Since there is so much knowledge here.....
My 498 will consist of the following:
Scat crank, Manley rods, SRP pistons.
Comp extreme energy roller 254/260 .660/.661 110 lobe sep.
AFR 305 heads with CNC chambers, 370cfm intake, 300cfm exh flow.
10:1 CR. Dart or equiv intake, 950hp holley with 2" hookers into a 3" DR gas x system.
My old 468 made 565hp with edel heads that flowed less at .700 lift than the AFR's do at .400 lift.
AFR told me their heads would add 100hp to that engine....of course they like to sell heads. But this engine will be 30" bigger, have a roller and much better heads with a bit more CR.
Just curious as I doubt I'll dyno this one....
Thanks,
Ron

Let me go a little out on a limb and say that the 1/4" stroke will not affect peak horsepower as much as it will flatten out the torque curve.

With just a few degrees less timing duration, but better intake flow, my 496 made 640 hp on a conervative dyno. Ultimately, the dragstrip is the best dyno - use the dyno for tuning, but don't get too hung up on the dyno numbers.

Thomas

Ok, I'm a little hung up on the numbers....
I dynoed my 468 cause I was shooting for 560hp, and cause I wanted the engine tuned and broken in before it went in the car. One jet change and a spring change in the carb secondaries got it in the tens second time out.
My engine builder agrees with you if the airflow of the heads stays the same, especially if the airflow can't feed the bigger inches.At least in this case, I have increased the airflow quite a bit.....unless the intake and exhaust aren't going to be the limiting factors now.
Thanks for the input, I appreciate it. And BTW....you are up too late tonight just like me! Ha!
Ron

Just curious what your last combo was. Cam, converter, gears, weight, traction devices.

The 468 used Edelbrock oval port alum heads out of the box. CR was 9:1. Cam was an ultradyne 255/263 ..612/.630 110 lob sep. Installed per the card at 4 degrees advanced. This cam btw was recommended by Harold at the time we built the engine, about 7 years ago.Intake was a Dart single plane port matched to the heads.he Edel's are neither oval or square, sort of in between. Carb was a vac sec 950hp (later switched to a 950dp, little to no difference. I don't think the vac model is offered anymore, but was a hell of a good carb)
Converter is a 10" B&M race model, approx 3500 stall. Gears are 4.10. 10x29x15 Hoosiers installed after getting to the track. Traction bars are hard to describe. Designed by a North West stock eliminator driver. They are essentially a ladder bar with a sliding front mount. The Nova of course is a leaf spring car and the bars mount where the lower spring mount goes and the pivot/slider goes right where the front spring eye is. I modified mine a bit to move the front pivot forward and connected it to the subframe. I didn't have to follow stock eliminator rules, and really didn't like the way the design had the mount plates welded to the whimpy front spring perches. If you are familiar with Cal Method, he uses these on his B/SA Nova. They are quite effective. The Nova short times around 1.50, runs 11.0 most of the time and slips into the high tens in good air on a good track. MPH is usually right at 120. 6.80's in the 1/8th. Of course Portland OR is at sea level which is a nice advantage.
Maybe I'm dreaming, but I'd like to see 10.3 out of the car with the new engine, although I might have to back the gearing off to 3.73. I'll start out in the 1/8 mile to see where the MPH falls. Not sure if the 498 will like 7000+ in the traps in the 1/4.
Ron

BTW....the car weighs 3500 with my butt in the seat....maybe 3520 this year.....stopping smoking cost me 20 lbs....and starting again didn't make it go away. Ha!'
Ron

No it will not make 700, closer to 650. Bump the compression up to 12.5 or so and it would be pretty close. You might get lucky and put it on a friendly dyno and you will see 700. Tom is right the drag strip is the true dyno, go see what kind of mph it will pull.

Well dang. I imagine low 10's will be out of the question.
I could have saved about $4500 by simply buying a 100 horse nitrous system.
Oh well, I had to ask.
Ron

Thanks,
I'm building an oval port, solid flat tappet 491 for my Nova and was curious about your drivetrain. I'll be shooting for around 600 real HP and want to go 10.90's in warm air with my 3.73's and ET Streets at 3600 lbs. With about 550 HP I've gone 11.1's with spray so hopefully I'll be there.

Well @ 3500 lbs race weight and 650 hp you should be in the lower 10's i would think. Brian's{motor martyr} buddy Ed, has an un gutted, creature comfort retaining 69' chevelle that weighs, 3900 or so lbs, with a 468 hes run in the 10.20 i believe, with stock oval ports. So well set up, you should be there.

I think Mike "Wolfplace" built a similiar 496 engine (I am thinking same cam and AFR heads). It made 670hp on an engine dyno. My friends 3200lb pump gas camaro has gone 10.0's @ 132 with a 502 that made 625hp.

Originally posted by 68chevelle533:
I think Mike "Wolfplace" built a similiar 496 engine (I am thinking same cam and AFR heads). It made 670hp on an engine dyno. My friends 3200lb pump gas camaro has gone 10.0's @ 132 with a 502 that made 625hp. =
Yep,,, & on a dyno that has been verified to be pretty conservative compared to some,, mine :D

Pretty much the same except AFR 315's, & the cam was on a 111 seperation & had 1.8's on the intake (.698 gross lift) & a vic jr with an 850 Demon.

I don't think that 10.30s are out of reach with enough bite. If that Chevelle you are refering to is Ed Bigley's it is a '68 model and bites like crazy (1.36 - 60' times) not at all average and has some suspension work done to it. The 3200 pound Camaro does E.T. good but if you drop 320 more pounds onto it it would slow down 3-4 tenths (recently ran 10.08 at same 132.76 MPH) at Houston Raceway.

Well,
Maybe I'll get to my goal.
Here in Portland we are starting a heads up program for those of us who are tired of bracket racing. Eventaully we will get to an NA class and a power adder class. We will be nowhere close to the times other folks in the country run....but we have to start somewhere..
Right now, the fastest NA car is in the 10.2 range, and he is planning to go with N2O
.....which I hate BTW.
Thanks for the insights folks,
ron
BTW....I feel my car is quite well setup

Is all I know....is it's gonna be fast....


Charles

Todd DeLaMuca

AKA......my butthead brother