"Qship" from toronto, and his "stage 1" cams ... fraud alert

[HotRodKid]

while bouncing around the web a few weeks ago, i came across the shopower site, which is the ontario, canada sho club

in the classifieds section, Qship had for sale a set of stage one cams, 1x,000km on them, a chip in one lobe, $200 takes them

i told somedude

somedude trusts noone when it cmes to used parts

somedude drove up there to purchase cams, but measured them before money exchanged hands

the cams are SMALLER THEN STOCK

thats right .... LEEEESSSSSS lift then stockers

it is assumed that they are from a reman head, and were "cleaned up" so they look pretty

Qship has lowered the price (again) and still intends to sell them as stage ones

just a heads up

 

[Mr Anonymous]

Ummm, that's how stage cams are made. Material is ground from the base circle to make the lobe smaller and a lash cap added under the bucket.

 

[HotRodKid]

so your sayin if you measure a stage one cam correctly to determine LIFT, the lift number will be less then stock?

base circle cam be .5" or 3 feet, but lift is lift, just like a man is 6 feet tall when hes standing on earth or standing on mars

b-c=a , and a will be different between stock, stage 1 and stage 2

 

[Bizzy]

If you search out posts here on the forum and read the following bit of info on Josh's website I think you'll be enlightened.

http://www.shonutperformance.com/SHONUTCams.htm

Crow for dinner?

 

[HotRodKid]

im fully awear of how the regrinds are done

notice i used the term lift, and by lift, i ment lift, not lobe height

lobe hight and base circle would obviously both be smaller then stock, because both measurements include the base circle in some way

lift has no bearing on base circle, and therefore as i said before

but lift is lift, just like a man is 6 feet tall when hes standing on earth or standing on mars

which if you need a further explination of, both planets have a different circumferance (ie, base circle)

 

[NovaSS]

so your sayin if you measure a stage one cam correctly to determine LIFT, the lift number will be less then stock?

base circle cam be .5" or 3 feet, but lift is lift, just like a man is 6 feet tall when hes standing on earth or standing on mars

b-c=a , and a will be different between stock, stage 1 and stage 2

as per your picture

 

[HotRodKid]

yea its a pretty easy concept to understand .. less lift then stock

unless you think lobe height determines lift .. which it doesnt (not directly)

and just because i had to explain this multiple times, ill explain it again:

alex properly measured the cam, and it has less lift then stock

and lift is determined by subtracting the base circle from the lobe height ... which is what he did

 

[30footSHO]

And when you add the lash cap, there is then MORE lift than stock. So add the lash cap and then you have your stage I cams properly installed. If the seller doesn't have these to offer with the cams, I am sure they can be found elsewhere. People that know what they are talking about are trying to explain this to you.

 

[Shoaz]

I'm following Hotrodkid's argument, but without the actual measurements or the cams it's hard to really reach a conclusion.

Clearly it's possible to screw up a cam grind and wind up with something worse than what you started with.

 

[HotRodKid]

holy ****

lift is the distance from base circle to the tip of the lobe. its that damn simple

it has nothing at all to do with the caps or them being installed... the new caps just take up the extra space

when your taking about brand new cams for a 350 chevy or a 426 hemi, they add lift by making the lobe taller

for regrinds like we have for the sho, you add lift by grinding the base circle smaller, hence the need for lash caps

on the cams qship is selling, the base circle is stock, the lobe height is stock, and the lift is stock

get it yet ?

 

[HotRodKid]

shoaz, that wasnt directed at you either. in response to you, the cams in question were never actualy ground down, all that was done was the lobes were cleaned up, a small amount of material taken off all the way around to remove imperfections

lets replace the "stage 1 cams" with a "3.6l stroker crank"

qship is saying hes selling a rewelded / reground stroker crank, but the hard numbers show its a stock crank that someone cleaned up the bearing surfaces on

no "heavy work" was done to the cams ... just a professional cleaning with sand paper to make them look new, no work was done to them that would add any performance to your car

 

[Power Surge]

holy ****

lift is the distance from base circle to the tip of the lobe. its that damn simple

it has nothing at all to do with the caps or them being installed... the new caps just take up the extra space

when your taking about brand new cams for a 350 chevy or a 426 hemi, they add lift by making the lobe taller

for regrinds like we have for the sho, you add lift by grinding the base circle smaller, hence the need for lash caps

on the cams qship is selling, the base circle is stock, the lobe height is stock, and the lift is stock

get it yet ?

