Has anyone seen good (> 600whp) results out of a street car, pump gas stroker?

My disappointing 449 dynojet run is attached.

Five years ago I hydrolocked my 6.1 Magnum motor. I replaced it with a 449 Mopar aluminum block (4.185 / 4.08" bore and stroke) with the biggest Thitek heads, a ported 6.1 manifold and 2" Kooks headers. Recently I completed a manual swap (Tremec Magnum) and added a larger cam (237/249 0.57/0.58").

Coming from the LS world, I'm very disappointed in the power. Especially as these heads are said to outflow almost anything LS-based. Granted I'm knock-limited to 18-20 degrees of ignition timing (11.6:1 compression; I would have preferred 11:1) on 93 octane. There may be more power with more timing; I'll know when I try E85. These heads have also always let a good bit of oil by the seals. Probably not much at WOT to drop octane, but who knows.

My 90 mm Arrington throttle body seems to limit me to ~98 kPA at 6500. So while there's a few ponies to be had with a bigger TB, it's not a lot. My Legmaker 4" pre-TB intake doesn't appear to be a restriction at all.

HHP told me they get "mid-500s" out of their street car 426 strokers. Again, not great.

I'm wondering if the intake manifold (ported 6.1) is the cork. It's certainly not the dual 3.5" exhaust, which was originally built for a Hellephant I'm not going to be able to get. Can the potential of these motors be unlocked without an extremely tall intake?

Modern Muscle Motors.

https://www.modernmusclextreme.com

Cam is too small for the Thitek heads 6.1 intake is too small for the CI your pulling...."Can the potential of these motors be unlocked without an extremely tall intake? " yes/No , the best of the shorter intakes from what I've seen from my Uncles testing is the PREXFIX intake manifold....the Drag pak and Ritters intake are hard to beat for all out G3 Hemi. and Holleys HI Ram wth the LS 2x 4 top is PHUCKING AWESOME .

Thanks I'll call them tomorrow.


Too small as in too little duration, or too little lift? The motor was originally specced with a 224/232 cam with the same lift, which I assumed was way too small. However when I went to the longer duration cam (again not specced by me; I don't know why they gave it so little lift) it barely made any more power up top. 7 more whp in exchange for less torque below 4,000 and far worse idle. Not a good trade off.

I did see someone got a Drag Pak manifold to hit under a Charger hood by cutting it down 2" and using a 6061.com throttle body adapter. I'll look in to that, thanks. Would you say the Holley Hi-Ram is better than the Drag Pak? Is this testing published anywhere?

I could put a bump in the hood, but can't run a big cowl. I need to be able to see right-hand apexes.

http://www.rylispro.com/ the guy who runs this site is also a good person to talk to , he's running a Big Alum G3 on road courses and he would know better what to do about oiling, ...

The lift is small for a Big Ci G3 engine, duration is fine for a road course car. I've watched my Uncle Ric dyno just over 100 different G3 combos in the last 2 years everything between 302ci to 476ci(bge with darton LSX sleeves) ...he'll tell you two things about the G3... one it loves intake valve size , .54-.56% of the bore and they come alive and they love lift.........ironically MA Mopar screwed the G3 with it's limited lift capabilities....650ish being max with out spending major money on lifters and valve gear.....and to add insult to injury , longer valves tilt the valve tip away from the rocker tips..lash caps will only go so far , then you have to move the shafts out towards the cover rails or go with a individual rocker arm set up.

My Cam is 250/250 @50 .645/.660 110 lobe separation, 107 installed CL. I'm running modified isky High seat solid lifters , use to have the PQX roller tip rockers but switched over to the Harland sharp about a month back. Heads are a set of Highly modified Eagles with 2.165 x 6mm intake valve and 1.63 X 7mm.Intake is a Edelbrock Victor with the runners cut down.

What Valve size are you running on the Intake side ?

Ah thanks that's good to know. I think I know what to do about oiling though: kickout oil pan and better (vertical) air-oil separators over each head vent. The stock 6.1 (horizontal) AoS in the intake manifold turned my catch can into an oil grenade once I exceeded about 1.1 g.


Maybe I'm too used to LS stuff but 0.650" sounds plenty to me; that's about what LS7 rockers max out at too. I need to take it easy on the valvetrain anyway, so things stay together on the road course. I'm surprised these motors like so much valve lift given how well the heads flow at lower lifts.


What are you doing for engine management to make that big cam drivable?


It's the biggest valve Thitek offers, I think 2.20".

Cam is too small for the Thitek heads 6.1 intake is too small for the CI your pulling...."Can the potential of these motors be unlocked without an extremely tall intake? " yes/No , the best of the shorter intakes from what I've seen from my Uncles testing is the PREXFIX intake manifold....the Drag pak and Ritters intake are hard to beat for all out G3 Hemi. and Holleys HI Ram wth the LS 2x 4 top is PHUCKING AWESOME .

My 345 in my 04 Ram is running a highly hogged out Edelbrock I'm spinning that 345 well into the mid 7k RPMs it's gone 11.80s @ 120 weighing in at 4650lbs I'm also running a .640ish cam