it has to do with the TDC lift not the max lift like .495 or .500 - the stock TDC lift is .070 x .049 -- i think this is close guess - EV 27 is .188 x .166 so the TDC lift on the exhaust is very shallow, and its the reason a stock cam has no issue. but the EV 27 would as the spec is at least .060 sooo what does it all end up as -- the valve .166 - .049 = .117 and the spec .060 the valve pocket in the piston would have to be at least .057 deep to avoid hitting - in the real world its .100 - johnjzjz

 

This is always a difficult subject! I have never seen a comparison of the bolt-in cams that helps us make a choice. If you ride mostly 2-up I suggest the EV13, but if you are mostly solo the safe bet is an EV27. If you use Search you will probably find that is far and away the most popular cam in here. Large numbers of us use or have used them!

One caution I would make is that if you have a high mileage on your engine, then a significant increase in performance from changing cam is likely to add extra stress to old and worn parts, so there is a risk of needing other work before long.

 

I had a EV3 cam in a 85 bolted right in no notching required pulled real good

 

Headquarters has been around for a while and it's base up North might be more popular than in the states, they are friendly towards their customers.

You are putting us in front of the firing squad with this one. You listed cams that work and a personel preferance like a Ford, Dodge, Chevy thing. With a big bike and not wanting to run deep into rpm's with stock compression a cam with a lower intake valve closing will be your base target. The lower intake valve timing builds compression and provides the giddyup, rest of the numbers compliment the intake valve timing in a smaller cam. Now if you have to replace pistons, W6, EV27 and the V Thunders start to shine.

Headquarters run a split duration as JohnJ mentioned in another thread that he likes and works with numbers, Woods cams work with steep lobes and squared off to the keep the valves open which is the EV27 design but Woods stepped it up a notch, V-thunders have been around and don't hear anything bad about them plus use a valve train friendly design. The SE3 is a EV27 design for the Screamin Beagle operation, throw in Dave Mackie cams that are a darkhorse in the market and your decision should be a simple easy decision.

 

Now its getting confusing,
Graham the bike only has around 50000 Miles so I still think if it as low millage, not looking for a monster just a little disappointed in the performance after being on my 88" for a while.
John where are theses numbers found the stock "TDC lift is .070 x .049 -- i think this is close guess - EV 27 is .188 x .166" I cant seem to nail them down and would like to be able to figure this out? I have the EV-27 Exhaust @46/14 with a duration of 240.
If the EV-3 was a bolt in @43/15 time and Duration of 238 for RHillbilly does anyone know off hand where the cut off point is without changing pistons.
I would like to try and stay under a grand for mods this year
Yes that is what I thought as well Bagger the SE=03 or EV-27 were my first choices but after talking to the local tech. he recommend the HQ and I thought I would check it out and see if anyone has used them. Might try oil next then tires
Cheers

 

Any Cam will be better than stock.

 

That sounds all right. Of the Andrews cams, I understand the single numbers, like EV-3, are their early designs, while their two-number cams, like EV-27, are later and better designs, one of the reasons I chose that over some of their others.

 

OK i think you just cant take the numbers i am posting and ASSUME anything - if you really dont do camshaft degreeing and completly understand "what its doing and when its doing it" -- you can not make an assumption having said that

a few examples of camshaft nomenclature what the terms actually meen

Definition: Theoretical valve lift is the figure often published in cam manufacturers’ specification charts and is the most common term used to describe the lift of the cam. Theoretical valve lift does not take into account valve lash, valvetrain deflection underload, variables in rocker arm ratio, and so on. Think of theoretical valve lift as maximum valve lift under ideal conditions.

Definition: Net valve lift is the real-world number that your particular powerplant experiences with all variables taken into account. Items such as valve lash solid lifter , valvetrain deflection, and rocker arm ratio variation < harley rockers are stamped and not exact they are considered when this particular measurement is determined. It should be pointed out that it is virtually impossible for any camshaft grinder to print a true "net" figure on its specification card. The only viable method of determining actual net valve lift is by setting up a dial indicator on the nose of the rocker arm and measuring the lift while the engine is in an "operational" mode turning it by hand.

Definition: Lobe lift or camshaft lift is the term that describes the amount of lift the camshaft provides without any benefit of rocker arm ratio multiplication factors. For example, the roller camshaft may have an advertised lobe lift of 0.350. If the engine makes use of a standard 1.625:1 ratio rocker arm, the final theoretical valve lift works out to .308 X 1,625 = ,5005 lift . Think of this lift as the true amount the camshaft lifts the valve lifter in the respective lifter block bore.

Definition: Advertised duration is the most common form of listing specific duration figures. It is measured in crankshaft degrees and basically expresses the length of time that a given valve is open. Unfortunately, this particular figure can be more optimistic than theoretical valve lift. A good portion of the discrepancy regarding advertised duration figures is due to the fact that many manufacturers tend to include the camshaft lobe clearance ramp in their duration figures. For example, camshaft has an advertised duration figure of 359 degrees on the exhaust side. Obviously, this is an extremely stout number and, when you give it some consideration, you can clearly see that the powerplant could hardly run with such a radical camshaft. This is where 0.053-inch duration figures come into play. Measured with the 0.053 - inch method, the very same cam grind features a duration figure of 273 degrees. That’s a significant difference.

