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Re: Just returned from the track....Something is wrong! [Re: 64Post] #254921
03/17/09 01:42 PM
03/17/09 01:42 PM
Joined: Oct 2003
Posts: 7,506
Az
Crizila Offline
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Az
Well, I suggest you fix the obvious problems first. The 5/16" fuel line you are running is too small. That blue Holley pump you are using has a 3/8" NPT on the "in" and "out" for a reason. I'm not sure what a decent CR means, but with that cam ( it is an older grind ), you my very well not be able to run todays pump gas by the time you get the DCR where it should be to make power in the 3-4 grand area.


Fastest 300
Re: Just returned from the track....Something is wrong! [Re: Crizila] #254922
03/17/09 01:54 PM
03/17/09 01:54 PM
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck Offline
Not enough dumb comments...yet
Mr.Yuck  Offline
Not enough dumb comments...yet

Joined: Jan 2003
Posts: 24,562
Brookeville, Md
"The 5/16" fuel line you are running is too small"
I'll say it again your fuel line is fine. You can run 11's w/ a 5/16 ine and mech pump...even w/ a 440-6 in a B-body. If it's fuel issue you either have a clogged filter or you car is lean. changing the line to 3/8 won't do squat.
If you have 140 across the borad you have a compression problem...either your valves are a tad open or you don't have the 11:1 you thought you had. 106 is decent mph. Your 60 foot looks to be a tad high. I'd think you should be in the 1.65 range. If you can find a way to cut those 2 tenths at the gate you'll drop your trap et by 4. What squirters are you running? 31's would probably work...what jets? I'd think 78-86's would be a start and as for the PV if you are only pulling 3-4 lbs, I'm not sure where you'd start w/ that.

Re: Just returned from the track....Something is wrong! [Re: Mr.Yuck] #254923
03/17/09 01:57 PM
03/17/09 01:57 PM
Joined: Jan 2003
Posts: 4,085
Indiana
W5Duster436 Offline
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Indiana
Just curious, were the compression tests that yielded 140 done with the carb open or closed? I can see the 140 if the throttle was not strung open.


'70 Duster - SDSS 436 W5 4spd (Gone)
'71 Dodge D100
'70 Dodge W100
Re: Just returned from the track....Something is wrong! [Re: Mr.Yuck] #254924
03/17/09 02:00 PM
03/17/09 02:00 PM
Joined: Aug 2003
Posts: 8,716
Baltimore/Denver
64Post Offline
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64Post  Offline
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Baltimore/Denver
Quote:

"The 5/16" fuel line you are running is too small"
I'll say it again your fuel line is fine. You can run 11's w/ a 5/16 ine and mech pump...even w/ a 440-6 in a B-body. If it's fuel issue you either have a clogged filter or you car is lean. changing the line to 3/8 won't do squat.




I agree. I'm running a 450" B engine with CNC Eddys, a big solid cam a 950 HP with a 5/16 fuel line. Fuel delivery is not a problem.

Quote:

If you have 140 across the borad you have a compression problem...either your valves are a tad open or you don't have the 11:1 you thought you had.




Also agree.

Re: Just returned from the track....Something is wrong! [Re: Crizila] #254925
03/17/09 02:25 PM
03/17/09 02:25 PM
Joined: Aug 2003
Posts: 8,716
Baltimore/Denver
64Post Offline
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Baltimore/Denver
Quote:

I'm not sure what a decent CR means,




Generally, I'd say a cranking pressure in the 180-185 range, and a DCR of 8.5 with the aluminum heads.

Just for grins, I ran my combo as installed vs. having the intake valve close 4* later. Here are the numbers: 12.4 static; 9.15 dynamic; 189# cranking. 12.4 static; 8.85 dynamic; 181# cranking. All @ 6000 ft. altitude.

I use this online calculator...www.wallaceracing.com/dynamic-cr.php

Last edited by 64Post; 03/17/09 02:27 PM.
Re: Just returned from the track....Something is wrong! [Re: 64Post] #254926
03/17/09 04:14 PM
03/17/09 04:14 PM
Joined: Oct 2003
Posts: 7,506
Az
Crizila Offline
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Crizila  Offline
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Az
Straight from a very well known carb MFG. " When your car isn't performing, alswys carry out the gas can test first - it's one of the least expensive diagnostic aids you will encuonter. Keep in mind that valve springs, ignition systems, torque convertors, even engines have been changed, when all the time the fuel system was at fault". I give on the line size ( but it's too small ) - if you wanna run in the 12's, your gonna have to fill a 1 gallon can in 35 seconds or less - from Barry Grant, Holley, and others. If you can do it with a 5/16" line, God bless you! Hope everyone remembers this thread when there motor goes lean through the second MPH lights and sections of the top ring lands on their hypereutectic pistons start exiting out their collectors! Been there - done that!!!!!! Here is a web sight with a ton of really good on line calculators: http://www.csgnetwork.com/compcalc.html


