single/dual plane intake

Gary Stubbs · #1 (**permalink**) 03-09-2010, 11:53 AM

Is a dual plane a more streetable intake. It is a vic jr with 650 holley on vic jr heads. With the nasty cam it does not like 1600 or lower when getting on it. You know that hesitation. Have a half inch spacer also. Just wondering if i can put a piece of aluminum in the intake and make it adual plane so it works better for the street. Any ideas would be appreciated.
gary

FWB · #2 (**permalink**) 03-09-2010, 12:07 PM

dual plane is more streetable.....

Ron61 · #3 (**permalink**) 03-09-2010, 12:15 PM

What FWB said. The dual plane gives you more low end torque. The single plane is more of a racing type. I have ran both types and the dual plane is far better for normal driving plus it also works well if you are not all out racing.

Ron

joyridin' · #4 (**permalink**) 03-09-2010, 12:19 PM

Unless you run in the upper RPM range all the time, try to find something like an Air-Gap style intake. Kind of the best of both worlds. Has a wide torque range with a decent upper limit, plus it is pretty streetable.

blykins · #5 (**permalink**) 03-09-2010, 12:30 PM

It also depends on the size of the engine as well. A Victor Jr. on a 351W will have different results than a 427W with a Victor Jr.

If your cam doesn't like to be pulled down that low, it may not help things to mix a wild cam with a dual plane street intake. That would be a mismatched combo.

What size is the engine? What are the cam specs?

Also, hesitations can be tuned out as they are generally because of a lean situation.

Gary Stubbs · #6 (**permalink**) 03-09-2010, 01:20 PM

The engine is a 347 stroker. Cam specs are adv dur of 286, dur @.050 of 230, lobe sep of 110.0 and lift of .598. A comp cam. I really do not want to change cams right now, maybe this summer. My goals have changed so a milder setup is probably best. Currently dynoed or 2 yrs ago at just under 480 at flywheel. Seems high but is a nasty rumble. Also, no choke on carb.
Txs gary

blykins · #7 (**permalink**) 03-09-2010, 01:21 PM

That cam shouldn't be that wild. I think an RPM Air Gap would suit the engine well. If you're having hesitation issues, it's most likely a carb tuning issue.

ERA Chas · #8 (**permalink**) 03-09-2010, 01:29 PM

Quote:

Originally Posted by blykins

That cam shouldn't be that wild. I think an RPM Air Gap would suit the engine well. If you're having hesitation issues, it's most likely a carb tuning issue.

X2-what Brent said.

CobraEd · #9 (**permalink**) 03-09-2010, 01:42 PM

The lift is very high for that mild duration. I have not seen that cam listed. Is it custom from Comp Cams?

.

FUNFER2 · #10 (**permalink**) 03-09-2010, 02:27 PM

(high lift) ? It looks like that's "advertised" duration.

Gary Stubbs · #11 (**permalink**) 03-09-2010, 02:36 PM

A 35-450-8 or a 286H-R10 by comp cams

CobraEd · #12 (**permalink**) 03-09-2010, 02:59 PM

That must be one of the two versions that Comp Cams makes specifically for the stroker 302 (331/347). I have seen them in Jegs.

With 286 total duration and .598 lift. I still believe that is a lot of lift the that small amount of duration.

However, if it works, it works. Just hope it lasts. With that lift to duration ratio, it can put a big strain on the valves.

.

vector1 · #13 (**permalink**) 03-09-2010, 04:06 PM

you're out of the rpm range with the cam. wait till 2000+rpm til you get on it, or fix the tune, or remove the spacer, or change the manifold. lot of variables here. i would do the easiest first though. o2 sensor and gauge setup could tell you a lot about the hesitation.

FUNFER2 · #14 (**permalink**) 03-09-2010, 04:16 PM

A lot can be done with just tunning to what the engine wants. Do you have a local business that has a chassis dyno, and a well trained mechanic, and not just a computer geek ?

Bernica · #15 (**permalink**) 03-09-2010, 04:32 PM

If I'm not mistaken, there is more of a difference between a single and dual-plane manifold besides just adding an aluminum separator. I may be wrong. If so, I'm sure I will be corrected. Agree with others above on other points.

vector1 · #16 (**permalink**) 03-09-2010, 04:36 PM

i was going to add what gear is this occuring?

Gary Stubbs · #17 (**permalink**) 03-09-2010, 04:40 PM

Don't get me wrong about this engine. It is one bad engine. When I nail it i better grab a gear or i am to late. Have only been into the secondaries a dozen times. Thru third gear is a kick even with granny shifting and a 6 k rev limiter bug in. Definitely has the old style lope of a roller. Just what i wanted when i asked gordon what he thought. My wants have changed is all. Had a 6.5k limiter in it at first and never nosed over.
gary

CobraEd · #18 (**permalink**) 03-09-2010, 04:42 PM

Quote:

Originally Posted by Bernica

If I'm not mistaken, there is more of a difference between a single and dual-plane manifold besides just adding an aluminum separator. I may be wrong. If so, I'm sure I will be corrected. Agree with others above on other points.

The whole design is different. You can put a divider in a single plane manifold, but it is a band-aid solution and not the same as a true dual plane manifold.

.

Mus408 · #19 (**permalink**) 03-15-2010, 06:10 PM

The RPM Air Gap dual plane would be the way to go on that engine,for excellent torque/power in the real world of street use.
Don't put a divider in the single plane intake. I had one break loose,after 6 months use,and it cost a block!

Barry_R · #20 (**permalink**) 03-16-2010, 06:05 PM

few ideas
You could advance the cam a few degrees (depending on where it's installed now).

Try adding some base timing and shorten the curve to compensate - this usually improves idle and low end.

As noted a surge or lumpiness at part throttle is often a fuel curve issue that can be tuned out.

I've tried a bazillion different intake inserts, stuffers, and spacers on the dyno. Most do nothing. A very few seem to help - but they're never predictable.