Early W2's and real-world performance gains?

-
chrispy1971gtx

chrispy1971gtx

Well-Known Member
Joined
Nov 4, 2007
Messages
140
Reaction score
43
Location
KCMO
What kind of performance gains can I expect when using a properly setup set of very early W2 econo's w/iron rockers, along with an matching MP Dual plane intake, with a stock 68-71 340 short block?

Baring a milder performance cam, like a 274/474, or XE268 C.Cam?

My point here, is .. to look stock. Retaining, even, the stock manifolds (slight matched) and a 2.5 exhaust system. 4spd, 355/391 gears, in a 71 demon. 6000rpm range.

Seems like I've read 40hp bolt on back in the day.
 
As I recall, not much over X heads. The power comes on when you run a high lift cam. It' all about air flow.
 
40 and even more if they are correctly ported !

I went on the dyno with my old 408 engine it end up
at 520 pounds of torque and 581 hp

with the w2 heads so...
this engine doesnt have alote of compression either
was running 10.50 cr
 
I've thought about a cast crank stroker kit with 11:1 max. The are pretty reasonably priced from eagle.
 
The problem here is a few things.
Besides a lack of info of what you have now to where you want the go is;

The dual plane is a copy of the old stock one. While it may flow better, it is still limiting.

The as cast W2 head isn’t the best flowing head. But it does perform (or should!) about as good as a well ported stock head. (Not fully ported!)
Exhaust manifolds would further hamper performance efforts. You would have to be crafty in your engine build & camshaft. It is possible!

Flow test the heads to see where they stand so you can get a little inside info for selecting a cam.

A call to a cam company for a FAST type of cam would be a good start.
I do like your idea though. A big stick Disguised as a small toothpick.
 
chrispy1971gtx said:
I've thought about a cast crank stroker kit with 11:1 max. The are pretty reasonably priced from eagle.
Click to expand...

It is all about your combination. I knew a class racer that did the W2 swap for X heads. No difference. You start changing things and the answer changes.
 
With the cast manifolds and a mild cam, I would say you'd gain little if anything on the strip, and due to the large ports take a hit in throttle response on the street.

X-heads, the XE268, an LD340/Performer RPM and a good old Holley 3310 would work better. Even better still with a set of common 1-5/8" headers. Would it look completely stock? Perhaps not, but it would be plausible for an early 70's street machine.
 
I was going to mention something like the Chief did! Perhaps a day two set up?
Headers and a Holley W2 Street Dominator intake manifold. Laugh it off with, “Naaa, just a mild cam, nothing big! I don’t need the headache.” LMAO!
 
Hmmm.... this very interesting information.
So, essentially, old school tricks are the best ones on a mild 340. I actually have all the stuff mentioned. LD340, carb, etc.

A local guy has a very stock appearing 390 javelin. Cool car. Its just street/bench racing thing in our small town. He's saying his engine is stock, but I know its a roller cam, roller rockers, and lightweight piston assembly. I know who built the engine.

I figured I could easily do something similar with a 340.

None of us locally drag race, its bragging rights on whats better. MOPAR, of course.
 
Thanks! I've looked at both, scat may have actually been the 1. But nice to which one is best for the money.
 
Unless you are going with a. 550ish cam or bigger you would be further ahead to send your exhisting heads to good porter...
And I am in the middle of a W2 build...
 
chrispy1971gtx said:
I've thought about a cast crank stroker kit with 11:1 max. The are pretty reasonably priced from eagle.
Click to expand...

Eagle Cast cranks are the ones that have a history of braking. Avoid them.

11:1 and cast crank seems mismatched. The good scat cranks are about 550 hp max.

An 11:1 stroker should have the rest of components for a 500+ HP motor.
 
you spend alot of money on getting the engine to breath then you choke it to death with stock exhaust manifold.....LOL
 
True. But I never met a set of headers that I liked. Especially in an a-body. Even expensive ones discolor, peel, rust.
 
You must log in or register to reply here.
-

Back
Top