Regardless of what Qship is selling.... your lift theory is wrong.

If you have reground cams that use lash caps, you must factor in the lash caps as part of the lift.

While you are correct that the lash cap just takes up extra space from the smaller base circle, that ONLY applies to the base side of the cam. The valve is at the stock location (closed) with the lash cap in place, and at that point the lash cap is only taking up the slack of where the cam was ground smaller. But on the lift side, you have to add the thickness of the lash cap to the lift, because that's adding to how much the valve is being pushed down.

Think of it like a 1.5 ratio rocker arm vs a 1.7 ratio rocker arm. Both will have the valve closed at rest, but the 1.7 will have more lift when open.

 

[Shoaz]

While you are correct that the lash cap just takes up extra space from the smaller base circle, that ONLY applies to the base side of the cam. The valve is at the stock location (closed) with the lash cap in place, and at that point the lash cap is only taking up the slack of where the cam was ground smaller. But on the lift side, you have to add the thickness of the lash cap to the lift, because that's adding to how much the valve is being pushed down.

It doesn't matter if there's a lash cap or a two-foot rod between the cam and the valve, if there's not a rocker arm involved the valve opens a distance equal to the lift on the lobe. The lash cap has the same effect as making the valve stem longer, and I don't think anyone thinks that affects lift.

Think of it like a 1.5 ratio rocker arm vs a 1.7 ratio rocker arm. Both will have the valve closed at rest, but the 1.7 will have more lift when open.

That's quite a bit different than the direct method used by an overhead cam. There's no additional mechanical advantage gained by the lash cap. As you mentioned previously it's just a spacer used to make up for the smaller base circle on the cam, and has the same effect as making the valve stem longer.

 

[Power Surge]

It doesn't matter if there's a lash cap or a two-foot rod between the cam and the valve, if there's not a rocker arm involved the valve opens a distance equal to the lift on the lobe. The lash cap has the same effect as making the valve stem longer, and I don't think anyone thinks that affects lift.



That's quite a bit different than the direct method used by an overhead cam. There's no additional mechanical advantage gained by the lash cap. As you mentioned previously it's just a spacer used to make up for the smaller base circle on the cam, and has the same effect as making the valve stem longer.

You're wrong, it absolutely DOES matter what's between the cam and the valve when you've changed the base circle. If you put a valve in with a longer stem, you WOULD have more lift on a reground cam with a smaller base circle. THAT'S HOW REGROUND CAMS WORK! The lift remains the same (because you're obviously not adding material to the lobe) and the lash cap adds to your lift.

 

[Shoaz]

You're wrong, it absolutely DOES matter what's between the cam and the valve when you've changed the base circle. If you put a valve in with a longer stem, you WOULD have more lift on a reground cam with a smaller base circle. THAT'S HOW REGROUND CAMS WORK! The lift remains the same (because you're obviously not adding material to the lobe) and the lash cap adds to your lift.

The lift measured on the lobe is the distance the valve opens if there's not a rocker arm for a given gap tolerance. You get more lift on the lobe from an existing cam by reducing the base circle. You put in a lash cap to make up the difference in the space, as otherwise you may *reduce* lift by just opening up the gap more, but fixing the gap tolerance takes care of that.

So, for a given gap in a valve-closed condition, i.e., pick a shim to fix the gap, it doesn't matter whether there's a lash cap or a twenty foot rod between the cam and the valve, the valve opens the distance of the lift on the lobe.

It's not complicated, but there's something getting lost in the communication here. I don't think Hotrodkid's made any mistake in what he's posted, and the graphic he posted illustrates it pretty well, but clearly there are/were some misunderstandings.

