tnz5106

Fellow C4 brothers. I have had a late '86 (aluminum head) Z51 coupe auto for 4 years now (144k miles). She has a rebuilt title( never been wrecked, just a theft history), no paperwork history, pretty much a project car I bought from California for around 2300.00 back in late '09. I wanted a Z51 car because after owning several c4s over the years including a '92 ZR-1, I have always felt the early c4 Z51 cars handled better than the later c4s unless you are talking about FX3 or Z07 suspension.

Anyway, here is my point. I am getting ready to buy a July '85 build date Z51 coupe with 82k 2 owner miles. It is bright red, with red interior(leather seats). The car comes with a ton of old paperwork including the original Bose manual. It has a glass top and is completely all original and has never left its home town since it was delivered in 7/85. The flaws are as follows. The clear coat has peeled badly, the seats are cracked some but not ripped and the carper is slightly faded.

Here is the thing. The car is 100% unmolested and original. I am a purist by heart and I love early c4s that haven't been ragged out like most of them have. The seller just did a complete walk around via FaceTime with me a little while ago. I am very knowledgeable about c4s and I have even been through all of Gordon Killebrew's classes.

My question is this. Can I expect much difference in the handling and performance of this '85 over my '86? Although I know it would be minimal, I have heard that the '85's were a little more powerful and stiffer than the '86s.i will be selling my '86 and replacing it with this '85, and I expected to only have about 1k out of pocket between the two. I figure the originality, color, glass top, and documentation will be well worth the 1k difference in getting this '85. At least I will have a well documented, original car.

Btw, my '86 has no glass top, is a dull silver metallic beige color, and needs probably 3k in cosmetic work just to look decent. It is mechanically sound and handles like its on rails

Like I said, I am a purist and the red on red is my #1 color choice for the '85s..............sorry to ramble, any opinions?

DinoBob

I thought the spring rates were the same from '85-'86. The '85 cast iron engine has five less horsepower than the late-'86 aluminum head engine, and the engine itself weighs more in the '85. But the difference is slight enough that it probably comes down to which car has been better cared for. My guess is that, at 82K, the '85 will feel tighter and handle a little better, and the engine pop will be negligible in difference. Tires will also make a difference.

I saw your new one on Ebay. Good luck with the new car.

tnz5106

Thanks for your opinion and I agree. I guess I am wanting to hear from some '85 z51 owners that have driven some late '86s. I love both years. I don't like '87s as well because you had to get the z52 with an auto even though the hp was bumped up 10 hp that year because of the improved roller lifters.
Just to be more clear on my question, I guess I would like to hear from some early c4 owners that have driven both '85 and aluminum head z51 '86 coupes extensively. I am aware of most of all the differences available in '86. For example, jus a few: anti lock brakes, brighter dash cluster, 5 hp increase, vats.

Anyway, although I appreciate my '86s excellent handling and great mechanical condition, like I said I am a purist and I think the color, original paperwork and glass top of the '85 will be worth the change. I just don't want to be disappointed in the handling or performance. I believe I will be content, and I know I will love the color and all the original docs. Plus, if I do decide to restore her, I will have a hell of a better car with more appeal than my tired, plain old '86 with a rebuilt title and no paper history.

Anybody looking for,a good reliable '86 z51 coupe for around 3k?........l.thanks

zr1fred

Sounds like you're looking for justification. From your description, other than the mileage (which after 25+ years is basically irrelevant unless its under 10k) the cars are pretty much the same. Paint is by far the most critical, and expensive cost, so that's a wash. The only real difference is the title, and in the range your looking, not so important. Sometimes change is good, sometimes not so much. Since the values (and potential) are about equal, it comes down to what ever makes you happy.

tnz5106

Yea, I know. You know I think a lot of it has to do with melancholy. In 1985 when I couldn't rub 2 nickels together, I wanted a new red on red corvette soooooo bad!! At 25 years old, I had dealer brochures and magazine articles all over my bedroom wall!........25 years old!!

Since then I have had 5 new c6s over a 4 year period including a '07 atomic orange z06. I have had a '92 ZR-1' and a few c4s. But i always come back to my true love. the c4!!Bottom line is this. I am 54 years old now and have yet to have that original red on red z51'85.............. In the last 14 months I have had some serious health issues and financially, I have lost everything I have worked for, for the last 25 years. The c4 is about the only passion I have left besides my family. So having an original '85, even though she's weathered means a lot. She's kind of like me..........worn and faded but still has all the original parts................I think I will make the swap...........chime in everyone, feel free to get personal, I did. Sometimes forums help just to be able to open up. It's nice to know you have a network of friends that share the same passion.............

