98 Z28 Project

[Drdave88]

So I had a thread going about my 01 Firebird project. That project sold off when I came across this car. I actually picked this car up back in July last year. I initially was just going to grab it as a drivetrain donor for the Firebird, but once I saw the condition of it, the Firebird quickly went up for sale. It's an early 98 Z28 with the Y3F (RS body kit) option. It's a pretty stripped down model, manual windows/locks, etc. It only has 99k miles on it and overall has been really well taken care of. It was a SBE LS1 with 243 heads ported, bigger valves, 234/238 - .612/.612 - 112+4 cam, LS6 intake, tuned, 1 3/4 Pacesetter headers, SLP LM1, SLP intake, dynoed at 407hp/378tq. to the wheels. 4L60E had also been built, 3.73s out back. Downside is the LS1 had spun a bearing (or several). I was able to pick it up, still running for $2700. Got it home, pulled the LS1 and picked up an LQ4 for $500. I stripped it down to a short block and swapped everything over from the LS1. I have the 6.0L in the car now, need a few odds and ends yet to finish up for the engine. I tore the front suspension out of it, to get all new bushings/ball joints/etc. That is still apart, but will be going back together next.

[Drdave88]

Here is what I found in the oil pan of the LS1. It was almost impossible to roll over by hand, and would not idle due to how tight everything was on the crank. I had to keep on the throttle to keep it running, knocking like mad too.

[Drdave88]

While everything was out of the engine bay, I decided to do a quick spruce up of the paint, cover any scratches and give it a bit of new color again. There's no rust so I didn't want any to start. Also tucked any wiring I could and relocated grounds to spots not so visable. The ABS was already removed when I got the car.

[DynoDave]

Looks like you got quite a deal!

So with the LQ4 short block, and the old LS1 parts swapped over (cam too I assume), you should have the same power as before, or maybe a few more? Any change in compression with this swap?

[Drdave88]

The LS1 stock had 10:1 compression (10.5 with these heads), the LQ4 has 9.4:1 (about 10:1 with the heads). So a slight drop. But the bump up in cubic inches should make it roughly a wash. Yes the cam was swapped too. The build on the LS1, from what I can tell from receipts he kept only had about 10K miles on it so everything was still in great shape. It looks like the oil filter kept any debris from getting around through the engine. There were no signs of wear on the cam, or anywhere else.

[Drdave88]

This is roughly how it's sitting now. Not too much left, mostly steering/suspension and buttoning up under the car, exhaust driveshaft, bit of wiring, etc.

[MP81]

Less compression obviously just means more boost!

[Drdave88]

Less compression obviously just means more boost!

lol not the first time I've heard that. I haven't ruled it out, just not yet. Rear axle will likely be the next big part that gets work. It's basically stock, aside from different gears.

[DynoDave]

The LS1 stock had 10:1 compression (10.5 with these heads), the LQ4 has 9.4:1 (about 10:1 with the heads). So a slight drop. But the bump up in cubic inches should make it roughly a wash. Yes the cam was swapped too. The build on the LS1, from what I can tell from receipts he kept only had about 10K miles on it so everything was still in great shape. It looks like the oil filter kept any debris from getting around through the engine. There were no signs of wear on the cam, or anywhere else.

That's going to be a fun car.

[Drdave88]

Finally got some more time to work on this over the weekend. Got all of the steering/suspension/brakes replaced and reinstalled. All new busings, ball joints, tie rods, pads/rotors. The shocks and springs weren't that old so they're staying for now, until I can decide if I'll be able to lower it or not, my driveway has a pretty nasty incline. Under hood is almost done, need to finish connecting the A/C, new starter has to go in, reconnect the exhaust and shift linkage. I think that's pretty much it, I should be able to start it up this week, as long as I get some free time and no set backs. It would be nice to finally bring something to the meet and greet!!

[Drdave88]

Didn't attach, trying again

[MP81]

It looks like your curbs are pretty soft - if you hit the driveway at an angle close-ish to perpendicular, you should be good.

[Drdave88]

The issue is getting the car into the garage, I pulled it in and dragged the hell out of the exhaust about center of the car.

[MP81]

Ahh, I see, the garage leveling out is the issue?

[Drdave88]

Yeah, the driveway has a big incline and the garage is level, so I drag as it levels off, right about middle of the car.

Got it running yesterday. It's still on stands, I have some exhaust leaks to fix, bleed brakes, finish hooking up the A/C and a few other odds/ends, but it's alive!!