All,

I recieved a recommendation from Comp on a cam for my engine build. I would like some educated opinions on that. Thanks

I have a cam that I think would work well for you. It is 08-468-8. The rpm range is 2200-6200. Duration @ .050 is 242 248 with valve lift of .584 .579. We need to change a few things about the cam though. We would need to put it on a small base circle to make sure you have ptv clearance. We may also want to widen the LSA to 114 to help with the nitrous when you spray.





Camshaft Recommendation Request




Note To Customer: The information below has been received by CAM Help� tech support. This email is for your records.




CONTACT INFORMATION




First Name:


Doug


Email:


dwsatterfield@yahoo.com




Last Name:


Satterfield


Day Phone: (8am-5pm CST)


479-670-4139




VEHICLE INFORMATION




Make:


Pontiac


Model:


Trans Am




Year:


1997










Weight:


4000 lbs.


Axle Ratio:


4.10




Transmission Type:


Manual


Overall Tire Height:


25.66




Torque Converter Stall Speed:


NA










ENGINE INFORMATION




Engine Block Type:


Chevrolet


Engine Family:


Chevrolet V8 265-400 1957-1998 with 1.5 Rockers




Engine Size:


383 c.i.










Number of Cylinders:


8


Bore:


4.30




Stroke:


3.75


Compression Ratio:


11:1:0 tenative




Connecting Rod Length:


6.00










Intake Manifold Type:


LT4 ported







Cylinder Head(s) Brand:


TEA/Trick Flow










Head Runner Volume:


205 cc


Ported Heads:


Yes




Intake Valve Size:


2.02


Exhaust Valve Size:


1.60




Rocker Arm Type:


Full Roller


Rocker Arm Ratio


1.6:1




Exhaust Headers:


Yes










RPM Range Low:


2000


RPM Range High:


6500




Nitrous Oxide:


Yes


Horsepower from Nitrous:


200 hp




COMPUTER CONTROLLED VEHICLES




Vehicle Computer Type:


Stock










Speed Density Sensor:


No










Mass Air Sensor:


Yes










FUEL DELIVERY




Fuel Type:


Pump Gas


Fuel Octane Rating:


94




Carburetor:


No


Carburetor Size:


N/A




Direct Port Injection:


No










Electronic Fuel Injection:


Yes


Custom Tuned:


No




AIR DELIVERY




Turbo Charger:


No


Supercharger:


No




Max Boost Level:


N/A










APPLICATION SPECIFICS




Application Type:


Street & Strip


Other Application Type:


N/A




Race Class (If Applicable):


N/A










VALVE TRAIN SPECIFICS




Desired Lifter Type:


Hydraulic Roller
Type: OE Hyd. Roller Engine










What type of camshaft are you currently using?




Camshaft Brand:


None


Part Number:


N/A




Specs:


N/A









Considering the current peformance of your vehicle, do you need:




More Low Speed Torque?


Yes


More RPM?


Yes




Is Idling Speed Important?


Yes


Is Emissions Compliance
Important?


No




Does Your Vehicle Currently Use the Following:




Air Conditioning?


No










Power Steering?


Yes


Power Brakes?


Yes




ADDITIONAL INFORMATION:




I am building this engine from the grounnd up to replace my bolt on stocker. The vehicle is used on weekends exclusively. I would like it to be a street monster. It will be run at the track maybe once or twice a year(its been over three since I've had it there). The nitrous will be seldom used. Pretty much only when racing. The bottom end is all forged, 4bolt splayed and should take anything that I throw at it. Email is the best way to get in touch with me. Please let me know if there is any other info that will be helpful for a good recommendation. Thank you for your help.

 

I'd completely disregard that recommendation.
That "tech" at Comp or whatever he/she is, is clueless about powerband in an LT1 and about nitrous applications. A 200 shot on a 383 is not nitrous cam territory and does not call for any departure from what you'd choose for your "street monster" NA use. You wouldn't make use of that cam's powerband with a stock PCM.
For your stated minimal track use, I think you want to target some lower duration numbers, maybe mid 130's, to get a more useable powerband for a street brawler. Numbers are just generalizations though.
Letting AI or LE spec a cam for you is going to put you miles ahead of relying on some "tech" at a company like Comp, and will bypass the bias you'll get on here from albeit knowledgable folks who have had success in their OWN applications. And I'll be the first to admit I fall into that category.

