The inspiration for this post is part boredom, part mid-winter crazy, and part "I hope I'm seeing the light at the end of the tunnel!" Here's something to think about w/ respect to what sort of performance increase I might see from the next generation of The MoPig, aka my 440 street/strip '73 Challenger.

I. Bottom end:

- Same OEM 440 block w/ Pro-Gram cross-bolted main caps on #2-4 w/ re-honed 4.380" bores
- Same Ross flat-top pistons & Eagle rods (new rod bolts)
- Replaced OEM forged crank w/ Eagle 4340 crank (same 3.75" stroke & bob weight)
- Replaced Total Seal "gapless" top ring set & 23# oil rings with a "conventional" ring set w/ Napier 2nd ring and 18# oil rings gapped @ .020"/.024"
- Replaced standard MP "Street Hemi" oil pan & OEM-type windage tray w/ some additional louvres added with a new Milodon "Street Hemi" pan (same design) modified w/ directional tabs & center-sump baffle, a new Milodon full-length windage tray modified with additional baffles & drainback holes, and a new crank scraper

(See https://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=7492739&Main=7480007 for details on oil system "stuff")


II. Heads:

Replacing my old "tried and true" MP Stage VIs - 2.14" / 1.81" Ferrea valves and full porting done by Porter Racing Heads. Intake runner volume 215 cc w/o RB adapters, 245 cc w/ adapters.

Lift-- Int / Exh / +2" tube
.100 -- 67 / 56 / 56
.200 - 142 / 104 / 107
.300 - 204 / 148 / 156
.400 - 253 / 185 / 198
.500 - 287 / 214 / 233
.600 - 307 / 234 / 257
.700 - 310 / 246 / 273

With these new (and unproven) Edelbrock Victors - 2.20" / 1.81" valves and Hughes Engines' "standard" (not MW) CNC porting program. IIRC, Hughes says the intake runner is ~ 310 cc after this work.

Lift -- Int / Exh / + Tube
.100 --- 72 / 54 / 54
.200 -- 154 / 105 / 108
.300 -- 222 / 162 / 167
.400 -- 273 / 200 / 211
.500 -- 310 / 219 / 239
.600 -- 336 / 236 / 263
.700 -- 346 / 247 / 275

The CNC Victors' flow increases right up to .700", whereas the smaller Stage VIs basically flatten out at .600" and only increase by a few CFM above that. Dyno-testing 1.6 intake rockers on the Stage VIs only showed 4-6 HP at peak IIRC and I ended up running 1.5s when the car was finally put on the street.

The CR is going to be bumped up slightly from 10.8 to 10.9 due to the Victors having slightly smaller chambers.


III. Cam:

As I've posted previously, this rebuild includes changing from my PRH (Porter Racing Heads) ported MP Stage VI heads and PRH-spec'd solid flat-tappet cam to a set of Hughes CNC-ported Edelbrock Victors w/ a solid roller cam.

Here are cam specs for what Dwayne Porter got for my old Stage VI combination compared to the solid roller he got me for the new heads. Both cams were profiled in the 452's block and the roller was checked using .800"-wheel IMM lifters:

The solid is from COMP's XX-series .875"-lifter family and is an older NASCAR-type lobe. It isn't as aggressive as the later .904"-type lobes, but has still proven to make good power and RPM.

Old COMP XX
@ .020" - 297.5 (adv 298)
@ .050" - 266
@ .100" - 232
@ .200" - 178.5 (adv 180)
@ .300" - 121.5
@ .400" - N/A

Lobe lift .3975" (adv .400")
Gross lift .596 (1.5)
LSA 108
Lash set to .020" hot

The COMP RX roller series is an endurance lobe which Dwayne has said has been very successful for his customers looking for decent valve train life.

New COMP RX
@ .020" - 300 (adv 298)
@ .050" - 266 (adv 265)
@ .100" - 233
@ .200" - 184 (adv 183)
@ .300" - 134
@ .400" - 68

Lobe lift .434
Gross lift .651 (1.5);
LSA 108
Lash spec on card is .018" hot

I do have 1.6 intake rockers on hand for the Victors, but figure it'll be a good baseline to use the 1.5s all around with this cam.

You can see in the #s comparison is how much more high-lift duration the roller offers that should be better suited to the new heads' flow capabilities. The lower end of the lift curve isn't as radical as I think most people expect when they see how much more aggressive any roller lobe looks compared to a flat-tappet. From a seat duration & overlap perspective, both cams are very close.


IV. Intake & Carb

I'll be running the same modified RB M1 intake, but I've had to open it up even more to suit the new Victors' larger intake runner size.

The baseline carb will be my BG Race Demon RS set up w/ 1.425" venturi sleeves and a 1.75" throttle body. It's the same config as I last ran w/ my BG Gold Claw. I'm keeping the Gold Claw as the test carb for trying out larger 1.500" and 1.562" venturi sleeves vs. the proven baseline tune of the Race Demon.


V. Exhaust

Same TTI 2" headers w/ their matching full-length 3" E-body X-pipe system and Dynamax Ultraflo mufflers.


VI. Performance?

Old - combination ran a string of 10.5s @ 126 MPH weighing 3750#s w/ driver in the fall of 2009. This was at MIR, a close-to-sea-level track in southern Maryland (Mid-Atlantic region). Going to a higher elevation track like 75-80 (also not paved as smoothly and -- I was told -- with a slight uphill grade at the end), it ran 10.7s-10.8s and 2+ MPH slower than at MIR.

New - Who knows! I'm really hoping to get it back on the track this year to see what it'll do, rather than just post b.s. about it.

Looking at the new lift vs the max flow you need a
good bit more lift... you wont even hit max flow once
and if you went past max flow lift you would hit it
twice and all the time/degrees under it

That old combo is similar to mine other then I have more stroke and compression and a little more lift. My car weighs a little less to. It will be interesting to see what it runs with the new setup. I would like to get rid of my stage VI heads for the victors.

Brad I am curious if you dont mind of wondering what it 60 ft before and the rear suspemsion ? Is it just SS springs or Cal Tracs or what ever. And do you race it thru the pipes as I have about the same exh with 2" TTI headers and 3" out to the rear bumper with the X-pipe and Ultra-Flows ? Thanks , Ron

Ron:
- On 275/60R15 ET Street Radials have pulled 1.45-1.46 60s when car was running 10.5s in the 1/4
- Rear suspension is CalTracs w/ their mono-leaf springs & older Rancho 5-way adjustable shocks
- Front suspension has 5+" extension travel from static ride height (lowered t-bar adjustment & cut-down control arm bumpers), small-block torsion bars and QA-1 R-series shocks
- I mentioned the front suspension because getting the front to work was critical to getting the car to hook consistently (at least on a good track)
- I run it fully capped up through the TTI system

FWIW, my car has run virtually the same times at Cecil as at MIR.

Gonna guess it will run teens at 130-131 ish.

I predict you slow down a few tenths due to the crank change....

First thought; what Dwayne said
My WAG; .1 to .2 quicker depending on how much the motor likes the heads. With the cam being basically the same, I figure a small savings in rotating friction, not a lot from the scraper (unless you had serious windage and puking oil problems) a 5 ft lb jump from the rings is possible, and the biggest improvement will be the heads. I suspect it may want a couple of hundred rpm more for best results. How much difference is there in the two heads; chambers? plug angle?
What were Dwayne's comments on the whole deal?

Best as I recall... that it'll either fly or be a pooch, depending on whether the significant increase in runner volume kills the way the engine responds at lower RPM.

---

Just means you need to up the launch rpm.. might be a
conv change