Urgent help needed, cam question...

[bpu699]

Sorry for the cross post, wasn't sure where to put this:

Sent my 88 930 cams to webcam due to pitting on one cam...

I was told by the prior owner that the motor had SC cams... Motor was modified up the wazoo, running 1.3 bar or so when I bought it...

The power is very linear, not peaky, and I have tracked the car with no issues, no "on/off" turbo spikes, etc.

Webcams called, and said my cams are stock 930 profile?!?!?

I find that really really hard to believe, and they will recheck...

They ran it on a "CAM DOCTOR" machine...

Now the cams, under than 1 lobe, looked great. Minor pitting on one lobe. I have no issues with the way the car drives...

If they are truly stock 930 cams...

Should I leave it? Regrind to SC?

My only issue with regrinding is that I suspect you need to take off a lot of material, and don't want to be left with issues...

Car ran great...

[RarlyL8]

I love SC cams and put them in all the street builds we do. If you can have that done (correctly) I'd go for it.

[bpu699]

Originally Posted by RarlyL8

I love SC cams and put them in all the street builds we do. If you can have that done (correctly) I'd go for it.

Thanks for the quick reply...

Any issues? I assume webcams knows what they are doing if that's the direction I go...

DO they then have to reweld the whole cam and grind down? Or just reprofile?

[RarlyL8]

Not a fan of regrinds personally, they are only as good as the welder/machinist. Webcams has been around a long time so if anyone should have the capability to do it right it would be them. Have a conversation with them taking you through the process.

[bpu699]

Originally Posted by RarlyL8

Not a fan of regrinds personally, they are only as good as the welder/machinist. Webcams has been around a long time so if anyone should have the capability to do it right it would be them. Have a conversation with them taking you through the process.

Thanks, I posted in the other thread too. I was a bit worried about doing a reweld and then a regrind to SC cams. Seems like more risk gets introduced. A mild regrind to take off a couple thousands seems less involved.

Plan to just regrind to same as I have now...

Perhaps upgrade to SC later...

Wish I had an unlimited budget...but kids want to go to college and all...

[spuggy]

Originally Posted by bpu699

only issue with regrinding is that I suspect you need to take off a lot of material

Think you'll find that taking 930 to SC profile will add a lot of material.

Originally Posted by bpu699

I was a bit worried about doing a reweld and then a regrind to SC cams.

Not rocket science, and gets done all the time. I wouldn't have any concerns with any reputable outfit. And there should be many of them. You'd think WebCams has to figure in that list...

Plan to just regrind to same as I have now...

Perhaps upgrade to SC later...

Why not source good used SC/3.2 cams (they're both the same profile)? Usually piles of these lying around unloved from N/A guys chasing HP with 964, or whatever proprietary grinds they think will make all the difference...

Then just get 2 holes drilled/tapped in the driver's side for the scavenge drive. Pretty sure that's all that's needed?

Mine already had SC cams when I bought it (still does), so I have no personal experience of the advantage provided - I just know I love the way it drives like an SC with a big-bore kit until the turbo spools...

But the guy that test drove it for my PPI has been working with turbos long time. He came back with glittering eyes and a grin he couldn't quite suppress no matter how hard he tried.

"Yeh, definitely SC cams. They really wake a 930 up...."

[K24madness]

The hardwelding process is something that’s quite appealing in my book. I did a LOT of reading on the topic and the materials used end up performing better than stock. The problem/challenge then becomes the rocker wear face. Once the cam becomes harder the rocker face should be hard welded as well. There is some debate over the ability to hold oil on the face too.

I can’t comment on 930 to SC profiles. I can say the factory 993 turbo uses a SC profile (really close) and takes to upgrades well. In your shoes even a 964 profile might be nice. Talk to camgrinder about options. He steered me in the right direction with my DC21’s.

[Eclectic911]

To gain max performance from SC cams in a 930 motor, is a change in pistons recommended?
Thanks

[RarlyL8]

No piston change needed for SC cams. They are a great upgrade for a street engine, adding torque everywhere. Drivability is greatly improved off boost, power improved on boost. I use them on all of our street builds. Typically have SC cams modified to drive the 930 turbo oil pump instead of regrinding stock 930 cams. There are two different drive hubs depending on the year of the engine. The only challenge is finding good used SC cams.

[1979-930]

I would not regrind
930 cams to SC. I have been told by Dema Elgin and Chris at TK that there is not enough material on them. The adjusters will be maxed out when setting valve lash.

Elgin reground mine to a custom Sport grind he came up with for the 930. I would see if webcam has something like this.
I will say webcam was called out for just doing whatever the customer asks and not advising people about the rocker adjuster issue.


Sent from my iPhone using Tapatalk

[RarlyL8]

I have been told by Dema Elgin and Chris at TK that there is not enough material on them. The adjusters will be maxed out when setting valve lash.

I agree with this as well. The end result is only as good as the welder/grinder.

[kevinbodman930]

If you have tracked it and there is no issues why mess with a good thing.I would keep enjoying the car and if and when you need to dive into the motor then swap cams.

Sent from my SM-N950U using Tapatalk

[flightlead404]

Brand new cams are a grand give or take, the differential between that and a re-grind isn't worth the $ IMHO

[K24madness]

Not sure where You stand in the process but based on comments made by RarlyL8 the SC grind sounds like the way to go. It’s a safe conservative bet.

Don’t be afraid of cams! Upgraded cams get a bad wrap due to tendency to over cam. I’ve driven a 930 with GT2 cams and honestly they felt pretty perky. I would not suggest those without entire engine build though. Just trying to make a point.

I’d be on the fence with 964/SC cams if it were mine. Without knowing turbine inlet pressures SC cams are the safest bet. As the exhaust side frees up further upgrading cams pays big dividends.