 

The Comp rpm ranges are completely wrong and seem to be based on gen 1 longer runner intake manifolds. Expect it to peak at or above the 6500 you are hoping to use as a limiter and need to go all the way to 7000.
The idea of spreading the LSA further from it already too ******* wide point for a little 200 shot just adds more evidence of the incompetence with which this cam was recommended.

11:1 compression is too low, most heads/cam cars run more and nitrous likes compression just fine remember is drastically lowers IAT, Boost on the otherhand raises IAT which is part of why it needs low compression and for some reason people like to missapply that idea to nitrous.


Whatever incompetent you are getting your guidance from and half of this forum will all argue with me BUT.
https://ls1tech.com/forums/lt1-lt4-m...ast-night.html
Pretty sure that cam is lower duration and tighter LSA and this is with lowly ported GM heads and LT1 intake.
That car is also genuinely over 4000lbs not pretend 4000lbs like you told them your car was.

 

4k pounds??!! Get your SCR up to the 12:1 range.

 

What in the world would a small base circle have to do with valve to piston clearance??????

ptv clearance is about actual lift at different given durations. Small base circle or stock base circle, it would still be the same if the lobe lift is the same. Why does this person have a job answering tech questions at Comp or any cam company? Maybe it's a typo and they meant to say cam to connecting rod clearance since it's a stroker and sometimes that is a problem. ???

 

If I were going to run a shelf Comp cam with that combination, it would probably be the xfi280.

 

The 280 would be a better choice with his self imposed 6500rpm limit, still though with a little 200 shot I would keep the LSA tighter unless emissions was a concern.

Generally you don't need to start thinking about a "nitrous grind" till 250+ shot. For a 200 shot I might add a couple more degrees exhaust duration but would not be spreading the LSA because spreading the LSA hurts peak torque and NA performance.

Most of the quick NA hydraulic cars run 107-110LSA.

Before someone jumps is in Yes I know LSA is not the most critical aspect it is valve events and overlap you are looking for, but the easiest shadetree way to talk about it is LSA.

 

Right, The LSA is usually a function or result of the desired cam specs. Opening up an "established" cam can have adverse affects on the power curve.
I also agree that a wide LSA is not needed on a relatively average shot of nitrous.

 

I applaud you for asking an opinion on a part BEFORE you bought it. Too many times on this forum people ask for opinions AFTER, and then get all butt hurt when people tell them it was a stupid purchase. You need to have someone who specializes in LT engines spec a cam, and your compression ratio. Not someone who is used to gen 1 sbcs.

 

I still am shocked noone has commented on this besides me!!

I agree 100% For barely more than the price of a new shelf cam, you can get someone who knows what they are doing to spec a custom grind for you. Or you could do like me and pick up something that will work "good enough to suit you" used and cheap. LOL

 

I meant to mention that too, but forgot about it after typing my other points above. Saw later that you mentioned it, and thought "Good!" Figured I didn't need to be another forum parrot!
But seriously, yes, that was just another indicator that the "tech" didn't know his **** from a hole in the ground.

 

I missed it completely and didn't bother to cover it once you had.

What I find interesting though is he has not come back.

Did we hurt his feelings and he doesn't want our input? Or id we cause him to stop and reexamine it all?

 

I was beginning to wonder if I was missing something and was just wrong. LOL

 

He was last seen as active by the forum 30 minutes after this was posted.

 

Not everyone checks threads every 30 minutes like some of us, maybe he just was on his lunch break.

 

Maybe he forgot to "add a subscription" and he doesn't know people have replied to the thread he started. LOL

 

it's been 4 days..................

 

 

I wasn't really sure if that was for us or just part of the big cam order cut and paste. Either way each of us emailing him is a joke, this wasn't his first post.

 

I agree. I think he should go with a Prison Sex 2 cam from AES.