That dreaded cam selection question!

[CTX-SLPR]

Howdy,

I've got the block, I've got the pistons, I've got the crank, I've even got the front cover. Now its time to pick a cam! I'm going roller since I have the lifters and 1.65:1 T&D's. The thing is, I'm also sort of broke so I've found a pair of used rollers both comp ductile units. One is the 206/206 and the other is the 212/212. On a 4.1 with about 8.3:1 compression, stock irons for now, and a nice big turbo, thinking GT42R sized turbo, how much difference would there be between cams? Enough to forget the small one or are they both viable options?

Thanks,

 

[Blown&Injected]

Do you really believe there is gonna be a definitive answer to this question?

Sounds like a strong engine so go with the bigger cam. I have been thru lots of cams in the GN and to be honest, there are other changes (confounding variables such as different chip and injectors at the same time as the cam swap) that happen that do not yield a fair comparison.

I'll bet most people do not do adequate testing before and after nothing but a cam change so comments may be hard to find on such a small difference as 206 vs 212.

After all that is said, my cam that was heavy on the exhaust seemed very good - that's how the factory did it.

 

[CTX-SLPR]

Not really looking for a definative answer as much as I want to see the debate and weigh the evidence. The motor will be running either an extender extreme or one of BoostKillsStress's WBO2 chips with the extender extreme stuff on board for the Trans+ to work. Planning on running 72's, 3.42 rear gears through a TH200-R4 with a 2800-3000 stall lockup. The car will be mainly a street and cruiser vehicle but I will be planning on hitting the drag strip atleast a dozen times a year.
More commentary is always apprecated.

 

[NCTURBOS]

My gray car had a 206/206 with 3188 lobes, and I really liked that cam. Very streetable! My blue car car has a 206/206 with 3311 lobes, and I guess that car runs pretty well. I like the 214/214 with 3190 lobes as well.


K.

 

[CTX-SLPR]

I wish I could get my hands on a PTE 214/214 roller used but that doesn't seem to be happening so I'm settling for what I can get now since I do need to get this finished up. Does Comp offer both the 206's in Rollers? I'm sticking to roller cams.

Thanks,

 

[NCTURBOS]

They are Weber Racing grinds, you can call them. Weber also offer the 214 I listed.

Weber Racing (440)327-7702

K.

 

[frankg]

I like the 212-212 Cam. Frank

 

[87GN_70GS]

Comp has the 3118 lobe which is the 206 magnum/high-energy hyd roller profile, and .333" lobe lift. Comp also has the 3107 which is 210 deg and .333" lobe lift. The 3108 is 215 deg and .333" . In the Xtreme energy profiles; the 3188 is 206 deg and .336" lift, the 3312 is 212 deg and .325", the 3190 is 214 deg and .353". The magnum/hi-energy series will be less noisier and easier on the valve train. With the 4.1L, I would go with the 3108.

Have you seen these ???:

http://www.gnttype.org/techarea/recipes/41recipe.html
http://www.turbobuicks.com/articles/4point1ForCheap/

HTH

 

[VadersV6]

Where do you want your powerband to be? If the heads/intake/exhaust are up to the task, every 10-15 degrees@ .050 over stock will move your powerband up about 500rpm. That is, assuming overlap is equally affected. If its mostly a street car, it will probably be faster with the 206....especially given that you're running stock heads. Screw the cam. Port those heads. Concentrate on the pockets, the roofs of the ports and do a 3 angle backcut on the valves. (45/30/15).

 

[CTX-SLPR]

Well it will be a street car and I have a set of half ported stockers that I'll finish up one of these days but I want an engine that will run well with un ported stockers and then run better with the ported ones later. I'm thinking about getting some of the proffessionally done ones if I can afford them, but I'm thinking that I'll need that money for a tranny, brakes, and the other myriad of things that come with making a hybrid.

Thanks,

 

[John Wilde]

Well it will be a street car and I have a set of half ported stockers that I'll finish up one of these days but I want an engine that will run well with un ported stockers and then run better with the ported ones later. I'm thinking about getting some of the proffessionally done ones if I can afford them, but I'm thinking that I'll need that money for a tranny, brakes, and the other myriad of things that come with making a hybrid.

Thanks,

I have a couple comments.

-Both cams are to small for a 4.1
-Your turbo is to big for the rest of your combination and it wants a 4 to 5 inch dp
-the converter is not big enough to spool on the street.

Maybe we should get you a GT-40R 67

 

[CTX-SLPR]

I really do want that GT40R but from what I heard they aren't making the GT40 in an ball bearing. I plan on running a 3" external gate downpipe with either a single or a pair of deltagates, already have'm. I would greatly appreciate any advice John. The reason I want that 212/212 is that it's a good $100 under a new one and is near new anyway. I really like the PTE billet 214/214 but I'm not really wanting to go back to the machine shop for a retention setup.

