Test Results - Mustang Geezer (track)

wsa111

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Jack, yes a 390 cfm 4 barrel vacuum secondary would be worth a try, cause when you calculate the cfm @ 1.5 the 500 2 barrel is more like 357 cfm.

Doug, i would sugest a 8.5 power valve in your 4412, not the 5.0 valve. The 8.5 richens up the part throttle mixture without over richening the full throttle mixture from too large a main jet.

Just a thought, Bill
 

MustangSix

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wsa111":1u4kn4po said:
Jack, yes a 390 cfm 4 barrel vacuum secondary would be worth a try, cause when you calculate the cfm @ 1.5 the 500 2 barrel is more like 357 cfm.

Doug, i would sugest a 8.5 power valve in your 4412, not the 5.0 valve. The 8.5 richens up the part throttle mixture without over richening the full throttle mixture from too large a main jet.

Just a thought, Bill

A 390 only gets him to about the same place at WOT and may not be enough. At WOT he may need to be running at zero inches of vacuum and it's possible that with a good manifold he could even exceed 100% VE.

A 390 might be a great choice for a street car that spends most of its time under 4000, but Doug's engine has evolved into a very high output piece that needs to be tuned for that end of the rpm range. A 600 might be overkill for a street car but could be just what he needs to shave several tenths from the rpm range.
 

Mustang_Geezer

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MustangSix":24pmpi1a said:
wsa111":24pmpi1a said:
Jack, yes a 390 cfm 4 barrel vacuum secondary would be worth a try, cause when you calculate the cfm @ 1.5 the 500 2 barrel is more like 357 cfm.

Doug, i would sugest a 8.5 power valve in your 4412, not the 5.0 valve. The 8.5 richens up the part throttle mixture without over richening the full throttle mixture from too large a main jet.

Just a thought, Bill

A 390 only gets him to about the same place at WOT and may not be enough. At WOT he may need to be running at zero inches of vacuum and it's possible that with a good manifold he could even exceed 100% VE.

A 390 might be a great choice for a street car that spends most of its time under 4000, but Doug's engine has evolved into a very high output piece that needs to be tuned for that end of the rpm range. A 600 might be overkill for a street car but could be just what he needs to shave several tenths from the rpm range.

Going with a 600 Holley! My Mustang is evolving into a street/strip car with the emphasis on the strip so.... ;)

As soon as Mikes 4 Bbl intakes become available, I'm getting one! I pulled the plugs last night and even after 12 or so trips down the strip and over 500 miles on it the spark plugs are still almost bone white. So i'm going to jet it up even more next time I go to the track.

Bill,

Cant go with an 8.5 power valve. I posted a topic awhile back about my low vacuum. It bounces around between 6"-9" vacuum so I had to go with the 5" power valve so it wouldnt be turning on & off at idle.

I'll throw a vacuum gauge on it and make a pass and see if it stays at 0 or if it comes up at WOT.

Later,

Doug
 

wsa111

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Doug
Cant go with an 8.5 power valve. I posted a topic awhile back about my low vacuum. It bounces around between 6"-9" vacuum so I had to go with the 5" power valve so it wouldnt be turning on & off at idle.

I did not realize your curb idle vacuum in drive was that low. However at idle you should just be getting fuel from the idle circuit & not the main discharge nozzles. The power valve has no effect on the idle circuit, unless the vacuum is so low that the throttle opening is bringing in the main nozzles, yes then it will affect your idle. During part throttle opening if the engine vacuum is still low then & only then will the power valve affect the idle.

The X factor is if the power valve diaphram is rupchured & leaking fuel at idle.

Jack & Doug, you can give the 600 a try, but remember the vacuum secondaries will only open when a sufficient amount of air flow is flowing through the primaries. Yes holley has different secondary springs in kit #20-13, which will change the rpm the secondaries start to open & will open at a rate with an increase in air flow through the primaries.

Holley also makes a quick change cover #20-59 so you can change springs in a matter of seconds.

Look in a holley book at the opening & fully open rpm's different springs have an effect.

I think the only way you can tell if the secondaries open all the way on a small engine is to remove the hood & visually observe what full throttle does.

Of course the ET will tell you real fast if the extra carburetion is of any help. Bill
 

Stubby

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The best way I have found to monitor the starting point and full open point of the secondaries is with two micro switches and LEDs.

I have also rigged out a throttle position sensor on the secondaries wired with an extra Edelbrock air fuel ratio monitor. Just remove the spring from inside the TPS and reseal it. Feed one and a half volts thru the TPS and into the AFR. Adjust the linkage ratio so the first light comes on at first movement of secondaries and last light comes on at full open.

I used these tricks on some dirt cars with Qjets to tell what the carb was doing.

I will avoid recomending a Qjet carb. :LOL:
 

kirkallen143

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Doug how about this being the answer to your 4-barrel situation, since you said "strip".



It is the Holley 450 cfm with mech. secondaries (good since your vacuum is low) and I think it would fill your niche just fine for the strip, well at least the street. I've heard its been a proven performer on these inline sixes.

Kirk
ps. who needs a choke anyways.
 

lyonsy

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good to see there starting to get around.
although it is a bit slower then the xflow atm in both turbo and n/a
will be interesting watching it develop but and should be quicker
 

xctasy

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What, the first incarnation of the 2V alloy head,
no mods,

no dyno tune, no black magic,


Verses what, a 30 year development on the first 1976 Cross flow?

I'd say it'll kill any similar X-flow dead, especially with those intake and exhast ports, quick induction warm up cycle from non crossflow design, great plug placement. These were the secretes to Datsun L-series and earlier R-series Toyota engines being so economical and long lasting.

