[Streetwize]

I've built a lot of engines over my lifetime and a fair number of stroker motors, certainly nowhere near the number Professional Builders like Mr. Brent Lykins, who's opinions I highly respect and who's contributions to this site keep me coming back again and again.

I was trying to decide in terms of streetable 500-ish HP and the broadest torque curve, with very high TQ/CI and HP/CI..so taking what I've learned from many bore stroke ratios and head flows...What combination would I like to put in another Cobra?

I certainly wouldn't replace my 427 Windsor, it's a solid 500/500 combo that accelerates at the slightest hint of throttle, will pull hard from ~2400 to 5600 in any gear and chugs along effortlessly at only 1800 rpm at 70MPH in 5th gear. It does all I can ask of it and the highest compliment I think I ever received was from a few people that either owned or driven Several original 427 S/C's , they told me the powerband and tractability from behind the wheel this one feels very close to the "real deal". The wall to wall torque from the long stroke and light weight (450-ish pound carb to pan) is really fun.

For me it very tempting to 'overbuild' a 427 W, which in my view would be something like a CHI headed 408 Cleveland (Clevor) for 600+ hp (which is very easy to do) ,but to me basically becomes untenable in a Cobra bodied car because it's accelerating so hard combined with the fact that you really have no aerodynamics to keep the tires and the car itself planted at higher speeds.

I've driven some serious firepower and I can tell you even with my "measly" 500 HP it feels like a sprint car without a wing at 90-120 going into a corner.

However...I would think the BEST overall combo (I'm looking to do next) would be an 8.2" deck big bore 302 block with at least a 4.125" bore and a 3.25" stroke for 347" combined with a big but not huge 205 CC head like the AFR Renegade or Trick flow 11R with a Ported Victor Jr type manifold (keep the carb height under the hood without a bigger scoop) built for ~10.75:1-11.25:1 with a small endurance type solid roller like the Bullet/Ultradyne .4033 lobe with 251/259 @.050 and 171/178 @ .200 Durations on a 109 lobe spread and a 107 intake centerline. With 1.6:1 rockers the lift would be .645 (~.620 with lash compensation) on both valves.

(I've used this lobe on several engines including a 440" (360 based) Mopar stroker with ported W2 heads.) I think this would be a great balance between streetability/endurance and easy revving spring rates and checked the lash yearly but it stays the same (this one I only rev to 5800 though).

I think this motors powerband would be "just about" perfect with a Close Ratio Tremec and ~3.70-3.90 Rear gears with a 28" tire in a Light independent rear axle car like a Factory 5 that was built for a road race handling. I think this would be a near perfect motor combination for a 289 FIA style car.

I think this combo would give a very nice tractable cruise range throttle response and a predictable roll-on power with great upper bottom but not Excessive torque through the middle, and when you romp on it, it would pull violently from about 3600 RPM up and over 7200 RPM.

I actually prefer the 3.25" stroke to the 3.40" with the 5.400" rod length for High RPM, but the same combo would obviously work at 363 as well. With the light weight of the Cobra, there is a 'sweet spot', just the right amount of torque to keep the car balanced, the tires planted and tractable, without either breaking the tires loose from excessive torque or bogging it from not having enough.


I would expect this combo to fairly easily make in excess of 530 HP which is a very efficient (1.4-ish HP/Cube) power and torque.

Curious to hear your comments and other opinions of what you would build and why.