Thanks Mike. I have not gotten to the ignition side of it yet. It is a stock rebuilt single point for a 413 engine. Probably stock weight springs. A good mechanic set my timing after driving the car for another issue. That really made a difference. I don't hear any pre ignition on hard acceleration. It does make one " ping" when starting the engine-right when it fires. Pump gas 91 octane , no ethanol. Carb. is a Holley 4250 double pump , mechanical secondariers. And it is not quite right with the idle mixture screws. A bit of a mystery there. Front and back accelerator pumps with extended nozzles-size .042. high flow nozzle attachment screw. Engine vacume 12 1/2 to 13 inches at idle.-- power valve 6.5 inches. Rear diff ratio is 3:54. with a 4 speed.
The engine actually is running well now. Has crisp throttle responce from idle with no load on the engine. idles good at 650-700 RPM. Still not quite right under hard acceleration. It very well could be ignition timing and advance.
After that carb kicking my butt for several hours , I finally figured out the problem with flooding. Will start another thread on that.
Right now, I have other issues with the drive train that have to be sorted out this week. Thanks Mike, ............................Steve............MO
On Saturday, July 1, 2017 at 7:39:24 AM UTC-5, mike creglow wrote:
steve,
sorry for jumping in here late,
what is your timing, ignition, and distributor situation? i would get get that figured out before you tackle the carburetor.
do you have light weight springs for your advance weights in the distributor?
what size accelerator nozzles do you have in your carburetor? (bigger may not be better)
what is your final gear ratio?
did you notice what RPM your stumble occurs at?
mike
On Tue, Jun 27, 2017 at 1:24 AM, MO
<mic...@xxxxxxxxxxxxxxx> wrote:
I am trying to figger out a stumble in my Holley 4250 with mechanical secondaries--750 CFM. Low gear, rolling at idle, punch the throttle and get a substantial hesitation--not really a bog. about 1500 RPM at full throttle it takes off like a striped a**ed ape!. I think I have plenty of accelerator pump now. I put a 2.5 power valve in because I thought I had low vacume ..my bad. I put the vac gauge on and actually have 12.5 inches at idle. Do I just put a 6.5 power valve in, or is there a better way to know which PV I should use? BTW the engine idles fine, but I have not fine tuned the idle mixture yet. .............................MO
--
--
--
Please address private email -- email of interest to only one person -- directly to that person. That is, email your parts/car transactions and negotiations, as well as other personal messages, only to the intended recipient. Do not just press "reply" and send your email to everyone using the general '62-'65 Clubhouse public email 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.
--
You received this message because you are subscribed to the Google Groups "The 1962 to 1965 Mopar Mail List Clubhouse" group.
http://groups.google.com/group/1962to1965mopars?hl=en.
---
You received this message because you are subscribed to the Google Groups "The 1962 to 1965 Mopar Mail List Clubhouse" group.
To unsubscribe from this group and stop receiving emails from it, send an email to 1962to1965mopa...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
Back to the Home of the Forward Look Network