Best cam option TC88
HDF Community Team
Joined: Jun 2006
Posts: 12,776
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From: san antonio
No I'm not a big guy, I weigh about 185 most days. LOL. That still don't mean I don't like loads of pulling power, torque is what gets you moving. Ever watch an Indy car? Extremely high horsepower race vehicles that can do 250 mph, but fall flat on their face and stall in the pits. My bike is a Harley not a Ducati.
True the beehives can go much higher lift than 500, However, pushing a spring to it's limits gives it a very short life. Furthermore what good is a lift of 600 when the head can only flow 500? All that extra lift is a waste... Worse than that is having a cam that really needs 10.1 compression to do it's best, and you've only got 8.9 compression. You'll get better performance with a cam that's matched with all the other components. That's what bolt in cams or baby cams as they're often called attempt to do. They're designed and tested to work with what's stock internally.
I had been leaning towards the Andrew 21, but the 509 might be better? I really don't know? Which is why I was asking for other people's opinion.s . It's true Dyno sheets can be misleading but as I said they're a still a valid tool. The same exact bike tested on two different days will have different results. However several different bikes with similar set ups, worlds apart and varying dyno's can give you a ball park estimate.
Andrews 21 states it's good from 1700-4800 rpm
Andrews 26 says 1800-5200 rpm
Whereas the S&S 509 claims 0-4500
I know car cams way much better than motorcycle cams. So, I'm in uncharted waters on this matter. I do know a few that did the Andrews 26 & 37 cams, most were disappointed with the results. I know some who did the 510 cams and said those too were a disappointment claiming it was because those cams like much higher compression than stock.
Thanks for the input fellas, just trying figure out what would work best in my application. This has turned into a much more detailed research project than I suspected it would.
True the beehives can go much higher lift than 500, However, pushing a spring to it's limits gives it a very short life. Furthermore what good is a lift of 600 when the head can only flow 500? All that extra lift is a waste... Worse than that is having a cam that really needs 10.1 compression to do it's best, and you've only got 8.9 compression. You'll get better performance with a cam that's matched with all the other components. That's what bolt in cams or baby cams as they're often called attempt to do. They're designed and tested to work with what's stock internally.
I had been leaning towards the Andrew 21, but the 509 might be better? I really don't know? Which is why I was asking for other people's opinion.s . It's true Dyno sheets can be misleading but as I said they're a still a valid tool. The same exact bike tested on two different days will have different results. However several different bikes with similar set ups, worlds apart and varying dyno's can give you a ball park estimate.
Andrews 21 states it's good from 1700-4800 rpm
Andrews 26 says 1800-5200 rpm
Whereas the S&S 509 claims 0-4500
I know car cams way much better than motorcycle cams. So, I'm in uncharted waters on this matter. I do know a few that did the Andrews 26 & 37 cams, most were disappointed with the results. I know some who did the 510 cams and said those too were a disappointment claiming it was because those cams like much higher compression than stock.
Thanks for the input fellas, just trying figure out what would work best in my application. This has turned into a much more detailed research project than I suspected it would.
1. The beehive springs are designed to operate at higher lifts so service life is as long as any other HD spring. Furthermore, you need not push the limit of the spring with .600" lift cams but .550", .570" or .590" would not push the limits of the beehive springs. .590" might be pushing things but the point is made.
2. The extra lift is not wasted, depending on cam profile and exhaust, if while flow might flatten at .500" lift, the head is still flowing and the valve being held open longer can increase the cylinder charge; more cylinder fill means more power.
3. You are looking at static compression which is just a number; the motor never sees static and operates on dynamic compression which is a function of the cam profile, i.e., the timing of the intake close event. The earlier the intake close, the higher the corrected, or dynamic compression which means more torque. Say the Andrews 21 makes 8.5 corrected CR, the S&S 583 will make about 9.0 which is a nice boost but static doesn't change; it's just a number and means nothing when selecting a cam.
4. Car cams are the same as motorcycle cams. A TC88 is just 1/4 of a small block Chevy V8.
Having run .570" lift cams on '05 beehive springs in a pretty stout 95" build, with no issues, I still maintain that with "mouse" cams, you are not taking advantage of what the stock heads have to offer with higher lift springs and better breathing. Your ride, you decide. As an FYI, I have attached dyno results of back to back tests of a few of the cams you are considering; the only change was cams. If you want to stick with "mouse" cams, the results might give you some insight.
