cpembach1

Hello, this is my first post here. I have a 1987 Firebird 2.8 V6 with the MPFI. The only mods so far are a Jet Performance stage 1 chip installed, no cat, and fresh tune-up. I want to do a max-effort n/a build on the top end; my bottom end is a stock rebuild with ~40,000 miles. I have ordered 1.6 roller tip rockers and chromoly pushrods, COMP, from summit racing. What is the biggest cam I can go with without a custom computer tune? I plan on eventually porting and polishing the heads and adding headers. I have heard that the COMP 260H with 1.6 rockers is like a 272 grind... but over the phone I was told none of their cams will work with the stock tune because I will lose too much vacuum. I thought the 260H cam worked fine with the stock computer, but just benefitted from custom tuning. I am set on 1.6 rockers, so please suggest accordingly. If I can pay someone on here to just burn me a custom chip to be able to run whatever cam I want, that would be great as well. In fact, I would love a custom chip for my car as it is now and once I install the cam as well. Please help everyone. For references, here are the links to the cam I and rockers I am looking at:

http://m.summitracing.com/parts/cca-k16-233-4

http://m.summitracing.com/parts/cca-rp1414-12

cpembach1

bump bump bump !!!

Gfunkill

I'm using a comp 16-232-4. You can look it up to give you more info. It's been in there for a year, and the only issue I have is that it runs rich. But, mine is also a 3.4 swap with 3.4 injectors, so I've been told that's a part of it.
Also, the 2.8's don't have a cam sensor like the 3.4's in the 4th gens.
So, I think when they say "computer compatible" it's because they are talking about cams that are equipped for the cam sensor.
Even the 16-232-4 says "not computer controlled", and mine runs like stink for a "lil bitty" v6.

cpembach1

Did you notice a significant difference in the powerband or hp after? I was planning on installing the 272 cam, seeing how it is for a while, then tuning it with that emulator and a laptop. What all did you install, the cam, pushrods, rocker arms too?

Gfunkill

It's hard to tell. The 2.8 that I took out was every bit of worn out that you could imagine.
It had a bad rod knock (or two) the cam was worn, the lifters were dished, the crank was scratched, the timing chain was as loose as a bicycle chain, and it was a pitiful engine.
I used a 3.4 block, with my 2.8 heads, cos they had the manifolds, and the 3.4 didn't. and I wasn't about to try to pull em off the old heads.
I put new cam, lifters, pushrods, oil pump, timing chain, water pump, dist.
I left the rockers and the heads totally as-is, which is a gamble, using 30 year old valve springs with a bigger cam, but, I get lucky sometimes.
Now, if I get into engine work again, I would like to get some proper valve work done, headers, 1.6 rockers, and stronger springs. But, I built this thing to get me to work, and to drive at least fast enough in traffic, not to slam around, so for now, it's doing it's job.

Gfunkill

But, in short, a freshened up 3.4 with that cam stomps the hell outta the beaten down 2.8, to answer your question.

cpembach1

What you said is encouraging and makes me want to do the swap. Would you suggest upgrading to a roller timing chain while at it? (to prevent the bicycle chain thing from ever happening lol)

Gfunkill

I dunno, you might want to ask that to someone with more experience. I would imagine that a great deal of the slack on the 2.8's timing chain was simply age and miles.
The only reason I did a new one on the 3.4 was because I wanted as much new stuff that would help longevity with the motor, and were way easier to do while the engine was on a stand.