How can this be ! ?

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mbaird

mbaird
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Why are oil pump drives so expensive ?
Seem crazy... almost as much as a custom roller cam !
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Is it a reground solid roller? I though only the billet rollers needed a bronze gear as even the roller magnums (and every other roller V8) run an iron gear.
 
Is it a reground solid roller? I though only the billet rollers needed a bronze gear as even the roller magnums (and every other roller V8) run an iron gear.

No its a new solid roller . Custom grind
 
You always have to check the cam core material for what it is exactly. That bronze gear price was crazy. I picked up 2 Hughes melonized gears. You can purchase them on the shaft already. IIRC, wasn’t it a Crane product?

This is another reason I can’t stand when another company purchases up another one. Comp bought them up, again, IIRC. I don’t know if you can find them over at Comp now.

Crane used to make rollers with an iron gear hood to go. There cam part number ended in “IG” for iron gear.
 
I was just reading a few Speedtalk threads on this and someone said the Hughes melonized gear is a Crane ( or was ) and is not for use on a used cam because of possible embedded marerial on cam gear.
 
That is freaking ridiculous. I don't understand these prices these days. I know @318willrun had some issues with a brass shaft leaving specs of brass all inside his motor and stopping up the oil pump.
 
That is freaking ridiculous. I don't understand these prices these days. I know @318willrun had some issues with a brass shaft leaving specs of brass all inside his motor and stopping up the oil pump.
Bronze is made to sheer..... and those little specks of bronze stuck my relief spring in the pump, and damaged one of the clover walls in the pump. I don't want/like bronze gear in a daily. Just my opinion, experience.
 
Well I will be taking my oil pump apart and checking for wear/debris so I will handle that . Hard to think that it would stick to polished rotors coated in oil ....
 
What cam blank did they use? Iron or steel? If its iron, you don't need the bronze. If its steel it was probably uber expensive to begin with and would have still been expensive as a regrind as the steel LA cores are all aftermarket.
 
Its a billet core .. I will post grind / blank when I get home . The current gear look a little wanky so I started researching .
 
What cam blank did they use? Iron or steel? If its iron, you don't need the bronze. If its steel it was probably uber expensive to begin with and would have still been expensive as a regrind as the steel LA cores are all aftermarket.

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Bronze is made to sheer..... and those little specks of bronze stuck my relief spring in the pump, and damaged one of the clover walls in the pump. I don't want/like bronze gear in a daily. Just my opinion, experience.
At least with an iron gear, you can use magnets to help remove iron grinding from oil. Not so with bronze. I think part of the issue with roller cams is longitudinal cam thrust. With flat tappets the cam lobes' tapers compensate for each other and reduce the "natural" thrust generated from a spinning shaft and the valve train pressures. Rollers have "flat" lobes, and probably need thrust plates on the front of the cam. Not a big deal for factory roller engines, but for engines not designed for rollers, there other remedies are usually needed.
 
At least with an iron gear, you can use magnets to help remove iron grinding from oil. Not so with bronze. I think part of the issue with roller cams is longitudinal cam thrust. With flat tappets the cam lobes' tapers compensate for each other and reduce the "natural" thrust generated from a spinning shaft and the valve train pressures. Rollers have "flat" lobes, and probably need thrust plates on the front of the cam. Not a big deal for factory roller engines, but for engines not designed for rollers, there other remedies are usually needed.

Not on Mopars from what I know .
 
The need for thrust bearing etc.. Chevys require them but we have thrust plates.
Correct me if I am wrong.
Well you are 100% wrong about reverse rotation mopar marine engines. I know SB's have thrust plates. I believe all SBC & BBC needed cam buttons. Not sure about BB mopes and slants.
 
You are correct. At the front of the cam is a thrust plate that stops the cam from walking forwards. The roller cam has flat lobes. There is no thrust forwards or backwards do to the lobes angle. There is however, room for it to move very slightly fore & aft. This motion is (mildly?) controlled by the timing gears and chain.

As the thrust plate is installed, the fuel pump eccentric is bolted to the cam gear holding the cam gear on the cams nose. The chain will provide some limitations in code and aft movement. As I push and tug on my set up, I can get no movement. There is no mic on it ether.

This boils down to how much flex is in the cam retainer plate while torqued down at spec. (35 ft/lbs)
There should be none really.

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