3.0SC with 964 cam regrets?

[PeteKz]

Ditto what Old H2S said, plus Neil and Henry, et al.

I run the M1 in my 3.2 build and I really like it. It gives a great combination of low to mid-range torque plus higher RPM power. Keep in mind also that I very carefully measured and minimized the clearances inside the combustion chamber and valves-to-pistons to make the combustion chamber as tight and efficient as possible, given the inherent constraints of the hemispherical shape.

Is it "better" than the 964, or a slightly modified 964 grind? Without side-by-side comparisons, I can't say objectively. Besides, as Neil and others have extensively pointed out, "better" depends greatly on what you want your car to do, how you use it, whether it needs to pass emissions tests, whether you will maintain it yourself, etc.

I do know this from my setup measurements: The M1 was designed to use all the available "area under the curve", that is, all the lift and duration possible, while still using the higher compression SC/Carrera pistons and stock valve train. It does not have to meet emissions. And it works well with CIS. Thus, it "should" provide a little extra performance over the 964 variants. However, whether that is enough to make a difference on the street or track I don't know. I also know this: I can mash the throttle to the floor just off idle in higher gears, and it will pull smoothly all the way to redline. Thus, I can attest that it provides a very tractable engine in street use with the CIS (and I would expect also with the Carrera Motronic).

If you are willing to change pistons and go to higher compression, with valve pockets for more clearance, then you can choose from more power-oriented cams with high lifts and durations, which will require new and stronger springs, titanium retainers, etc. And add the appropriate number of zeros to your build budget...

[Old H2S]

And I forgot...Just to really mess with your head.
Holley 500 CFM NASCAR 4412 set up.

[PeteKz]

Always fun!

[Henry Schmidt]

I'm coming to this conversation a little late but here goes.
There is very little "top secret" about the 911 air cooled engine.
Camshafts are right there.
When it comes to a camshaft for a CIS engine one of the best ever designed is the WEB 2021. It was designed by a real legend in the high performance engine world of the 50s and 60s. Harry Weber. Harry was a So. Cal. Hot Rod guy who just understood what made horse power. I had the pleasure of knowing Harry as a kid, Jeff, his son and I race together, so hanging at his shop was a regular deal. Weber Clutches, Cams & Flywheels. He was doing a lot of cams for local Porsche guys 396,911, 914/4 -6, RSR some IMSA stuff so I don't remember what triggered the interest, but the Porsche CIS cam was something he just drew up on the fly and sent off to the dyno. The challenges, lobe center to reduce pulses so the cis would idle and maximize lift and still clear the squish chamber piston dome. This cam was designed in the mid 70s and still today is tough to beat. It's "problem" is a lumpy idle so smog is a challenge.
I'll tell you, this thing has the ability to create huge vacuum right off of idle which pulls the metering plate up and acts like an accelerator pump.
Sorry about running on. All that said, on a street stock SC driven in anger but mostly to the store any of the choices listed by others here will offer plenty of year of happy motoring. All that leaves us with one fact, the most popular upgrade is the 964.

[Jeff Alton]

Originally Posted by Old H2S

Jeff, you are right, I have made a mistake in my cam choice. I had the M1 in my old 3.0 CIS engine which it was designed for and it worked great. My new engine is a 3.2ss high compression ported home build that I DLC coated every moving part because there is nothing new under the sun on a 3.2ss build. And I used the old M1 cam, which is completely wrong for the build I did.
It was newish
I had it coated
It worked fine in the correct application
I already got 30k into the build.. will it ever end?
Now I'm the one going " How much to change the cams"
The M1 is in the 3.2ss, the car runs.
I will be at Cecil County Drag Way in Maryland this fall for the east cost Porsche blast that ICARP is attending so we will see what it will run and anyone can drive my car, It will not break. Nobody beats their car like I beat the Blue Mule.

Sounds like a cool engine! I am sure that cam works well in your engine. Sounds like you can easily do the work yourself, so parts only for you if you decide to swap them out.

Cheers

[Old H2S]

More critique..
Since we all have helped/hijacked this thread let me muck rake some more.
Neil offers 3 different 964 cams? Now we are really splitting hairs. He would have to build your engine to get the right one installed unless he can trust the numbers you provide, I don't know if I'm that good. This is why you go to a real engine BUILDER.
But then you get to Henry.." this engine is too much" or "I wanted more", and "how much to change the cams?" The threads are all here for your edification.
Then you have home assemblers like me.."But it worked on the internet, they said so"
The advantage some of us have is moving side ways on a whim... with the wife hitting me on the head,
"it worked fine, why did up F*CK it up"
I make changes like changing my socks.

