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Cam gears


wd6681
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17 minutes ago, Black Magic said:

Don't know. Given there are several free methods to adjust the cam timing on most DOHC belt driven engines, i think most people stay away from adjustable cam gears. 

 

Are you sure your really need them? Repositioning your stock parts might be much more reliable.

Free, or undetectable?

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Some cam gears are held in place with friction and only require positioning and retorquing, others have a keyway or dowel. 

 

On Pontiac OHC sixes on the dyno, I use my adjustable cam gear to find the sweet spot then transfer that setting over to a stock gear by lining up the cam gear teeth and redrilling the dowel hole. Last I checked, holes were still free. 

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^^^^this exactly. The motors I work with have no keyway or dowel from the cam to the pulley/gear. You can set it anywhere you want. No rules against that.

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22 minutes ago, Black Magic said:

 

Methods include leaving dowel out, drilling new spot for dowel, using file to open up keyway/hole, drilling and tapping new hole.....

 

If leaving a non safety part off adds points (pulling dowel pin), rule book is going to explode in length.....

 

 

I was being somewhat sarcastic.   Buuut,  I also think at one time the series could have benefitted from a “ if it doesn’t say you can you can’t rule”.    But the cat has been out of the bag chasing the horses out of the barn for quite some time now.      It’s all good, adjust away.  

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36 minutes ago, JDChristianson said:

I was being somewhat sarcastic.   Buuut,  I also think at one time the series could have benefitted from a “ if it doesn’t say you can you can’t rule”.    But the cat has been out of the bag chasing the horses out of the barn for quite some time now.      It’s all good, adjust away.  

I think we are sort of on the same page, if the rules called out better what outcomes they want vs what parts....life could be better\easier. 

 

Like end of day, how many points to have non oe valve duration\lift, vs adding up points for parts.

 

I think our big struggle is the number of car types to balance....

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On 9/30/2019 at 3:30 PM, mender said:

Some cam gears are held in place with friction and only require positioning and retorquing, others have a keyway or dowel. 

 

On Pontiac OHC sixes on the dyno, I use my adjustable cam gear to find the sweet spot then transfer that setting over to a stock gear by lining up the cam gear teeth and redrilling the dowel hole. Last I checked, holes were still free. 

 

 

Hmm, something about  "camshaft or valve-train, non-OE: 50 points" doesn't play into this equation?

 

Don't quite see how re-drilling the dowel fits as an OE part or factory recommended repair method. 

 

Yes, "holes are free" but where the rules specifically outline what the modification of a part is worth, I think drilling the hole then counts as a modification.  Otherwise it needs to be a "stock" component. 

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2 minutes ago, MMiskoe said:

 

 

Hmm, something about  "camshaft or valve-train, non-OE: 50 points" doesn't play into this equation?

 

Don't quite see how re-drilling the dowel fits as an OE part or factory recommended repair method. 

 

Yes, "holes are free" but where the rules specifically outline what the modification of a part is worth, I think drilling the hole then counts as a modification.  Otherwise it needs to be a "stock" component. 

I don't see where it says in the rules that drilling a hole in a cam gear is worth points.

 

I do see a trend in the rules away from builder rules and toward buyer rules so it wouldn't surprise me to see an aftermarket cam gear be equated points-wise to a drilled hole in the near future.

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7 minutes ago, mender said:

I don't see where it says in the rules that drilling a hole in a cam gear is worth points.

 

I do see a trend in the rules away from builder rules and toward buyer rules so it wouldn't surprise me to see an aftermarket cam gear be equated points-wise to a drilled hole in the near future.

I really hope not but do see some strange things going on.

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22 hours ago, mender said:

I don't see where it says in the rules that drilling a hole in a cam gear is worth points.

 

I do see a trend in the rules away from builder rules and toward buyer rules so it wouldn't surprise me to see an aftermarket cam gear be equated points-wise to a drilled hole in the near future.

Doesn't need to say that the hole is worth points, it calls out that any non-oe cam or valve train is worth 50 points. 

 

In that same light, how about I take my stock cams and re-grind them to a higher lift/longer duration?  The hydraulic lifters have enough float in their size to make up the grinding.  It doesn't say I can't grind the cams right?  I'm using a stock cam, just one that I modified the crap out of.  So no points eh?

