Hey guys! I'm new to the site but no stranger to third gens. I've always wanted one since I was 12 and earlier this year, at 19, I finally bought my first Camaro, a 1990 IROC-Z 305 Auto Hardtop, red on red. It's all original and has 150k miles on it.

That being said, I'm very torn on whether to keep it original or to do an engine swap. I can tell regular maintenance on the car was ignored for most of its life because there's heavy carbon build up under the valve covers. It's been leaking oil from the valve covers for quite some time as the entire engine and front K member is soaked in oil. My main issue with the car is that it seems under powered, has an awful burnt oil smell when the car is running, constantly leaks and burns oil and has a rattling cat.

Other than that the car is great, needs paint and dent work but there's no rot anywhere which is a plus.

So my question here is, should I keep it original or should I do an engine swap? If I did an engine swap it would have to be a 350 as I don't have the fabrication abilities that come with doing an LSx swap. I'd be most likely buying a crate 350 from summit racing or ebay. I think rebuilding an old 350 would be cool but once again, I don't really have the ability to do that.

 

Welcome aboard thirdgen.org, and congratulations on your project car.

Sludge build-up in the engine is not a good sign. You can use flushes to try to break it up and drain it out, but that's only a stop-gap. Irregular oil changes will deteriorate gaskets and seals as well as wearing out the mechanical stuff, although the former is probably more of an issue than the latter. If you are burning oil, that is likely due to hardened/cracked valve stem seals, a common problem with small block Chevys, and even more likely in a neglected engine.

The rattling cat is probably also a factor in the car running poorly. A loose cat brick will usually also block flow, so replacing that is likely to improve performance.

As for whether to keep it original, that's really up to you. These cars don't have much collector value except for a few model types (like the turbo TA). I suppose it could be argued that the more people modify their 3rd gens, the fewer there will be that are original, and that could up their collector value in the future. But, your car already has 150k miles on it, so rebuilding it to original would detract from "collector" value, even if you held on to it for a couple of decades. And, you probably wouldn't be able to enjoy it as much if you're trying to maintain a collector value. Kind of a lose-lose, in my mind.

But it's your car, so you decide how you want to use it. A 350 crate engine isn't a bad idea, but not all 350 crate engines are created equal. The 195 or 260 HP "Goodwrench" 350s in my mind are a downgrade, for several reasons. And, a '90 TPI will offer some "challenges" when going to 350. One, it's a "speed density" system (vs. mass air flow system), which is more sensitive to changes such as a larger engine or better flowing exhaust; meaning computer tuning required. Another, since you said "cat"-singular, is the entire exhaust system is restrictive to a 305 (even without a rattling cat), which means it is even worse for a 350 - typical "fix" for that is to go with shorty headers (Hooker 2055HKR is an excellent off-the-shelf choice), free-flowing cat (one for the '86-'89 TPI single cat will fit the Hooker headers, and flow well), and aftermarket 3" cat-back (same '86-'89 TPI single cat application for that). All of that would also help the 305, of course. Oh, and 350 TPI used larger injectors than 305 TPI.

The last issue with a 350 crate engine is your '90 TPI base will have a slightly different bolt pattern than the typical crate engine. That can be handled by elongating the center two bolt holes on each side of your base, or getting an aftermarket base for the '86-earlier bolt pattern. Not too big if a deal, but something to be aware of.

Okay, that's a lot of dumping on you. One final thing I'll mention, since you brought it up, is that LS swaps are getting closer to "bolt in" than ever before. Swap mounts are available, swap exhaust is available (headers to tail pipe tips now that Hooker has gotten in the game - even have the swap mounts), and if you do a GM "ERod" engine, even the computer and wiring are taken care of - very little fabrication. All of this is, of course, more expensive than simply putting in a crate 350. But, you can't ignore an LS3 ERod with 430 HP that will probably rival your 305 TPI for gas mileage.

 

I'll continue the dumping with a few 350 crate possibilities (these are GM engines - non-GM crate possibilities are practically endless, but typically more expensive). Assume exhaust upgrades for any of them.

http://www.summitracing.com/parts/na...8758/overview/
This engine will basically "bolt in" in place of your 305. It will have slightly lower compression than your 305, but the extra displacement will make up for that. It probably has flat tappet lifters, which aren't as good as the roller lifters your 305 has, but not a deal-breaker, either. Yes, it has "swirl port" heads, not liked by the typical 3rd gen enthusiast, but they actually work well with stock TPI. You'll probably need larger injectors for wide open throttle power, and likely computer tuning (chip), but it'll probably run fine with that.

http://www.summitracing.com/parts/na...0282/overview/
This is the later light truck engine with "Vortec" heads. The downside is you'll need a Vortec TPI base (not real cheap), but everything else is a plus. This would be a nice running combo (with larger injectors and some computer tuning).