 

[Power Surge]

So, for a given gap in a valve-closed condition, i.e., pick a shim to fix the gap, it doesn't matter whether there's a lash cap or a twenty foot rod between the cam and the valve, the valve opens the distance of the lift on the lobe.

You're still not getting how reground cams work. The whole point of making the base circle smaller, is to keep the same LOBE lift, and then add a lash cap to make the valve stem pyhsically longer. By doing that, you increase the overall valve lift. That's how it works.

 

[Shoaz]

You're still not getting how reground cams work. The whole point of making the base circle smaller, is to keep the same LOBE lift,...

No, the point of reducing the base circle is to INCREASE the effective lobe lift in order to get the valve to open further. To make up for the smaller base circle, though, one needs to either move the cam closer to the valve, make a valve with a longer stem, or use something (e.g., a lash cap) to fill the gap. Clearly using a lash cap is the simplest and most cost-effective solution, so that's typically what's done.

Perhaps the confusion is in what is meant by lobe lift, but Hotrodkid tried to clear that up with the posted diagram. The diagram makes it clear that reducing the base circle increases the lobe lift, if the lobe height from the cam center is kept the same. This provides a means for increasing the lift capability of a stock cam by grinding down the base circle region not under the lobe. Since it's difficult to add material to the lobe to increase lift in any reliable manner, this is the common way to regrind stock cams to increase lobe lift.

...and then add a lash cap to make the valve stem pyhsically longer. By doing that, you increase the overall valve lift. That's how it works.

The lash cap doesn't make the valve stem longer, but it has the same effect and that was my point.

The bottom line is that the cam lobe height determines the maximum potential distance that the valve can be traversed on an overhead cam system, not the lash cap or the stem length or any other spacer that you care to put in between the cam and the valve. That's pretty much why people grind cams to change the valve lifts.

 

[Power Surge]

No, the point of reducing the base circle is to INCREASE the effective lobe lift in order to get the valve to open further. To make up for the smaller base circle, though, one needs to either move the cam closer to the valve, make a valve with a longer stem, or use something (e.g., a lash cap) to fill the gap. Clearly using a lash cap is the simplest and most cost-effective solution, so that's typically what's done.

Perhaps the confusion is in what is meant by lobe lift, but Hotrodkid tried to clear that up with the posted diagram. The diagram makes it clear that reducing the base circle increases the lobe lift, if the lobe height from the cam center is kept the same. This provides a means for increasing the lift capability of a stock cam by grinding down the base circle region not under the lobe. Since it's difficult to add material to the lobe to increase lift in any reliable manner, this is the common way to regrind stock cams to increase lobe lift.



The lash cap doesn't make the valve stem longer, but it has the same effect and that was my point.

The bottom line is that the cam lobe height determines the maximum potential distance that the valve can be traversed on an overhead cam system, not the lash cap or the stem length or any other spacer that you care to put in between the cam and the valve. That's pretty much why people grind cams to change the valve lifts.

No, you're still completely wrong. But I think I see where your confusion is, after your last post....

The centerline of the cam does not change, when you make the base circle smaller. All you are doing, is making the "at rest" part of the cam closer to the centerline. By doing that, the lobe lift height obviously does not change. But, then you are adding in a lash cap. So now when that same lobe comes around, it's pushing the valve open an additional X amount, where X equals the lash cap thickness. That's where the extra lift comes from. That's how "reground" cams work. The valve "starting point" is up higher, so that when the stock lift lobe pushes down, it pushes the valve down farther, i.e. more lift. The whole point of a reground cam, is because you can't add lift via lobe size, you are adding lift via stem length and a closer starting point.

 

[Shoaz]

Who knew? You can increase effective valve lift just by making the stem longer.

So all I really need to increase performance is to add lash caps. Forget grinding the cams, then, I'll just by a set of lash caps.



:shakehead

 

[TYSHO]

somedude drove up there to purchase cams, but measured them before money exchanged hands

the cams are SMALLER THEN STOCK

thats right .... LEEEESSSSSS lift then stockers

on the cams qship is selling, the base circle is stock, the lobe height is stock, and the lift is stock

get it yet ?

This thread is ******** in many ways!