Is the Andrews 21 the 26 of the 07+? : V-Twin Forum: Harley Davidson Forums

mikevr007 · 12-14-2008, 10:23 AM

I've done a good bit of cam reading on here and it seems that the 26 was the cam of choice on slightly modified pre-07s. I suppose because of the 5 spd/a bit higher RPM setup?
I was pretty much set on getting the 26 for my 08 eg but through reading many opinions and tech articles I think I've changed my mind to the 21.
At least 95% of my riding is under 4K, at least 60% of that under 3500 and I can't remember the last time it was over 5K. You can see my bike setup in my sig.
I travel back roads most of the time but enjoy an occasional stint on the slab on which I travel about 10 over and turn around 3K in 6th.
Obviously I'm not a "high" rpm rider so I want as much torque as low as I can get it (a little oxymoronish...).
Anyway;
The specs, 21 vs 26 show that the 21 closes earlier (30vs35) has shorter duration (220vs 226) and higher lift (.498vs.490). I read somewhere that the stock cam lift is also .490?
I also read somewhere that to get the most torque in the "usable" rpm range (below 2300) you want your valves to close no later than 30 degrees.
Am I thinking right that the 21 is a "better" cam for my 08 eg? It seems to me that the 21 would not only give more grunt down lower but because it has a bit more lift would perform slightly better at higher rpms too (around 5K).
I guess I'm looking for more opinions specific to 21 vs 26 grinds. I've only found one thread that makes any comparison between the two.

Doshi · 12-14-2008, 12:14 PM

Mike,
I too had a similar question and directed it to Andrews through their website. My riding habits were not as clearly stated as yours however, here is my request along with Andrews response. Hope this helps.

Question::
TC 96, 09 Ultra Classic, 890lbs, Stock 9.2:1c/r, TTS Mastertune and Zippers Hi Flo A/C. Looking for cam suggestions based on the following. Ride two up 75% of time combined weight of rider/passenger approximately 345lbs. Do two 1500 plus rides per year.

Response::
The 26 cam sounds like it would be perfect for the type of riding you do and will work very well with the 96" engine and the stock compression ratio.

Thank you,

Gary Wallace
Technical Support
Andrews Products, Inc.
847 759-0190 Ext. 38
847 759-0848 Fax

claydbal · 12-14-2008, 03:12 PM

you just wont feel these cams as well as you would on earlier bikes. the too-tall gearing takes more motor to engage the butt meter. pitfall is you will haveto change riding style----no more under 2500 rpm, run it at 2800 rpm min.

mikevr007 · 12-14-2008, 07:52 PM

So, install the 26 and ride at a higher rpm? Seriously?

skyhook · 12-15-2008, 07:11 AM

the 21 is so similar to the stock cam it's kinda a "why bother" cam...26 really is most popular cam if ya ain't pulling the heads

Eleft36 · 12-15-2008, 07:41 AM

A 4* advance/retard sprocket question.

Would there be any advantage to using this on the stock Harley cams?
I.E. better fuel mileage or running cooler?

Al

claydbal · 12-15-2008, 08:52 AM

Quote:

Originally Posted by mikevr007

So, install the 26 and ride at a higher rpm? Seriously?

the 26 and ride above 2500.
woods 6 and ride above 2500
tw37 and ride above 3000
tw55 above 3500

see the pattern, forget about harleys sounding like a panhead,twin cams work best 3000-5000 rpm. even stock!

mikevr007 · 12-15-2008, 01:02 PM

Quote:

Originally Posted by skyhook

the 21 is so similar to the stock cam it's kinda a "why bother" cam...26 really is most popular cam if ya ain't pulling the heads

I think I've found the stock cam specs and other than the intake timing, I don't see how the stock cam and the 21 are that similar. Actually, it looks to me like there is more of a difference between the stock cam and the 21 than there is between the 21 and 26.

I think I understand what you are saying but (and I'm no cam expert) more isn't always better.

