got another 117 build going together my local machine shop usually does my headwork last build used 2.00 intake valves .had good luck with last set done he sugested using 2.020 this time around since im going from a 55mm tb to 58mm tb trying to get hp up a tad in the higher rpms any downside ? or just stay with 2.00 . Running 9b cams 5.3 inj comp 11.0
CVO heads and assuming a build off of a 110?
As I recall, CVO 110 heads have 2.080" intakes out of the gate. The 110+ and MVA heads use 2.120" intakes. So I don't see why 2.020" would be any issue as long as the seat used supports it.
Depending on exhaust size I never found the return worth it since so many other things become a factor, shrouding, valve to valve, etc. 2.0" can flow over 300 with a well done port/seat.
if using 110 heads,you really should be using 2.100,the throat ratio is bad enough with the oem 2.080,no clue why anyone would use a 2.0 or 2.02.if installing seats on regular 88 or 96 heads,2.0 or 2.02 would work great as long as the rest of the port is done right
bike started 103 heads weel see what happens his work has always been super results first time he suggested this ill keep ya posted he does them by hand no cnc machine takes forever but I got all winter .
Used 2.02 intakes a while back ,watch the valve to valve clearance :scratch:
It will take a small exhaust unless they are sunk deep.
Quote from: RTMike on February 19, 2020, 08:12:03 AM
Used 2.02 intakes a while back ,watch the valve to valve clearance :scratch:
i agree.with regular heads,valves that big dont allow for much valve to valve clearance unless sunk so far the get shrouded & protrusions are way over spec
Protrusion gets adjusted according to the valve lift with my heads. Chamber gets fixed, valves not shrouded
2.020 intake & 1.630 exhaust in an 883 head ... yeah, it can be done ...
(http://www.hammerperf.com/images/120+rearhead.jpg)
The cams have TDC's of .259/.250 after the 1.725 stilts, which is getting up there. Getting enough v-v to support those TDC's at these valve sizes requires not only sinking the valves hugely, but also altering the angles, moving the valve heads farther apart. This is enabled by the 3.600 bore that goes with this work, but of course, on a Twinkie you've already got more than that. The chambers ended up north of 80cc, which is quite a jump from the stock 49cc, but still smaller than a stock Twinkie. Paired with a 30 degree .500 dome piston to get the CR where we wanted it. 210psi ccp was the final result, along with 132hp at 8000rpm, on 77.6ci.
So it can be done. It's just a matter of doing what it takes. But as you can imagine, it ain't cheap to do all this work.
:up: :up:
Nice job
That's getting it done :koolaid:
Quote from: aswracing on February 21, 2020, 09:03:04 AM
2.020 intake & 1.630 exhaust in an 883 head ... yeah, it can be done ...
(http://www.hammerperf.com/images/120+rearhead.jpg)
The cams have TDC's of .259/.250 after the 1.725 stilts, which is getting up there. Getting enough v-v to support those TDC's at these valve sizes requires not only sinking the valves hugely, but also altering the angles, moving the valve heads farther apart. This is enabled by the 3.600 bore that goes with this work, but of course, on a Twinkie you've already got more than that. The chambers ended up north of 80cc, which is quite a jump from the stock 49cc, but still smaller than a stock Twinkie. Paired with a 30 degree .500 dome piston to get the CR where we wanted it. 210psi ccp was the final result, along with 132hp at 8000rpm, on 77.6ci.
So it can be done. It's just a matter of doing what it takes. But as you can imagine, it ain't cheap to do all this work.
sure,anything can be done (beleave me in the early days of racing,we used OEM parts for gas & fuel bikes) but is it cost preventative or just way easier (with a better outcome) to use 110 or aftermarket heads when going that big on valves.i see those are 883 castings,how much would these cost a customer?
1.7hp / cubic in. Pump gas street bike I assume.
Quote from: prodrag1320 on February 22, 2020, 04:45:36 AM
Quote from: aswracing on February 21, 2020, 09:03:04 AM
2.020 intake & 1.630 exhaust in an 883 head ... yeah, it can be done ...
