Best cam profile for 3.0 rebuild

[shamrok]

Hey all, currently have my motor torn down after discovering a broken head stud and dealing with constant CIS headaches. I'm about to send the heads and cams out and hope to have her put back together by July. I'll be running the stock P&Cs, but adding ITBs and EFI. I was planning on running a 964 grind, but wondering if there's another profile that will work with my setup. Car will be for mostly daily street use, maybe some track thrown in on occasion.

This forum has been incredible while I go through this rebuild. Thanks Pelican!

[lvporschepilot]

Dumping CIS and using EFI unlocks a lot of possibilities. 964 is pretty conservative but if you're running stock compression that's not a bad choice. Easy to bump the compression a bit while you're there and run something like a DC40 or mod S.

[chrisbalich]

My 3.0 (79SC) is apart b/c of head studs.
It's getting EFI, ITBs, and P&Cs from an 83SC (9.3:1 instead of 8.5:1).

My cams are currently with John Dougherty being ground to DC19. They're just smidge hotter than 964 cams but will work with stock pistons. I won't be able to confirm this until they return, but John assured me that it was 100% ok.

[Trackrash]

You may want to reconsider your choice to stay with stock pistons. With ITBs you can really wake up that motor with a more aggressive cam. But the stock pistons will limit your cam choice to 964 or similar.

[shamrok]

I'd love to go nuts on my rebuild and put some new P&Cs in but budget matters and I've gotta draw a line somewhere. Looking at the various specs, the DC21 and 993SS don't seem that far off from the 964 profile....do we think they're too hot for CIS pistons?

[targa72e]

My two cents. While ITB are sexy you are spending a lot of money and not getting the best benefit if you use the stock pistons and compatible cams. The main advantage of ITB is that you can run hotter cams as the throttles keep the intake revisions on overlap from traveling up the intake. If you are going to keep the stock pistons you would probably be better off sourcing a 3.2 Carrera manifold to use with your EFI. I did this many years ago and you can see some dyno results in this thread.

dyno tuning results

If you are dead set on ITB the extra cost to go with JE or CP pistons with you stock cylinders or bored out 3.2 Cylinders (short stroke 3.2) paired with a more aggressive cam and a good exhaust system would be money well spent HP wise.

john

[Trackrash]

Originally Posted by shamrok

I'd love to go nuts on my rebuild and put some new P&Cs in but budget matters and I've gotta draw a line somewhere. Looking at the various specs, the DC21 and 993SS don't seem that far off from the 964 profile....do we think they're too hot for CIS pistons?

You should contact John Dougherty, aka camgrinder, and ask his advice. He is the go to guy around here, with decades of experience with 911s.

[shamrok]

Originally Posted by targa72e

My two cents. While ITB are sexy you are spending a lot of money and not getting the best benefit if you use the stock pistons and compatible cams. The main advantage of ITB is that you can run hotter cams as the throttles keep the intake revisions on overlap from traveling up the intake. If you are going to keep the stock pistons you would probably be better off sourcing a 3.2 Carrera manifold to use with your EFI. I did this many years ago and you can see some dyno results in this thread.

dyno tuning results

If you are dead set on ITB the extra cost to go with JE or CP pistons with you stock cylinders or bored out 3.2 Cylinders (short stroke 3.2) paired with a more aggressive cam and a good exhaust system would be money well spent HP wise.

john

I've already got the ITBs and EFI, I'm just hoping to maximize my planned setup. Of course, new P&Cs would be great, but they're cost prohibitive considering the car was running very well, outside of CIS headaches. I had great leakdown and compression, wasn't burning much oil and had no smoke issues. Not wanting to dump money into the antiquated CIS is what sent me down this road to begin with. I just happened to discover a broken head stud and happen to have the cams out.

Great thread btw, very interesting reading, thanks!

[shamrok]

Originally Posted by Trackrash

You should contact John Dougherty, aka camgrinder, and ask his advice. He is the go to guy around here, with decades of experience with 911s.

Yeah I'm going to reach out to him next week. Sounds like it's been difficult to get a hold of him lately, but seems he does solid work...eventually.

[trond]

consider planned use of car when choosing cam profile. Car may be less effective with a too hot cam if you find yourself below powerband often. Stock cams give useful torque from much lower RPMs. Screaming along above 4000 rpm on public roads may be tiresome for some. Myself I went stock cams with my 3.2SS build and could not be happier with power (torque) delivery. Especially 2500-4000 rpm. Correlates well to real world driving for me. Many end up with a too hot cam for their use

[911SauCy]

Originally Posted by shamrok

Yeah I'm going to reach out to him next week. Sounds like it's been difficult to get a hold of him lately, but seems he does solid work...eventually.

My cams have been in his possession for 2 months now...he does not answer the phone, there is no voicemail available, and the shop that had them sent out has done business with him for over 20 years...

...I know of other folks on this board having experiences with him taking 6-8+ MONTHS to get their cams back.

Rethink your choice for who is going to do the work if you want them back before 2020

I'm likely going to buy a set of Webcams so I can actually get the car on the road for the '19 season at this point

[Mark Henry]

A set of JE pistons and WEB 120/104 cams, makes for a torque monster that behaves on the street.
It's what I have, but I'm using Mahle RSR style pistons and running one point higher on CR because I have twinplug.

[chrisbalich]

Originally Posted by 911SauCy

My cams have been in his possession for 2 months now...he does not answer the phone, there is no voicemail available, and the shop that had them sent out has done business with him for over 20 years...