I have also attached a chart showing head flow of 2002, 2005 and 2006 OEM heads out of the box. As you can see, the flow of the '06 heads is much better than previous iterations and although flow flattens at .500" lift, it is still flowing the same at .560" lift.
Last edited by djl; Jun 20, 2019 at 01:23 PM.
HD EFI Guru
Joined: Jan 2008
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LOL, that's a good way to put it.
Dyno's are merely tools, and should be taken as such. The same exact bike will produce very different numbers on different days. The same is true when dynoing a car. However, dyno readouts can give you a nice ball park figure to gauge things. This is especially true when the dyno's have been performed by two or three different shops, worlds apart. This helps to eliminate several of the mitigating factors that would fudge the numbers. When HP & TQ numbers are within a number or two of each other through out the run, one can be fairly confident you'll have a similar experience with the combo being tested.
I still haven't managed to figure out what cam I should select? I'm not wanting to do a BB kit on the bike . Many of the bigger cams require more compression than what my bike has. A big lift cam needing 10.0 compression won't be much of an improvement, as a lower lift cam that works best with 8.9 compression. And I'm not interested in big HP numbers at 6000 RPM as I'm never revving my engine that high. I don't think I've ever hit the rev limiter which is set at 5800 from the factory, but maybe once or twice in the 13 years I've owned this bike. What I do know is it ain't got much get up and go from 0-70. About the only time I've ridden at 95 MPH is when I was on the interstate and that was only for a short while. The bike just isn't much fun riding at high speed, so I tend to keep it below 80 MPH. The vast majority of my riding is normally between 35-75 MPH. I do live in the city so there's lots of stop and go and when I do manage to get out for a back country ride it's usually 60 MPH and under.
Making more HP/TQ from 1500-5000 RPM would suit me best. I was hoping someone here had some experience in swapping cams on a stock twin cam 88.
Dyno's are merely tools, and should be taken as such. The same exact bike will produce very different numbers on different days. The same is true when dynoing a car. However, dyno readouts can give you a nice ball park figure to gauge things. This is especially true when the dyno's have been performed by two or three different shops, worlds apart. This helps to eliminate several of the mitigating factors that would fudge the numbers. When HP & TQ numbers are within a number or two of each other through out the run, one can be fairly confident you'll have a similar experience with the combo being tested.
I still haven't managed to figure out what cam I should select? I'm not wanting to do a BB kit on the bike . Many of the bigger cams require more compression than what my bike has. A big lift cam needing 10.0 compression won't be much of an improvement, as a lower lift cam that works best with 8.9 compression. And I'm not interested in big HP numbers at 6000 RPM as I'm never revving my engine that high. I don't think I've ever hit the rev limiter which is set at 5800 from the factory, but maybe once or twice in the 13 years I've owned this bike. What I do know is it ain't got much get up and go from 0-70. About the only time I've ridden at 95 MPH is when I was on the interstate and that was only for a short while. The bike just isn't much fun riding at high speed, so I tend to keep it below 80 MPH. The vast majority of my riding is normally between 35-75 MPH. I do live in the city so there's lots of stop and go and when I do manage to get out for a back country ride it's usually 60 MPH and under.
Making more HP/TQ from 1500-5000 RPM would suit me best. I was hoping someone here had some experience in swapping cams on a stock twin cam 88.
A few things that your over looking here. Lift is not the end all be all, but it does play a very important role and running a beehive style spring to higher lifts is not different than running it at lower lifts provided you do not go to high. That point (to High) is typically about 0.040" from coil bind. So any camshaft that is less than say 0.560" in your application is fine. Sure the heads do not flow any more air above 0.5" but you need to look at how long the lift is at or near that peak flow area. So if you cam of choice only has a peak lift of 0.5" it means your never really using the peak flow area of the cylinder head. So say you run a camshaft with 0.53" lift it will have the head at that peak flow area for a longer amount of time, which will improve the power output of the engine.
Stellar HDF Member
Joined: May 2015
Posts: 2,099
Likes: 307
From: mid Michigan
My bike has always wound up great w/stage 1. Then cams wore out and I put the tw21's in it gave me two more HP and I think 7 more torgue than stock. Different Dyno and tuners, but seat of the pants I would say that is about right. Now the 99 was better year for cams and can't really go much more with out work on it. I'm happy with it for a bagger riding two up most the time. It seams to me there is some valid points from some smart guys about going bigger for your bike being later and able to go bigger. I think with that year even in a bagger I would want to try the tw37 noing that the 21's just aren't that much more. I can understand not wanting to go to big and having to deal with the things that come with that.
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Jun 11, 2012 09:31 AM
