I was having a discussion about Camaros, and a friend of mine claimed the third gen 305's and 350's were under rated... for insurance, or other reasons. Any of you techies know if this is true?

 

I don't think so since they are dog slow.

 

A common myth

 

That's what I was going to say. Dyno runs on stock vehicles generally show that when in good tune GM actually rated them pretty accurately.

 

They arn't as fast as my 68 Charger R/T, but I wouldn't call my IROC or my RS "dog slow".

 

I'd say it depends on what rating you look at. The L98 in my Camaro is not much different than the old 300hp 327 of the 60s, maybe better with the roller cam specs. But in the 70s when hp ratings were downrated it would be quite a bit lower.

 

the only things downrated from GM these days...are LS motors...the 3rd gens power claims were pretty much spot on, and in some cases...seem over inflated judging by how terrible ALOT of these cars run.

the ls1s were putting out RWHP numbers, that matched, and exceeded the flywheel sae numbers.

even to this day, the ls motors put down rwhp numbers VERY close to those advertised numbers...which is nuts.

 

ok, so they are not that fast. I thought the lg4 made good progress compared to the earlier ones, and much improved since the lg3. A few minor mods, and they come alive.

 

few minor mods? I had a motor that the owner claimed was a 350 i pulled out of my 78 trans am to have rebuilt, turned out it was a 305. I said screw it and just rebuilt that one. I put 350 heads on it, nice size cam that pulled to 6500, 5 speed w/ 3:73, edelbrock carb, full ignition, full exhaust and headers. Best time was 14.6@93 with a pro driver. When it had the 3:08 or 3:23 (not positive) i managed a whopping 18 second run spinning all of first lol

Bottom line to my story is 305's just plain suck and are slow. Out of all the 305 f-bodys my friends have owned, am talking 20+, one of them was decently kinda quick. Mint condition late 80's Iroc Z he picked up for $6500, 305 TPI auto, he could hang with a 2000 ford lightning, which we thought were fast at the time.

 

I don't think any engine in a 3rd gen was under rated. Given the technology of the time they were struggling to make the advertised numbers while meeting emission and fuel standards. People like to talk about cars being under rated but its usually bs.
The old 300hp 350 was rated at 300 hp gross. If you tested one using the sae net standards you would have much less impressive numbers.

 

The LG4 is a dog. It takes more than a few minor mods to make them come alive. It would take damned near the full gamut of bolt-ons just to get where a 305TPI engine starts. Its sad.

Pretty much. 305's suck. The 305TPI is tolerable for general driveability but even that one isn't really fast.

As I understand it the LC2 in the Turbo Trans Am was underrated from the factory. If any of them were that's the one.

 

I had an LG4 305 in a Monte Carlo once. I put on an Edelbrock manifold, Crane 2030 cam and Edelbrock headers with Hooker Exhaust. With 373 gears and a higher stall converter it ran pretty hard for what it was.

 

I'd call a cam a bit more than a "minor mod."

 

I put a an Edelbrock 1406 carb, Edelbrock 7101 Performer RPM intake manifold, Open Element Air cleaner and a K&N on my 86 LG4 and was able to run a 14.9 @ 92mph. Stock T5 with stock 3.27 gears.

That is faster than I can get my 88 Formula with the 305TPI, Holley Stealthram, Headers, Borla exhaust, 3.73 gears and 4.10 gears.
15.2 @ 93
stock with the Auto and 3.23 gears it ran a 15.7 @ 86mph.

 

I'd chalk that up to the T5 for the most part. Its lighter and with a good driver I believe what you are talking about is possible. As for your TPI car an HSR won't give you much on a stock or near stock 305. In fact I'd imagine you probably lost some low end torque switching from the stock TPI intake manifold and runners. I've had a couple TPI cars now and they were WORLD's BETTER than my dog slow LG4 was. My LG4 was in good tune and had the same carb and intake manifold you did with an aftermarket air cleaner and it still sucked. I also had the 1987 LG4 which by most accounts was the best of the LG4's. It still sucked ***.

The LB9 cars make much more torque than the LG4's do and all things being equal, they are going to be faster than the LG4 if similarly equipped. They'll also be more fun as they've got more punch of the line.

 

Its one of those things that once you do a few you dont think its a big deal.

 

The LG4 came out in 82 making from what I remember about 140 hp, with 3 speed turbo 350... by 86 they were putting out 165 hp. Not THAT big a deal, but a significant improvement. Put some taller gears as I did and it really makes a difference. It doesn't do donuts on asphalt, but it's not dog slow..

 

14-15 second quarter mile times aren't exactly all that impressive. Don't get me wrong, I enjoyed my LG4 based car quite a bit. It was nice to cruise around in but lets not kid ourselves, few to zero stock thirdgens are a whole lot better than "dog slow." The Turbo TA and Firehawk's come to mind as being pretty quick but short of that, none of them really were. Even the L98 cars in stock form aren't all that fast by today's standards. I'd put 305 TPI cars with a 5 speed and dual cats and L98 cars just above dog slow and that's about it.

