69 Big Block Corvette to 308? What to expect

I think you'll never see the tach needle go above 4500 rpm and you'll likely never see a buyer when the time comes to sell.

I would recommend a Pantera.

-F

 

LOL, that was my first thought as well. But think he is talking of trading the big block for the 308.

It would be interesting to read some true specs, but given the shift configuration and gearing of the 308 I would not expect a huge change in 0-60.

 

This was done to the first 308 GTSi I ever laid eyes on. It was back in the 80's and the car was a victim of a gas station timing belt change failure. Not kidding.

The car drove about 4 miles before it let go. It then sat for about 8 years in his front yard near were I lived until someone offered him cash, drug it off and put a 350 in it. I never saw it again.

 

Yeah, a 1969 Corvette is faster than a 1977 Ferrari in a straight line? That was news to me but hey, what do I know?

Edit: I apologize if I misunderstood. I thought you were proposing creating a FrankinFerrari which never turn out nice.

-F

 

me too

I never would have told my story if I understood the question the first time

 

The base 69 427 vette engine was rated at 390 hp and and an equal if not greater amount of torque. These are real stump pullers. The cost to modify your 308 to anywhere near this output (and make it live) would probably cost more than the car is worth. Yeah it's nose heavy as 500 plus lbs of iron over the front wheels will do that but there are many mods available to "correct" any handling issues.
You really can't compare the two...

 

Is this another one of those April Fools postings?????

As was said, you can't compare the two. If you want a 308, buy a 308. If you want a 0-60 stump puller, stop light racing machine, look elsewhere. Don't waste your money trying to make one into the other. The 308 was never intended or designed to be a stop light racer. Period, end of story.

If you want a great European sports car to run on the twisty back road and enjoy the sound and smell and feel of a Euro, then by all means, look at the 308s. If you want to beat Bubba from stop light to stop light, look at the 'Merican iron. Oh, wait, you already have that.

 

I don't think the OP is really trying to "compare" the two cars in any direct manner... I think he's just asking whether anyone has actually documented the performance of any of the 3.4 and 3.5 litre 308s running around, and wondering about the parts cost involved in performing one of these builds...

 

It's my 2007 ZO6, lotta bang for the buck. Tons of nice ones 30-40 K range. The LS7 motor will make your eyes water going thru the gears. Just my thoughts. Cheers John.

 

Does Norwood still do the turbo kits?

But if you're looking at a hard top GTB, why not look at a 512TR?

 

I have a 3.5L but had Carobu do all the work. If you go that route, expect to spend 25-30k on the engine work. If you can do the assembly yourself, you will probably end up spending 12-15k.
My spedometer is dragging and needs to be rebuilt so I can't get you an accurate 0-60 time but I just met up with a writer for Forza magazine this past weekend and he absolutely loved driving my car. He flogged it for the better part of a morning through the mountains and came away thoroughly impressed. He has driven and written about many Ferraris (308's, F40's, 430's 360cs's) and is convinced that doing a big bore is the way to go for a 308. The car is simply unrecognizable after this. Unless you use forced induction (tons of other issues to deal with), big bore is the only way to get more torque and a good hard pull.
Zach has recently done an article on another 308 that had probly over $10k worth of throttle body efi work done to it but still kept the 3.0liter displacement and said it wasn't even close to the torque that my car had.
I think it's easily worth it if you can do the work yourself but if you can't, you are talking big bucks that you will never get back on resale, but boy what a ride!

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My 3.4L engine makes 272bhp and 225lbs tq at the wheels, which translates to around 330bhp at the flywheel. These engines lose between 17-18% through the drivetrain due to the additional 3 drop gears from the flywheel to the gearbox mainshaft. Anyway, this is about a 100bhp and 50lbs tq increase from a stock early carbureted engine or QV engine (the 'real' bhp figure that is, obviously different from Ferrari's figure which is......creative).

Performance increase is massive and is primarily felt by the amount of torque gained below 4500rpm, think low 5 second 0-60 and upper 13 second-ish quarter mile (I've done a 5.2 0-60 without beating on it overly hard, that was per a calibrated acceleration measuring iphone app). Quarter mile figures are sort of a moot point with these cars as the gears are just not designed for that type of driving, but I know for a fact I am a taste quicker than a stock 3.2L Acura NSX. Fast enough. The look of the car under the hood is unchanged, yet it drives like a group IV Michelotto machine when pushed and retains daily-driver stock-like ease of driving on the road, and that was the point.

If you are good with engines and have built a few then you should be fine with this build, just take your time and triple check everything and keep a thread here with the project, ferrarichat have some amazing resources to tap into and there is no issue the group here cannot or hasn't handled already.

As far as cost is concerned, you obviously save a substantial amount in handling the project yourself, but parts are indeed pricey.

Heads (new valves, guides, intake seats to accommodate 44mm intake valves required for project, and bowl opening for intake flow, seats cut)
$2000-2500.

Cat Cams (Belgium) camshafts: .425 intake lift 248 dur @ .050 .390 exhaust with 239 dur @ .050 (set to very very tight lobe centers, think 100-104) $2000

valve springs for above cams (stock won't work) $200

pistons: $1500 (10.5:1 JE run flush with the deck. JE has the spec for these already, ask myself or Paul and we can point you right regarding where and who to speak with)

gaskets, engine bearings, seals, tappet shims, belts, timing bearings $2000

Ferrari 360 crankshaft (used) $2500 (with titanium rods, add another $1k)

other machine shop work: bore/hone, align hone crank journals, dial bore rods, small end bushing replacement for rods, clean all aluminum, crank polish $1500

figure $200 more per liner if the liners need to be replaced, but they usually don't. ALWAYS bore/hone them with a deck plate though.


clutch $400

Electromotive ignition if it doesn't already have it (makes life infinitely easier for this setup) $1600

maybe an exhaust to finish it off? $2000

replace the 1-2-3 gearbox synchros while you have it easily accessible, some torque nuts must be replaced when they are removed as well. $1000


More or less, the above is about right although I'm sure I'm missing something and I'm probably a bit high on some things. When it's together, jetting carbs for this setup has pretty much been deduced so just ask once at that point and it can be pointed out easy enough.


It will be an experience doing something like this, and the juice is certainly worth the squeeze.


Regards,
John

 

I'm going to go out on a limb here and give you an analogy.

Think of the 308 as maybe an older but elegant super model , lets say Cindy Crawford and think of the 69 big block as a hot porn star like Sasha gray. From what I gather, you are trying to make Cindy more like Sasha. Now, though Cindy maybe able to perform in that category , I think the performance would be lacking , and you would be disappointed in Cindy transforming to being like Sasha. I'm not saying it won't be fun to try, but I don't think Cindy will give you that type of fun , unless you are prepared to accept Cindy not being the same as Sasha.

Just sayin'

 

Or in other words making a hot nun a whore, interesting idea but it ain't going to work.

 

Yours just seem wrong on so many levels, so, I'm going with no, not the same

FYI- I never recall one good looking nun in my lifetime, let alone 'hot'

 

There is nothing so far that would lead me to believe this build wouldn't last longer than a stock engine simply down to the fact that it uses modern engineered components and materials and all the benefits that go along with them. I also run gapless top rings in all my builds which keeps bottom end leakage very minimal.


In all, this build is not really about changing the car in a fundamental sense, rather it's about making it more of what it already is. I was an inch away from selling this car before I did this, now there is no way. It's a healthy dose of analogue in a digital world.

 

LOL. Post of the year. Needed that, thanks.

 

You've never been to St. Peter's square I take it. Lots of cloaked tail walkin around.