993 style cam (no keyway) in a 3.0 engine?

[Mark Henry]

Hope my deal cams don't become a headache.

I have new WEB cams (mod-b, 120/104 ) they are built on 993 cores, they are the no keyway type. I also have the 993 sprockets and correct bolts and washers.

Can I use them this way or should I get them cut for keys and use earlier sprockets?
If I did get the cut for keys is it OK to cut off the pump drive (guessing it's a PD) or should I keep it?
If I did keep the drive what parts would I need to seal it up?

914/6 conversion, carbed, twin plug 3.0 engine.

Thanks

[Mark Henry]

I think I have my brain around the 993 sprocket, it's the same height as the early cam sprocket assembly when you lose the thick washer.

So I take it that you run just the needed shims?
It doesn't need a key? just presses on?

I need different tools and of course I bought new early sprockets and pins

I have the correct (good condition) 993 sprockets, washers and I believe the bolts are correct, but the bolts seems to have fair bit of play.

I guess I also punch out the rear cam tunnel plugs and buy or make covers?

[Flat6pac]

What are you doing with your oil cooler?

[Mark Henry]

After a bit of research how these are timed and the tooling I think I'll look into cutting in a keyway and go with the early style sprockets. I could easily make my own tools but cutting the keyways would be faster.

Likely will cut off the drive as well.

Originally Posted by Flat6pac

What are you doing with your oil cooler?

The 914/6 cooler? most likely welding on a T to the 3.0 cooler.

[KTL]

Originally Posted by Mark Henry

I guess I also punch out the rear cam tunnel plugs and buy or make covers?

Why do you have to knock out the cam bore "freeze plugs?" Are the ends of the cams too long even if you cut off the drive section?

Here's a good place to get them. Scroll down to the very bottom

Porsche

[earossi]

I'm actually going the other way from you! I'm backdating a 993 motor so that I can put in different cams and be able to time them via the old system. I did this for several reasons, not the least of which is that to set up the normal, non-keyed cams on a 993 requires special tools to lock in the cams and TDC on the motor before tightening a bolt that fixes the cam sprocket to the cam. These tools are about $1200. And, I don't like the idea of friction being the only element to lock the cams to the sprocket. So, I am back dating my cams.

Unless there is a particular reason why you want to move to cams without a way to key in the sprockets, I suggest that you consider having the necessary keyways machined into your cams. It is not expensive. And, all of your "old" style cam timing sprockets are then a perfect fit.

[Mark Henry]

Originally Posted by KTL

Why do you have to knock out the cam bore "freeze plugs?" Are the ends of the cams too long even if you cut off the drive section?

Here's a good place to get them. Scroll down to the very bottom

Porsche

Two reasons
1/ if I use the 993 sprockets the timing tool hooks into the "back" (or other end) of the cam.

2/ one side (right) has a either cam sensor or power steering drive sticking out of the tower.

Thanks for the link, but it's looking like cutting a key slot is the cheapest route.

[Mark Henry]

Originally Posted by earossi

I'm actually going the other way from you! I'm backdating a 993 motor so that I can put in different cams and be able to time them via the old system. I did this for several reasons, not the least of which is that to set up the normal, non-keyed cams on a 993 requires special tools to lock in the cams and TDC on the motor before tightening a bolt that fixes the cam sprocket to the cam. These tools are about $1200. And, I don't like the idea of friction being the only element to lock the cams to the sprocket. So, I am back dating my cams.

Unless there is a particular reason why you want to move to cams without a way to key in the sprockets, I suggest that you consider having the necessary keyways machined into your cams. It is not expensive. And, all of your "old" style cam timing sprockets are then a perfect fit.

Pretty sure that's what I'm doing as well, just checking on a cutter.

[earossi]

Web Cam can cut the keyway for you.

[Mark Henry]

Originally Posted by earossi

Web Cam can cut the keyway for you.

Not going to send it to California for something as simple as this.

[Walt Fricke]

For the pump drive, you could just pull the cap on that side and install the seal. Any or no cover would then be fine. I've got a 2.8 with a cam with a drive end, and leaving that part hanging out hasn't caused problems, though a simple cover keeps the dust off. You wouldn't want to leave out the seal and expect a cover to do the job of keeping the oil where it belongs, though.

[Mark Henry]

Does the seal just press right into the cam housing?

I assumed it installed in the PS pump housing.

[rsscotty]

Mark,

If you are going to the adjustable cam timing route, you need to look at the ends of the cam where the gear would index. If it is not the same size as the area where you are going to machine for a keyway, then you need to weld the ends of the cam and re-machine them to correctly index on the cam gear.

You can leave the snout on the end of the cam and use a p/steering block off plate, but if you use an engine oil cooler you can't go this route. If you use the engine oil cooler, then cut the end off the cam and use the proper freeze type plug for the cam housing. Freeze plug 3.0 liter and later factory part.

The seal does not press into the housing since it is 49mm and the seal is 47mm. I have seen an adapter used there but I don't know who fabricated it.

Welcome to Rothsport Racing - Engine Products

Made In USA

[Mark Henry]

rsscotty you're a real buzz kill...but you are right. At least I found someone who knows their poop.

So what's involved in welding it up...or should I just keep the 993 sprockets.

Do I just MIG weld the end and cut it on a lathe?

If I did keep the 993 sprockets I can make the tooling... it's just time. But I have no clue (or manual) on how to time this way.

Never thought about the cooler, I'll have to cut the drive off. More time if I keep the 993 sprockets as I would have to figure out a new timing lock.

Crap-crap-crap.

[rsscotty]

I prefer TIG welding the cams as the metal added is minimal and more exacting...less to machine in the lathe. If it was mine I would convert to the good old timing method and sleep well at night.

[KTL]

Originally Posted by rsscotty

Welcome to Rothsport Racing - Engine Products

Made In USA

Very true. The one I linked is made in Taiwan. Sorry 'bout that.

[Cupcar]

I would cut off the power steering drive and simply install old style freeze plugs available at the dealer for cheap.

I would also cut the groove and go with the old style sprockets and adjust the cam timing in the usual old dial indicator way.

My $.02

[Mark Henry]

rsscotty nailed it, to do this you have to:

1/ weld up the tip of the nose and machine it back square.
For about the last 1/4 inch on the tip of the nose it's .015" under size, there is also a bit of bevel on the very end. Cutting and bushing it may be an option, but I think welding would be better.

2/ you need to cut for a 4mm woodruff key. Cutter on order.

3/ I will have to cut off the PS drive gear shaft to keep the stock oil cooler. My SC cam towers already have the "Freeze plugs".

[rsscotty]

Mark,

I you want, we can weld and machine your cams and supply you with all needed parts to do your conversion. Please call us @ 503 885 9626 if we can help.

Scott


Rothsport Inc.

[Mark Henry]

Originally Posted by rsscotty

Mark,

I you want, we can weld and machine your cams and supply you with all needed parts to do your conversion. Please call us @ 503 885 9626 if we can help.

Scott


Rothsport Inc.

If I lived in the US I would send it to you in a heartbeat, but shipping from Canada and back makes it costly and I already have all the parts.
Thanks for the info though.