Thanks,

 

[John Wilde]

I really do want that GT40R but from what I heard they aren't making the GT40 in an ball bearing. I plan on running a 3" external gate downpipe with either a single or a pair of deltagates, already have'm. I would greatly appreciate any advice John. The reason I want that 212/212 is that it's a good $100 under a new one and is near new anyway. I really like the PTE billet 214/214 but I'm not really wanting to go back to the machine shop for a retention setup.

Thanks,

The Garrett Sponsored Racers are running the GT-40Rs.
I am not sure how easy they are to get for us normal people.
Get the 212/212 and we will find you turbo to fit your needs.
Are you stuck on a GT Turbo or do you want ball bearing?
If you just want BB Innovative can build you a BB in almost any size.
I am pretty sure that Jack C could help you out on the Turbonectics Stuff.

This was taken from Garrett's Site

Driver Matt Hartford
Vehicle Summit Racing / Hartford Enterprises
2004 Chevrolet Cavalier
Where Seen NHRA Sport Compact Pro RWD
NOPI Pro Compact
Career Bests 6.523* ET at Atco, NJ (5/15/05)
* current track record 215.05 mph at Atco, NJ (5/15/05) - Also No. 12 on All Time NHRA Summit Sport Compact Drag Racing Winners List
Garrett Twin GT40R Turbos
2003 NOPI Atlanta Race War Champion
No. 14 on All Time NHRA Summit Sport Compact Drag  Racing Winners list
2002 NHRA Summit Sport Compact Champion: Modified  Division

 

[CTX-SLPR]

Get the 212/212 and we will find you turbo to fit your needs.
Are you stuck on a GT Turbo or do you want ball bearing?
If you just want BB Innovative can build you a BB in almost any size.
I am pretty sure that Jack C could help you out on the Turbonectics Stuff.

I'm honestly looking for a turbo that will let me run a good top end and utilize those extra cubes from the 256cid motor while still running a ~3000 stall lockup for the street. I'd like to have as much power at as low of an rpm as possible since the high rpm stuff really rachets up the stress levels on the motor.
From working in the research lab and calling the bearings guys, ball bearings are the way to go for low friction if you can make sure that they don't get debris in them. I plan on running an external double filter setup and running oil straight from there to the turbo like a turbo-luber setup. I plan on putting some sort of rev limiter on it to keep it below 6k since I don't want to over stress the block and bust the valley open or crack one of the main bulkheads as I am running 3 billet caps but no girdle.

Thanks,

 

[John Wilde]

I'm honestly looking for a turbo that will let me run a good top end and utilize those extra cubes from the 256cid motor while still running a ~3000 stall lockup for the street. I'd like to have as much power at as low of an rpm as possible since the high rpm stuff really rachets up the stress levels on the motor.
From working in the research lab and calling the bearings guys, ball bearings are the way to go for low friction if you can make sure that they don't get debris in them. I plan on running an external double filter setup and running oil straight from there to the turbo like a turbo-luber setup. I plan on putting some sort of rev limiter on it to keep it below 6k since I don't want to over stress the block and bust the valley open or crack one of the main bulkheads as I am running 3 billet caps but no girdle.

Thanks,

Check this out..../

http://www.atpturbo.com/Merchant2/m...OD&Product_Code=GRT-TBO-007&Category_Code=GRT

 

[CTX-SLPR]

ooooooooo, I'm drooling over here. Then I nearly choked when I saw the price $1.5k thats going to take a huge bite out of the budget. Might make me run a TH400 till I can afford a TH200-4R from Lonnie or CK. Guess you pay a price for the best.

 

[VadersV6]

Just use another 4.1 turbo combo as a measure. Look at their power curve, if its available, and adjust your cam accordingly, to where you want your powerband to be.
I would never use a hot cam with stock heads. Heads can yield tremendous gains compared to a cam, if they flow right, and the bottom end/midrange will not be hurt like it will be with a cam. So, if you choose some heads that have really good low lift flow numbers, you wont need alot of stall, and the turbo will spool up great. Dont worry about the peak flow numbers. Those are only good for bragging rights, but they dont mean squat in the real world.
Heads are the foundation for power. I would just be patient and focus on getting some real heads. Then just about any moderately sized cam you run will work well.

 

[CTX-SLPR]

Just use another 4.1 turbo combo as a measure. Look at their power curve, if its available, and adjust your cam accordingly, to where you want your powerband to be.
I would never use a hot cam with stock heads. Heads can yield tremendous gains compared to a cam, if they flow right, and the bottom end/midrange will not be hurt like it will be with a cam. So, if you choose some heads that have really good low lift flow numbers, you wont need alot of stall, and the turbo will spool up great. Dont worry about the peak flow numbers. Those are only good for bragging rights, but they dont mean squat in the real world.
Heads are the foundation for power. I would just be patient and focus on getting some real heads. Then just about any moderately sized cam you run will work well.

Well I have no cam at all to begin with so I need one. I already have roller lifters and thats a lot of the battle in getting a roller, especially a used one. I do plan on doing the heads, but right now I have 0 time, working 40 hours a week and taking 10 quarter hours at night leaves very little time for much more than my girlfriend and she is more important than this project by a good margin. I'll do the heads, don't worry about that, just I want a cam for now and for later.