3.0SC with 964 cam regrets?

[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?

[zztot]

Not expert but I believe a factor may be CIS or carbureted.
Using 964 with cards but thinking there was better choice. Strong enough but may have been better.

[PeteKz]

Another option which several others here and I use is the M1 cam from Knight Racing. It was designed to specifically work with the CIS and SC/Carrera pistons, to use as much lift and duration as available without pistons hitting valves. Contact William Knight ("Knightrace") or Ian Carpenter (Icarp) here. Cost is about $1000 for a pair of cams.

[Glenfield]

All good adds. Folks will steer you to M1.

‘82 has small intake ports which will limit some of the top end gains. If you’re adamant about keeping CIS, think hard about picking up some early SC heads or enlarging the ports you have. If you don’t, time your cams to bring in torque sooner since you won’t extend legs much.

Think long about taking opportunity to up the displacement. Then there are a long list of smart upgrades like clevite bearings, arp rod bolts, modded oil pump, etc etc. I know you didn’t ask, but things it took my a lot of research and some good fortune to find when I did mine and they don’t add measurably to cost.

Good luck.

[Jeff Alton]

Lost count of how many mostly stock 3.0 SC motors we have built with 964 cams. Works great.

We have built one with the M1 cam. The butt dyno says no better, no worse.

964 cam profile can be reground on an SC cam, which if on a budget, can be a better choice. Like I said, can't say in the real world that the M1 was any more impressive. I understand the theory of duration vs lift that was the genesis of the M1, but we are talking a low compression (relative) CIS motor, so gains are not huge either way.

Cheers

[GTT]

Thanks everyone for all the great feedback and suggestions. It definitely helped as I map out my plans for putting this motor back together.

[Neil Harvey]

Originally Posted by Jeff Alton

Lost count of how many mostly stock 3.0 SC motors we have built with 964 cams. Works great.

We have built one with the M1 cam. The butt dyno says no better, no worse.

964 cam profile can be reground on an SC cam, which if on a budget, can be a better choice. Like I said, can't say in the real world that the M1 was any more impressive. I understand the theory of duration vs lift that was the genesis of the M1, but we are talking a low compression (relative) CIS motor, so gains are not huge either way.

Cheers

I agree with Jeff on this one. Cannot speak about the other cam suggested but the 964 has been beaten to death with use other than in a 964 engine.

I read these posts but usually hold off as my approach is different to most. If the engine is still apart, (heads not attached) here is how I would go about this. Let the engine tell you what you should use, not a lot of opinions, mine included.

Do a valve drop test to establish the real estate you have to work with. This will tell you the lift v LSA v timing you can fit. Remember, the 964 profile can be cut on a shaft with different LSA than a stock 964. My guess is, the stock 964 LSA is way too wide for your engine.

Then have the complete Intake system flow tested to see what the actual airflow is at the back of the Intake valve. Otherwise, what you choose is a guess and you then have to be prepared to have made the wrong choice.

Once you have the drop numbers and the airflow, the choice is wide open. You can decide upon Lift, Duration, LSA and the timing.

Remember too, there are many copies of cams out there. Copies of copies of copies. What you end up with often is nothing like the original.

Anyone of good substance supplying cams will be able to provide you with the gross lift numbers at any crank angle at any timing position so the drop numbers can be used to establish the clearances.

Good luck.

[Old H2S]

After all this time and the M1 cam specs are a mystery to everyone? It is a Solex cam grind for CIS, and it rips when used with carbs or S type, CP, JE pistons.

[Neil Harvey]

Not to pick apart others opinions. I'm a certified idiot and I have one.

Just because 100+ 964 cams have been sold, does that answer the question or just cement the whole notion of mediocrity when choosing and selling cams.

The question can be asked, how do you sell with integrity a cam to a customer if you do not know any of the actual engine details. You cannot. Its all about guessing and making a sale.

I have no issue with the gentleman selling the "M" Cam discussed here, not divulging the spec's. Its his cam and he can sell it anyway he chooses.

I was the same for many years as the problem selling anything to the DIY community is, it has no problem telling the world what they have bought, spec;s and costs. When you are in business and make your income selling Porsche parts, some of this info can hurt you.