LongBeachC4

The 86 has 5 more hp, but the aerodynamic efficiency of the 85 without the third brake light on the roof delivers far more performance as explained to me by some fellow named Fernando Alonso. That's why I bought my 85 Z51, well that and the fact it was near mint. Remember 85 is a one year weirdo half 84 and half 86 when it comes to parts. Buy a real good car and you'll be ok

tnz5106

I disagree on the '84/'85 comment. The '85 corvette was a total revamp drivetrain wise compared to the '84. The '85 z51 is identical to the '86 z51. I have always thought of the 85/86s as being brother and sister. By '87, all heads were aluminum, the camshaft was different, and there were no more z51 auto's.

The '84 was a bastard child with a held over crossfire engine. Even the wheels were not 9.5" wide all the way around like the '85/'86 z51. The only good thing about the '84 performance wise in my opinion was the stiffer springs. So I would never compare the '85 to an '84............

DanielRicany

I have an 85 and I love it. Even though I have iron heads, with the mods I did it feels like a rocket. And yeah there is a lot of documentation comparing 85 to 86 and according to that the 85 is a few tenths faster.

I like 85 because it doesn't have a 3rd brake light, if it had a 3rd brake light then I would buy a 1990 corvette because of the improved performance. I personally like the early c4 body style more than the later, and I don't want an LT series engine because they tried a lot of new things and I have heard bad things about them, I'm content with my L98.

Aside from that, my seats are cracked too, mine is red with silver interior, and when my seats rip I will swap them out with black.

Mine is a 4+3, only problem with it is I can't seem to locate the leak on the OD unit so I have to add to it once and a while.

And there was another problem I am hunting down too for a while, the cold start hesistation when you rev it. Not really a big deal but it bothers me a little.

Overall I am very satisfied with the 85 and would not trade it for anything.

I don't have the z51 package but she still handles pretty damn good!

milsurpman

There is slight suspension changes between 85-86 z51 cars. It appears the 85 received a 24 mm rear sway bar and the 86 was changed to 22mm. Also somewhere in the 85 to 86 model years the front spring rate increased from 63.5nm to 66.5nm. All in all minimal changes.

tnz5106

That's the kind of info I am talking about. I have a couple of corvette black books laying around, so I know the changes and specs. I am literally talking about the SOTP feeling between the two.

I also remember back in or around spring/summer '85, that's all the hot rod mags were talking about. The baddest corvette since the early '70s!! 0-60 in 6 seconds? Wow, we couldn't believe it!!Believe it or not, that seemed unreal fast!! The new l-98 was going to be the baddest thing since the original LT-1.
I remember by early '86, road and track mag did a road test against a red '86 coupe and an all original 1968 L88 and the '86 walked all over the bad *** L88 even in the quarter mile because the original reline tires on the L88 went up in smoke. There was no comparison in the handling. The '86 would run circles around it.
You have to remember. These were the days where we never thought we would have a fast corvette again. That's why I have always preferred the early c4. If not for the '85/'86 corvette, there probably would not of been a C5 and beyond...........IMHO

LongBeachC4

Like I said, the 85 is a one year weirdo. Maf burn off box, exhaust system 84/85, dash, 84 standard springs used for 85 Z51.

tnz5106

Thanks for your input, but I guess we will have to agree to disagree...........

Greg Gore

From the standpoint of handling the 84 Z51 is in a class all by itself. As was mentioned above, 84 standard suspension was very close to 85 Z51. I bought an 84 new with Z51 because it really was a big deal at the time. Chevy won the skid pad tests in all the popular buff magazines at the time and put the serious Z51 hardware back on the shelf for 1985 when 84 owners started complaining about the rough ride.

tnz5106

I remember that very well...........great info, thanks

DinoBob

Those early C4s are fabulous.

yd328

FWIW I had an 85 z51, red/charcoal. It was a great car. The difference in the 85 to 86 dash was that they set the 86 dash in about an inch or so to help eliminate sun glare. Sounds like you have an intereset in the 85, I don't think you'll be disappointed. Good luck and post some pics if you go for it.

3JsVette

I have a '85 Z51 4+3 and if the car you buy is mechanically sound I can't imagine you would not be happy with it since you know what to expect from the ride quality you get in your '86 Z51. Now if you had a base car and were concerned about ride of a Z51 over handling that would be a different story.

artvette

Sorry to burst your bubble, but the L88 had fresh rubber on it and kicked the snot out of the '86 in the quarter mile runs. I have the original mag in front of me from Feb of 1986.

BGZQ8

The spring rates for the 1985 AND 1986 Z51 are 66.5 nm front and 57.8 nm rear.
The 1987 got a 5 hp increase from the roller lifters.

tnz5106

That hp increase was 10. From 235 hp (aluminum heads), to 245 hp..........check the books