...I know of other folks on this board having experiences with him taking 6-8+ MONTHS to get their cams back.

Rethink your choice for who is going to do the work if you want them back before 2020

I'm likely going to buy a set of Webcams so I can actually get the car on the road for the '19 season at this point

This is the boat I'm in. Tracking shows my cams were delivered on April 29th, but I cannot for the life of me get JD to confirm they showed up safely, or at all. Complete radio-silence since the day I shipped them and he assured he would LMK when they arrived. I'm reasonably sure that at this point, if they were damaged in shipping, I'm just out cams as the period to file a claim has expired. They shouldn't have been, but I've had things damaged in shipping before. So I'm always eager to know if the things I ship arrive ok and similarly, let people know the things they ship to me arrive ok.
Very frustrating to hear nothing.

[shamrok]

Sorry to hear about your DC woes, that's exactly what I wanted to avoid. I ended up just sticking with a 964 profile due to keeping the CIS pistons. If I ever do a real engine build, I'll go crazy, but there's no need right now. Ended up using Delta cams here in Washington. Turnaround was less than a week with shipping and it came out to $200 for the pair.

[chrisbalich]

Originally Posted by shamrok

Sorry to hear about your DC woes, that's exactly what I wanted to avoid. I ended up just sticking with a 964 profile due to keeping the CIS pistons. If I ever do a real engine build, I'll go crazy, but there's no need right now. Ended up using Delta cams here in Washington. Turnaround was less than a week with shipping and it came out to $200 for the pair.

holy crap. I feel like I've been hustled twice now.
Glad you're on the way to driving.

[mikedsilva]

Originally Posted by shamrok

I'd love to go nuts on my rebuild and put some new P&Cs in but budget matters and I've gotta draw a line somewhere. Looking at the various specs, the DC21 and 993SS don't seem that far off from the 964 profile....do we think they're too hot for CIS pistons?

Shamrok, I was in the exact same position as you a year or so ago.. Luckily, William Knight reached out and helped me choose some CP Pistons to go along with some WEbcam 464/465.

I already had efi and ITBs.. and to only use stock pistons and a 964 cam would have left about 25 hp on the table.
My motor is STRONG and William taught me a bunch. Look him up if you need advice or assistance.

[sp_cs]

Originally Posted by mikedsilva

Shamrok, I was in the exact same position as you a year or so ago.. Luckily, William Knight reached out and helped me choose some CP Pistons to go along with some WEbcam 464/465.

I already had efi and ITBs.. and to only use stock pistons and a 964 cam would have left about 25 hp on the table.
My motor is STRONG and William taught me a bunch. Look him up if you need advice or assistance.

Agreed re William Knight - the elgin cams he spec’d on my 3.5 are perfect my use.

[Nux]

Originally Posted by chrisbalich

This is the boat I'm in. Tracking shows my cams were delivered on April 29th, but I cannot for the life of me get JD to confirm they showed up safely, or at all. Complete radio-silence since the day I shipped them and he assured he would LMK when they arrived. I'm reasonably sure that at this point, if they were damaged in shipping, I'm just out cams as the period to file a claim has expired. They shouldn't have been, but I've had things damaged in shipping before. So I'm always eager to know if the things I ship arrive ok and similarly, let people know the things they ship to me arrive ok.
Very frustrating to hear nothing.

There are multiple threads on this forum about DC and the issues you describe. I got his cams 4 months after Wire transfer and after many many unanswered mails and Phone calls.

Never doing that again. WebCams will deliver in 2 weeks, and they are very responsive on Phone and mail - just good service and good cams.

Or talk to William Knight about his special SC grind

[chrisbalich]

Originally Posted by Nux

There are multiple threads on this forum about DC and the issues you describe. I got his cams 4 months after Wire transfer and after many many unanswered mails and Phone calls.

Never doing that again. WebCams will deliver in 2 weeks, and they are very responsive on Phone and mail - just good service and good cams.

Or talk to William Knight about his special SC grind

I haven't even paid. I'm going to call on my way home from work and see if he'll just send them back and I can send them to Web. It's fully absurd to hear nothing for 7 weeks and not be able to get an email back....even more so when I got all my questions answered in hours leading up to me sending my parts.

It would be most cost (and time) effective at this point if I just bought some used 964 cams off the classifieds and considered my cams that went to DRC a donation.

[Neil Harvey]

We are slowly putting together our inventory of new designs for the 911NA engines. We are taking a more modern approach to the designs that have not typically be applied to Porsche 2V camshafts. I guess its more of a if "it ain't broke don't fix it" approach, but many of these leave a lot of performance untapped.

The most common cam many choose is the 964 and the 1/2 step version copied by many. This is one of the new designs currently undergoing redesign. Most of the new designs will include an A symmetrical lobe with the exhaust lift lowered as we have found more performance with this set up. The limit with these profiles is having to run the Intake centerline retarded and the LSA wider for piston clearance. Not the best combination for small street driven 911 2V engines. Along with the cam work we are doing, we are combining this with new Pistons and rods for these engines, so when rebuilds are done, we can offer a more complete kit.

After spending many years in the water cooled arena, we are now spending a lot more time developing parts for the air cooled engines.

We do have all of the original masters for the 1/2 step cam designs. SC 1/2 step, 964 1/2 step to name a couple. These can supplied on new shafts or a s regrinds if they fit your doner shafts.