[Neil Harvey]

Originally Posted by Old H2S

More critique..
Since we all have helped/hijacked this thread let me muck rake some more.
Neil offers 3 different 964 cams? Now we are really splitting hairs. He would have to build your engine to get the right one installed unless he can trust the numbers you provide, I don't know if I'm that good. This is why you go to a real engine BUILDER.
But then you get to Henry.." this engine is too much" or "I wanted more", and "how much to change the cams?" The threads are all here for your edification.
Then you have home assemblers like me.."But it worked on the internet, they said so"
The advantage some of us have is moving side ways on a whim... with the wife hitting me on the head,
"it worked fine, why did up F*CK it up"
I make changes like changing my socks.

Actually I looked and we have 5 different designs that can be called" 964 derivatives".

From those we can adjust the LSA and make a "different Cam" with the same lobes.

We give as much info as we can to make the assembler's job as easy as possible. The 'Cam Card" I posted shows what is typical. Intake timing by full lift degrees and by lift at TDC, all the Valve lifts before, at TDC and after so P?V can be checked and calculated. I have said before that checking the Piston to Valve clearances can be done with 1 head attached with the Valves loose. I have written how to do this. Why do we do this.

It is all about the Camshafts. Maybe the cam supplied needs advancing or retarding. Maybe the clearances at the start are on the limits of the customers safety. Before any changes are made the clearances can be re calculated. Maybe a Cam change is made and again, the clearances can be checked.

For us, it makes our life a lot easier with timing changes to find the best Torque or Cam changes to have a different engine response. Without having to assemble the complete engine, this way makes it real easy. Today, the modern engines make this a lot easier with electronically controlled camshafts. But we still need to know the limits. Especially with cam movements upwards of 52°+.

I can say this conviction, I will not sell a cam until I have beaten the customer to death with questions. The more I know the more I can suggest which of our designs is best. Often, we design a custom cam but this is a lot more $ and only when the need is for something we do not have.

This is why I was critical of the statement that "100's had been sold" and the feed back was "not aggressive enough".

This is not good customer support in my book.

[Turbo_pro]

Originally Posted by Neil Harvey

....edit....

This is why I was critical of the statement that "100's had been sold" and the feed back was "not aggressive enough".

This is not good customer support in my book.

Your arrogance is unmatched. You just can't let it go.
Read the statement again. The only negative feedback is not aggressive enough.
That is not to say all feedback is "not aggressive enough".
When a customers comes to a parts guy and says "I want 964 cams" and you sell them 964 cams, you have fulfilled your duty as a parts supplier.
If a customer comes to you and you use you superior knowledge to push what you want them to have, you are simply a prick....Niel, your attitude leans towards prick. Own it.

I did some quick research and the #1 requested cam at Webcam and Dougherty Racing Cams for street SC applications is 964. I guess these guys offer poor customer support as well. Geeze man....you think pretty highly of yourself.

[winders]

Turbo_pro,

Don't you know he used to work in F1! You are supposed to bow down to his posts.

Me? I would just call up William Knight and tell what I had and what I was using it for. He would then tell me what cams would be best. I would buy them from him and be on my way!

[Turbo_pro]

Originally Posted by winders

Turbo_pro,

Don't you know he used to work in F1! You are supposed to bow down to his posts.

Me? I would just call up William Knight and tell what I had and what I was using it for. He would then tell me what cams would be best. I would buy them from him and be on my way!

None of us need bow down to anyone...that kind of nonsense is for gysmos that can't think for themselves.

As for "Calling William Knight", that is your choice. We all get to pick the expertise we respect.
The original question was: 3.0SC with 964 cams regrets? A contributor offered a response that he sold many with few regrets but the only regret for some was not aggressive enough". Simply put, people who chose that cam may have wanted something more aggressive. That is exactly what the OP was asking.

Neil chose to challenge that person's integrity because of what? he didn't challenge the customers choice. That kind of input is arrogant and counterproductive to a forum seeking participation. To make things worse, Neil keeps trying to justify his condescending drivel. Sorry, not bowing down today.

[RDM]

Originally Posted by Turbo_pro

Your arrogance is unmatched. You just can't let it go.