(http://www.hammerperf.com/images/120+rearhead.jpg)
The cams have TDC's of .259/.250 after the 1.725 stilts, which is getting up there. Getting enough v-v to support those TDC's at these valve sizes requires not only sinking the valves hugely, but also altering the angles, moving the valve heads farther apart. This is enabled by the 3.600 bore that goes with this work, but of course, on a Twinkie you've already got more than that. The chambers ended up north of 80cc, which is quite a jump from the stock 49cc, but still smaller than a stock Twinkie. Paired with a 30 degree .500 dome piston to get the CR where we wanted it. 210psi ccp was the final result, along with 132hp at 8000rpm, on 77.6ci.
So it can be done. It's just a matter of doing what it takes. But as you can imagine, it ain't cheap to do all this work.
sure,anything can be done (beleave me in the early days of racing,we used OEM parts for gas & fuel bikes) but is it cost preventative or just way easier (with a better outcome) to use 110 or aftermarket heads when going that big on valves.i see those are 883 castings,how much would these cost a customer?
Bingo- :up:
I've gone stock, to over 5 grand for heads (worth every penny for the application), so yeah, sure....anything can be done$$$
Wanna see a 2.3 I valve on a TC head? I'm running it on my street bike.
For sure, a set of 110 heads, bang for buck is a no brainer.
Posting a highly worked 4 cam head is apples to orange$....
Now, back to reality-
2.160 intake
Quote from: HD Street Performance on February 22, 2020, 07:48:23 AM
1.7hp / cubic in. Pump gas street bike I assume.
I guess it depends on what you want but a good set of heads in my option is what is needed to build a motor that will really stand out and perform .
Quote from: prodrag1320 on February 22, 2020, 04:45:36 AM
sure,anything can be done (beleave me in the early days of racing,we used OEM parts for gas & fuel bikes) but is it cost preventative or just way easier (with a better outcome) to use 110 or aftermarket heads when going that big on valves.i see those are 883 castings,how much would these cost a customer?
Absolutely! When someone comes to us asking for this level of work in a Twin Cam, we point out how it can be done cheaper by starting with 110 castings. The valve angles are already altered for you.
But in the XL world, there's no off-the-shelf casting like that. Since STD closed up years ago, we're stuck with 27 & 31 degrees. So we've got to massively rework the factory head. We also weld up the intake port floor and redo it. We like the 883 casting because it gives us enough material to do the long side correctly without welding it up, but we still have to redo the short side. The whole job runs about $1550 with the hardware, including a conical spring pack. It's part of what we call our "120+ hp package" which is around $5K. You'd be surprised how many of'em go out the door, despite the price tag. Helps Dan make the payment on that 5-axis machine ;)
90% plus are pump gas street applications.
All of that said there are not many street riden twin cams, NA, even with 2.1" plus intake valves that make 1.7hp/in. Heck even the Hurricanes have a 2.175 intake and a generous oval port and they don't set the world on fire. They do make a flow bench very happy though at least on one side.
Good job to aswracing. :up:
Quote from: aswracing on February 23, 2020, 06:46:53 AM
Quote from: prodrag1320 on February 22, 2020, 04:45:36 AM
sure,anything can be done (beleave me in the early days of racing,we used OEM parts for gas & fuel bikes) but is it cost preventative or just way easier (with a better outcome) to use 110 or aftermarket heads when going that big on valves.i see those are 883 castings,how much would these cost a customer?
Absolutely! When someone comes to us asking for this level of work in a Twin Cam, we point out how it can be done cheaper by starting with 110 castings. The valve angles are already altered for you.
But in the XL world, there's no off-the-shelf casting like that. Since STD closed up years ago, we're stuck with 27 & 31 degrees. So we've got to massively rework the factory head. We also weld up the intake port floor and redo it. We like the 883 casting because it gives us enough material to do the long side correctly without welding it up, but we still have to redo the short side. The whole job runs about $1550 with the hardware, including a conical spring pack. It's part of what we call our "120+ hp package" which is around $5K. You'd be surprised how many of'em go out the door, despite the price tag. Helps Dan make the payment on that 5-axis machine ;)
90% plus are pump gas street applications.
Damn that must be a hell of a ride lol I do like a motor to run an not lay over . Reminds me of my old 302 chev I had that I use to buzz up to 7800 . The rush must be really nice on the bike lol
install 1.980 intake and 1.610 exhaust offset valve seat 1mm these heads will rock and roll