Ran Kyle Clark's new 436 W5 motor on Thursday night & Friday morning, was interesting to see what a few changes did.

As quick refresher, his motor was one that was purchased from the Mancini racing "Chrysler Engineering Sale" Section a few years ago as an old mid 90's built 365" W5 motor complete. Kyle dropped it off @ the shop after purchasing it from Mancini & I just freshened it, reground the cam, did a valve job, put new set of HS rockers on it etc.

We dynoed it @ Rider racing on their SF902 dyno & it made 594 HP/460 TQ.

Kyle ran it for a year or so & then felt the need for bigger cubic inches.

So he brought it back out this winter & prior to tearing it down for the changes we ran it on our Stuska in same state of tune as it was ran before, same dyno headers, same 950 HP carb (jetting was hair different) same 1" HVH spacer & I set timing to 38 where it made best power on dyno before. Made 576 HP/469 TQ. We only put 2 pulls on it, & the AFR was a bit rich in the 12.2 range, if I had leaned it up I think we'd have been in the 590 range. So all looked good.....

The old combo was 4.02" bore & 3.58" crank. I sold him a used 4.125" rotating assy out of another customers motor who was going even bigger. That was a 4.10" bore piston & so we bored the R block to 4.10 & I took .040" off the pistons to make the CH work out to Zero deck with Kyles funky 9.46 deck height of the Mancini block.

I reground the cam to almost identical specs as was in the 365 except I bumped up the ramp speed a little bit. I thought I had changed duration @ .050" but now that I look back on the 365 cam card I see that the @ .050" #'s were identical @ 274/278 on both cams. I thought I had little more duration the 365 but did'nt.

Did not change the heads at all except I milled them .030" to get chambers to 49.5 CC to achieve a little more compression since pistons had a large dish in them, final compression ended up right around 10.8:1 on the new 436" motor. The old 365 was a flat top motor in the 11.3:1 range. I did not even do a new valve job etc, the old combo had around 1000 miles on it & everything looked like new in the heads....

We changed water pump from a mechanical to a new Moroso electric....

& one of the big changes was replacing the small runner M1 intake manifold with a new 360-3O Indy intake. The old M1 was a heavily modified piece with alot of weld on the top of runners to accommodate the extra tall port shape in these heads along with the low 9.46 deck height. The M1 had been heavily worked inside by Arrow racing who did the original head & intake work. To get the INDY to fit I had to take .230" off of it & we also took .500" off the plenum for hood clearance issues, so I set height to same as the M1 small runner intake. Was alot of work to get the Indy on it, but it payed off...

So basic combos:

365"
59 degree "R" block
4.02" bore
3.58" MP Billet crank
C&A Billet 6.2 rods
Custom JE flat tops, 1/16" 3/16" ring pack
11.3:1 compression
274/278 @ .050" .700" Lift 108 LSA solid roller
Moroso oil pan & mechanical water pump
1.6:1 Harland Sharp rockers
3/8" .145" wall Manton pushrods
Arrow Lg Port W5 heads, 2.08"/1.60" valves
Arrow ported M1 small runner intake
1" HVH super sucker
950 HP carb

436"
Same 59 Degree "R" Block
4.10" bore
4.125" stroke K1 crank
6" Callies CompStar rods
Custom Diamond Dish pistons, .043"/.043"/3MM Total seal napiere rings, gas ported
10.8:1 compression
274/278 @ .050" .700" lift 108 LSA solid roller
same moroso oil pan & new moroso electric water pump
Same 1.6:1 Harland Sharp rockers
Same 3/8" X .145" Manton pushrods
Same Arrow Lg Port W5 heads & all same valvetrain.
INDY 360-3O intake converted to W5 port 4150 flange.
Ran with both 1050 Quickfuel 4150 series carb & 1050 QF Dominator

Both motors ran with same 1 7/8"-2" step headers with 3.5" collectors.

Same ignition system, breather system etc in both combos.

Really the only changes were addition of 71 cubic inches, better ring pack, better machine work on block, little more ramp speed on camshaft, electric water pump & the INDY intake. We actually gave up 1/2 point of compression on new combo.

We ran the motor on Thursday night with a customer custom 85p Holley & then went to my 1050 Quickfuel Dominator on a 2" adapter & made the big #'s in that state of tune.

Kyle came on Friday & we put his new 1050 QF 4150 series carb on & tried it with several different spacers & jetting combos. It worked ok, but was never able to come near the Dominator in power production. & last pull of day we put on an untested 1050 King demon just to put a pull on it & even being way lean it was still hair better than the 4150 carb. Fattened up it would ahve been right with the QF Dominator. We're going to add some Jet to it & pull it on a W9 motor this week. Last 2 motors I had on the dyno, last week were a 302 head 318 & a Edelbrock head 340, so did'nt want to test either Kyles 1050 or my new King demon on either of those LOL.

I was happy to see the #'s as high as they were... this is the best W5 I've built to date, we've had 4 other W5 combos on this dyno including a pair of 440 inchers, a 400 & a 416 & they have all been in the 650-680 range. The heads on this motor are quite large in cross section, & were a bit big for a 360, but the 436 eats them up nicely.

Lack of cyl pressure sure did not seem to hurt this one @ all. 1.41 TQ/INCH @ 10.8:1 on pump gas is good # for this big of a piece. AWBDARTs 440" Indy 360-1 CNC head motor with vaccum pump & half point more compression made 1.42/INCH on this dyno. So this should work pretty good in Kyle's 4 speed duster.