Author Topic: The $50 Street Master is History.  (Read 6232 times)

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Cyclone03

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The $50 Street Master is History.
« on: April 23, 2011, 09:20:13 PM »
Thanks allot Jay. :)
I went to our local once a year "good swapmeet nobody knows about"
SM with a worn out 600 Holley $200!

But I did sell one for $150. ;)

Do I have to send you a cut? I bought a book,will that cover it?

BTW I swapped from a SM to RPM the low end carb tuning and cruise,2000rpm ish,became much less touchy and the mixture became more stable according to my LC1 O2 indicator...
Lance H

jayb

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Re: The $50 Street Master is History.
« Reply #1 on: April 23, 2011, 10:15:19 PM »
Yes, I've been accused of causing Streetmaster inflation before  :D  What can I say?

That's interesting information about the stability of the A/F.  Lowest I normally run on the dyno is 2500, so I don't have anything that provides data at the lower engine speeds unless I do a cruise test, and I don't recall if I have any cruise test data on the Streetmaster.  I wonder if the A/F was less stable on the Streetmaster as a result of the single plane vs. dual plane thing, or if there was some other reason?  My brother's 428 with the Streetmaster runs beautifully on the street, but it may have the same issue and just be tuned very well; he doesn't have a wideband on it.
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

Cyclone03

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Re: The $50 Street Master is History.
« Reply #2 on: April 23, 2011, 10:33:42 PM »
I think it has more to do with the draw on the booster in the carb.
I'm running an 850 Demon,I like to say it has been molested (adjustable everything).
I think the RPM just gives a stonger signal to the booster so the carb pulls into the main either quicker or more likely just "cleaner".
I was running a 4 hole spacer on the SM but the package wouldn't fit under the hood on my Mustang with the RPM,so I have only a 1/2 four hole now.

Anyway it did what I wanted,which was tame it at the 1800-2200 rpm band I seem to drive in.
Lance H

jayb

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Re: The $50 Street Master is History.
« Reply #3 on: April 23, 2011, 10:48:42 PM »
Wait til you see the Performer RPM dyno data in the book.  The area between 2500 and 3000 RPM was where that manifold really struggled.  It did not want to run well until it hit 3000 RPM.  Kind of the opposite of what you have observed.  I'm sure its carb related; on the lower horsepower engines I ran the same carb on all the 4V intakes, a 750 double pumper, and maybe the Performer RPM just didn't like that carb.

My book is filled with test results that are not easily explained.  Too bad the engines can't read ...
Jay Brown
- 1969 Mach 1, Drag Week 2005 Winner NA/BB, 511" FE (10.60s @ 129); Drag Week 2007 Runner-Up PA/BB, 490" Supercharged FE (9.35 @ 151)
- 1964 Ford Galaxie, Drag Week 2009 Winner Modified NA (9.50s @ 143), 585" SOHC
- 1969 Shelby Clone, Drag Week 2015 Winner Modified NA (Average 8.98 @ 149), 585" SOHC

   

Cyclone03

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Re: The $50 Street Master is History.
« Reply #4 on: April 23, 2011, 11:02:21 PM »
Well they do say we don't "drive"dyno's.

I can't really say what I lost or gained,other than that very low rpm cruise, if it's "gathering up it's skirt" below 3000rpm I can't tell, it still blows the rear tires loose in third gear at the magic 3000rpm(and below). Matter of fact it spins the tires after the 3-4 shift too........oh yea....... 8).
Lance H

Qikbbstang

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Re: The $50 Street Master is History.
« Reply #5 on: May 07, 2011, 09:09:05 PM »
That thread took Jay into the land he shies away from: The land of Off-Idle to 2,5-3,000 and part throttle which is rumored to be like Kryptonite to him. Very interesting you found the Perf RPM smoothed things out. Of course By-The-Book not Jays Book, the dual plane is "supposed" to shine Low & Midrange BUT the Perf RPM is really not a true dual plane, it's unique in being 4cyl half a single plane on the lower runners and 4cyl conventional dual plane on the upper runners.

rcodecj

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Re: The $50 Street Master is History.
« Reply #6 on: May 07, 2011, 10:19:51 PM »
That thread took Jay into the land he shies away from: The land of Off-Idle to 2,5-3,000 and part throttle which is rumored to be like Kryptonite to him. Very interesting you found the Perf RPM smoothed things out. Of course By-The-Book not Jays Book, the dual plane is "supposed" to shine Low & Midrange BUT the Perf RPM is really not a true dual plane, it's unique in being 4cyl half a single plane on the lower runners and 4cyl conventional dual plane on the upper runners.
Jay does dyno tests, a dyno is hard to control under 2500 rpm, that's easy enough to understand. Even my mild builds get a 2500 converter. Post some pictures if you would BB of the difference between the Edelbrock RPM and other dual planes that makes it unique. I would like to see them.

Qikbbstang

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Perf RPM Pic
« Reply #7 on: May 09, 2011, 10:26:03 PM »
Here's the bottom of a Perf RPM.  When you look into the lower plenum it's like a single plane feeding the cylinders directly from the plenum. All the runners on an RPM are very uniform in their height and width where as many manifolds have runners that funnel-down to the head. The funnel's are simple to hog out because one only needs to go-into the ports a few inches. However with the Perf RPMs uniform port sizes, if you take off metal from the port walls you can only go a few inches deep then your left with hour glass runners.   The typical Dual Plane uses a single passage for two cylinders with branches that break off that and go to each cyl.
« Last Edit: May 09, 2011, 10:39:15 PM by Qikbbstang »

Cyclone03

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Re: The $50 Street Master is History.
« Reply #8 on: May 10, 2011, 10:38:28 AM »
Oh yea I got the book!

I think my "gather up it's skirt" could very well be Carb,spacer,and spacer type thing.

I could use a 1" 4 hole and 1/2 open or 4 hole under the hood on my Mustang with the Streetmaster.
With the RPM I have room only for 1  1/2inch spacer.
What I'm using now is a 2 hole 1/2".Why? I noticed Edelbrock sells spacers that basically extend the "double plenum" and it made me wonder why only them?

I got a deal on some 1/2" 4 hole phenolic 390cfm carb spacers so I ported one and tossed it on.
I don't have a dyno but it does seem to run clean off idle and going down the road,and like I said the mixture swings on the O2 indicator seem tighter,IE: I can cruise with the O2 ind at 14.5 target and it only pulses 14.2 to 14.7. I know that's allot but the swing was a full point each way with the Open Streetmaster.

Frankly my data logger (eyes) are busy at full throttle so I can't track trends but with the double spacer it runs richer at WOT,I say it's pulling on the boosters harder.

Anyway back to the book.....
I want an Edelbrock X66 with Fuel Injection Please.
Or a Dove Tunnel Ram.
I'm available to test either of the above for drivability in hot weather,I'll help pay for the testing with gaskets,gas and whatever fuel pumps/lines required to make it run.

BTW I'm not kidding.
Lance H