You probably first had a conversation with him, took up the time he would be working making money and asked for him technical help. He probably gave this and suggested his cam design.

Having the spec's changes what? You bought it so use it. Would having the spec's give you any information you can use? Not many here could use any of the technical specs' of a cam profile to any use. How many posts ask "how do I time my cams".

Sure, it can be said, "I bought those cams and in my engine they worked really well". That's a fair comment and one that would help someone. As long as the engine spec's were the same.

One side benefit in designing and selling A-symmetrical cams is not many places want to copy them as the cost to create them is twice the price, Two designs per lobe and if Masters are used 4 masters per cam.

Copying cam designs is something that has been going on since the car was invented. Porsche copied Cam designs designed here in the US by Henry Crane. Porsche had no clue how to design a cam profile back in the day. Not many did. Henry was well ahead of his time and everyone else. He was one of the first to apply differential" math equations when designing cam lobes.

Just about every cam sold is based in some degree on Henry's designs. The only reason that they be different is the "cut and paste" that has gone on for years.

These are mechanical devices that can be mathematically configured. Air flow numbers can be found, VE numbers calculated and Cam choices based on this and other info.

Or, use someone else's trial and error, and their failure to tell you the truth that it did not work as well they had expected. Include your own guess work.

Choosing any engine part is no different for the DIY or the Pro. Both can resort to guessing or do their due diligence. Make you own choice.

Idiot out!.

[GTT]

Originally Posted by Neil Harvey

I agree with Jeff on this one. Cannot speak about the other cam suggested but the 964 has been beaten to death with use other than in a 964 engine.

I read these posts but usually hold off as my approach is different to most. If the engine is still apart, (heads not attached) here is how I would go about this. Let the engine tell you what you should use, not a lot of opinions, mine included.

Do a valve drop test to establish the real estate you have to work with. This will tell you the lift v LSA v timing you can fit. Remember, the 964 profile can be cut on a shaft with different LSA than a stock 964. My guess is, the stock 964 LSA is way too wide for your engine.

Then have the complete Intake system flow tested to see what the actual airflow is at the back of the Intake valve. Otherwise, what you choose is a guess and you then have to be prepared to have made the wrong choice.

Once you have the drop numbers and the airflow, the choice is wide open. You can decide upon Lift, Duration, LSA and the timing.

Remember too, there are many copies of cams out there. Copies of copies of copies. What you end up with often is nothing like the original.

Anyone of good substance supplying cams will be able to provide you with the gross lift numbers at any crank angle at any timing position so the drop numbers can be used to establish the clearances.

Good luck.

Thanks Neil for your input and suggestions. Yes, I still have the heads off and have plenty of time so your approach makes a lot of sense.

[Turbo_pro]

Originally Posted by Neil Harvey

Not to pick apart others opinions. I'm a certified idiot and I have one.

Just because 100+ 964 cams have been sold, does that answer the question or just cement the whole notion of mediocrity when choosing and selling cams.

The question can be asked, how do you sell with integrity a cam to a customer if you do not know any of the actual engine details. You cannot. Its all about guessing and making a sale.

I have no issue with the gentleman selling the "M" Cam discussed here, not divulging the spec's. Its his cam and he can sell it anyway he chooses.

I was the same for many years as the problem selling anything to the DIY community is, it has no problem telling the world what they have bought, spec;s and costs. When you are in business and make your income selling Porsche parts, some of this info can hurt you.

You probably first had a conversation with him, took up the time he would be working making money and asked for him technical help. He probably gave this and suggested his cam design.

Having the spec's changes what? You bought it so use it. Would having the spec's give you any information you can use? Not many here could use any of the technical specs' of a cam profile to any use. How many posts ask "how do I time my cams".

Sure, it can be said, "I bought those cams and in my engine they worked really well". That's a fair comment and one that would help someone. As long as the engine spec's were the same.

One side benefit in designing and selling A-symmetrical cams is not many places want to copy them as the cost to create them is twice the price, Two designs per lobe and if Masters are used 4 masters per cam.

Copying cam designs is something that has been going on since the car was invented. Porsche copied Cam designs designed here in the US by Henry Crane. Porsche had no clue how to design a cam profile back in the day. Not many did. Henry was well ahead of his time and everyone else. He was one of the first to apply differential" math equations when designing cam lobes.