And Bill57's Mustang gets 23 US miles per gallon, thats way better than our X-flow 200 cube engines do with 5-speeds, let alone the last of our 5-speed 250's!


As you know, drift, I'm am the X-flow man, but

I quiver with fear ;)
 

lyonsy

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we quiver with fear that is true but we do have a trump card.
doch head they say it cant be done......
but they also said you couldent fit a xflow head on red motor lol
 

wsa111

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Linc wrote:
You need to be using either a wideband O2 sensor

Linc, i have learned so much about carb tuning since i purchased my innovate wideband A/F tester.

I now have the tools to tailor the idle orifice which controls the A/F mixture till the main jet takes over. All holley carbs are pig rich in that area just to make sure that perticular carb does not have a lean hesitation on a large engine.

You have complete control of the cruising A/F ratio & the full throttle ratio by changing main jets & the PVRC below the power valve for the correct full throttle A/F ratio.

Also a great link for plug reading, thanks, Bill
 

Mustang_Geezer

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Heres an update (for the record) on how my car is running with Classic Inlines aluminum head.

1st of all I installed a 600 cfm Holley 4 bbl and the new Classic Inlines 4 Bbl intake on my freshened up (as of 200:cool: 206 cubic inch inline 6.

I also installed a Boss 429 hood scoop on my car last weekend and sealed it to the carb.

I'm running the stock power valve and its pulling between 7.5 and 9 " of vacuum at idle. For the rearend I'm running Rancho drag shocks set at number 4 on the right side and 3 on the left with BFG radial T/A 225/60/15 tires and 3:80 rear gears with a 3500 rpm stall converter.

On the front I'm running Summit 90/10 shocks and no sway bar.

Heres all the times in order from last nights (7/5/0:cool: test & tune and the changes I did.

Carb stagger jetted #68 & 70 on the primary side with the long yellow secondary spring.

The car always runs its fastest time on the 3rd pass for some reason....I am running a cool can that I ice down every other pass.

Launching on the convertor @ 3200 rpms

60' 2.28 1/8 mile 9.76 @ 72.57 1/4 mile 15.26 @ 88.07

Lots of wheel spin so I start leaving @ 2000 rpms,

60' 2.12 1/8 mile 9.56 @ 73.08 1/4 mile 15.04 @ 88.34
60' 2.11 1/8 mile 9.49 @ 73.43 1/4 mile 14.93 @ 89.17

Yippe! in the 14's for the fastest et its ever done!

Problem is its lean surging in 2nd and 3rd gear going down the track.

I switch to the short yellow secondary spring.

Still leaving @ 2000 rpms,

60' 2.13 1/8 mile 9.55 @ 73.67 1/4 mile 14.96 @ 89.67

Decide to try leaving @ 3000 rpms,

60' 2.27 1/8 mile 9.64 @ 74.00 1/4 mile 15.07 @ 89.29

Obviously blew away the tires, and the lean surge is still there but is better so I installed the white spring which is the lightest spring Holley makes for the secondaries.

Leaving at 1200 rpms now and just standing on it.

60' 2.09 1/8 mile 9.39 @ 74.38 1/4 mile 14.76 @ 90.34
60' 2.09 1/8 mile 9.41 @ 74.02 1/4 mile 14.80 @ 90.15

Now I stop and pull the plugs. They were brand new plugs when I started the night off.

They are pure white and havent colored at all.

So I rejet to number 70's on the primary side. I cant rejet the rear because it just has the jet plate with no jets in it.

Still leaving the same way and still shifting @ 6000 rpms just like I have all night.

60' 2.09 1/8 mile 9.39 @ 74.52 1/4 mile 14.7351 @ 90.38
60' 2.08 1/8 mile 9.34 @ 74.63 1/4 mile 14.69 @ 90.98
60' 2.08 1/8 mile 9.38 @ 74.49 1/4 mile 14.7309 @ 90.57
60' 2.08 1/8 mile 9.36 @ 74.51 1/4 mile 14.71 @ 90.58

The plugs are still not really colored. Its been mentioned repeatidly on other forums that I'm over carburated and thats why I'm having to do this but its not blowing out any black smoke and the plugs are not sooty in the least.

Best pass was a,

60' 2.08 1/8 mile 9.34 @ 74.63 1/4 mile 14.69 @ 90.98
 

addo

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I think the "overcarbed" bit refers to venturi size/design more than jetting.

A greater velocity of air (with a smaller venturi) should suck fuel more efficiently out the jets - which may in fact mean a richer mixture on demand.

By the time air is inside your aircleaner, you want the flow to be smoothing out - this give most velocity, most draw on the jets. Excess turbulence at the top of your carb could also be compromising airflow and fuelling.
 

wallaka

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Nice! I'd say that you'll be in the low 14's when you get some drag radials on there and get that 60' down.
 

Bort62

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wallaka":1wr49g5a said:
Nice! I'd say that you'll be in the low 14's when you get some drag radials on there and get that 60' down.

He does have DR's and I think his (new) 60' is pretty good for his projected power levels.

I would not expect to see great gains on the hole shot. Also, his MPH indicates that he is possibly outperforming his projected ET based on HP, which suggests that his launch / car setup is very good.

Conversely, if he was running 14.6's @ 100 MPH, I would suggest that his car setup / launch was suffering and costing him a lot of ET.
 

82F100

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Bort, Geezer is runnin' the BFG D/R if I'm not mistakin and he's havin a hard time getting them to hook where his launch rpm needs to be with his stall . I think the M/T radial or a slick would help with the 60'
Doug, what tire pressure are you runnin now in the rears?
 

wallaka

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Ah, I thought he was running regular T/A's. My bad then! I've seen a couple tenths difference changing from regular T/A to the drag tire.
 
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