Fastest 300
Re: Just returned from the track....Something is wrong! [Re: Crizila] #254927
03/17/09 04:32 PM
03/17/09 04:32 PM
Joined: Feb 2003
Posts: 12,675
Columbia, CT
M
moper Offline
I Live Here
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Columbia, CT
I've also supported 550hp with a factory mechanical and 5/16 line. Many lines now have kinks and guy dont cut them properly so the flow is much lower than it should be. That fact is, overkill sells, and in many cases, meaning a car that runs in the 12s or high 11s, they simply dont need that much pump or line. In somecases, you add so much volume in the line the milder pumps have trouble pumping against the inertia of the fuel in the line in first gear.


Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.
Re: Just returned from the track....Something is wrong! [Re: moper] #254928
03/17/09 05:51 PM
03/17/09 05:51 PM
Joined: Oct 2003
Posts: 7,506
Az
Crizila Offline
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Crizila  Offline
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Az
overkill = cheap security. If you are pushing the edges of the envelope, you will only go lean once! Could I see a show of hands of those on this thread that even have a fuel pressure guage in their car?


Fastest 300
Re: Just returned from the track....Something is wrong! [Re: Crizila] #254929
03/17/09 06:04 PM
03/17/09 06:04 PM
Joined: Dec 2007
Posts: 7,759
So Cal
HealthServices Offline
Why would you even post that?
HealthServices  Offline
Why would you even post that?

Joined: Dec 2007
Posts: 7,759
So Cal
Quote:

overkill = cheap security. If you are pushing the edges of the envelope, you will only go lean once! Could I see a show of hands of those on this thread that even have a fuel pressure guage in their car?




for two cars

but I've seen many a car run 11s with just 5/16 lines

Last edited by HealthServices; 03/17/09 11:40 PM.

Allen Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first. Life was a little easier when I was just a wrench.
Re: Just returned from the track....Something is wrong! [Re: HealthServices] #254930
03/17/09 06:17 PM
03/17/09 06:17 PM
Joined: Feb 2008
Posts: 711
Montana
P
Posest Offline
super stock
Posest  Offline
super stock
P

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Posts: 711
Montana
Me too. Both cars in fact.
Shawn

Re: Just returned from the track....Something is wrong! [Re: 64Post] #254931
03/17/09 06:23 PM
03/17/09 06:23 PM
Joined: Apr 2007
Posts: 2,327
Glendale, AZ
6
69L78Nova Offline OP
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Theyre not flat tops. They have a .050" quench dome, and a .039" head gasket, sitting .009 in the hole...with a .050" recess machined in the chamber

Re: Just returned from the track....Something is wrong! [Re: HealthServices] #254932
03/17/09 10:11 PM
03/17/09 10:11 PM
Joined: Aug 2003
Posts: 8,716
Baltimore/Denver
64Post Offline
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Baltimore/Denver
Quote:

Quote:

overkill = cheap security. If you are pushing the edges of the envelope, you will only go lean once! Could I see a show of hands of those on this thread that even have a fuel pressure guage in their car?




for two cars




Dude, is that Hitler, or what???

Re: Just returned from the track....Something is wrong! [Re: 64Post] #254933
03/17/09 10:22 PM
03/17/09 10:22 PM
Joined: Dec 2007
Posts: 7,759
So Cal
HealthServices Offline
Why would you even post that?
HealthServices  Offline
Why would you even post that?

Joined: Dec 2007
Posts: 7,759
So Cal
Ippon

Judo Referee Signals

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Allen Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first. Life was a little easier when I was just a wrench.
Re: Just returned from the track....Something is wrong! [Re: 69L78Nova] #254934
03/17/09 10:27 PM
03/17/09 10:27 PM
Joined: Aug 2003
Posts: 8,716
Baltimore/Denver
64Post Offline
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Baltimore/Denver
Quote:

Theyre not flat tops. They have a .050" quench dome, and a .039" head gasket, sitting .009 in the hole...with a .050" recess machined in the chamber




So do you have all the piston numbers to run the calcs (dome volume, valve reliefs, chamber volume, etc.) starting with the static CR? Cam card?

You can also work backwards using your known cranking pressure of 140# to come up with a theoretical static CR.

I'm at a loss to explain how a small fuel line effects cranking compression readings. Unless of course the motor already went lean and pinged itself on to life support.