You may want to consider taking your own medicine here.

The things you condemn you seem to be practicing with reckless abandon. Log, speck, and all that.

[Helix8]

Some people sell parts, some people buy parts, some people buy engines and some people actually build engines.

[Turbo_pro]

Originally Posted by RDM

You may want to consider taking your own medicine here.

The things you condemn you seem to be practicing with reckless abandon. Log, speck, and all that.

I notice that you have 964 cams in you 911 SC. I assume that was your choice or do you feel like the person who sold you those cams acted unethically?
Accusations of unethical conduct about a contributor to this forum to bolster your own credibility is the reason for my condemnation.
The person accused of unethical behavior is a friend and did absolutely nothing wrong.
Bruce Anderson, Wayne Dempsey, WebCam and Dougherty all recommend 964 cams as an upgrade for SC.
There is no perfect solution to any engine question, everything is a compromise and those who claim to eliminate all the compromises is selling snake oil.

[Turbo_pro]

Originally Posted by Helix8

Some people sell parts, some people buy parts, some people buy engines and some people actually build engines.

You are correct: Some of us, design parts, patent them, manufacture them, test them, sponsor teams to test them, build engines using those parts parts, drive vehicles in competition to verify their quality and then sell those parts.
What's your point?

[mikedsilva]

Originally Posted by GTT

I know there have been lots questions/discussion about the pros and cons of installing 964 cams in a 3.0 on the forum, and I feel like I've spent hours reading threads with tons of good information, but what I'm really interested in is some feedback on those who installed the 964 cam and would you do it again, or do you regret not keeping your cams stock or possibly a "cheater" cam like the DC15 that somewhat splits the difference?

I'm rebuilding an '82 3.0 with 9.3-1 compression ratio, plan to keep CIS and am changing my exhaust to SSI with a Dansk sport muffler. I'll use the car pretty much as a street car, but it won't be my daily and I do expect to have some spirited drives. Now I'm trying to decide between the 964 grind or the DC15.

If you put the 964 cam in your 3.0, are you happy with the result? If not, why and what would you do differently?

They work well.
Couple the cam with a set of 1&5/8 headers and a free flowing muffler and the 3.0 ends up running really well.
Advance the cam a bit more than 1.26mm (but check your piston to valve clearance): this tends to bring the torque in a little earlier.

The guys that I've done this for end up with a reasonably punchy little motor that makes for a fun car.

[GTT]

Originally Posted by mikedsilva

They work well.
Couple the cam with a set of 1&5/8 headers and a free flowing muffler and the 3.0 ends up running really well.
Advance the cam a bit more than 1.26mm (but check your piston to valve clearance): this tends to bring the torque in a little earlier.

The guys that I've done this for end up with a reasonably punchy little motor that makes for a fun car.

Thanks mikedsilva. This is the kind of feedback I was looking for.

[Turbo_pro]

Originally Posted by winders

Turbo_pro,

Don't you know he used to work in F1! You are supposed to bow down to his posts.

I may have missed the sarcasm, if so, I apologize for the snarky response.
It's often very difficult to interpret nuance in delivery.
Sorry Scott

[winders]

Originally Posted by Turbo_pro

I may have missed the sarcasm, if so, I apologize for the snarky response.
It's often very difficult to interpret nuance in delivery.
Sorry Scott

No worries, mate!

I figured that second sentence and then the emoji would have made it pretty clear I was mocking the idea that Harvey’s post are somehow divine. You probably weren’t in the right state of mind for that kind of humor. I understood exactly where you were coming from.

[PeteKz]

C'mon guys. Neil has contributed greatly here and has helped many of us. He has strong opinions, but those are based on his extensive experience. And some of you have extensive experience to share too. You can agree or disagree or offer something new, but let's not be snarky about it.

Criticize the information, rather than the person.

[Turbo_pro]

Originally Posted by PeteKz

C'mon guys. Neil has contributed greatly here and has helped many of us. He has strong opinions, but those are based on his extensive experience. And some of you have extensive experience to share too. You can agree or disagree or offer something new, but let's not be snarky about it.

Criticize the information, rather than the person.

Isn't your, "C'mon guys" comment just another way of criticizing a person.
Questioning another contributors integrity simply because they sell what the customer wants, deserves condemnation. To believe that you alone can answer the "what cam is best suited for an application" is simply arrogant.
If you don't get that, we will have to agree to disagree.