Definition: The 0.053 - inch duration figure is determined when the valve lifter has risen 0.053 - inch off the camshaft base circle (opening side) and closed to within 0.053 - inch (closing side) on the ramp. < the other side of the lobe, This particular duration figure is quite accurate for comparison purposes and in most areas is much closer to true duration than the advertised number. the camshaft manufacturers began using the 0.053 - inch method to determine a universal number that could be used for camshaft comparison. The 0.053 - inch number is more accurate and can, at least, be compared Cam To Cam without worrying about variables such as ramp clearance.

Definition: Several camshaft grinders have begun to use the 0.020-inch duration figure in addition to the previously mentioned 0.053 - inch number. It is primarily a seat duration figure and most often is used to determine valve timing at the seat. This figure is helpful when plotting a specific cam profile on graph paper and also can be of some assistance when comparing various camshaft profiles. < super high end stuff i put it in now so i dont have to answer later out of sequence,

Definition: Overlap was once a very common figure but, much like advertised duration, it has fallen from favor as a comparison tool among many cam grinders. Basically, overlap is the number of degrees that the camshaft features with both the intake and exhaust valves open simultaneously. Overlap takes place at the beginning of the intake stroke and also at the end of the exhaust stroke.

Definition: Lobe center is the amount of camshaft degrees between the point of maximum lift on the intake lobe and the point of maximum lift on the exhaust side of a given pair of cam lobes. As an example, lobe center is calculated for cylinder number one Front only and does not deviate between number one and the other cylinder in the motor. To make a representative sketch of lobe center, draw a line between the very center of a camshaft intake lobe and then draw a similar line through the respective exhaust lobe for the same cylinder. The number of camshaft degrees between these two imaginary lines is the camshaft lobe center. You need a cam doctor to do this but its part of it so its been added , Also called lobe displacement angle (LDA), the lobe center has a definite bearing on how a particular camshaft will operate in a specific motor. If the lobe center of the camshaft is increased, the valve overlap will be decreased. The overlap decrease is created because the exhaust timing will occur earlier and the intake timing event will occur later in relation to crankshaft position. Conversely, if the lobe center or displacement angle is decreased, overlap increases. Note that lobe center cannot be changed once a camshaft has been ground.

Definition: Lobe centerline should not be confused with lobe center or lobe displacement angle. The term "lobe centerline" refers to an imaginary line drawn through each respective lobe but does not combine the separation angle between the intake and exhaust lobes in a given pairing. Lobe centerline can be altered by advancing or retarding a camshaft, while lobe center is a figure that cannot be altered since it is incorporated into the camshaft when it is designed and manufactured. if you dont have a multi index gear you cant do this with out special tools jims sells one for 250 bucks,

Definition: A symmetrical camshaft makes use of the same profile on the opening and closing side of a specific lobe. In other words, the opening side of an intake lobe features a shape that is exactly the same on the closing side of the lobe. This term should not be confused with single-pattern or dual-pattern camshafts (see below).

Definition: An asymmetrical camshaft features a lobe shape or profile that is different on the opening side than the closing side of the same lobe. For example, a camshaft could feature a very rapid valve opening profile, but when the valve is closing on the same lobe, the shape could be extremely smooth and gentle.

Definition: Single-pattern camshaft grinds feature identical intake and exhaust lobe configurations. 235* X 235* duration -- This actually means that the valve timing is the same for both the intake lobe and the exhaust lobe. It should be pointed out that a camshaft can be asymmetrical in design yet still be a single-pattern grind woods 6 verses EV 27 . On the other hand, a camshaft can be symmetrical yet also be a single-pattern configuration

Definition: Dual-pattern camshaft grinds make use of different profiles on the intake and exhaust lobes. This means that the exhaust lobe and the intake lobe are not identical in shape. A cam profile of this type could feature an asymmetrical lobe on the intake and a symmetrical lobe on the exhaust. It also could be symmetrical in both, asymmetrical in both, or any combination of these types of profiles. in my shop we try and use this type cam BUT its getting harder to find because you need very good equiptment to grind this type

sooo shorter duration cams have more static compression / give way to more bottom end power with reasonable lift - harleys like duration to make big power it has to do with the connecting rod length the Time the piston stands still at TDC but that is an entire different subject --

for the cut and paste Police yes i hate to type sooo i cheated just a bit

the cut and paste chart < i hope that answers some of the questions

http://www.nightrider.com/biketech/h...o_byman_ql.htm


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Thanks John that's awesome,
The chart is excellent and with your description I have much better understanding of the cam, I will be digestion this for a while lol.
Appreciate the time you took to put this together, I had looked at Nightrider but never found that chart, might print it up and stick it on the wall, food for though or projects one might say.
Respect,
Mark

 

What a mind bender cams can be ... John has laid it all out but for most of us pliebs , the numbers etc. can be very daunting and confusing.
From what i have seen , the Andrews EV 27 cam is a tried and true unit to provide the usually required extra umpth. in the low revs. to make most standard riders happy.
If you are looking for umpth. in a rev. range that is not considered " normal riding " you have to be prepared to do some serious math. and include all the variables related to your particular motor etc. This usually ends up with you spending some serious money to build the motor to the cam specs.
As this is a " older evo site " the recomondations are usually in regards to standard motor refurbishing and mild cam replacements to essentially bring a older evo motor up to its best power potential.
There are standard checks to be made before any mods. are installed .
Is the compression ok ., is the oil pres. ok.? etc.
The rest of the process includes ... Never replace a cam without dealing with the cam gear issue in older motors , never replace a cam without replacing the lifters , cam bearings etc.