66BBCoupe

I visited the original owner of a 1966 427/425 Coupe similar to my own. In with his pictures were his actual time slips from New York National Speedway in early 1967 - 11.24 127mph in the quarter mile !! The only mods he admitted to were M&H slicks and open exhaust. He said he went far past the redline and the motor never blew up .... and we wonder why so many big blocks don't have the original motors ! :smash:

66427-450

Yup, that's where the BB Sting Ray's reputation came from, it didn't just look and sound fast :-).

With 4.11's or 4.56's the solid lifter BB's were/are screamers all right. Add slicks and headers and they were tough to beat........Came off the line much better than a GTO or a big Mopar due to the weight distribution, and pulled like a bear at the other end.

They rev'ed better than any other big street motor (valvetrain seemed ok to 7000 or a bit more), however, the rods were the weak link in the early years, and when one went, it pretty much took out the block (I've pulled down a few after rod failure, and what a mess!). The average street racer didn't have very many options back then as far as rods went......... Today, you can pick up a set of super strong, nicely prepared, Eagle H-beams with 7/16" ARP bolts for a very reasonable price.

Blkblt

:D :D :D :D :D :D :D :D :auto: :seeya :seeya

********************

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Jeff; Charter CCC
1966. Modified L72
The Silver Beast
Keep on :cheers: :seeya :flag :steering:

olredalert

--------Anybody running an 11.24 in a stock suspension mid-year Corvette was just waiting for severe rear-end damage. Id love to look under the back of that car and see just how much carnage there ever was on the car. Broken half-shafts were common when running in that ET range. You just cant imagine till you have seen it just how much damage could be done when an axle shaft twists in two. Almost worse than a clutch explosion! At the very least the pumpkin crossmember bracket had to have broken off the frame on the drivers side. I have seen midyear big-block Vettes that had damage there and never had anything but a stock tire on them. Oh well, it sounds like he had fun,and back then I would have been clamoring for a ride!!!!!!.......Bill S

66427-450

I hear ya, I've been lucky so far, no catastrophic failures. I'm currently adding ~150HP... and am beefing everything up back there a bit in preparation. I think how hard you "shock" the drivetrain during launches is a key factory to rear end life (big sticky tires, high RPM launches = broken IRS parts).

btw: there are gussets you add to the x-member mounts to strengthen the area you mentioned, see Tom's (Rear End) web page if your interested.


[Modified by 66427-450, 4:53 PM 1/13/2004]

aworks

i tore a halfshaft out doing a burnout and what a mess but worth it. i have a ball with these cars. just like they where meant for. thanks Zora.

olredalert

------In 1970 I was at Dragway 42 in West Salem Ohio one Sat. and a 69 L88 roadster came to the line. It sounded extremely healthy as he wound the engine up and side-stepped the clutch. That was his first and only mistake. By the time he got the car and engine stopped the halfshaft had taken out everything in its path. It broke at the pumpkin and went all the way up and thru the seat-back. In the pits as I was surveying the damage the driver said if he hadnt leaned forward it probably would have hit his back,although when I looked the half-shaft hadnt made it thru the vinyl seat-cover!!!!!!
------The amazing thing about this story is that these guys were back at the strip the next weekend. I didnt get a close look at the repairs but from a distance it looked like nothing at all had happened............Bill S

Denney

My 66 bb convertible (originally 425hp/4.11:1 rear) was obviously in a similar situation when I examined it during the resto, but from what I could tell it was the inner U-joint that gave way. The only real "safety" feature on the mid year big block monsters was the fact that the stock tire would break loose and spare the rest of the components... :yesnod: :D

DansYellow66

:iagree: Put my car (427/425 4.11:1) down for the infamous half shaft launch. That was one of the major time-consuming jobs of my restoration, repairing where a half shaft tore out about half of the right side storage well behind the passenger seat. I was also extremely impressed when I noticed the yokes on one of my half shafts were no longer timed 90 deg apart - as in twisted about 5 degrees off. Big grippy tires on these is just asking for trouble. I think the L72 has been unfortunately overshadowed by the later tri-power motors because in their day they were the real animals. Car & Driver drove a stock 427 convertible to a 12.8 @118 mph in the quarter in 1966. I know I'm prejudiced but my 2 cents are that the 66 big blocks were the quickest of the C2 and C3 cars, except for the L-88s. :steering:

Maximillian

I should probably leave this one alone.....but I can't resist.

No offense but no C2 or C3 Corvette in ANYTHING remotely close to "stock" config. traps that high....except maybe in a 1/2 mile.

The fastest C2 or C3 "Vettes (I'm talking ZL-1 and L88's) could only pull off 115 on their best day as I recall and best ever runs. I believe ALL such 115 mph runs (remember we're talking ZL-1 and L88) were with OPEN HEADERS and 4.11 gears. I think just manifolds would only get you to around 110 mph or less as I recall. Trap speeds don't lie. Tires don't matter and the driver matters very little.

I know lots of guys like to talk about the legend of the old big blocks (me included), but those who really know this stuff must admit that they just aren't that fast (I'm talking the "for street" big blocks)......particularly the trap speed, due to aerodynamics.

