Cam upgrade questions

[BrianACR]

I am looking to upgrade from my 'creampuff' cam in the near future. There are quite a few places that have cams for Vipers. Any thoughts or experiences from those of you who have done this to your car? I know Roe Racing has some. Anyone dealt with or used a cam from JMB?
Thoughts and info would be appreciated! Thanks in advance :)

[Vipernoob]

Call Todd at A&C Performance.

[Camfab]

If I was doing it now in 2017 like you. I'd call Arrow and do the Gen IV head conversion with a Gen V manifold. I personally would not spend the time and money to put a cam in to gain virtually nothing but "Cool" factor. Stock heads are the equivalent of 1970's Chrysler port tech. You could send the heads to Greg Good who certainly has proven packages, but stock head castings can suffer from core shift. Greg could likely set you up with a proper set of heads if new castings were out of your reach. One other thing, that 708 cam all the '99 and earlier guys have a hard on for is an old antiquated design. Sorry I had to say it.

[BrianACR]

If I was doing it now in 2017 like you. I'd call Arrow and do the Gen IV head conversion with a Gen V manifold. I personally would not spend the time and money to put a cam in to gain virtually nothing but "Cool" factor. Stock heads are the equivalent of 1970's Chrysler port tech. You could send the heads to Greg Good who certainly has proven packages, but stock head castings can suffer from core shift. Greg could likely set you up with a proper set of heads if new castings were out of your reach. One other thing, that 708 cam all the '99 and earlier guys have a hard on for is an old antiquated design. Sorry I had to say it.

I wish a full head conversion was in the budget, sadly its not. Makes it even worse that the Canadian dollar is low. IT costs me an extra 30+% on everything I purchase.
I'm not going for big power in this venture. I just want a bit more kick and better sound. I don't track my car either.

[Camfab]

Ok, then at the very least call Greg. He will set you in the right direction. Your going to want to change your lifters as well. The high bleed lifters are the opposite of what your trying to achieve.

[slitherv10]

If I was doing it now in 2017 like you. I'd call Arrow and do the Gen IV head conversion with a Gen V manifold. I personally would not spend the time and money to put a cam in to gain virtually nothing but "Cool" factor. Stock heads are the equivalent of 1970's Chrysler port tech. You could send the heads to Greg Good who certainly has proven packages, but stock head castings can suffer from core shift. Greg could likely set you up with a proper set of heads if new castings were out of your reach. One other thing, that 708 cam all the '99 and earlier guys have a hard on for is an old antiquated design. Sorry I had to say it.

Any idea what this would cost. Roughly of course.

[Viper Specialty]

I am looking to upgrade from my 'creampuff' cam in the near future. There are quite a few places that have cams for Vipers. Any thoughts or experiences from those of you who have done this to your car? I know Roe Racing has some. Anyone dealt with or used a cam from JMB?
Thoughts and info would be appreciated! Thanks in advance :)


We have multiple cams available, and none of our cams drive like hell, and are all able to pass OBD2.

[Viper Specialty]

Any idea what this would cost. Roughly of course.

Our package is 17K, installed and tuned, including headers, cam, tuning, K&N, and every other needed component... in a much fancier package than the Arrow version.

[BrianACR]

Ok, then at the very least call Greg. He will set you in the right direction. Your going to want to change your lifters as well. The high bleed lifters are the opposite of what your trying to achieve.
I have HS 1.7 rockers, and some lifters as well.


We have multiple cams available, and none of our cams drive like hell, and are all able to pass OBD2.
Good info. Thanks!
I'm not worried about passing any OBD2 stuff. No emissions requirements here....yet

[99RT10]

I have a set of Gen 3 heads modified to work on a Gen 2. Greg does not like to do Gen 2 heads because they tend to crack. The gen 3's are just a better casting and flow better. PM me if interested.

https://driveviper.com/classifieds/engine-and-drivetrain/p1457-gen-3-heads-modified-for-gen-2.html

[Viper Specialty]

I have HS 1.7 rockers, and some lifters as well.


