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Motor guru's I need advise!

dogdaysunrise

dogdaysunrise

1/2 ton status
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Jan 19, 2005
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Winterpeg
Okay I have been looking at some Cams as of late, and Im tempted by these summit cams, now I have been researching them, and some guys on here are saying that they are real computer friendly. There are 2 in particular that I am hoing and humming about.

The summit cam part # sum-k1102:
Basic Operating RPM Range: 1,500-4,000 RPM
Intake Duration 050 inch Lift: 204
Exhaust Duration 050 inch Lift: 214
Duration at 050 inch Lift: 204 int./214 exh.
Advertised Intake Duration: 262
Advertised Exhaust Duration: 272
Advertised Duration: 262 int./272 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.420
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.442
Valve Lift with Factory Rocker Arm Ratio: 0.420 int./0.442 exh. lift
Lobe Separation (degrees): 112

and the summit cam part # sum-k1100:

Basic Operating RPM Range: 1,000-3,000 RPM
Intake Duration 050 inch Lift: 184
Exhaust Duration 050 inch Lift: 194
Duration at 050 inch Lift: 184 int./194 exh.
Advertised Intake Duration: 242
Advertised Exhaust Duration: 252
Advertised Duration: 242 int./252 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.368
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.398
Valve Lift with Factory Rocker Arm Ratio: 0.368 int./0.398 exh. lift
Lobe Separation (degrees): 109

my other options are that of Comp Cams CL12 239-2:

Basic Operating RPM Range: 1,300-5,600 RPM
Intake Duration 050 inch Lift: 218
Exhaust Duration 050 inch Lift: 226
Duration at 050 inch Lift: 218 int./226 exh.
Advertised Intake Duration: 262
Advertised Exhaust Duration: 270
Advertised Duration: 262 int./270 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.462
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.480
Valve Lift with Factory Rocker Arm Ratio: 0.462 int./0.480 exh. lift
Lobe Separation (degrees): 111

or

Comp Cams CL12-235-2

Basic Operating RPM Range: 1,000-5,200 RPM
Intake Duration 050 inch Lift: 210
Exhaust Duration 050 inch Lift: 218
Duration at 050 inch Lift: 210 int./218 exh.
Advertised Intake Duration: 254
Advertised Exhaust Duration: 262
Advertised Duration: 254 int./262 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.447
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.462
Valve Lift with Factory Rocker Arm Ratio: 0.447 int./0.462 exh. lift
Lobe Separation (degrees): 111


All have the powerband about where I want it, im leaning towards the 1102 because of the rpm range is a little more in my favor, looks like it goes across the band, as well as the comp cam.

Now I ask you motor god's are these worth my time? Im running a stock 350 tbi, with plans of ordering headers at the same time as the cam is going in. The exhaust is going to be free'd up this fall as well.

Should I get the 1102 or should I go towards Comp Cams?
 
A few months ago I put a Comp Cams 270H in my 350. Hydraulic flat tappets, not a roller. Engine sounds great, got a decent bit of power out of it. Going for a bigger cam with a TBI might make you run a bit rich, upgrading my cam did (just another thing to consider).
 
Only deciding factor for my new cam was I got the 270H and tappets free :D
 
If ya want torque then go with the Summit K1100, that 109 LSA will pull stumps put the ground..........
the CL12-235-2 would also be a good choice.

Personally i prefer Comp Cams....good stuff
 
The main question is, will either of those be computer friendly? I was reading on some old posts, and one guy was saying the lower the LSA the less computer friendly it is. I dont want to be messing around with getting a new chip, or getting mine reburned.
 
With all the upgrades you are doing, I'd be counting on getting a chip burnt. TBI is very senstive to engine upgrades, just like any speed density system. Less restrictive exhaust, and more air into the engine all mess with the ECM's reaction to different engine conditions. It is programmed for a stock 350, and how a stock 350 responds to different conditions, not for a cammed 350 with big free-flowing exhaust, lol :)

Talk to Brian Harris at TBIChips.com -- He is always very willing to talk with you without pushing towards a sale of a chip. Give him your exact engine specs, and he'll let you know if you can squeak by with a stock chip, or if you'll need a new one burnt, which he can do relatively cheaply as well.

Also, keep in mind the throttle body's capabilities. Don't be expecting more than 4800 rpm out of it, tops! EFI depends on strong low end torque, so build your engine to start making big torque right off idle, and right through to 4800 rpm or so. If you are only starting to make power at 2500 - 3000 rpm, you won't have much go at all with the engine running out of breath at 4800. My stock 700r4 shifts at about 3800 - 4000 RPM at WOT, those trucks typically red-lined about 4500 rpm, so yeah, make sure that you have your powerband in a usable stretch :)
 
the exhaust isnt going to be anything crazy, really its going to be a better flowing muffler and the headers. and the cam and lifter kit are the only other thing im looking at. If these cams are going to be a little to much for the chip, then im willing to tone it down, these just seemed to be the best choice so far.
 
Take a look at some of Comp Cam's EFI cams, they have some pretty healthy cams that are pretty EFI friendly :)

Check out their specs, and see if anything is near what you are looking at.

That said, neither of my fuel injected trucks has an EFI cam in it. My TPI 355 has a Comp Cams XE262-H, and the TBI 355 has the stock 73 Nova cam. Neither engine seems to suffer too much, but the TPI is a Mass Air Flow setup, and the Nova cam has a very smooth idle. I have noticed that the TBI is a bit on the rich side, but I do believe most of that has to do with the exhaust leak I had above the 02 sensor, lol I'll let you know how it does on the stock, non-EFI cam as soon as my new oil pan gasket gets here, and I've done some plastigauging to see if I destroyed any bearings in the bottom end when the gas saturated oil chewed through my oil pan gasket, and caused all the oil to seep out, causing the truck to knock rather visiously on my way home from school the other day :O

Yep, if I were to do the TPI 355 again, I'd probally have gone for a smaller cam. The one I have in there has a 110 lobe sep angle, and is good for 1300 - 5400 rpm. I bought the cam before I decided to go EFI, and got a spankin good deal on it (75 bucks for the cam and lifters, brand new) so I decided I'll try it out. If it doesn't work, I know a few fellas who'd want it, and I'd probally go for the XE580-h
 
yea im still lookin around, but those 4 caught my eye. I dont know enough of what to look for so thats why I figured I would ask the experts ;)
 
The wider LSA (lobe separation angle) of the Comp will work fine...........
the stock chip is providing a air/fuel ratio that is marginal at best and most likely programmed for a lean mixture (14:1) thruout the rpm range as is,
the exhaust mods will lean out the motor even further as will any cam that is larger than stock.

Replacing the PROM (programmable read-only memory)chip is not a option if you want to maximize engine power at all rpm ranges, a richer mixture on the order of (12.5:1) will reduce engine temps while increasing power and torque.
 
well I guess I could look into getting a new chip, that will have to be down the line, truck runs pig rich already so it might bot be such a bad thing.
 
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