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Wipe pattern look ok?


Zmanco

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I'm getting ready to install my reground cam and as this is the first time I'm doing this, wanted to get inputs to see what you think of the wipe pattern? These are from two different lobes and lash pads. Cam is a 284/.480 regrind from Delta Cams, and the lash pads are 0.180.

 

Edit: I forgot to set the valve lash before I took the original pictures. Here are the wipe patterns with an exhaust on the left, intake on the right. Lash is .010 exhaust, .008 intake (cold of course :) ) I'm worried it's a bit too close to the top.

P1020278 copy (Medium)_thumb.jpg

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The wipe pattern looks fine to me, it is closer to the top but it is not close enough to warrent concern IMHO. I know it is not good to assume but I am going to make the assumption that you replaced your valve springs, rockers, etc. when you replaced the cam. If you did not it might be in your best interest to change your lash pads to move the pattern to the exact center or just below the center. Here is a pic of mine assembled but you can see were the wipe pattern is.

 

P2150004.JPG

 

Dragonfly

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I'm getting ready to install my reground cam and as this is the first time I'm doing this' date=' wanted to get inputs to see what you think of the wipe pattern? I'm worried it's a bit too close to the top… [img']http://www.k-c-electronics.com/zcars/wipe.jpg[/img]

 

 

 

 

 

You have PLENTY of room left on “both” sides. Good job btw. If that were my daily driver L-series, I’d call that perfect and not try to adjust or cheat the wipe pattern at all. If you are one of those guys trying to extract every last “oz/lb” of power, you could very well cheat the geometry towards the back side of the rocker, (towards the bottom in your pictures), by using a thinner lash pad. This “cheating” essentially increases the ratio of the rocker slightly by altering its ratio between the cam lobe, pivot and valet stem, giving the valve just a skosh more lift and a frog hairs more duration. For most daily driven street cars, it is debatable if the extra 1-3 hp is even with the trouble, and depending on how radical of angle the rocker sets the more vale train noise that can be induced as well. Judging by how narrow the wipe pattern of your cam is to begin with, if you wanted to cheat the wipe pattern, you might even be able to get away with as thin as. 160” lash pad. A word of caution for those wanting to do this. If you do cheat your cams wipe pattern, make absolutely sure on each and every rocker that you are not going over the edge of the wiping surface itself, i.e. check the wipe patter of each and every rocker, and then make sure you put those rockers in the same place you measure them from as the rockers are not all machined the exact same.

 

As you can see in this picture, the wipe pattern of this .580” lift Schneider cam doesn’t leave much room for moving the wipe pattern around as it pretty much used more than 90% of the available wiping surface. This sort of gives you an idea of how close to the edge you can safely get the wipe pattern.

 

WipepatternCustom.jpg

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Every cam is different. For certian, the aggresiveness of the lobe profile is the major contributing factor, the more aggresive the lobe profile, the more wiping surface it wil ltake up. Also, the region that is responsible for the "lash take up", on the opening and clsoing ramps of the lobes are ground with differing rates from different cam manufacturers/grinders. Some cams are noisy no matter what the lash is set at, (an indication that the cam grinder paid little to no attention to detail in regards to the the lobe profile itself, "lift jerk" curves are more than likely out of whack and in a worst case scenario could cause undue valve float, premature cam and rocker wear, or just a cam that doesn't perform as good as it specs suggest it shuold).

 

Well, I'm performing a "format C:" on my PC in the next few mintues, so if I dont respond again within the next day or so, you'll know why...

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Wow, I fired the motor up tonight to break the cam in and was amazed at how quiet the valve train is compared to my old cam. I forgot how nice the L6 is! Unfortunately she's still on stands waiting for a replacement strut, so I don't get to try out my handiwork :) But in a few days...

 

And a hearty thanks to all of you on this board who share your experience. For a person like me who "plays" with his car on the weekends, there's no way I could accomplish the improvements I've achieved without this group's advice and assistance. This is without a doubt the best of the Z boards out there!

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And a hearty thanks to all of you on this board who share your experience. For a person like me who "plays" with his car on the weekends, there's no way I could accomplish the improvements I've achieved without this group's advice and assistance. This is without a doubt the best of the Z boards out there!

 

I totally concur. Great post! I vote for a sticky.

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The Grease is a little hard to make out when compared to Dykem which is what I use. Yea for a daily street driver I use a centered patturn. For all of my TOP performance customers and myself, I use a closer to the pivot wipe patturn. The closer to the Pivot the wipe patturn is, the noiser the cam will be also, but yeild more performance. ALWAYS check EACH rocker IMHO. You never know what sort of valve job was done before, so always check. Looks good though.

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I’m back!?!?!… Performed a “c:format” on my PC, reinstalled Winders XP, made some fine tuning adjustments for a more refined interface between the keyboard, mouse, my eye balls, and all the goodies stored on the hard drive. All in all, it went very well.

 

 

I’d agree that the Sharpie or Dykem is probably a better choice than the non drying Prussian blue, mainly because the sharpie isn’t so thick and wont “drag” as the cam approaches the and leaves the wiping surface leaving a false or distorted smear across the wiping pad.

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The reason the valve train is quiet is because the wipe pattern is a little closer to the lash pad side of the rocker (thicker lash pad). When the wipe pattern is set up closer to the pivot ball or even centered, the valve train will sound like a diesel (thinner lash pad). All the noise is from slop at the rocker tip and lashpad.

 

I prefer to set the wipe pattern closer to the lash pad side of the rocker like you did. If I want a diesel sound from my engine, I would buy a Ford Super Duty or use a centered wipe pattern on my Z.

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If I want a diesel sound from my engine, I would buy a Ford Super Duty or use a centered wipe pattern on my Z.
That's exactly what my previous valve train sounded like. Now I wish I had checked the wipre before I took the cam out. I'm curious what the wipe pattern would have looked like.
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