cam centerline opinion

[Nuttin_but_Dust]

Been a while, I have a engine putting together for a guy, he ordered a comp 12-945-9 cam, for 355 3.48x6", 12:1, Brodix Track1 heads(basic), 1.5 I&E, typicall basic SBC. Where should I install cam, card says 106.
Long straight, TIGHT turns, heavy99.9% of the time. Not wanting to make record HP, just good driveability.

Thanks!

[perfconn]

Cam is ground on 106* and should be degreed at 102* on intake lobe.Cam is actually too big for that application.You need the 12-901--9 but if you already have it then put it in on 102* Any time the cam is too big then the more you need to advance it.You would probably make more power and come off the corners harder if you put it in on 100* but you probably don't have enough v/p clearance and the driver would require better throttle control so 102* would be a compromise.

[dirtdevil]

Along the same question, I am putting together a 3.75 stroke, 6.125 rod, 4.155 bore w/ some Pro-Action 235's. The cam I have is an older Lunati roller that is .430 on both lobes, @ .050 257in - 265 ex with lobe seperation of 105. I degreed it @ 101. Also 1.6 intake - 1.5 exhaust rockers.

Am I close?

[perfconn]

The 406 needs a bigger cam than that.If you don't have a bigger cam then move it to 103* If you swapped the cams in the two engines both would be a lot better.The 406 would run best with that rod with a 260-264-106.

[Nuttin_but_Dust]

Thanks, its what I was afraid of..... I was thinking installing it at 102, I split the difference ended up around 104. I was trying to figure out how to get in touch with you, you done our last cam selection and has worked great. If it ends up being undriveable we will look at something else.

[dirtdevil]

Thanks again Perfconn, you are a much appreciated help.

[perfconn]

Nuttinbut dust,the engine won't be undrivable with a cam thats too big.In fact it will be just the opposite.It will be a lot easier to hook up off the corner. Its just that on a hooked up track and too big of a cam you will be getting passed at the flag stand.
Dirt devil,you are certainly welcome.Just trying to keep the racers from spending money they don't need too.

[dirtdevil]

I did not mention that this is in a open wheel mod on decent size 3/8 track. Not a latemodel big tires and a big track. Sorry,

[perfconn]

Even more reason that you need a bigger cam but if your on alcohol you need to keep the exhaust duration close to 260@.050,the ideal cam for you would probably be a 260-262-108 on alcohol or a 260-264-106 on gas.

[turner]

Hello Perf Conn. How about a 428 sb with 14.8 comp and 227 afr cnc'd heads from AFR. I know there are alot of things to take into consideration with heads, compression etc, but im looking for a rough idea. Gonna be on a 3.8 mile tack track with sweeping corners . Stays tacky and it's going in a mod.

[perfconn]

Alcohol or gas? How long are the rods? Titanium valves or stainless? Roller or flat tappets? Max rpm?

[turner]

It' going to be on Gas , 6" rods, Stainless valves with Titanium retainers and it's going to be a roller. Im looking for around 700 Hp and 600 ft torque with a smooth power curve if it is even possible.Thanks for your input.Would like to keep Rpm to 7800 to 8000 MAX.

[perfconn]

Turner,
A couple of things to keep in mind.Stay under 7800 with the 4 inch stroke or you will jerk the wristpins out.Try to use a good 950cfm carburetor.You can make 700hp easy but can you hook it up on 8 inch tires.To make the most power you will need about a 264-270-106 cam but be wary of cam advice because if you stay with one cam company like Comp Cam you can get about 10 different lobes that will all check 260-270-106.Starting with very mild lobes to really radical lobes like the TK series.

[turner]

Thanks for your advice. My buddy's engine made 686 and 595 lb torque, and when the track is heavy, he can flat foot it from mid corner on, and says he could use more power.He has pretty much the same combo, but he is at 13.1 comp and a diff cam.I used a camcraft cam in my street stock with good results.Not sure if he does bigger engines though. I appreciate your advice. Thanks alot.

[perfconn]

Turner,
Just as example,my last 406ci engine had 23* ported Brodix 11X heads,ported 2925 intake,T&D 1.9-1.8 rockers,6.125 rods and it made 715hp and 610 torque.The driver says he rarely gets over 1/2 throttle on 12 inch tires and he uses an 850carb.Most tracks are really slick by feature time.