I had a kinda cool engine on the dyno this week
 

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

http://i38.photobucket.com/albums/e1...7EFIFE2009.jpg

http://i38.photobucket.com/albums/e1...427EFIDyno.jpg

Barry Rabotnick
Survivalmotorsports.com

Barry,
Beautiful job and torque curve. This one is begging for more cam. HP not nosing over at 6500. With an aggressive cam and no other changes, might this do 50-75 points higher on each?
Also is that a DTS?

It is a DTS

I had to push the customer to go that far on the cam - he was extremely concerned about lowend and driving characteristics. I can only guess - but those heads will support over 700HP - so a bigger stick would certainly help get us closer to or over 600. The TQ won't move much higher though...

The header tubes look small???

Very nice motor. Looks great too:)

Very impressive Barry! That one should be a blast to drive with a torque curve like that.

When you get a chance take a look at the alternator as you bring the engine speed up. It starts to move around. It may have been loose or perhaps some part of the mount is flexing.

The engine is visually stunning, definitely high bling!

Ed

The alternator bracket is an out of the box March part. It uses heim joints for the adjustment and obviously needs rearward bracing for rigidity.

Barry, Nice Motor!

Thanks for posting this Barry

Its always interesting to see what people are doing and the results that they're getting - especially when it looks this good :)

LoBelly

Barry-
Looks like you hit a homerun with that one. And boy do those TWMs look good!

Nice Barry
 

Barry_R What size are those TWM throttle bodies? RickL. Ps I also have some more ideas for the EMC. :) Need to know about the power to the motor issue

One word - STUNNING! An engine like this is in my future, that's for certain. ;)

Paul :cool:

Barry,

Looks fantastic, all flat aluminum.

What management system is used for the TWM injection?

Eric

Barry-
One more question for you. Since this is going to be a street motor, why didn't use a hyd roller instead of the solid roller?

Its a street rod - he wanted the "sound".....

Which solid rollers did you use?


Depending upon the valve lash setting ( 0.015 vs 0.020 ) , the engine may not be very friendly if you try to start it in colder 35 degree weather. If I remember correctly, my lash is 0.012" tighter at 70 degrees.

Lash was at .003-.004 in the shop at +/-60 degrees. I don't expect that the car will see much winter driving - but starts in 30 degrees could be an issue.

Morning Barry
 

Barry_R Barry what size where the TWM's and size of injectors where you running? Rick

And now for the 64 million dollar question: What does in cost to build that motor?

FIA Mike

...less than the federal tax on the average AIG bonus;):LOL: