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TBI roller cam options

7

77crewcab

1/2 ton status
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The TBI engine I have to go into my burb is origionally from an 89 cop car ("its dark and we are wearing sunglasses") It still has the factory cam in it but I would like to try and put in a new cam before I install it in the burb. I am already doing a full gasket kit so I might as well. I am looking for something with low end grunt that will work well in a heavy burb and would like some input from those of you that have done similar. Future plans included Vortec heads and Edelbrock intake, and headers with dual exhaust.
 
Since no one else responded... :)

I don't know as I've ever seen a dyno test where low end was the focus. A big, heavy truck is at it's best with much torque, and the factory cams seem to be focused solely on that point. If you bump the HP/TQ up, as far as I've seen, youmove it up in the powerband.

That's fine if you change your torque converter to match, but just a cam swap, don't think you'll improve over factory.

If someone has some testing numbers of a factory cam/after swap that shows improvement even at the low end, I'd like to see it. Not saying it isn't possible, but given a modern roller cam and fuel injection already, I don't see increased power production "across the board".
 
Pretty darn mild!

Lift is right around .450" @ .050, I believe the some of rest of the specs were 204/212 with 112* lobe seperation.

A smaller cam would *probably* make even more low end, but the TPI system is pretty restrictive anyways to upper end, so I decided to go small on the cam. Probably should have been a bit more liberal in that decision, runs out of steam pretty quick.
 
Here is the cam i installed in my new engine i just built. It makes huge tq from 2000-3500rpm. Comp Cam XFI 08-464-8 This cam is good from 1000-5000rpm and the specs are 202/212 @ .050" .550/.546" with a 1.6 rocker on 113* lobe sep. angle. Now add a good set of heads and 9.5:1 compression and you're set.

My 355 engine will be making 392hp @ 4500rpm and 506ft. tq. from 2000-3500rpm
 
Watch out for big lift cams and/or rocker ratios and Vortec heads. I don't think they like over 0.500" (at the cam w/ stock rockers). I'm sure somebody here knows more about it than me, but I remember reading that somewhere (Hot Rod Mag maybe?). You may be able to machine the Vortec heads to accomodate more lift, but I don't know how much.
 
The vortec heads flow fairly well but are thin wall castings that are prone to cracking. Almost every set i've had in my shop have been cracked. If you want big torque numbers i would be looking at a set of AFR 180cc heads. The AFR 180cc heads outflow almost every head available under 200cc. Yes they cost about $1500.00 but HP and TQ comes at an expense.
 
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Not really looking for a TQ monster just want something better than the tired 350 I have in the burb now. The cop car 350 I have never driven so I don't know how it did in the car or how it would do in the burb. I just figured that since I have easy access to it now maybe I would swap the cam for something geared more towards a truck assuming that the cam was a car only design. By any chance would the stock cam be the same in a cop caprice and a burb of the same year?
 
Those prices look high to me. I bet you can find Votec heads and a manifold to match cheaper elsewhere.
 
BGKYK5 said:
I don't think they like over 0.500"
Click to expand...

It was worse than I thought, they don't like more than 0.450".

77crewcab said:
What about one of these kits?

http://www.sdparts.com/product/SD806...keHeaders.aspx

http://www.sdparts.com/product/SD806...keHeaders.aspx
Click to expand...

Those prices look high to me. I bet you can get stock Vortech heads and a manifold to match cheaper elsewhere. The second (more expensive one) may be a better deal with the ability to run bigger lift cams.
 
77crewcab said:
Not really looking for a TQ monster just want something better than the tired 350 I have in the burb now. The cop car 350 I have never driven so I don't know how it did in the car or how it would do in the burb. I just figured that since I have easy access to it now maybe I would swap the cam for something geared more towards a truck assuming that the cam was a car only design. By any chance would the stock cam be the same in a cop caprice and a burb of the same year?
Click to expand...

No the cams are not the same. The cop TBI is a roller as you know. The truck engines were regular flat tappet hydraluic lifter.
For a basic good all around cam(s) I would use either a Comp Cam PART #08-464-8 (252XFIHR13) Its the same cam 4x4HIGH recomended. It is a low to midrange roller cam that will work with the stock chip
Or
Comp #08-407-8 (XR252HR) Will work with the stock chip. It is a lowend power cam good for a heavy vehicle, towing ect
 
Are you going to dyno that 355?

I am a little skeptical about the 500 ft lbs torque....

Not trying to start a war or pissing contest here as I have always respected your opinion....

If you can get 500 ft lbs from a 355, then I should be able to get 600 from a 406....
 
I'm working on trying to fix up a stand alone wiring harness so i can get it on an engine dyno and not just a computer program. The only thing that's really going to hinder my decision is the $600.00 for dyno time. :eek1:
 
I know nothing about your shop, but wouldn't installing your own dyno help bring in more business? I know it is a much more popular decision these days for people to spend their money on some dyno time now than in the past.

It might pay for itself soon enough....;)
 
There is no way i would want or even have anywhere near the money to buy a dyno and build a dyno room. The dyno is the cheap part at anywhere between 10K-20K but to build the dyno room that meets requirements is closer to 100K. Take ALOT of dyno runs to pay for that.
 
4X4HIGH said:
Here is the cam i installed in my new engine i just built. It makes huge tq from 2000-3500rpm. Comp Cam XFI 08-464-8 This cam is good from 1000-5000rpm and the specs are 202/212 @ .050" .550/.546" with a 1.6 rocker on 113* lobe sep. angle. Now add a good set of heads and 9.5:1 compression and you're set.

My 355 engine will be making 392hp @ 4500rpm and 506ft. tq. from 2000-3500rpm
Click to expand...
is that a roller cam???im running a 400 40 overw/flat tops with worked double humps and 2.02/1.60s...i have a solid in it now but the powerband is to high...i use desktop dyno useually to find out my powerband and witch cam to run...its acturate to a degree...
 
Yes it is a hydraulic roller. If you have a 400 block you would need a retro fit hydraulic roller.
 
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