 

My advice would be first and foremost, to BE REAL CAREFUL about how and where you're spending your money time and effort, and WHY.

If YOU want an "original" car because YOU like "original", then KEEP IT THAT WAY.

If YOU THINK YOU WANT an "original" car because YOU THINK it will have "more" "value" that way, YOU ARE MAKING A BIG MISTAKE.

These cars aren't like 60s and very early 70s muscle cars, unfortunately. No fault of their own. It's not that they're "not as good" or anything of the kind; in fact I would argue that they are SUPERIOR IN EVERY WAY to things like 1st gen Camaro or old Mustangs or the like, with ONE CRITICAL EXCEPTION: the time they were born into. By the time these cars were introduced, the whole "car culture" of those earlier years had entirely vanished, never to return. They simply don't have the grip on the pop culture mind that 60s ones did. Never did, don't now, never will. That means that "value" as measured in auction selling prices is NEVER going to even vaguely dimly remotely approximately approach those old cars, with only occasional highly rare exceptions. Which a plain-vanilla 305 TPI car (as yours is... single cat auto trans) ISN'T.

DO NOT make the mistake of thinking that spending wheelbarrows of money keeping it "original" is going to be some kind of "investment". It ISN'T. In fact it isn't even for a 1st gen Z28: if you had bought a brand-new 67 or 68 or 69 Z28 back then and parked it in a garage and sold it today, sure, you'd get some eye-popping sum of money for it. But if you had taken the same $4800 or whatever, and bought a mutual fund with it, and parked THAT in a "virtual garage" for the last 45 yrs, you'd have ALOT more money. ALOT LOT LOT. Like, twice as much. Meaning, buying even one of the most desirable cars EVER as an "investment", was a mistake: you'd be TWICE as rich, maybe more, buying the plain common ordinary boring mutual fund. You would have thrown away half your millions. Car as "investment" = MISTAKE.

Moving on...

It sounds to me like you bought a car with serious neglect issues. That's REAL hard to overcome. Pretty much the whole car deteriorates all together, and if nobody fixes the one thing here and one there that just sorta pop up as time goes on, what you end up with is, a car where EVERYTHING is wore out and used up. Which sounds like what you've got now.

My recommendation would be, IGNORE the motor for the time being. Concentrate on other things that are equally, if not MORE, in need of repair. Brakes, suspension, tires, and so forth. If you devote all your money to the "motor" you will end up with a giant pile of money tied up in a garage ornament you can't drive. Take care of all those other things FIRST before getting too wrapped up in the "motor". Sure, fix what can readily be fixed about it (valve guide seals, tune-up, massively leaking gaskets, busted-up cat, etc.), but DO NOT make your first priority buying a new one. Those "bleeding" issues can be handled for surprisingly cheeeeeeeeep. And of course, buying a new motor won't fix a rattling cat; you'll STILL have to deal with the cat somehow. My recommendation is, deal with the cat FIRST.

Take the car to the quarter car wash. Take your floor jack, lug wrench, a Tyvek personal cocoon, and a set of 4 jack stands with you. Stop along the way and buy several cans of engine degreaser; just the plain cheeeeeeeep kind, NOT the "foamy" kind. When you get to the car wash, jack the car up as high as you can get it, and support it on the stands. Take off the wheels. Douse EVERY BIT of the thing with the engine cleaner; from above, from the wheel wells, from below, from the right, from the left, from above some more, .... you get the point. You want the entire thing to be DRIPPING engine degreaser. Wait about 10 minutes. Douse it again. Wait another 10 minutes. Hit it with the "wash" function from every angle including laying up underneath the car, just be careful not to hit the distributor directly. Do that until the whole thing is CLEAN ENOUGH TO EAT OFF OF. Drive it home. You will be able to see EVERY leak, because instead of 10,000 years of funk and disgustification built up on every surface, you will have a CLEAN engine with acoupla drops of this and that here and there, which you now know what gaskets leak where. Fix them. Repeat until the engine stays clean.

Come back when that's done and we'll help you take the next steps.