 

Buyer/builder - I'd go for a purchased cam gear any day over re-drilling the dowel.  You even commented that you used an adjustable cam gear to sort out the timing, then re-drilled it.  Sounds like you paid for it twice.

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3 hours ago, MMiskoe said:

Doesn't need to say that the hole is worth points, it calls out that any non-oe cam or valve train is worth 50 points. 

 

In that same light, how about I take my stock cams and re-grind them to a higher lift/longer duration?  The hydraulic lifters have enough float in their size to make up the grinding.  It doesn't say I can't grind the cams right?  I'm using a stock cam, just one that I modified the crap out of.  So no points eh?

 

Buyer/builder - I'd go for a purchased cam gear any day over re-drilling the dowel.  You even commented that you used an adjustable cam gear to sort out the timing, then re-drilled it.  Sounds like you paid for it twice.

Well, it's a stock cam gear with an extra hole. No points.

 

The reground cam thing was settled a while ago. Points.

 

Buyer/builder - I'm a machinist so I can either build an adjustable cam gear for each engine or I can redrill the stock cam gear and get the same thing for about ten minutes of work and zero points. 

 

And I don't redrill dowels, I redrill the dowel hole. Sounds like you'd be better off buying stuff. Let me know what you need. ;)

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On 10/6/2019 at 8:32 PM, MMiskoe said:

 

In that same light, how about I take my stock cams and re-grind them to a higher lift/longer duration?  The hydraulic lifters have enough float in their size to make up the grinding.  It doesn't say I can't grind the cams right?  I'm using a stock cam, just one that I modified the crap out of.  So no points eh?

 

While I don't see it in print any more, I'd say the spirit of the series still applies - "basic hand tools". Re-drilling holes seems to fit.  

 

I understand that it seems we are getting past that, but maybe that old mantra should get a push.

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8 minutes ago, MMiskoe said:

So, we follow the "spirit" of the rules or what is written in the rules?

 

 

 

Then I guess it's time to check spark plug gap @ post race tech? Or we just trust in rule 4.3.3

 

Unless you want to document doing it yourself in your garage and not sending it out to a cam manufacturer. I'm sure you'd get a lot of youtube hits. I'd give it a like. 

 

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I don’t need valve springs or cams for my 5500 rpm engine because it is what it is, a factory stock engine. However, I do need to get the most power possible from my stock engine. Seems to me adjusting the cam timing would give decent results, and I believe it could be termed as a rebuilder blueprint so long as high performance parts aren’t required.
 

Anybody with a degree wheel can locate an intake center, so that operation really doesn’t need to be farmed out by a pro. I’d say that if you have to drill a new dowel hole or widen a woodruff key slot to get the cam centered to the crank where the engine runs its best, you’re really only adjusting for the deviation of specs created by mass production. I don’t recall ever seeing a list of factory engine specs which calls out intake centerline or LSA.

 

Back to the point we are trying to clarify. Where exactly does Champcar tech draw the (center) line on cam timing adjustments? Seriously, will somebody be called out for 50 points if there’s an offset dowel hole bushing found in a tear down?

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1 hour ago, fordoval said:

I don’t need valve springs or cams for my 5500 rpm engine because it is what it is, a factory stock engine. However, I do need to get the most power possible from my stock engine. Seems to me adjusting the cam timing would give decent results, and I believe it could be termed as a rebuilder blueprint so long as high performance parts aren’t required.
 

Anybody with a degree wheel can locate an intake center, so that operation really doesn’t need to be farmed out by a pro. I’d say that if you have to drill a new dowel hole or widen a woodruff key slot to get the cam centered to the crank where the engine runs its best, you’re really only adjusting for the deviation of specs created by mass production. I don’t recall ever seeing a list of factory engine specs which calls out intake centerline or LSA.

 

Back to the point we are trying to clarify. Where exactly does Champcar tech draw the (center) line on cam timing adjustments? Seriously, will somebody be called out for 50 points if there’s an offset dowel hole bushing found in a tear down?

 

Removing material is almost always 0 points, so drilling an extra dowel hole, or widening a key slot is going to be 0 points. If you are adding a non OE part, it needs to be claimed. 

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29 minutes ago, red0 said:

Removing material is almost always 0 points, so drilling an extra dowel hole, or widening a key slot is going to be 0 points. If you are adding a non OE part, it needs to be claimed. 

Indeed.
The only specific exception to that rule (that I can think of) is camshaft regrinds, which receive the non-OE camshaft point value. 

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