The fastest stock 'Vette ever built (again, guys will argue this one but not guys who are knowledgable and are being honest) is the current Z06. It will, in stock trim, pull off legit. 12.4 @116-118. Even the not for street ZL and L88 would likely get beaten by a new Z06 with the same tires.

Now if you're asking which car I'd like in my garage....that's different :cheers: I'm not saying he didn't show you a time slip. I'm just saying it isn't his and/or it didn't come from a '66 427/425 that won't trap higher than about 104 mph downhill with a stiff wind at it's back.


[Modified by Maximillian, 6:56 PM 1/14/2004]


[Modified by Maximillian, 6:59 PM 1/14/2004]


[Modified by Maximillian, 7:03 PM 1/14/2004]


[Modified by Maximillian, 7:06 PM 1/14/2004]


[Modified by Maximillian, 8:21 PM 1/14/2004]

LT1driver

OK, I will join in the fray. Personal experience; my first vette, 67 427/435 with G70/15 tires, side exhause and m21 trans, 3.55 rear ran at carlisle, Arkansas drag strip 13.8 @ 108, not once but twice. Nuff said. :hurray: :party:

Maximillian

Not sure if you're on the side of a 120 something mph trap out of a stock BB. Either way, that's amazing considering the fastest ever documented L88 trap with stock manifolds was 107 mph. You running headers? If the 108 is accurate, you had to be.


[Modified by Maximillian, 10:19 PM 1/14/2004]

66427-450

:lol: it would be interesting to compare dyno results of the two (L-88 Engine and Z-06 Engine), from say 3500-7500 RPM. (What's the Z-06's red line anyway?)



[Modified by 66427-450, 8:33 AM 1/15/2004]

Maximillian

Here's the trick to the L88-- these engines were designed to be run off-road. They came with manifolds, but that's just not compatible with the cam timing of an L88 or ZL1.

With manifolds (flywheel hp): under 400 (although more was claimed)
With open headers: I've seen documented 500+ hp pulls at 7200 rpm

It kinda blows me away that just the exhaust restriction and lack of scavenging could cause such a difference, but that's what I've seen.

With open headers, ZL1 has been shown to pull off 115 mph 1/4 mile runs. That seams just about correct considering aerodynamics (or lack thereof). The motor has roughly the same peak hp as a Viper and would probably trap just about the same if it would just cut the air better (remember, atmospheric drag increases geometrically and is massive over 100 mph).

66427-450

yes, I totally agree..... headers, and a free flowing system, are an absolute must if you have a BB and are at all serious about preformance.

:seeya

Silver-6

I've never been much of a drag racer, but did do several runs many years ago.

It's been quite a while, but I remember running a 13.6 @ approx. 100 mph with my '66 427/390 on narrow street tires. Most of my times were higher as it was very hard to hook up on launch.

I'll see if I can dig out my old time slips and post the exact numbers.

DansYellow66

All right - I should know better than to quote figures from memory, especially when I even own the magazine with the 66 road test and could have looked it up first. But not untypically of someone getting up to my age, what I remembered as 118 mph in the quarter was actually 112 mph when I went back and checked. At least I got the 12.8 sec quarter right. These are still fast cars. You can check out the article in corvettearchive under 1966. The spec sheet is under the Car & Driver site, page 1. Sorry for the senior moment. http://www.corvettearchive.com/ :steering:

SBR

I have spoken several times to the original owner of my 69L88 and while the car was not heavily raced it did see a few trips to the drag strip. To make a long story short he said he ran in the mid 11s with a best of 11.3. He could not remember the exact mph but said it was better than 120. Mods were slicks and open headers and thats it! There is another forum member that still owns his 68 L88 and ran 11.2 at over 120 with the same mods as my car. I also spoke with a gentleman in my area that owns a 69 L88 and recently took it to the track and he ran 11.8 at 122. He ran a 4.11 gear slicks and open headers but was not powershifting. Dave Walters of Vette Magazine owns a 67 L88 and has run 11 second ets at over 120 also so saying 115 is all an L88 can is not an accurate statement. I do not know why the cars that you saw were running slower all I am trying to say is that an L88 Corvette that is tuned to perfection with slicks and open headers with a 4.11 can run mid to low 11 second ETs at over 120.

66427-450

:thumbs: :thumbs: :iagree:
I think the point is, the car has to be in the hands of someone that knows what he's doing (experienced hot rod/racer type)..... GM gave you the "Raw Material" with the L-88 package, or at least all they could (i.e. no headers and competition tires).

You don't just try to race a L-88 as delivered, that's just dumb !! They were MEANT to be completed by the owners, not like the 327/350's, etc., that were much more "ready to go" as they came.

LOL......Don't you think GM knew the cam was to big for manifolds !



[Modified by 66427-450, 10:07 AM 1/16/2004]

SBR

Chevy knew that the L88 cam was best suited with open headers, thats why they really did not promote the car for street use. I have over the years spoken to several people that own or have owned L88 Corvettes and the ones that were raced ran about the same as my car did ie. low to mid 11s at over 120mph.