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 Post subject: Re: lays over at 5000rpm
 Post Posted: Fri Oct 28, 2011 12:14 pm 
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Joined: Wed Dec 06, 2006 9:24 pm
Posts: 5071
Location: Elizabethtown, KY
The reason I asked is some times people put stock rockers on a higher lift cam. Then wonder why they don't RPM higher. One last thing I would look at is make sure the throttle opens all the way with the pedal. I've seen too many times that happen.
=; =;

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 Post subject: Re: lays over at 5000rpm
 Post Posted: Sat Oct 29, 2011 6:25 pm 
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Joined: Fri Jul 16, 2010 2:41 pm
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WR169 wrote:
The reason I asked is some times people put stock rockers on a higher lift cam. Then wonder why they don't RPM higher. One last thing I would look at is make sure the throttle opens all the way with the pedal. I've seen too many times that happen.
=; =;

thank you for the throttle tip I actually did not check that yet


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 Post subject: Re: lays over at 5000rpm
 Post Posted: Sun Oct 30, 2011 3:27 pm 
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Location: Elizabethtown, KY
Your welcome =;

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 Post subject: Re: lays over at 5000rpm
 Post Posted: Wed Nov 09, 2011 4:06 pm 
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Joined: Fri Jul 16, 2010 2:41 pm
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Ok heres where I'm at. I replaced the fuel regulator and gauge (havnt done a pressure test while driving yet, but it seems to pump great into a bucket) Set the timing at 34* total, and replaced the malary unilite. Ordered a valve spring testing tool. By the way- this is a 13 second car. Checked to see that the throttle was opening completely. Could it be a carb problem. While I am waiting for my valve spring tool do you have any other things for me to check. Thanks.


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 Post subject: Re: lays over at 5000rpm
 Post Posted: Wed Nov 09, 2011 4:26 pm 
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Location: Adelaide Australia
If the carby jetting is too lean the engine will go good until it hits high revs. You should check the carby for cleanliness and jets. Set all jets to stock or one size richer from the listing in the Holley catalog, that's a good start point. That should ensure the jetting is adequately rich enough to be OK.
Another thing to do is when its gone past 5000 and it's losing power, if you lift your foot a bit so its not WOT does it pick up power? If it does its a sure sign its too lean.


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 Post subject: Re: lays over at 5000rpm
 Post Posted: Wed Nov 09, 2011 11:16 pm 
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thanks/thanks I'm going to check the jets. The plugs look lean.


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 Post subject: Re: lays over at 5000rpm
 Post Posted: Tue Dec 13, 2011 12:25 pm 
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Joined: Fri Jul 16, 2010 2:41 pm
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Ok, heres where I'm at-
ran a fuel gauge into the car, no loss of pressure in a run
bought a spring tester (cool tool) spring pressure is almost 120lbs like the cam instructions recommend
TDC was corrected on the flywheel, distributer advance removed, timing set at 38* advance
Jets checked, none clogged but are 65's not the 70's that came in the carb (I'll try the 70's when I get them)
cam specks checked with a dial gauge

Car now revs to 5800rpm but no further. I called the cam manufacturer and they said the cam only makes power to 5400rpm. I've never owned a motor that only reved to 5800rpm. What is the limitation here, do you think it is simply running out of air or are the valves floating? If it's running out of air every now and then thats fine but I dont want to hurt anything by floating the valves every now and then.I really appriciate you guys helping me with this car. If everything is right then I'm happy using it as it is. I think I've tested all your recommendations, am I missing anything?

found this on Elgins website, the intake duration on my cam is 248*-

Range D (Hydraulic: 225° - 240° Effective Duration)
(Mechanical: 235° - 250° Effective Duration)

Rough idle quality - (Note: Intake vacuum may be too low for power brakes, etc.) Good mid-range torque in 3000 - 4000 RPM range. Good mid-range power operating range 2200 - 5400 RPM. Average fuel economy cam not recommended for towing. Increased compression ratio best, 10.5 to 1 or 11.0 to 1. Some engine modification required. Use manual or automatic transmission with high stall converter. Recommended spring pressure 120 lbs for valve on seat; 300 lbs for valve open. Axle ratio at 3.90 to 4.50 to 1 is best. Recommended for limited oval track.


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 Post subject: Re: lays over at 5000rpm
 Post Posted: Tue Dec 13, 2011 3:36 pm 
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Location: Adelaide Australia
fasthappy wrote:
Jets checked, none clogged but are 65's not the 70's that came in the carb (I'll try the 70's when I get them)
cam specks checked with a dial gauge

Car now revs to 5800rpm but no further. .

The jets are too small the plugs are telling the story. But even with bigger jets its not going to rev much more but it should pick up top end power.


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 Post subject: Re: lays over at 5000rpm
 Post Posted: Tue Dec 13, 2011 3:42 pm 
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Joined: Fri Jul 16, 2010 2:41 pm
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thanks shrinker


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