Chevelle updates

[scuncio]

Nice 60' time. What tires were you running?

[VintageMusclecar]

MT Drag Radials, 275/60/15.

[EZ Nova]

Sorry, but I'm a little confused trying to follow this thread??

Here's what I THINK (??) I got so far:

1. Do did a GREAT job restoring the Chevelle. It's a BB 496 you did, and stick.

Confusion starts with:

1. It's a 496 that you did a separate "build thread" on. You linked it back a few times. BUT that thread say "Remember, the results up to this point are still with 100% original, UNPORTED cylinder heads with stock 2.19 1.72 valves."

2. In the update thread you go on to say you got 840 casting in 2 weeks and of to Chad for porting as shown in the picture. Page 11

3. See on page 13 that Chad got some nice results out of the 840's.

4. Never got it back to the dyno? 25 pulls on it with stock heads and NOTHING to figure the new heads?????


I missed cam timing so cant say what I figure the heads help was, say 70hp?? So a 670 hp motor and only getting 12.0's or high 11 with a Mt 275 Dr tire (which by the way probably has the most advances as any tire today for racing)??? I thought hat car should have been over a second faster. My '69 Nova set-up like this (M21, 4.56, 9" slick) but with a lil mild 396 went 10.47. Basically a STOCK balance L-78 STANDARD bore 402 with only ARP rod bolts. Stock pan, PORTED 840's, but did have a strip dom intake and reworked holley 800. UT I did have a solid roller .660 cam.

Seems like you know what your doing, and been around these cars for a while, but what are we missing???

John

[VintageMusclecar]

(1) 496 is still running with UNported heads--just received new heads from Chad, haven't gotten them installed yet. Motor made just over 600 on the dyno (30 pulls) in current form.

(2-4) Heads aren't even built yet, will be built and will go back to the dyno shortly.

First, remember this is a NEW combination that's only been down the track twice. First pass was an EASY pass and went 7.74 @ 90+ with a soft launch and short shifting. That equates to ~12.07--again, on a soft pass. It only 60'ed 1.76.

The 2nd pass blew the tires off losing over .4 in the 60' AND I missed 3rd gear. I just drove it the rest of the way down the track, still went 12.7 @ 111.

Both runs were also with cold tires--I didn't even do burnouts, just wanted to get a feel for the car on the track.

Like I said, the car has EASY 11's in it as it sits, it's the DRIVER (me!) that needs work. I haven't made a pass down a dragstrip in over 20 years! Give me some time to get the hang of this again and to get the car shook down.

There's <span style="font-weight: bold">plenty</span> left in it!

[Jim Ferron]

Eric, Man it's great to see you have so much enthusiasm for getting your combo dialed in! My get up and go...got up and left.

Please update us all on you combo [I've sure it's listed more than once in the 55 pages ..

496 4 speed I know..[true 496 or 489?]

Carb?
Gear?
Intake manifold?
Distributer?
Heads big port open chamber?
Compression ratio?
Roller cam?

Thanks, When you are done with your car will you do mine for me? [img]<<GRAEMLIN_URL>>/[/img]

[VintageMusclecar]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jim Ferron</div><div class="ubbcode-body">Eric, Man it's great to see you have so much enthusiasm for getting your combo dialed in! My get up and go...got up and left.

Please update us all on you combo [I've sure it's listed more than once in the 55 pages ..

496 4 speed I know..[true 496 or 489?]

Carb?
Gear?
Intake manifold?
Distributer?
Heads big port open chamber?
Compression ratio?
Roller cam?

Thanks, When you are done with your car will you do mine for me? [img]<<GRAEMLIN_URL>>/[/img] </div></div>


Thank you Jim. [img]<<GRAEMLIN_URL>>/smile.gif[/img]

496: 4.310 X 4.250
10.5 compression
BONE STOCK 291 heads (soon to be replaced with ported 840's)
2.19 1.72 valves
Crane 131311 solid flat tappet cam: 256°/264° @ .050, .618/.638 lift
Crane stamped steel 1.7 rockers
99893 springs
163 intake, stock except for plenum divider removed
1000 HP Holley built in-house
OEM points distributor with Crane XR-i electronic conversion
Hedman 65002 headers (2&quot; primary 3&quot; collector)
3&quot; Torque Tech exhaust w/X-pipe and Walker #17665 3&quot; mufflers
Legend 5 speed manual trans: 2.66, 1.78, 1.30, 1.00, .69 OD.
12 bolt with 4.56 gears
M/T Drag Radial 275/60/15
Car weight-unknown at this time but approx. 3800+ with me in it

I would be more than happy to help you with yours any way I can.

[VintageMusclecar]

First pass--I wasn't expecting it to hook, took me a bit by surprise:



Compare to 2nd pass where you can clearly see it blew the tires off the line. Also note the track guy mopping fluid from my lane from the car before me:



Alternate view of 1st pass:



Alternate view of 2nd pass--note the car nose over about mid-track...this is when my hand slipped off the shifter causing me to miss 3rd gear. I stuffed it back in gear and drove it the rest of the way down:



Time slips:

[Jim Ferron]

If memory serves me the 291 and 840 heads are semi interchangeable [except maybe for the spark plugs..one was a small plug if I remember..] I think they CC'ed within 1 0r 2 CCs...

Are you thinking maybe you'll need a bigger, better intake manifold with the ported heads?

Any reason you went closed chamber in the original build?

[VintageMusclecar]

I have several intakes I can use, but I'm planning on staying with the stock 163 as I don't think it will be much (if any) of a restriction on this build. I've already tested a heavily ported Holley Strip Dominator on this engine (during the last dyno session) and the power differences were low single digits.

Why I chose closed chambers--I wanted to see what I could do with them since everyone's always so quick to dismiss them.

[markjohnson]

Oh snap! I didn't realize that you had the infamous Crane #131311 camshaft in that motor. Crane really hit onto something with that great camshaft and Ive known many cars that have flown with it. One in particular was an early Camaro , crate LS6 with that exact camshaft that spit out 10.60's.