05 classic · 12-16-2008, 06:41 AM

mike stock cam on 07 and up closes at 25 degrees. the 21 and stock timing are not even close. with the tall gearing the 21 should work good. i am waiting for crane 300 cams to be delivered as we speak 33 degrees close also have 30 cometic gaskets coming which will bring cranking compression back to around stock. if you go with the 26 i would use the thinner gasket to keep cylinder pressure up. with just a cam change the 21.

strokerjlk · 12-16-2008, 07:08 AM

Quote:

Originally Posted by 05 classic

mike stock cam on 07 and up closes at 25 degrees. the 21 and stock timing are not even close. with the tall gearing the 21 should work good. i am waiting for crane 300 cams to be delivered as we speak 33 degrees close also have 30 cometic gaskets coming which will bring cranking compression back to around stock. if you go with the 26 i would use the thinner gasket to keep cylinder pressure up. with just a cam change the 21.

.
Not sure where you got your info? maybe you confused stock cams with SE 255 ???
The intake on stock 07 A motor closes at 30 deg not 25 deg.
.
IMO. NEITHER 21 OR 26 have enough overlap 18-20 deg to help cool the motor. (just something else to consider) Although it will help produce the lower rpm tq.
Good Luck in your quest!!

05 classic · 12-16-2008, 11:38 AM

the 07 and up stock cams do close at 25 bigboys cam comperason shows 30 but look the calculater and it shows 25 as does andrews and others. i have found that in bikes and autos if the compresion, cam timing and gearing are matched you have a nice ride, if one is off you dont get the results.

softailguy · 12-16-2008, 02:34 PM

Someone said >>>IMO. NEITHER 21 OR 26 have enough overlap 18-20 deg to help cool the motor. (just something else to consider) Although it will help produce the lower rpm tq.<<<

In all my years of tinkering with cars and bikes this is the first time I've ever heard of associating overlap with engine cooling. My understanding is that the purpose of overlap is to enhance cylinder fill at a specific rpm range and I suspect that any associated cooling effect would be negligable at best.

If anyone can post documentation supporting the overlap associated cooling effect theory, I'd love to see the numbers.

And this is not a flame, if there is a documented cooling effect associated with cam overlap I'd really like to know about it as I somehow missed that.

Thanks,

Doug

strokerjlk · 12-16-2008, 05:09 PM

Quote:

Originally Posted by 05 classic

the 07 and up stock cams do close at 25 bigboys cam comperason shows 30 but look the calculater and it shows 25 as does andrews and others. i have found that in bikes and autos if the compresion, cam timing and gearing are matched you have a nice ride, if one is off you dont get the results.

Stock ’07-’08 models .484"/.484" 198°/222° Intake: 12° ATDC/30° ABDC 0.041"/.102"
Cam Specs Exhaust: 38° BBDC/04° ATDC
.

From the screaming eagle catalog.
I have never read or heard anyone else refer to the 07 up A cams as closing at 25 deg. The Andrews site has the 06 Dyna on there spec page as there stock cams of reference closing at 40deg.I could be wrong as I have been before. I see what you mean as far as the compression chart on big boyz site.

mikevr007 · 12-16-2008, 05:13 PM

Quote:

Originally Posted by strokerjlk

.
Not sure where you got your info? maybe you confused stock cams with SE 255 ???

That very well could be.
Here's what I'm going by:

Stock 07-08 models
Lift: .484"/.484"
Intake/Exhaust duration: 198°/222°
Intake: 12° BTDC/30° ABDC
Lift ATDC: 0.041"/.102"
Exhaust: 38° BBDC/04° ATDC

mikevr007 · 12-16-2008, 05:28 PM

I really appreciate the discussion. As you may be aware of by now, I'm anal when it comes to doing it "right" the first time. Since I'm not made of money I have to do as much research as possible before I feel completely comfortable about spending money (and investing the time which is also at a premium).
Part of my reasoning for banging on the 21 is a tech article I read in a recent magazine. The author's background and his recommendation for the 21 impressed me to do more research. So, thanks for the patience and the input.