W2's vs. Edelbrock RPM

[nivvy]

I was down at a friends today and he has a 1969 Dart 408 Stroker motor 435 HP I believe... the crate motor mopar sells... anyway he is thinking of selling the heads.... 

[72bluNblu]

Sounds interesting to me, shoot me a Pm if he decides to, I'd be interested. Are they magnum heads?

[71chally416]

If it's the 406/435 MP crate motor it has the iron 2.02 Intake valve Magnum R/T heads. Very similar ports and chambers to the Commandos. They're 406 cubes instead of 408 because they're .020" over blocks, not .030". 

[72bluNblu]

Now the magnums need a special valvetrain to go onto the LA blocks don't they? offset rockers or something?

[Chryco Psycho]

magnum heads oil through the pushrod so they need AMC lifters & hollow pushrods

[72bluNblu]

Interesting...

[Chryco Psycho]

the rockers are not offset but they are Chev / Ball Stud style which I am not a fan of

[nivvy]

Sounds interesting to me, shoot me a Pm if he decides to, I'd be interested. Are they magnum heads?

says magnum on the valve covers and are 10 bolt valve covers.... he is supposed to get the info for me off the sheet that came with the crate... I believe he said they were swirl port also.....  I looked inside the 710 cap and it doesnt run a shaft sytem

[tactransman]

Now the magnums need a special valvetrain to go onto the LA blocks don't they? offset rockers or something?

Here is a good article on the conversion http://www.moparts.org/Tech/Archive/smallblock/7.html

[72bluNblu]

Here is a good article on the conversion http://www.moparts.org/Tech/Archive/smallblock/7.html

Awesome! That'll make things easier if I go that route!

[73challenger_TN]

The 302's are the best stock based rocker shaft type heads to use if you can find a set, and they are much better with the right porting. The W-2's? 1980's technology. Back then they were the shizzle, but not so much today and they use ALL special parts and most use long stem valves. $$$$$$$

I Disagree about the 302 heads. Maybe on a 318 but j heads flow better.http://www.shadydellspeedshop.com/302.htm

If he changes his mind about those r/t magnums I might be interested.

[71chally416]

There's more to heads than just total airflow. The chamber greatly affects tha motor's ability to make TQ, and the 302 chamber is much better than the J head.

[cudadave72]

I hate to jump in this late but I am more than pleased with the Edelbrocks on my car. Sure I know there is more power in a set of Indys, which is a plan for down the road, but my car makes great power with zero problems! Just my 2 cents!!

[72bluNblu]

Thanks Dave! 

Seems to me the edelbrock heads are pretty good for a bolt on and go operation. Definitely better heads out there, but they seem well suited to a street and occasional strip car that needs to retain some reliability.

[71chally416]

The ED heads are OK to use stock on a smaller motor if you check the valveguide clearance before running them. I've heard that some come a bit too tight. They flow about like ported J heads the way they come.

For a bigger motor over 400 cubes, I don't think the Intake valves are big enough and the port volume is inadequate, unless you're happy with a short winded grunt TQ motor that throws the anchor out at 5,000rpm. At high RPM you get little more cylinder filling than what is contained in each cylinders port, so the bigger the motor is the more port volume is needed to feed the motor. That's obviously a different requirement for a 340 than it is for 416. Even the BB Mope engines like the old 413 have 2.08" Intake valves, and they're thought to be on the small side for anything bigger than a 383. A wedge head can only flow a finite amount of air with a 2.02" valve.