 

Your numbers aren't quite right - check the model year links at the bottom of the page. But, there was about a 20 HP improvement to the LG4 during the 3rd gen years, due to raised compression, improved computer management, and switch from engine driven to electric radiator fan.

3rd gens never got TH350's. They were TH200C's.

I've seen a couple of magazine articles that dyno'd 305's. The one LB9 article could only get the same gross HP number on an engine dyno that the factory published for the net value (I suspect they didn't try very hard so that the advertiser's parts would show more of a difference when installed and another pull made). A more recent article used what appeared to be an '87 LG4 block, cast iron q-jet intake (never used on U.S. 3rd gen LG4's), dyno headers, electric water pump, etc., that made 200+ HP - that's mostly the difference between gross and net HP ratings.

 

I gotta agree, 14s are slow.

 

That is a terrible sounding combo I'm surprised it even made it out of the garage, let alone down a drag strip. A motor spinning to 6500 rpm and a motor that makes power there are two different things. A 305 that makes power at 6500 rpm is displacing enough to make 350-400hp easy.

It's strange we always here about all these poor performing 305's out there, then we also here about these great 350+ hp that are well tuned. It kinda makes you wonder what the problem really is.

 

In dead-stock form they were rated about right. And that means stock air cleaner, stock exhaust, stock base timing setting, stock carb calibration (older carbureted engines), etc.

They were rated at the flywheel, but with all the stock stuff in place that would represent an as-installed configuration.

They were also very "constricted" in certain applications. Open up the intake and exhaust, bump up the timing, tune it a little better, etc. and you could often find quite a bit of easy-to-get power increases without ever digging into the motor.

 

How much advance could I set the timing? Would it cause ping?? or would the knock sensor stop the ping? And, how much hp would bumping up the timing get me?

 

Depends on the engine how far you can advance them. In almost every case you can advance the base timing (using proper factory procedure) 4* over stock. Some engines can take more than that, some can't. Anything beyond 4* additional advance is a try-it-and-see thing, even with premium gas.

My experience is that most low-output 305s like LG4s and TBI engines can be advanced to around 6* BTDC or a little more vs. a stock setting of 0* BTDC. Higher output 305s like L69s and 305 TPIs usually like a 10* BTDC setting vs. a 6* BTDC factory spec.

 

The motor had nowhere near 300 HP, Yet it did pull up to 6500 no lies. I had raced my father plenty of times in his 04 stock mustang gt 5 speed and he would pull about a 1 to 1 1/2 car length to 80. i ran a 14.0@99 in his mustang. Those were only rated at 260hp to the crank.

Moral to my previous post was just that the 305's are dogs, no matter how much work you do to them its still gonna be slow and be a weak motor.

 

I gotta agree for a sports car 14s are SLOW...My 6,000 lbs pickup truck runs 14s @ 90 mph with nothing more than long tube headers, exhaust, pcm program, and 170*F thermostat.

 

I HIGHLY DISAGREE with this statement....Granted a 350 will always have more potential, a 305 can RUN.

 

6500 on a stock tach...thats off by 1k rpm or more...


theres no way, a 305 is going to willingly pull to 6500 rpms, without making a decent amount of horsepower...it just doesnt happen.

YEARS back in my 82 t/a...i blew the 355 up, and we tossed my friends BUILT 310 ci "305" with heavily ported 416 heads,10.5 to 1 cr, and a comp 281hr roller cam...it made well over 300...and it didnt even spin to 6500.

was 8 years ago probably, but if i recall, it made like 330rwhp@ something like 5800 or 6k, we spun it on the dyno to 7k TRYING to blow it up..of course it made no power up that high, but was still hearing a 305 spin to 7grand haha.

 

mw66nova used to spin his 305 to the damn moon... I would have sworn that thing would break one day but it never did. I think he spun it up to 7k every run... and he daily'd it. Insane.

Of course, he had a big mechanical flat tappet cam in it.

 

Whats a cheap way to get more power out of the 350 engine? Im tired of losing races against these cars that have smaller engines with better gas mileage beating me!

 

see my sig...

for the money invested, i cant beleive how well it runs and performs...

its gotten 25mpg before on a trip to michigan!

 

Well they make about the same horsepower as my hyundai and its smaller lighter and faster so no they didn't lie.

 

Only with nitrous or boost.

 

Hyundai?

 

I've had my '91 LO3 pull to 6200 in first, pure stock. That doesn't make it a good idea.

 

You're doing it wrong. I had a '78 LG3 pull 6100 in first, pure stock.
Getting rpm is easy with lazy lobes and fresh mild springs.
With a 700R-4, you need to go well past the powerband in first for best acceleration, because of the huge rpm drop into second.
Getting to 7000 rpm is fine, that's doing it right. If you have forged crank, rods, pistons, and great springs.

