headwork aka port & polishing info

[BryGuy900]

I just want to see a pump gas dyno run..mr12 is nice but hard to compare gains as its a power adder its self

[bsinclair]

Originally Posted by kismetcapitan

I'm fairly certain BMW was running over 15,000rpm on their WSBK bikes. Have no idea if they were using different valve springs or cams, but I'd guess yes?

they have ported heads,larger cams,valvesprings,retainers,rods, over 14:1 compression pistons and a unobtainable ecu...nothing stock in those motors...

as far as brock having a happy dyno i guess the other dynojet 250's ive been on in different states is happy also as they read within a few hp of each other.

[russianvr4]

Originally Posted by bsinclair

thought i would give a update.. here is what the head flowed..
We gained 10%@ .05 valve lift which should be good for 5-7hp over stock ports..
7@.1
7@.15
7@.2
10@.25
10@.3
15@.35
19@.4

are those percentage gains or what?

[George Villar]

When you post flow-bench numbers for the ported heads, the normal (and I know this because I own a Superflow bench and have 20+ years experience), you record the baseline that the intake port flows at a certain degree cam lift, then record the the new (ported) intake runner results next to the baseline for comparison. When I used to port heads, I used to experiment with a few shapes and cast them in rubber. This meant that we would go through 2-3 sets of heads to test the different shapes - not the port size - the shape is what flows better as we all know. I'm curious to know why you choose to grind away the valve guide completely instead of knife-edging it so that if you opt for a larger set of cams at 14,000+ rpm - the valve stems would remain stable. Was there a reason?

Thanks

George Villar

[bsinclair]

Originally Posted by George Villar

When you post flow-bench numbers for the ported heads, the normal (and I know this because I own a Superflow bench and have 20+ years experience), you record the baseline that the intake port flows at a certain degree cam lift, then record the the new (ported) intake runner results next to the baseline for comparison. When I used to port heads, I used to experiment with a few shapes and cast them in rubber. This meant that we would go through 2-3 sets of heads to test the different shapes - not the port size - the shape is what flows better as we all know. I'm curious to know why you choose to grind away the valve guide completely instead of knife-edging it so that if you opt for a larger set of cams at 14,000+ rpm - the valve stems would remain stable. Was there a reason?

Thanks

George Villar

george, i dont question bill's work as he's been knocking out some of the fastest bikes in this area. head porting is something i've never tried or want to do. the heads that carpenter and kws did look the same so i guess knife edging is not nesasary ...i will ask his theories on why he does it though and report back. the pictures you see are of a unfinished head. i will post of some of the finished pics when its done..

[VanDahl]

Originally Posted by BryGuy900

Ya i had talked with bill at port tech before to see if had done any s1000rr heads..at the time he had not seen one.. Very nice guy to talk with..btw would you know what stock cam timing numbers are? Would you be willing to give out some suggested timing numbers? I know most people like to keep them secret but i would at least like to know what the stock timing numbers are

Found this site:Specifications: 2010 BMW S1000RR
Is this the best choice(set with the tool) or might there be a benefit in slight degree change?

[dagor6]

Originally Posted by George Villar

When you post flow-bench numbers for the ported heads, the normal (and I know this because I own a Superflow bench and have 20+ years experience), you record the baseline that the intake port flows at a certain degree cam lift, then record the the new (ported) intake runner results next to the baseline for comparison. When I used to port heads, I used to experiment with a few shapes and cast them in rubber. This meant that we would go through 2-3 sets of heads to test the different shapes - not the port size - the shape is what flows better as we all know. I'm curious to know why you choose to grind away the valve guide completely instead of knife-edging it so that if you opt for a larger set of cams at 14,000+ rpm - the valve stems would remain stable. Was there a reason?

Thanks

George Villar

George, in this day and age, you can open the port as far as you want to and then add epoxy in subsequent versions and test various configurations. You'll end up with a series of motors designed for different tracks.

The reality is that it's not about the most power but the best curve, and it's different for each track. Examples might be Miller and Daytona, wide open, Barber, restricted and shaped a bit.

Either way, it's the same initial head porting job.

Anyway, I'm not sure any of this matters in amateur hands these days, what's much more important is proper injector timing because the different fuel choices have such a big vaporization range. With most modern motorcycles way out of optimal injector timing on stock or kit ECU's, proper flow isn't going to help much.

Sort of the small end of a bigger problem I think.

[BryGuy900]

Ya i have seen that before..problem is the valve lift is measured at 3.0 mm which really it not a problem but there is not something not right with those numbers.

[George Villar]

Thank you, I would love to see what the final porting job photos look like. Also, if you could post the baseline and ported flow-bench numbers (they usually get printed out like a dyno sheet), that would be perfect.

George Villar

[bsinclair]

Originally Posted by George Villar

Thank you, I would love to see what the final porting job photos look like. Also, if you could post the baseline and ported flow-bench numbers (they usually get printed out like a dyno sheet), that would be perfect.

George Villar

i dont have a printout but here are the numbers...

lift stock ported
.05 26.95 36.26
.1 64.14 71.20
.15 99.50 106.50
.2 137.30 144.30
.25 170.15 180.10
.3 199.00 209.40
.35 220.00 235.00
.4 229.00 248.00

this was done on a superflow SF300 at 28" of depression