Several vendors sell "exact replacements" of the original S90/SC cam, f.ex. NeuTek SC-200, Stoddard's "german ground" (whatever that is).

I just wonder if these replacements are exactly as the factory original, or if they are modified to take into account that most rebuilds nowadays are with 86 mm pistons.

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No, Roland; they're the same as OEMs and will work OK w/any PC setups. (IMHO)

Dick

I agree. The stock cam is better than most of the aftermarket cams for how most owners drive their cars.

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Cliff Murray

 

'55 Cabriolet Racer

'57 Speedster

'59 Sunroof

'63 Coupe Pushrod GS 2133

'67 911 S

Hi
the SC-200 and most cams that are being marketed are basically an upgrated grind which usually give better performance than the stock grind. i don't know of any cams that are offered that are true copies of the S/S90/SC/912.
jacques

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Jaques,

That's what I thought. A little more duration and/or lift to fill the larger cylinder.

Do you happen to know the specs of some of these grinds?

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Hi Roland
http://www.willhoitautorestoration.com/CamSpecs.php
the RO200.5 is the most common cam that is available in the aftermarket. I beleive that it has become the default "stock cam". in evaluating cams besides the lift and duration and the Lobe center seperation we now have easy acess to the area the lift/ velocity/acceleration/jerk and quirk nos. all that is probably more info than anyone would use. There are many variables that affect the performance of an engine. the RO200.5 works well in most basically stock engines. The best thing you can do is degree the cam on the engine to install it where it will best fit your expectations. modifying the cam gear to be adjustable is easy. I think PM should devote some time to making Cam checking easier for the DIYs that have the inclination to do an engine assembly that is comeasurate with the cost of the better parts that are available to achieve a synergy.
KTF
jacques

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Jacques,
You're using some 50 cent words here, can you tell the challenged what " jerk, quirk, PM" relates to?
Thanks,
Gary

Gary
PM refers to Precision Matters Ron LaDow's the Vendor of overkill parts and tools. Cam profiling software will from the lift vs angle table provide the Cam lift and duraration the cam center seperation and area under the lobe if the ratio is known the same for the valve. Jerk is the 3rd derivative and Quirk the 4th derivative(rate of change of lift) if i got the names right i think subesquent derivatives have names also but are of little use.
KTF
jacques

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Quark. That's the 5th derivative.
And while I'm 'charmed', I find it 'strange' that you refer to Pre Mat's offerings as overkill. We do offer 'top' products, and others have talked our products 'up', while some are 'down' at the cost of producing them.
Sorry, I might be scraping the 'bottom' of the barrel here............

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It costs money to develop good products and get them manufactured. I don't think there is any overkill involved. Just good products that are good for our cars. Frankly, I don't know why everyone who owns a 356 doesn't have a full-flow filter, either from Ron or from anyone else. I happen to have one of Ron's. Expensive? Yes, but I couldn't get it machined for less. You guys are forgetting warp and woof.... or was that somehow related to sailing????

Cheers,
Wes

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Wes,
Textile terms,...presumably some such connection with the sail.
Now, I would be intersted in an adjustable cam gear for indexing. Jacques,..how do you approach this to make it easy to adjust for gee and haw?

Pretty sure you multiply gee X woof, and you'll find haw is very close to warp. Or the theta of warp as a function...
Oh, the hell with it...............
(hey, I got every quark in that post needling Jacques......)

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Wes
Probably the easiest is to use 3 offset washers. a significant change can be made by rotating the gear 120. Elgin Cams provides a instruction sheet. a little known fact is that some cam grinders will advance the cam when they grind them. I find it interesting that most engine builders relenquish the indexing of the cam to the camshaft manufacturer.
Ron
i love overkill and think you should address the proper installation of the Cam in your products.
jacques

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"Ron
i love overkill and think you should address the proper installation of the Cam in your products.
jacques"

Jacques,
I'd be happy to do so, but posting as an absolute ignoramus regarding issues with cams, I'd need an education from you and others I won't name (for fear of leaving someone out) to be of any help whatsoever.

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Hi Ron
You have great products. i wish you would address the instalation of the cam to "IMPROVE" the quality of engine rebuilds and performance. what we need is more precision in cam installation without which all tne nos mean very little. I am sure Alan can help us.
jacques

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