RE: Top end response

[Steven Charette <stevec@xxxxxxxxxxxxxxxxxxxx>]

Rich,
	Unless there is insufficient float drop, I wouldn't think that fuel
supply is an issue.  At 318 cu in, (unless there is something you're not
telling us - we know you've been hanging out with that Pavlovich character
:P ), application of the old carb sizing formula of CID X RPM X VE /3456
(using a VE of 95% for a healthy, fresh motor) nets the following:

318 X 6000 x .95 /3456 = 524 CFM

	It sounds like the rest of the fuel system is pretty solid, so
unless you have a plugged tank sock or something like that you're probably
looking at a carb issue.  Even with just one AFB there should be sufficient
fuel available unless there is a physical problem with a seat backed out
(been there, done that), a swollen viton needle (from additives),
insufficient float drop, or something of that nature, exclusive of flow
problems to that point.  Since you have two of the carbs, I'd say it's
pretty unlikely it's a carb problem unless one carb is just not working at
all.

	I'm not sure how you would even check it, but I suspect that the
weighted secondary flappers may not be seeing enough airflow to pull open.
If the carbs are seeing equal opening, at 95% VE each carb is theoretically
only flowing 262 CFM, and half of that is going down the primaries, all
things remaining equal.  I'm guessing you're running on the primaries of
each carb, the equivalent of one four barrel.

	It's been a while since I've been inside of one of the newer carbs,
but if possible I would suggest maybe removing one or both of the secondary
air flappers.  I'm thinking it shouldn't cause any problems but simply don't
recall.  Don't be surprised if you get a bog, but with sufficient
accelerator pump stroke hopefully you can tune that out.  I don't recall the
old 3258/3259 carbs used on the 343hp 383's having the air flaps and they
would launch okay.  Even if the bog kills your short times, if this is the
problem your MPH should show the difference if you can't feel it in the seat
of your pants.

	If nothing else, does Edelbrock have a tech line that you could run
this by to get their take on it?

Just my recession-adjusted $.01 cents worth.
SC




-----Original Message-----
From: Rich Kinsley [mailto:rlkinsley@xxxxxxxxx] 
Sent: Thursday, March 11, 2010 9:39 PM
To: 1962to1965mopars@xxxxxxxxxx
Subject: RE: Top end response


I have a pair of Eddy 500cfm with all choke mech removed. It doesn't exactly
"nose over" in that it doesn't lose acceleration but it just climbs very
slowly from that point comparatively. It doesn'tmatter whether I'm in 2nd or
3rd the speed is the same. I'm hitting around the 6000 mark when in 2nd at
the end of the 1/8th. I find it's better to leave it in 2nd and avoid the
extra shift. I have tried shifting it  at lower rpm's 5200-5500 but it
doesn't run as well as at the 6000 rpm's. 
It does kinda feel like a governor which makes me think it needs more fuel
supply.

Rich Kinsley '64 Dodge Polara 4dr 318poly w/goodies
=====================================================================
Steve Charette wrote:
> 
> Rich,
> 	Refresh my memory, which carbs are you running?
> 
> 	If I'm understanding what you are saying the car feels like it
"noses 
> over" or stops pulling when it gets around 70mph?  Roughly what RPM?
> And I'm assuming high gear?
> 
> Thanks,
> SC
> 
> -----Original Message-----
> From: Rich Kinsley [mailto:rlkinsley@xxxxxxxxx]
> Sent: Thursday, March 11, 2010 1:04 PM
> To: 1962to1965mopars@xxxxxxxxxx
> Subject: Top end response
> 
> 
> I have been thinking about my top end performance. I have improved 
> leaps and bounds in my ET's but my top-end is frozen around 70mph in 
> the 1/8th. It almost feels like a governor. I'm thinking I may have 
> fuel delivery issues at sustained WOT. I know I have plenty of fuel 
> available with my new 3/8's lines and the macho Holley blue 110gph 
> electric pump.
> So I'm thinking that since the carbs are bumped up rich a couple 
> stages maybe I should put in the larger needle and seats and high perf 
> accel pumps.
> I may be lacking in flow capacity at sustained top-end. The accel 
> pumps have larger nozzles currently but I feel it may need more volume 
> also for the initial launch. I've ordered the Edelbrock #1980 
> needle/seat assy ($11ea
> local) and the #1982 Hi-perf accel pump plunger assy ($14ea local). 
> I'll try that out this season and see if it's the key to the top-end.
> 
> I was kinda wondering before if my Engine Dynamics 9&1/2" 3000 stall 
> converter was slipping. In retrospect I think fuel delivery is more 
> likely.
> 
> What are your thoughts?
> 
> Rich Kinsley '64 Dodge Polara 4dr 318poly w/goodies
> 
> 
> ----
> Please address private mail -- mail of interest to only one person -- 
> directly to that person.  I.e., send parts/car transactions and 
> negotiations as well as other personal messages only to the intended 
> recipient, not to the Clubhouse public address. This practice will 
> protect your privacy, reduce the total volume of mail and fine tune 
> the content signal to Mopar topic.  Thanks!
> 
> 1962 to 1965 Mopar Clubhouse Discussion Guidelines:
> http://www.1962to1965mopar.ornocar.org/mletiq.html and 
> http://www.1962to1965mopar.ornocar.com/general_disclaimer.html.
> 



Rich Kinsley '64 Dodge Polara 4dr 318poly w/goodies


----
Please address private mail -- mail of interest to only one person --
directly to that person.  I.e., send parts/car transactions and negotiations
as well as other personal messages only to the intended recipient, not to
the Clubhouse public address. This practice will protect your privacy,
reduce the total volume of mail and fine tune the content signal to Mopar
topic.  Thanks!

1962 to 1965 Mopar Clubhouse Discussion Guidelines:
http://www.1962to1965mopar.ornocar.org/mletiq.html and
http://www.1962to1965mopar.ornocar.com/general_disclaimer.html. 


----
Please address private mail -- mail of interest to only one person -- directly to that person.  I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic.  Thanks!

1962 to 1965 Mopar Clubhouse Discussion Guidelines:
http://www.1962to1965mopar.ornocar.org/mletiq.html and http://www.1962to1965mopar.ornocar.com/general_disclaimer.html.