Good info. Thanks!
I'm not worried about passing any OBD2 stuff. No emissions requirements here....yet

Not so much what I was getting at. A cam that is not able to properly pass OBD2 will also be a tuning headache- the two go hand in hand, as the inability for the closed loop system to operate properly will cause drivability issues.

[BrianACR]

Not so much what I was getting at. A cam that is not able to properly pass OBD2 will also be a tuning headache- the two go hand in hand, as the inability for the closed loop system to operate properly will cause drivability issues.

Ah ok that makes perfect sense! Thanks for clearing that up :)

[SlowPoke McGee]

Not so much what I was getting at. A cam that is not able to properly pass OBD2 will also be a tuning headache- the two go hand in hand, as the inability for the closed loop system to operate properly will cause drivability issues.

Sorry this sounds like French to me and I'm not ashamed to admit it. :)


Ah ok that makes perfect sense! Thanks for clearing that up :)


Good maybe you can translate it for me:smilielol:

[plumcrazy]

One other thing, that 708 cam all the '99 and earlier guys have a hard on for is an old antiquated design. Sorry I had to say it.

THIS ! there are much better options

[SlowPoke McGee]

THIS ! there are much better options

I keep hearing that. But better for what? Track racing? Quarter mile? Red light burn outs?Cross country? What other mods are on the car? Wouldn't it make sense to figure out what the intended purpose and design of car is first and then decide if there's something better? The 708 is a tried and true cam at a great price point for entry level street applications.

[Viper Specialty]

I keep hearing that. But better for what? Track racing? Quarter mile? Red light burn outs?Cross country? What other mods are on the car? Wouldn't it make sense to figure out what the intended purpose and design of car is first and then decide if there's something better? The 708 is a tried and true cam at a great price point for entry level street applications.

The 708 cam is a waste of money. It is BARELY different than stock creampuff specs. You can go with a moderate cam grind and give up absolutely nothing while gaining across the board. Its not until you get to the more aggressive cams that it starts to become a bit a of "give and take".

[ACR_VP]

The 708 cam is a waste of money. It is BARELY different than stock creampuff specs. You can go with a moderate cam grind and give up absolutely nothing while gaining across the board. Its not until you get to the more aggressive cams that it starts to become a bit a of "give and take".

To add to Dan's expert knowledge (not like I could really add anything), think of it this way, the 708 cam is over 20 years old, in all the years since obviously many many different cam grinds have been tried and tested, trust Dan on this one. Also he puts together a great package, I'd have gone with him for my build, but logistically it worked out way better to use arrow, and I needed basically everything replaced except for the block haha FML

[BrianACR]

The 708 cam is a waste of money. It is BARELY different than stock creampuff specs. You can go with a moderate cam grind and give up absolutely nothing while gaining across the board. Its not until you get to the more aggressive cams that it starts to become a bit a of "give and take".

Thanks for the great info Dan!!
I will definitely be going with something 'better' than the 708 after reading all the comments posted.
Thanks guys for all the words of wisdom

[mackzilla]

+2 for Dan. I just bought my cam package from him 3 weeks ago.

[ViperTony]

THIS ! there are much better options

Agreed its a waste. Dan is the man heed his advice.

[Martyb]

So ive heard many say the 708 is a waste, I spent money adding one to my 01 GTS a few years ago so I guess I blew it. I wanted a cam that made a little noise at idle and would run fine on the factory pcm, which is why I went the route I did.

My question is, with all of these great cams available, has anyone truly measured the gains vs a 708? If so what type of hp/Tq gains were seen over the out dated 708?

