I had a kinda cool engine on the dyno this week

[Barry_R]

I posted this on the "other forum" but thought it would be equally - or more - interesting to the Cobra crowd here.This was a fairly complicated - but very much street oriented build.

All aluminum 427 (actually 429 with 4.25 bore and a 3.78) stroke with a Pond Block and CNC ported early generation Blue Thunder medium riser heads. Compression for pump gas, and a very small solid roller - 234/240 @ .050 & under .600 lift. Also has very high quality components throughout - including coated custom pistons, impinged titanium retainers, and a billet crank. Modest horsepower targets but very high durability. Oh - almost forgot the TWM Weber style electronic fuel injection system up on top. It will end up in a street rod with no hood - so all the cool stuff will be on display.

The power was good considering the cam - peaking at 530 on one pull, and repeating at 528-529 on subsequent pulls. Of note is that - with the IR setup, good heads and a small cam - the power never really dropped off like you see in many other combinations. It just sort of "hung there" between 533 and 526 for +/-700RPM. It also had a nice strong & flat torque curve peaking at 505 on one pull - approaching 1.2/cube is pretty decent for a street engine.

It was very interesting to compare this to a 445 cube stroked 390 EFI engine we did, as well as a 2x4 427 with 12.5:1. This one has a smoother power band - matching or beating the peaks of both the bigger engine and the racier flavor, while being easier on street manners. Of course it cost about the same as both the others together...


I have a pic and dyno chart below and have posted a dyno pull of this engine to youtube (my first try at that). I won't know if that link works until I try it.... The induction noise was "significant" . You also have a lot of noise from the fans in the dyno room...

http://www.youtube.com/watch?v=PvZAS...e=channel_page





Barry Rabotnick
Survivalmotorsports.com