cobra venom article

[wrench87]

does any one know if they ever dynoed the cobra venom project?, i was not able to find any thing more on this. i was curious how the crane hydraulic roller did for tourque and horsepower?.

[Chaplin]

Wrench-
Look at the below link- they dynoed 3 engines. The engine identified under the heading "thumper" (about halfway through the article) is the one you are looking for. The dyno sheet for that motor is on the second to last page of the article. Very nice little motor.

http://www.webrodder.com/article.php?AID=100&SID=4&CID=

[wrench87]

that looks pretty good, i am building a 445 so i will have a 4.250 crank i have the dished diamond pistons, i am trying to decide if this cam will be ok i dont like the fact that is only good to 5500 or 5600 rpms i want a little more so i can rev to atleast 6200 rpm i am also thinking about cyl heads kc's are nice but at 2495.00 they are a little pricy. what do you think i can get a way with for a cam and heads?.

[wrench87]

so any one running the crane cam part number 349521, just curious to what rpm this cam will pull to?.

[blykins]

I'm designing a 445 Windsor, so I've went through some of the same scenarios that you're going through.

For 445ci (and using a hydraulic roller), you'll want a cam in the 248-250 range (duration at .050") to get your hp peak up to 6200 or so. To spin a hydraulic roller that high, you'll want some good valve springs (probably 150-155 seat pressure, 400-425 open pressure) to keep the valves from floating. Also, the lighter that you make the valvetrain, the better...i.e. using titanium retainers, etc.

That Crane 349521 cam would be way too mild for 445ci in my opinion unless you're wanting a truck motor. It would definitely be torquey, but I think the peak would be around 5200rpm. If you're wanting to pull yours a little higher, this probably wouldn't be a good choice.....However it would be an awesome daily driver cam.

Just remember, cubic inches calm camshafts down. Larger displacements offer larger volumes that the cam has to try and fill up. You have to hold the valves open longer to completely fill the cylinders.

KC uses a hydraulic roller in a lot of his FE engines that he builds....and uses a 252 degree duration at .050". I think that would be a good choice for a 445ci FE if you're wanting to pull it a little higher than 5800-6000 rpm. It will be a custom grind through Comp Cams as they don't offer any hydraulic roller FE cams through their catalog.

As for the heads, I would suggest contacting Barry Rabotnick at Survival Motorsports. They are testing some new Blue Thunder heads that flow really well and don't break the bank.

[RICK LAKE]

wrench 87 I am running 349521 cam in my 484 motor with a Barry R. kit of flat top pistons. My heads are gasket ported and the bowl area is been cleaned up. I don't have an CFM on the Shelby heads but around 300 should be close. I am running a beehive spring which lightens the wieght per valve by 44 grams. The motor is new and have not been to the dyno yet. The Idle for a 484 is nice with a little lope. Very strong and flat torque band, motor still pulling hard at 5,800 rpm hitting the rev limiter in my MSD box. Should make about 450 HP and about 560 ft of torque. With lighter weight springs you can rev to a higher rpm without float or lifter pump up. You can degree the cam for less torque and more hp. I am running -6 degrees. Motor is strong down bottom. I will have to wait until next year to get to the dyno for the real numbers and raise the rpm limiter to 6,500.00 The Float on the valve train should be 6,700 rpm with my changes. I also have an Aluminium flywheel at 22 lbs and not the 40 lbs steel one. I have a KCR cam with .622" number that will go into my 498 motor. Should hit about 500 hp and 600 ft of torque. 484 is very streetable to drive. Rick L. You can make a motor pull to over 7,000 rpm with the correct valve springs and light valve train. A rev kit would help upper RPM control but nobody is maken one at this time. The links between the lifters is some of the problems. Its all about controlling valve float and the bouncing of the valve off the seat on closure.