427 Stroker kits, Which?

[ScatStroker]

Ben,

Stage 3 is a reseller of Probe/CHP. Your components would be dropshipped from CHP/Probe if that's the route that you decided to go. To the best of my knowledge there is only one source for a 4.17" crank and companies then private label the crankshaft to whatever they want (CHP, DSS, ect - all resellers, none of which manufacture crankshafts.) We're also a dealer for Probe/CHP, as are a number of other sources. If you're interested we can blueprint the crank before its shipped to you - a step most others aren't willing to take (because it's being dropshipped or they're not capable of the service.)


Wize,

John's use of a short connecting rod really didn't have anything to do with the reasons you cite - It had to do with detonation and limited octane fuel. John's motor was running over 13:1 on 92 octane spec gasoline, a short rod pulls the piston away at TDC faster than a long rod and is less prone to detonation. As an EMC competitor we're pretty familiar with the builds. His Big Block was also a 460 based entry, not an FE. But the arguement is correct, IMO, the examples are just a bit flawed.


Think about it this was as well... (devils advocate)

IF the "poor" rod ratio caused the engine to prematurely wear out - What would it get 50%? Figuring a "long lasting" performance engine at 100k, the "poor rod" ratio combination would get 50k miles. We have customers that have ran motors past that with the "infamous" pin intersecting 347's and other combo's with lower rod ratios than the 427 kits. Most of these cars are driven 2-3k/year - If the engine lasted 20 years would you be dissapointed?


If it's the magic 427 number you're looking for then build the kit, it'll be fine.

$.02

Brian
www.ADperformance.com

PS: Thank you LMH.

[Streetwize]

Brian

Point taken on the 460, I could have sworn it was an FE. Thanks.


Yes the fast pull away from TDC is less detonation prone but as a result it also draws a little harder on "too big ports and cams", allowing him to make the big power up high and still have decent torque down low in the 2500-4000 range. In other words the pumping eficiency given up by the shorter stroke at higher piston speeds is offset by the surplus of valve timing and headflow.

I'm primarily a mopar guy but I've built strokers of all makes, I'm building a 517" version of my buddy Steve Dulcich's third place 470 from the '03 contest, using a 4.30 stroke and 6.535 rods with the same Chapman 380 cfm heads that Steve ran. The only other difference is, I'm running a roller (268/274 @.050, ~700./680 lift). I'm going for the same 2500-6500 EM style powerband.

[ScatStroker]

Wize,

The contest is a good example of possibilities but people need to understand that they are PURPOSE built engines... replicating them can achieve similar results but there is a lot of details in the motors that aren't covered and make a big difference in the overall build. The compression and camshafts are also unrealistic, they're just nowhere close to streetable.

You'll see different rod lengths and bore sizes this year, our motors have a compression restriction. I personally generally prefer a longer rod but the proof will be in the pudding when it's all sorted out...

Mopars are a little different, we do quite a few strokers for them but they're far from my expertise.

The bottom line on a build like the 427 is that it doesn't matter. A 6" rod or a 6.250" really isn't going to make a noticable difference, you can go either way. Go with the rod that clears the counterweight and has a shelf piston to match, that's the correct rod length in this equation.

Brian