trail riding speeds, but when it got up to 6000 rpm it really came alive instead off dropping off[img]i/expressions/face-icon-small-happy.gif[/img] so best of both worlds came together when i went to the 760 (still running rwr head A1 cams) now good pull all the way up. would like to ride a ds with cams and piston only to see iff head work helps that much with stock bore? NOTE: check with you'r cam supplier about welding gear direct to cam, i broke 2 cams because the gear loosened up and broke off cam collar[img]i/expressions/face-icon-small-disgusted.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-mad.gif[/img][img]i/expressions/face-icon-small-shocked.gif[/img][img]i/expressions/face-icon-small-mad.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]

 

My buddy was looking at the valves and spoke with Ron Wood. They say the gains with the head are HUGE!

I did everything at once (Piston, head, cams, carb) so can't tell you the gain of just the head.

I think my power curve is a sharper inverted "V" than before but the power in the low and mid is a little higher than before where the peak HP is MUCH HIGHER than it was before. So, when I am in the low RPM's it feels like I am low on HP but, I think I just have gotten used to the peak HP punch I have now and when I don't have that HP it feels weak.

I have done some jetting changes and just completed one other mod so, I'll report back after this next weekend (weather permitting)!!!

One other thought, don't change the cams at all. The stock cams are pretty good, I wonder if the Sport Cams will really get you much.