Would it be possible for a 468 BBC with fully ported 781 heads, DCR of 8.0ish/11:1ish SCR, on 93 octane, with a Q-jet, in a generously estimated 4000lb car, to push a 12 second-ish quarter mile? If not would a 496 be able to? Sure I can use drag radials for the track or something...mildly geared with a 4-spd tranny would probably be in the car.

I'm just curious if it's possible. I've asked a bit about this before (though not as to the point). I notice, for example, among other's, 10secbu's amazing time with only 414 CID, with the same heads I have, so I figure even if mine's not as 'properly' set up that 50-80 more cubes would have to come pretty close? Though I bet his car is a lot lighter too, but still. Mr 4 speed runs great times (though with closed chamber stock iron GMs) with mild gearing and stock Chevelle, too.

Just trying to figure where to go. Sort of debating what to do still. Don't want to put too much unusuable power to the ground but still don't want to be too thirsty, if that makes sense.

I really appreciate all the help and advice. I ask a lot of questions but I've learned a lot, and want to learn a lot more to make my first big block incredible. Thanks!

Taylor;

I had a mild 468 (about 500 hp) in a 64 Chevelle weighing about 3200 4.86 gear 12 bolt, TH400 at Bandimere Speedway, altitufe 5800 feet (density altitude almost always over 9500 feet. We ran low 11's.

So, is it possible? Yes it is. You may have to work at it, but you should get there.

Good Luck

Ken Gasbarri

EASY :D

I think your goal is do-able...the challenge is the manual trans. Jim (Epistuff) has a very good running manual trans combination. Hopefully he'll chime in and drop some ideas for you.

BTW, for the record, my ride weighs 3600 lbs with driver.

Why would a manual be a challenge? Is it because no torque converter so you would have to gear lower than I want to?

I think the easiest way to do what you are asking is get over not, "driving it like you stole it"..

I say this b/c of possible breakage concerns!!

Beat on her AND run h-ll outta her AND see what happens up to the breaking point...

Fix it by making the part that broke stronger and repeat!!!

You will go faster and faster if you learn by each trial not to repeat former errors..

Isn't that how Ed does it at the strip???

pdq67

this might be something to think about.....before my 81 camaro became a total drag car it was driven for several years in full street trim and taken on long road trips.....i wanted the car to be super fast at the track and on the streets but i knew i would have to kill the low end torque to get it to hook on regular street tires and i knew i was going to be using pump gas all the time 91 octane.......my combination provided me with 12.teens 1/4 mile times at just over 115mph thru the mufflers and on 275/60-15 bfg regular tires with a best of a 1.72 60 ft time........so i knew the car would have to be kinda a slug down low but would scream up top to get me what i wanted........my engine combination as follows

396 bored 60 over
factory grind ZL-1 cam 262/273@ .050 .561/.600 lift
390 closed chambered heads ported (myself) with 2.19/1.88 valves
crane roller rockers
11.7 to 1 compression
victor jr intake with a highly modified 850 double pumper with adjustable jets
1 3/4" headers
tci 10" convertor/th350 tranny
3.70 gears
weight was just at 3700 lbs with me in it
the one and only time i figured gas mileage on the highway 11 mpg
shift point 7200 rpms

street life for this combination about 6 years

with slicks, open headers and a shot of nitrous (150) it would just hit the 10.90 range........this was done only a few times since i kept recieving warnings about having no roll bar and saftey equipment.....

it had a wicked idle, crappy bottom end till 4000 rpms but it idled at 700 rpms in gear.....and was fun to drive around anywhere........

3.55-3.73's and a T10 4 speed w/a 2.88 1st gear would be a sweet combo.
Thanks for the compliment Taylor

Originally posted by soccerguy045:
Why would a manual be a challenge? Is it because no torque converter so you would have to gear lower than I want to? No, it is because without a lot of practice, you will spin off of the line and no matter how much power you have, your ET will suffer. Then if you do get traction, you run the risk of breaking stuff. But overall, your goal is very attainable. I am @11:1 CR, over 8:1 DCR, run on 93 octane pump gas, drive to the dragstrip, run low 12's and drive it home. Once I got it to "60-foot" good, the ET's followed. There are a few tricks I learned along the way that helped for a stick-shift,(tire selection, rear suspension, carb setup, clutch setup, launch technique....) so get your combo together, put it on the track and post some results. We can help you.

Yares ago, I had a mils 454 70SS that ran high 11's. Incredibly simple combo.
So here is what it was:
461 CID
Don't remember the casting 3 for the heads....but they were 1970 semi open chamber stock on the LS5.
I pocket ported them myself, used stock valve sizes.
Pistons were TRW cast flat tops.
Cam was a Comp Cams 280H.
Performer RPM manifold with an old 750 vac sec 3310.
HEI distributor. Properly curved of course. Ran 40 total timing.
Hooker 2" headers with a full 3" exhaust setup.
TH400 with a 10" B&M superholeshot converter.
3.55 12 bolt posi.
This engine was less than 9:1, and managed a best of 11.90 @ 113. Always ran 12.0's....and when it snuck into the 11's and they got on my case for no roll bar, I just put the aircleaner back on.
It was simple simple simple, and ran well.
Easy to duplicate.
Ron

