Got a few minutes here before I head off to a wedding this afternoon, figured I'd post results of a 481" W8 we dynoed last week....

Basic combo:

R3 Siamese 48* 4.20" bore
Custom Callies 4.34" stroke 340 main crank, 2.0" journal
GRP Rods, 6.20" .866" pin
Diamond flat tops, gas ported, X style forging, .043" ring pack, 15.6:1 compression
Custom Moroso 4" kickout oil pan
Custom Comp solid roller cam, low 280's @ .050", under .800" lift. 110 LSA
1.8/1.75 T&D rockers, PAC 1326 springs & Ti retainers, Ti locks.
Heads are virgin never ran Phil Coleman W8 Nascar truck heads with original valve job etc. 2.16"/1.625" 7MM/5/16" valve combo, Had Ti intakes, Custom Ferrea stainless exhausts.
SDSS modified P5007420 intake, with .625" manifold spacers blended on to fit 9.56" deck. 4500 flange/plenum conversion.
Crane utra pro .210 offset .903 lifters, 1/2" .168" wall manton pushrods.
ATI Super Damper/MSD crank trigger/Meziere water pump/Moroso 4 vane vacuum pump/Liberty timing chain & tensioner/MSD distributor/Stock Car products 1.45" rotor single stage oil pump


I had a pair of these custom 4.34" cranks made last fall for a pair of 481's, the other one we ran a few weeks ago with an 11:1 pump gas setup & N20 camshaft, 772 tall deck manifold & Bob Dowling CNC W9 heads made 770HP/680 TQ. So I knew this one with the wick turned up a bit should be pretty decent...

This motor is for a friend of mine here in State College who wanted to go faster than 9.80s the old pump gas Arrington head motor used to run... We took car to Long Island few months ago & had custom set of 2 1/8" into 2 1/4" headers made for it ('72 Challenger) with 4" merge collector, by guy who used to work for Kooks before they moved to NC. We had headers done before motor was dynoed so we could see exactly what we'd have in the car VS the dyno headers.

We ran these headers on the other 481 few weeks ago & they absolutely killed it... down like 60 HP & 70 TQ. We swapped the merge collectors out for a traditional Hooker non merge & was able to gain back ~30 HP, but was still off a good amount in TQ. So I was'nt really looking forward to swapping the headers on this one, after all the aggrevation we went through to have the headers made as well as $.

Anyhow.... We started tuning it on C16 fuel.... tried few different carbs, spacers, timing, vacuum settings etc. Played with lash & got 840 HP, 710 TQ out of it on C16.

Switched to Q16 & re-tuned motor for that, liked 31 degrees of timing best... 2" HVH spacer ontop of the 420 & 882 HP, 742 TQ.

The switch in fuel alone was basically 40 HP/ 30 TQ across the board, this was in same air on same day. We ended up having to go up 3 Jet sizes on 1050 QF carb & I think we dropped 20-25 high speed air bleeds & 10-15 on intermediate & idle bleeds to get it rich enough on the oxygenated fuel, but eventually with enough screwing with the air bleeds we got it to work. Looking back, I think the carb is a bit small for this motor, if we "need" more power in future, will probably try a larger carb, I just did'nt have anything bigger than a 1050 on hand, should have had a new SV1 made for it, but ran out of time. We put 26 pulls on it on gas... then the next day we tried methanol...

The shop owner has a brand new 1050 QFX metahnol dominator on his 500" BB GM pulling tractor motor, so we pulled that off & fired it on.... was lean, jetted & messed with timing, & best with it was 871 HP/732 TQ. The TQ down in the 4500-5400 range was up about 20 on metahnol, but after about 6000 RPM the meth dropped off & the oxygenated gas took over...

So then we switched back to Q16, made a baseline pull with dyno headers back on... 871 HP/738 TQ...

Put the Challenger headers on... Made some pulls, tweaked a little bit & 862 HP/717 TQ. For whatever reason they do hurt TQ quite a bit from 4500-about 5300, but in mid range & top end they are pretty close to the 1 7/8"-2" 3.5 collector Schoenfeld Sprint car dyno headers... So I was happy that they worked well on the engine they were designed for (We used Pipemax program to design steps & sizes) Was just funny that they did not work well at all on same size motor, but with much different cam & compression... learned a good bit there.

Biggest surprise of the 2 days we thrashed on it was the lack of changes the vacuum pump made... Did'nt care whether I had it at 8 inches or 18 inches.... relaly did not pick up hardly any power at all, putting vacuum to it, so for simplicity in the car (the owner HATES draining the breather tank) we put a pair of moroso circle track breathers on it & eliminated the pump, also gives us a place to easier mount the alternator.

Put motor in the car last weekend & spent evenings this week getting everything plumbed for new motor & we fired it 11 PM Wednesday night, sounds good, very crisp & responsive. It's at exhaust shop now having set of 4" pipes made for it & the n goes to chassis shop for scaling & alignment the following week. Hope to have it out for test & tune in July. Car was 3260 last year, BGR did an all new moly cage for it & all new back half... we did set of Holeshot bead locks & 31 X 13.5's in it... I did a significant lightening program on block, so I'm hoping we will be in the 3120 race weight range this year. Would be nice to see it in the 8's by end of year. Unfortunately with the owners schedule & mine we will not have alot of time to run it this year... but will get it sorted out along with my turbo car so we can put in a dedicated year of racing next season.

One thing you can't argue about with CID, the torque is awesome... I've only built one motor that ever made over 700 FT lbs NA before, & that was a 471" with W9's @ 16:1, Sheetmetal tunnel ram, 2 1050's on Q16. That one was around 714 TQ. @ 1.54 TQ/INCH Rick's new motor is even better. The TQ #'s these really big motors make with really good induction systems & big compression is neat.

One of coolest things was to compare this motor to 481" Big Block Chevy on same dyno... The owners pulling tractor motor (which is currently 1st in his points chase after 4 events, so it's not exactly a slouch) is a 481", Brodix "Big Brodie" heads, 2.30" valves, Profiler Sniper 4500 intake, 1050 QFX on methanol, 12.5:1, Lunati 286 @ .050" .800" solid roller, with a wet sump oil system... that motor on this dyno made 780 HP/625 TQ this spring after some changes over the winter to pick it up. Last year it was 710 HP/585 TQ on same dyno.. I re-worked the combustion chambers in the heads & we changed intakes over the winter to make the gains from the 2010 setup. Amazing to see this motor, up 100 HP & 115 TQ, but really shows how bad of a piece a traditional valve layout BB GM is. Piston dome design, combustion chamber design & too big of ports/valves actually contribute to hurting power, not making it.

I'll post a copy of dyno sheet tomorrow night, I forgot today my camera is sitting at the shop with them on. Here are couple pics I snapped with my iphone when it was on dyno & one of it sitting in car... Should be a fun ride.