[tagoo]

I think it is wrong to assume there was any gain with a 708 cam. I'm no cam expert, but I've been convinced that a high performance cam typically has more lift and more duration than a lower performance cam. The 708 cam had the same lift (actually .001 inch more) and the same duration as the later cam. It did have 6 degrees more overlap which makes it sound better. When they changed the cam in 2000, there was no stated decrease in power. In fact, there are a number of threads that suggest the 2000 made more power than the 1999. I don't want to start that discussion again. I just use that info a further evidence that the 708 cam makes little, if any, more HP than the 2000 and later cams.

Greg Good specified a cam for my 2000 GTS that had both more lift and more duration. It sounds awesome and combined with GG heads, 1.7 roller rockers and belenger headers makes 150 more WHP than stock. Unfortunately I don't know if anyone has done back-to-back comparisons with just a cam swap. People usually do heads or headers or rockers at the same time.

[Dan Cragin]

Dan Lesser is correct.

There are some great cams out there now that are easy to tune, make good power and pass emissions. We just did a Gen 3 with 10.1 compression, bigger intake valves (no porting) and a 232/238 116sep cam.

It made 650hp. Passes emissions and makes power 2000-6200rpm. Needed to run special lifter and pushrods, otherwise that was it.

[slitherv10]

Dan Lesser is correct.

There are some great cams out there now that are easy to tune, make good power and pass emissions. We just did a Gen 3 with 10.1 compression, bigger intake valves (no porting) and a 232/238 116sep cam.

It made 650hp. Passes emissions and makes power 2000-6200rpm. Needed to run special lifter and pushrods, otherwise that was it.

Was this accomplished with the Gen IV head conversion with a Gen V manifold or a different set up? At what cost is your set up?

I'm trying to garner whether its worth dumping another 17K into my 1996, or save to the money, sell the car and move into a Gen V.
I know most will say its up to what car you want and the type of driving you do. I cruise 90% of the time. When i do i am out there for 3-5 hours sometimes in 26 degree celsius (79 F) weather. So I need it to withstand the temps and not overheat. Driveability is very important.

[Martyb]

Again, has anyone done a cam only swap to see what gains are made over the 708? Swapping heads, exhaust, rockers, etc is not a fair comparison.

[Camfab]

I'm betting Dan has, likely both Dans.

[Viper Specialty]

Was this accomplished with the Gen IV head conversion with a Gen V manifold or a different set up? At what cost is your set up?

I'm trying to garner whether its worth dumping another 17K into my 1996, or save to the money, sell the car and move into a Gen V.
I know most will say its up to what car you want and the type of driving you do. I cruise 90% of the time. When i do i am out there for 3-5 hours sometimes in 26 degree celsius (79 F) weather. So I need it to withstand the temps and not overheat. Driveability is very important.


The one that Dan was quoting is not a conversion package, it was a Gen-3 with modified Gen-3 heads and a moderate cam.

I think you may be confusing "Dans", because the price indicates you were referring to our package.

Drivability is the most critical factor in anything I build. If it wont drive well, wont build it. Period. I have turned away more potential basket-case builds than I can count.

[Viper Specialty]

Again, has anyone done a cam only swap to see what gains are made over the 708? Swapping heads, exhaust, rockers, etc is not a fair comparison.

Technically, what you are asking for is basically a 1999 vs a 2000. Why even bother with the cam swap? It is splitting hairs, just compare a few stock cars and average them out. I for one, would never waste the time to do that comparison, thats a lot of money in gaskets, time, and hassle for basically nothing.

[Dan Cragin]

For those that currently have a 1996-1999 GTS with the production 708 cam. If you are considering doing cylinder head work and not doing a cam change, I would strongly suggest setting the intake centerline
of the production cam at 117 degrees and milling the heads for a .2 increase in compression. We have achieved the best results with this. Never seen more than 520rwhp with a 708 cam.

[Martyb]

Technically, what you are asking for is basically a 1999 vs a 2000. Why even bother with the cam swap? It is splitting hairs, just compare a few stock cars and average them out. I for one, would never waste the time to do that comparison, thats a lot of money in gaskets, time, and hassle for basically nothing.

