Timing, Cam and Distributor

I have a 2.8v6 with the typical lack of power. I am wondering if anyone with a 2.8 has tried advancing the timing beyond the factory setting and what gains or lack of gains you might have gotten. I have installed a weber 38/38 and am quite happy with the gains that gave me.

Another question that I am really curious about is advancing the cam timing. I would never have dreamed of setting the cam timing at anything other than stock but I have read on other forums people advancing the cam timing on their ohc 2.8s and gaining increases in torque and losing their top end. I know my 2.8v6 isn't ohc but has anyone tried this?

Advancing/retarding timing usually results in moving the power band up/down in the available RPM range (I'd have to look it up to see exactly what results come into play.) This also assumes that your camshaft is actually ground to a 0* centreline to begin with - variations do exist, and are more common in production cams than in aftermarket.

One of the single best things you can do for your 2.8L, however, is to don't. Consider this idea instead:

Look for an S-series donor (whole drivetrain) or an F-body donor (engine only.) Get a 3.1L or 3.4L engine, it's a drop-in replacement if you swap the intake. It's a bit more work if you want to carry over the fuel injection, but that's not a bad idea and would be worth the effort (grab the electronics as well.)

The V6-60 typically came with a THM700R4 behind it, if you grab a 4WD version out of an S-series you'll pick up overdrive as well. You'll want a 1988 or later donor, since 1987-earlier THM700R4s have a fatal flaw that makes them more suitable for scrap than anything else. IIRC, the S-series usually has an NP231C transfer case, but the THM700R4 uses the "Dana 300" mounting pattern - which is also common to NP/NVG cases anyhow.

I don't recall when nomenclature changed, but the THM700R4 became the 4L60 (hydraulic control) and then the 4L60-E (electronic control - bigger swap than you want to get into.) But, swapping in the THM700R4/4L60 would allow you to pick up an overdrive gear as well, since the A904 used behind the 2.8L in the XJ is a three-speed box.

Note that, if you have to assemble parts piecewise, you can also find the 4WD THM700R4/4L60 in the K-5 and K-10 (and some K-10 Suburban,) but you'll need to replace the bellhousing, as the SBChevvy bellhousing pattern is different from the "GM Metric" used on the 60-degree V6.

More information on the 60-degree V6 engine series can be found at www.60degreev6.org (I think that's the URL.)

So that's a no on the camshaft advance? lol
I have been looking at swapping a 3.1l but haven't found a suitable donor. If I go that route I will probably keep my manual, I got lucky and have one of the few t-5s.
Thanks though, that is a lot of information I may be referencing if I go the automatic route. and I may, I love clutches but I am not sure if the benefits outweigh the cons.

Ah - didn't know it was a T5. That does simplify finding a donor - opens it up to S-series, F-body, and FWD with GSR blocks.

(GSR = Goodwrench Service Replacement. An aftermarket engine block with the starter mounting pads on both sides of the engine. The typical FWD engine has the starter motor mounting pad on the wrong side of the block for RWD/4WD applications.)

So, if you go the 3.1L/3.4L route, be sure to check the FWD vehicles with that engine for a starter motor mounting pad on the back side of the engine (as mounted) that would go unused in FWD.

There are two principal issues that I've seen with the 2.8L (I had a Cavalier with the 2.8L and a Corsica with the 3.1L, so I do feel somewhat qualified to hold an opinion...)
1) The damn thing leaks like a sieve. Not just mine - everyone I knew personally that had one had the same leak - at the "rear" of the cylinder head (toward the bellhousing,) where the cylinder head, intake, and valve cover all come together. Never could fix that damned leak, and I spent a lot of time trying!)
2) It's a dog. It was underpowered for the Cavalier (kerb weight of around 2400#, IIRC,) and it's hideously underpowered for the typical compact truck (kerb #3000) or compact SUV/Wagon (kerb 3200-3400#) in production trim.

The best upgrade I can think of? 300# of ready-mix and five hundred feed of 1/2" proof coil - give it to your buddy with a boat. That damned Cavalier couldn't get out of its own way, while that Corsica was a screamer!)

I'd look for a 3.1L or a 3.4L with PFI, and bring over the electronics.

Another option? Call up Advance Adapters and look into one of their Small Block Chevvy mount cradles, and find a suitable transmission (the T5 would be borderline. T5WC is a maybe.) That would let you drop in a V8 with a rock solid history - it's more work to do the conversion, but might be what you're trying to do.

Advancing/retarding the camshaft isn't a bad thing - I've done it before on performance buildups as a way of "fine-tuning" the powerband. You can usually take it up to four or five degrees either way - and that's actually a lot! I don't think I ever went more than two. I wouldn't say it's an outright No, but I would go on record as saying you'd do well to start with a better base to work from, over that wretched thing...