Re: Just returned from the track....Something is wrong! [Re: moper] #254935
03/17/09 10:31 PM
03/17/09 10:31 PM
Joined: Aug 2003
Posts: 8,716
Baltimore/Denver
64Post Offline
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64Post  Offline
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Baltimore/Denver
Quote:

I've also supported 550hp with a factory mechanical and 5/16 line. Many lines now have kinks and guy dont cut them properly so the flow is much lower than it should be. That fact is, overkill sells, and in many cases, meaning a car that runs in the 12s or high 11s, they simply dont need that much pump or line. In somecases, you add so much volume in the line the milder pumps have trouble pumping against the inertia of the fuel in the line in first gear.




There have been many threads on that subject. There is also the matter of friction loss in the lines. The more pressure you force through the line the higher the friction loss.

Re: Just returned from the track....Something is wrong! [Re: 64Post] #254936
03/17/09 10:56 PM
03/17/09 10:56 PM
Joined: Apr 2007
Posts: 2,327
Glendale, AZ
6
69L78Nova Offline OP
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Glendale, AZ
Im working on getting a degree wheel. But heres another "long shot". Edelbrock recommends the use of adjusteble rocker arms when using cams with a greater-than-stock lift. There has to be a reason for this. Since Im running the MP509, is it possible the rocker stands themselves might not be machined at the same height as say a stock cast iron head, therefore causing the valves to "hang open"? Much like a Chevy with the rockers adjusted too tight? I do have experience with that scenario and the effect is great. I should have a degree wheel tomorrow and Ill take a crack at it.

But who here thinks I could benefit from an adjustable rocker setup? Id like to rule that out as a possibility as well. I appreciate all of the replies. Its all very interesting. I just hope I can get to the bottom of this.

Re: Just returned from the track....Something is wrong! [Re: 69L78Nova] #254937
03/17/09 11:19 PM
03/17/09 11:19 PM
Joined: Dec 2007
Posts: 7,759
So Cal
HealthServices Offline
Why would you even post that?
HealthServices  Offline
Why would you even post that?

Joined: Dec 2007
Posts: 7,759
So Cal
Quote:

Im working on getting a degree wheel. But heres another "long shot". Edelbrock recommends the use of adjusteble rocker arms when using cams with a greater-than-stock lift. There has to be a reason for this. Since Im running the MP509, is it possible the rocker stands themselves might not be machined at the same height as say a stock cast iron head, therefore causing the valves to "hang open"? Much like a Chevy with the rockers adjusted too tight? I do have experience with that scenario and the effect is great. I should have a degree wheel tomorrow and Ill take a crack at it.

But who here thinks I could benefit from an adjustable rocker setup? Id like to rule that out as a possibility as well. I appreciate all of the replies. Its all very interesting. I just hope I can get to the bottom of this.




I don’t understand something since I know very little about small blocks and valvetrain setup.

  • This is a hydraulic cam

  • It uses shaft rockers right?.

  • You have aftermarket heads.

  • You have non adjustable rocker arms?



    How is preload done on each lifter?


  • Allen Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first. Life was a little easier when I was just a wrench.
    Re: Just returned from the track....Something is wrong! [Re: HealthServices] #254938
    03/17/09 11:22 PM
    03/17/09 11:22 PM
    Joined: Apr 2007
    Posts: 2,327
    Glendale, AZ
    6
    69L78Nova Offline OP
    Banned. Forever.
    69L78Nova  Offline OP
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    Joined: Apr 2007
    Posts: 2,327
    Glendale, AZ
    Yes, it uses shaft mounted non-adjustable rockers, it is a hyd cam, and Edelbrock heads. Both small block and big block Chrysler used this setup. Im thinking that could be contributing to my problem as well.

    Re: Just returned from the track....Something is wrong! [Re: 69L78Nova] #254939
    03/17/09 11:26 PM
    03/17/09 11:26 PM
    Joined: Dec 2007
    Posts: 7,759
    So Cal
    HealthServices Offline
    Why would you even post that?
    HealthServices  Offline
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    So Cal
    So you checked preload and adjusted it by using shims?


    Allen Here's a novel idea, let's not throw a bunch of parts at the car hoping it will fix the problem and instead spend a little time diagnosing it first. Life was a little easier when I was just a wrench.
    Re: Just returned from the track....Something is wrong! [Re: HealthServices] #254940
    03/17/09 11:28 PM
    03/17/09 11:28 PM
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    Posts: 9,826
    las vegas
    70AARcuda Offline
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    las vegas
    you can run the stock non adjustable rockers with the eddy heads with a hydraulic cam...

    been there...done that...


    Tony

    70 AARCuda Vitamin C
    71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield)
    71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas)
    71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)
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