Ron,what was your 60 ft. with that combo?
When you say stock valve sizes,you mean 2.06/1.72 correct?
Impressive numbers for a mild combo graemlins/thumbsup.gif

Hey Mr 4 speed,
I of course ran slicks.....10.5x28x15 M/T's.
I believe the all time best 60 ft was 1.67....but more typical was 1.72 plus or minus. I used a set of Lakewood?? slapper type traction bars for the Chevelles. They worked amazingly well.
And for the valves, yes, 2.06 and 1.72.
It was just a good combination of cheap parts!
I loved that car......should have kept it.
The block at least is still alive and well in my Nova. Wasn't the orig for the Chevelle anyway......
Ron

A friend of mine ran 11.2's consistantly for a few years with a 9.5-1 454 with ported 781's, teamG, 1050 dominator, 292 magnum hydraulic cam, 4.10 gears and a turbo 350 trans. The car is a 78 cutlass weighing 3700lbs. This was a simple combo that held up well. Now he went rectangular port alluminum and is running in the high tens.

I guess one thing to consider is, I don't want to take one good run at the strip and them tell me not to come back without a rollcage or something, hehe graemlins/thumbsup.gif Though it would be cool, but..nah..

But thanks for the help all. I'm trying to research a bit on purchasing a Muncie 4-spd that needs a rebuild and putting one of those gear kits in it that makes it a 3-spd + OD, so I could live with having 3.73's or 4.10s in back (29'' tires). I'm not sure if this is a good idea or not, so I asked in Transmission section, but not getting anything yet, if anyone wants to chime in here.

Check into the TKO 600 5 speed, by the time you buy a used muncie, the gear kit, and the little extras I think you'd be much further ahead to save a few more coins and go for the TKO 600. I've got two rebuilt muncies going on ebay shortly and the funds will be put towards my TKO 600. A friend of mine blew up 6 Muncies before going to his G-force 5, he would have been thousands of dollars ahead had he just bought the good tranny first. JMO

So would it be a good guess I'd be putting 450 HP to the wheels (but not necisarily to ground)? 500ish? I know it's hard to say without having a for sure combo ready, and even then not dynoing or taking to strip, but just wondering.

Also, Mr 4 speed (not trying to just single you out though), I notice you're a pretty big advocate of just using the drag strip as a 'dyno', but I'm wondering if you've even ever dynoed for the heck of it? Or even had a guesstimate on your combo?

Originally posted by soccerguy045:
Also, Mr 4 speed (not trying to just single you out though), I notice you're a pretty big advocate of just using the drag strip as a 'dyno', but I'm wondering if you've even ever dynoed for the heck of it? Or even had a guesstimate on your combo? Taylor,a fellow TCer "cmt454" built my motor exactly except he used the 2.19/1.84 valves instead of the 2.06/1.72's and his motor dynoed at 490+ HP and 530 ft/lbs. tq

Dynos are great for tuning is all. Numbers don't impress me, performance does.

Soccer guy, yes the thing about manual trannies is just that, no torque multiplication other than gears. Even with a 10.06:1 1st gear ratio, I could use more. HOWEVER, it's a 427, not a 496. 9- 10:1 would be fine with a torqey motor.

The 1/2 shift happens right after launch, before the 60' mark btw.

I would opt for a more modern 5-6 speed gearbox btw, giving you both a deeper first gear, and OD at the other end. Having said that, I've got some 'sketches' of a 496 that should run 12.XX with an M20 and 3.08s, beleive it or not. ( if the suspension can hold it!) Someone else here is building something similar but its TOP SECRET.

12 seconds is quite easy with rat power BTW. I'm doing it with nothing more than an old 435HP 427, bad old GM heads and all. That's with a 2.15 60'. Anything under 1.95 60', is an 11.xx. Not bad for a car that can be driven cross-country, without any incident, pulling 16 mpg. According to a very good racer here, if I could ever pull a great 60' ( not likely ), the mph indicates an 11.60 ET. ( a T350 and 4300 stall would do it!)

Very, very doable. BTW, I'm curious as to whether extremely torquey motors ( over 550 lbs ft) mate well with manual gearboxes. Seems an HP motor might be a better deal, but I'm just curious. I will, one day, build a stump puller and see how it launches with a manual gearbox and shallow rear gears.

There are no secret formulas for rats IMHO. And no "one way" to do it, IMHO. You build a powertrain 'system in balance' and you'll hit your number with ease. I've obviously proven that you can build an HP motor to run down a torque motor and be just as 'streetable' ( with the proper gears). It's all in the system design. And I don't think you'll need a 4.25" crank to do it. Since I only own a block and 049 heads, I'll opt for 4.25" crank, longer rods, etc, only becuase they're relatively inexpensive. Unless a free 4" crank falls in my lap. Plus this will be a 396/325 hp look alike Qj/low rise, etc, so need all the help we can get. ( may even go hyd roller)

Recommend you always keep engine operating band and gearing constantly correlated and the power of the rat will be with you!

Talked to my engine builder today. Looks like we're slowly gonna get things going and stuff. Thanks for everyone's help. I'll be working closely with my engine builder (very good guy, you may have possibly seen him in some magazine, because I have...Tom Lucito?), and I'm sure I can count on you guys for a little bit of help too, as always! graemlins/thumbsup.gif Thanks again!