cpi question

[THA_BAD_ONE-0]

Did they make a cpi motor without balance shaft. If so did it have the good cam in it, and what year was it

[rlith]

Did they make a cpi motor without balance shaft. If so did it have the good cam in it, and what year was it

Most early 92 CPI's didn't have a balance shaft, everything from late 92 did. Cams are all the same from 92-95

[THA_BAD_ONE-0]

so a good cpi cam would be good for the tbi engine. Cuase i have heard of some people doing that

[rlith]

so a good cpi cam would be good for the tbi engine. Cuase i have heard of some people doing that

Doing that is going to give you little return for time invested unless you switch to a CPI intake and injection system as well.

[rat]

Doing that is going to give you little return for time invested unless you switch to a CPI intake and injection system as well.
Why? The cpi cam is terrible, it is a major chokeing point. There would be a major improvement going from a stock cam to the cpi cam, assuming one could be found for the non ballance shaft motor.

* '87-'94, Vin Z, w/o balance shaft
- Lift (I/E) - .351/.386
- Dur @ .050 (I/E) - .179/.195 (Ductile)
* '92-'95, Vin W, w/ balance shaft
- Lift (I/E) - .432/.440
- Dur @ .050 (I/E) - .208/.208

Throw some cpi heads on, an edelbrock intake and tune accordingly and you are up to cpi power levels. Cpi is a pita to upgrade at all, tbi there are larger injectors, larger tbi units, aftermarket intake manifolds, the list goes on.

[jdhogg]

have any of you guys tried a 454 tbi yet?

[T Man]

You will ahve to machine your intake for the larger bores, otherwise you wont get all the potential out of it. Other than that, its the next logical step, bigger intake flow. Just make sure you machine off the risers that restrict air flow. I did mine in about an hour with a dremmel and an aluminum bit

[jdhogg]

how much throttle response did you gain?quite a bit or??

[rlith]

Why? The cpi cam is terrible, it is a major chokeing point. There would be a major improvement going from a stock cam to the cpi cam, assuming one could be found for the non ballance shaft motor.




That statement makes no sense. How can you say the CPI cam is terrible, then say putting the CPI cam in would be a major improvement?

[j894]

think he mean to say tbi but typed cpi ??

[rat]

That statement makes no sense. How can you say the CPI cam is terrible, then say putting the CPI cam in would be a major improvement?
I apoligize, i got the acronyms all mixed up. The tbi cam is terible for top end horsepower. The cpi cam has much more duration, so it should move the power band up a bit compared to the stock tbi cam that is in his motor now.

[THA_BAD_ONE-0]

thanks for all the help i'll try it. If fails then you will hear .LOL