Just about every cam sold is based in some degree on Henry's designs. The only reason that they be different is the "cut and paste" that has gone on for years.

These are mechanical devices that can be mathematically configured. Air flow numbers can be found, VE numbers calculated and Cam choices based on this and other info.

Or, use someone else's trial and error, and their failure to tell you the truth that it did not work as well they had expected. Include your own guess work.

Choosing any engine part is no different for the DIY or the Pro. Both can resort to guessing or do their due diligence. Make you own choice.

Idiot out!.

Wow, that seems rather aggressive. All he was saying is 964 cams are popular. He wasn't claiming any expertise. He sells parts and 964 cam sell well. Where do you get off questioning anyone's integrity?
Get over yourself.
As for "secret cam specs" I would never plan an engine build around an unknown spec. Of course any cam can be measured, the thing is, there are very few "secrets" in the air-cooled Porsche world. Pretending there are is simply an ego trip.

[Neil Harvey]

Working in this business and making my living from it, I have an opinion.

Developing many parts for these air cooled engines I know there are many secrets. Many are ours to keep private. If you feel differently, then I question you do not know this business well. I do agree that there is a side of this business that has stagnated and the same parts are continually sold.

Having had many of our parts copied, particularly our cams, I have reason to say what I have.

As for questioning anyone's integrity, I have good reason to do so. In general as I do not know the person who wrote that he sells 100's of 964 cams it is blanket opinion. Here is why.

I want to sell the very best parts I can. We spend huge amounts of our own money developing parts. Not to mention the time. Cams are just one line of what we do. If a potential customer came to me to buy a set of cams and all I said was I have sold 100's and only comment's given to make the sale was, they were not aggressive enough, then I would say, I failed. I sold them the wrong cam and or I did not listen to what they asked for.

I obviously did not respect the customer enough to ask the right questions and my sales pitch was about all the many I have sold in the past. One cam does not fit all engines. One of the reason some of us stay in business is, we can offer something different, more aligned to what the customer's engine needs. Not just selling what many thinks is better. Never is the 'better" choice proven against what is also available.

This is not what and how I wish to do business. That is called integrity my friend. Our business name is Performance Developments. If we just sold what's is available we would not be developing. We would just be part changers.

I'm not trying to come across as an "ahole", just telling the truth. This is a tough business and one of the part that makes it tough is there is large and strong DIY element. I make my living in this business. I have a strong commitment in making it a better and a more honest community. I take personal pride in this and are offended by those that do not respect the community or the customer. I offer my advice when I can both here and privately.

When I read or see parts just been whored out purely to make a sale without any technical backup, I take it personally.

There are many places that offer different cam choices. The place that designed and sells the "M" cam is one. I do not know of him nor have I ever talked to him. I think. But I have the utmost respect for anyone in this business who dares to try something different and offer it. It makes this whole community better. How he sells it with or without spec's is his business. Not for any of us to criticize. I'm sure the basic spec's are available, lift, seat Duration and LSA. But numbers at 0.050" or whatever the cam was designed with are protected by most.

Cams as you suggest can be copied but then one part of that that helps all of us is, typically the copies are horrible. At least the person who is "stealing" the design was not just handed the info. They at least had to work a little for it.

This is my playground and want to take care of it.

Call me what you like.

[Neil Harvey]

Correction, it is Harvey not Henry Crane.

[aasco]

Please, Please it's Harvey not Henry

[Billthebuilder]

Who is Henry crane ? when I google it I come up with a toilet manufacturer

[Jeff Alton]

Originally Posted by Old H2S

After all this time and the M1 cam specs are a mystery to everyone? It is a Solex cam grind for CIS, and it rips when used with carbs or S type, CP, JE pistons.

You sure about that? It mimics intake and exhaust lift on a stock SC/Carrera cam. Increases duration, from what I was told by the person who devloped it. Again, we had good results, just did not make me think "better" than a 964 on an otherwise stockish 3.0. Just my opinion mind you. And, he was easy to get ahold of and was very free with his time and knowledge.