 

I agree that it was a terrible combo.
But if you want power from a 305, here's a solution:
Get that World block that's made just for putting LSx heads on an SBC block, then double-sleeve it down to a 3.736" bore. Now you have a 305. For heads, the 5.3L heads were intended for a 3.7795296" bore, so use those. Add a custom-ground roller cam, and 350 rwhp through an automatic is cake. This is the only hope for a 500-horse N/A 305. Add boost, 1000 hp is possible. But for what you'd spend, just do the LQ4 instead.

 

Bore size. 305s have a tiny little bore that restricts the size of valves you can run, which is why all those Fox-bodies with 302s are so much faster, and even the older GM 302s could hit higher power numbers pretty easily.

 

Third gen camaros were not really made for strait line speed anyway. The "magnum" Ferrari GTO only put out 240 hp, and that's an expensive Italian Sports car, but hardly a drag car.

 

They are faster because they have better camshafts and heads, and we won't even talk about exhaust, from the factory. If it has a better base of course the "hear say" about it is it's faster.

People mod and tune their 305's poorly and blame the motor. Most add a open element and a flowmaster and run 16's and complain about the 305 being the problem. But at the same time you have guys who have put good combination's together with good parts and a solid tune that have 350-400hp with their tiny bores.

 

No, stock '87-'95 Mustang 5.0 heads flow 155 cfm. Stock 416 heads are over 180 cfm. The Mustangs didn't do it with better heads. They did it with worse heads.

 

Those 302 mustangs were not impressive in stock form either.
Take a look at the 5.3 and 4.8 LS engines. They have a bore around 3.78". The engine bore is not the only factor in the lack of power.

 

Even with the small valves if tuned a 305 by modern standards then you could still hit 6000rpm and make atleast what the foxbody did. You can always buy better heads,camshaft,pushrods,pistons and make whatever you want out it.

The slowest ferrari was the dino if you would even consider that a ferrari. The ferraris in the 80s where still pretty quick they ran 14s because they where fully carbin fiber. Many may not remember the f40 but todays cars are just catching up to that preformance.

It was first car to hit 200mph and do 0-60 in 3.8 seconds in the 80s, another good example of small engine low horsepower and fast cars where the 80s jaguar xj220.

A camaro is what it is, a high torque low horsepower car that isnt very light, its not a corvette because that is gms top model car so only the best goes into a vette. Its also not a pick up truck and handles as such.

It doesnt mean gm couldnt have used the corvette engine at the time like all the other camero eras, they where trying to sell a v8 sports car by the 80s standards and emissions that most people could afford without having to invest in a corvette, 300zx tt or 3000gt vr4.

Many of those cars sold well over 30000 and you could get a camero and have your v8 too for under 25000. Then in the mid 90s turbo 4 cyl and v8 production cost and odb2 made it so the standard camero and car could be produced cheaply by federal standards.


But the v6 became standard then and they introduced the z28 not so cheap lt1 with 260hp to start with as top model z28. Most cameros are the v6 on newer ones and in the 90s.

Now days cars are very heavy a charger r/t 5.7 hemi only does 14.53 with all that emissions and silencing crap and has a nice 350hp. Its also rated lower in gas mileage then the older v6 and v8 14 second cars. In the real world im not sure.

But this is what happend and I hope we go to nice higher horsepower hydrogen and ethonol cars. The days of big torquy v8s are numberd and people are convinced a torquless 2.0 liter civic si with 195 horsepower is where is the fun is at.

 

Sorry for misinformation I get my ford knowledge from ford owners.

My point was it isn't the valves that have given the 305 such a bad rep, it is the poor factory setup that it has. That combined with a 350 being just as costly, and cheaper in some cases, to modify make most people not want to work on them at all.

The first time I drove my Z28 I thought GM was over rating the HP it was such a turd.

 

I'd say the 305's main problems were mostly airflow related, the main exception being the overuse of 2.73:1 gearing, which should've been discontinued for '83 because of the overdrives. Had I been running the show, the L69 would've absolutely replaced the LG4, the LM1 would've never been dropped, and so on.

 

I agree with the engine thing. Apparently they discontinued the HO due to vapor lock or what ever, but something that could have been easily remedied. I do like the 273's on the highway though. The Lo3 just goes to sleep. I replaced the gears on the IROC to 342's and it made a world of difference.

 

Admittedly, my '91 LO3 did fine with 2.73s on the highway. But even when I went to 3.42s, and recalibrated the speedo, it still kept averaging 23 mpg in combined city/highway driving, and was still comfy and quiet on the interstate. Acceleration was dramatically improved.
When I did my '88 LO3, it also ran well, but going from 2.73s to 3.08s, again with speedo recal, it improved both acceleration and mileage. I went from averaging 25 mpg on the interstate, to 27 mpg.
Liking what you have is good, but refusing to make it even better seems ridiculous.

 

So the 308's did better than 273's as far as gas mileage. Must be the 273's lugged it down a bit. Yeah the speedo thing. I had to put a new driven gear in it to get it right again.