1987 Firebird V6 2.8 MPFI Cam Selection Help
 

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

Re: 1987 Firebird V6 2.8 MPFI Cam Selection Help
 

bump bump bump !!!

Re: 1987 Firebird V6 2.8 MPFI Cam Selection Help
 

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.

Re: 1987 Firebird V6 2.8 MPFI Cam Selection Help
 

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?

Re: 1987 Firebird V6 2.8 MPFI Cam Selection Help
 

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.

Re: 1987 Firebird V6 2.8 MPFI Cam Selection Help
 

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

Re: 1987 Firebird V6 2.8 MPFI Cam Selection Help
 

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)

Re: 1987 Firebird V6 2.8 MPFI Cam Selection Help
 

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.