But in my opinion it's the only way to see the gains from the better cams Dan. I have heard so many times that I wasted my money doing the upgrade to the 708. So can you substitute a better cam, have the same driving manners, run on the factory pcm and gain 35 horsepower with the so called better cams? I'm just asking, I honestly don't know.

[WDW MKR]

But in my opinion it's the only way to see the gains from the better cams Dan. I have heard so many times that I wasted my money doing the upgrade to the 708. So can you substitute a better cam, have the same driving manners, run on the factory pcm and gain 35 horsepower with the so called better cams? I'm just asking, I honestly don't know.

Are you saying you gained 35 rwhp with only a swap to the 708 cam in your '01?

[Fatboy 18]

I wish a full head conversion was in the budget, sadly its not. Makes it even worse that the Canadian dollar is low. IT costs me an extra 30+% on everything I purchase.
I'm not going for big power in this venture. I just want a bit more kick and better sound. I don't track my car either.

Respectfully, the monies people are talking here for modifying the engine (Heads and Cam) seem crazy for a few extra HP!

Many say the best bang for buck is to go with 355 rear end which makes the car feel much faster.
As for sound, the exhaust note that comes out of my car is armageddon! Its simply Awesome.
I still have stock headers (I did buy a used set of Belanger Headers off the Alley, had them shipped to the UK,only to find I was stitched up as one side were bent and had previous patch repairs) :stickmen_burningsti

Anyway back to my set up. Stock headers, into 3" tube cat delete and belanger cat back exhaust, that equates to 127db and sounds Awesome!

[Martyb]

Are you saying you gained 35 rwhp with only a swap to the 708 cam in your '01?

No, that's just a number I threw out. Just wondered what kind of numbers the better cams could generate while keeping stock drivability, run on stock pcm, etc.

[Viper Specialty]

But in my opinion it's the only way to see the gains from the better cams Dan. I have heard so many times that I wasted my money doing the upgrade to the 708. So can you substitute a better cam, have the same driving manners, run on the factory pcm and gain 35 horsepower with the so called better cams? I'm just asking, I honestly don't know.

Note quite. You stated you were curious about a 708 cam swap in a creampuff. My argument is that it is pointless, and a ton of time and effort for virtually nothing. The 1999 vs. 2000 is effectively the same comparison, and based on average numbers, there is no significant difference between creampuffs and earlier engines in stock form. Hence, why its an irrelevant cam swap to bother with. The cams are literally nearly the same specification with a slightly different lobe separation angle.

If you are now making the argument for Cam-Only Gen-2 swaps vs. the 00+ cam, that is a completely different conversation altogether, and yes, there are substantially better cam grinds out there then the 708, that make more power, drive like stock, and have no issues. The costs for one of these setups would be nearly identical to swapping the 708, its the same parts and process... so why bother with the 708? I think that is the argument everyone is making.

All that said, the Cam isn't the issue. The Gen-2 heads are the main problem with making lot of power, they simply don't have the flow of later heads. So far as the limits of properly driving cars, look no further than our own VS-X700 package. These setups make 700 horsepower, on the OE PCM, drive like a factory setup, WITH CONVERTERS and still pass emissions! To add insult to injury, this is done without even porting the heads yet. This is a 250 horsepower gain over stock... so, yes, there are substantially better setups than stock, in many ways.

Do I have numbers for cam swaps on stock heads? Nope. Personally, I would not bother, and same argument applies. Its a lot of money and work to try and squeeze power out of heads that are sub-par at best, swapping Viper cams is not like an LS1 to say the least. Its a given they will make more power than a 708 just based on extrapolated evidence, it doesn't take a rocket scientist to come to that conclusion given how small the OE cam actually is. But, how much of a gain with no other changes in the heads... that I could not really tell you. I would expect Gen-2 castings without porting to top out somewhere in the 525-550 range, and no cam no matter how large is going to push them much further, and of course the drivability is going to suffer.