I would never chose that cam with higher compression pistons and carbs (or itb) as it is, in the big scheme of things, is a VERY mild cam for that sort of application. I am willing to bet the designer of that cam has a design that is better for the application you proposed, He is smart and well versed in the cam designs and applications.

Maybe he will chime in.

YMMV

Cheers

[Turbo_pro]

Question:
3.0SC with 964 cam regrets?

Sold over 100 sets with only regret, maybe not aggressive enough.

Another option is the M1 but specs aren't readily available.

M1 are good but not much to choose between 964 and M1

If you have the inclination you can reinvent the wheel....good luck

"I'm an expert so I only want the PERFECT cam".... if you don't sell the perfect cam you have no integrity.

"This is my playground and want to take care of it."

Maybe saving the condescending attitude will allow others to enjoy this Playground as well.

[Old H2S]

Yes he is, William has built many engines for people on this forum.
My point poorly made is every time a cam argument comes up and I look at the specs there is nothing new, just a new cam between 2 other cams that are well known. Is the new baby going to be a radical change.. No. It will be a new child with the DNA from the 2 parent cams. Might not have the top end of Dad but a better idle and low end from Mom.
My uptake on the M1 secret sauce is it works with stock valve train parts and that leads to longevity of your build.
We have a lot of cam choices here including custom grinds from the top engine builders here on Pelican. These guys are BUILDERS, we are assemblers. We talk, fight, call, listen to advice, discount it, and make a choice.
Neil gave a good procedure for getting the right cam BUT that required more effort for maximum success. As soon as we get out of the Porsche designers comfort zone for street car cams much more measuring comes into the build with higher performance parts required and that leads to lower engine life. If you go to Extreme Head Service and spend more money you can run cams with 15mm of lift, you can not do that on a stock low pressure spring. The 964 cam is still an emissions grind from 1985 and the extra performance it produced required an offsetting clean up somewhere else in the down stream system to pass California requirements. An upgrade in emissions control
made a bigger cam possible. Technology marches on. Which comes back to:
What do you want?
What can you afford?
How fast do you want to go?
How low will it last?
What state do you live in.
Who is capable of maintaining it?
As HENRY said the most common question he gets is "How much to change the cams"

[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.

[Neil Harvey]

In an effort to be transparent, I have attached one of the 964 cam files. This is what we supply with every Camshaft order. It gives all relevant information to install the camshaft with our suggested starting position. We add all of the Valve lifts at this timing position so Piston to Valve clearances can be checked without total engine assembly. I believe this is one of our A-Symmetrical designs.

I am not saying this is what the engine in question should have. This is just an example of what we supply for those that are sure they need a 964 cam derivative.
There may be a better choice by someone else.

Certainly was not trying to be condescending. That was never my intention. However, I have paid my dues in this business to have an opinion that may not be agreed with by many.

As for reinventing the 'wheel", we have. I go back to my statement about how stagnant this community has been for so long. When PD got back into the air cooled world a few years ago, we decided to re invent just about everything required. I have posted some of these parts in my air-cooled development posts.

I read and see posts by Henry and many others including who ever is the person who sells the M1 cam, showing they are always adding new parts and contributing to this community. I take my hat off to them as I know how hard this is. They come on here and offer their advice for free. They do not have to. It all makes this community better. More options gives everyone more choices.

As for "reinventing the Cam Wheel" we have done this. We are one of only very few who offer modern designs for the Porsche 2V air cooled engines. I am not aware of any of the major suppliers offering A- symmetrical designs. We have these for Porsche 2V air-cooled engine displacements from 2.4L up to 4.1L. Remember, the best application is based on air flow numbers and other known spec's.

I cannot remember exactly but I think we have 2 or 3 variations of the 964 Cam. I think we offer a 1/2 step of the stock lobes, new A- symmetrical design of the 964 and its own 1/2 step. We supply these on new billets with any LSA required, within the limits of the chamber and valve sizes. We supply these with a "Cam Card" as shown above.

You cannot copy a Cam profile off a cam card but I guess it could give some a point of comparison and a starting point. Its a choice of the supplier to supply this info. I understand why some may not. If we can offer a good staring position, and info to make the use and assembly go quicker, that's a service we are happy to provide.