The "Right" Cam

[FAST3V]

S&H is building my TT Kit..and I am preparing on my end. I've been thinking that my current cams might not be that good for the setup, so I'm considering switching them out for another custom grind. What say you smart folk?

Gross Valve Lift: .535 .555
Duration @ .006 Tappet Lift--- 264 279
Valve Timing Open @ .050--- 12 36
EXH: 58 bbdc 2 atdc


Specs for Cams installed:
102 intake center line
duration @ .050 229 240
Lobe Lift .5350 .5550
Lobe Separation: 110


Will these work, or do I need a serious change?

 

[jodadejss06gt]

I'll give you my specs, can't say how well they perform just yet though...

Duration @ .050 222/227
Separation 115.5
TE @ .050 Intake: OP 0 / CL 42 Exhaust OP 53.5 / CL -6.5
GVL: .525/.525

built by Bullet Racing Cams, call them up and get an idea of what he'd like to put in your car based on turbo sizes, CR, trans, weight, etc.....

 

[FAST3V]

Yea, that's a lot different than mine. I'll do that. The more opinions I get, the better.

 

[tigerhonaker]

Leo,

This is just a (Suggestion) ............

If it were me I would go with the shop doing the work on mine.

They should know which cams are the best choice for your combination.

Terry

 

[hamish]

Big difference in lobe seperation.
Bullet cams you say...hmmmmm might have to give them a call.

 

[lito]

Not all cams are for everybody, depends on what you want out of the car, if track only car, how driveable you want it, how you would like your idle? Before keeping your current cam on the turbo setup probably the stock one would be better.

For custom, I suggest giving Michael at LM engines a call and discuss your plans with him, pretty sure he will ask who will tune your car.

If you plan to street your car, you can have a nice mannered cam that performs (the one he ground for me while turbo'd, is).

 

[BadPiggy]

I'm thinking a custom grind from RGR through JPC. I'd give them a ring and talk it over. RGR custom grind is no more expensive than anything else out there.

 

[FAST3V]

Tiger, I do all of my own work.

Thanks guys.

 

[RED09GT]

You'll likely get backpressure issues with those cams, even with the twins. The overlap is a problem as well.
Sell 'em, recoup some cash and get a fresh pair of cams ground.

awesome autocorrect malfunctions brought to you by tapatalk

 

[TexasBlownV8]

Can someone explain how backpressure can be affected by the duration changes? Is it because the exhaust is open longer, to make the engine breathe better under other f/i operations, but with turbo, you want a shorter duration to get better spooling?

If going back to stock cams, would springs need to be changed as well? What about VCT?

(yeah the "shop" doing the install has no "experience with spec'ing out cams"..only putting them in.)

 

[v8venomgt]

I've heard 2nd hand from an extremely reputable tuner that hotrod cams are the way to go in most applications. Despite them not making the most peak power out of *xyz* combination they maintain average power best with acceptable gains. Until 7k+ rpms at least. He also stated that they wont make as much power as a ground specifoc cam or custom cams, but they offer good gains, and more average power throughout the rpm band. Considering this tuners experience and name I'd be highly skeptical to challenge it personally but found it to be an interesting statement since he also grinds cams.

 

[FAST3V]

In both Mike and I's application..we wouldn't do anything short of a Custom Grind Cam. 1k + HP demands custom grind...NOT shelf cam.

 

[BruceH]

I've heard 2nd hand from an extremely reputable tuner that hotrod cams are the way to go in most applications. Despite them not making the most peak power out of *xyz* combination they maintain average power best with acceptable gains. Until 7k+ rpms at least. He also stated that they wont make as much power as a ground specifoc cam or custom cams, but they offer good gains, and more average power throughout the rpm band. Considering this tuners experience and name I'd be highly skeptical to challenge it personally but found it to be an interesting statement since he also grinds cams.

For a turbo? Who is your tuner? I was under the impression that an lsa of 114-115 was more ideal for a turbo. Something to do with spooling it.

 

[BruceH]

S&H is building my TT Kit..and I am preparing on my end. I've been thinking that my current cams might not be that good for the setup, so I'm considering switching them out for another custom grind. What say you smart folk?

Gross Valve Lift: .535 .555
Duration @ .006 Tappet Lift--- 264 279
Valve Timing Open @ .050--- 12 36
EXH: 58 bbdc 2 atdc


Specs for Cams installed:
102 intake center line
duration @ .050 229 240
Lobe Lift .5350 .5550
Lobe Separation: 110


Will these work, or do I need a serious change?

That's a Comp 127450 with 110 LSA instead of 113.

 

[FAST3V]

Thanks Bruce. Good to know my previous custom grind was BS. :/

 

[v8venomgt]

For a turbo? Who is your tuner? I was under the impression that an lsa of 114-115 was more ideal for a turbo. Something to do with spooling it.

i actually went a different route as far as who i had tune my car. i always go against the grain. that said, those words came out of modular powerhouse. i wasnt present for that conversation though. that said, i guess my car was brought up (my friend was having his 3v car tuned there), and while the hotrod cams arent 100% *ideal* for a turbo application, theyre still well suited from my understanding because of how it maintains average power throughout. thats my very, very rudimentary understanding of a conversation i wasnt present for. IMO, tim knows mod motors extraordinarily well and has a highly proven track record from my understanding. i dont think hes as internet famous as he once was when he had the MPH forum/store going in the earlyish 2000s, but i think his perspective his worth noting due to his experience.

 

[BruceH]

Thanks Bruce. Good to know my previous custom grind was BS. :/

I'm sorry. It sounds like a great cam to me. Not so sure about with a supercharger but I don't claim to know any more than enough to get into trouble with.

I've run cams with a 112 LSA and supercharger before. Worked great. Also ran Hot Rods (110) with one and they worked just fine but not as much power as the 127400 (112).

 

[TexasBlownV8]

My specs: (intake, exhaust)
Gross valve lift: .547 .560
duration @ .006 tappet lift: 272 287
valve timing @ .050
open close
int: 14 btdc 42 abdc
exh: 70 bbdc 2- atdc

installed at 104.0 intake center line:
duration @ .050 237 248
lobe lift .5470 .5600
lobe separation 115.0

"lsa" 115..hm...

 

[retfr8flyr]

I got mine from Comp and they are basically the 127500 but on 115° lobe separation. l like them a lot. I would give the guys at Bullet a call and they will go through your whole combination and recommend a grind for you. They don't cost any more then the Comps, from what I hear.

 

[FAST3V]

getting a lot of recommendations to Mark @ Bullet Racing Cams