Distributors
Thread Starter
Instructor
Joined: Jul 2004
Posts: 210
Likes: 0
From: Missouri
Distributors
Well I am having a miss at approx 3500 rpms and above on my 350. Carb is fresh rebuilt, new plugs & points. I had a slightly bent push rod that was replaced and all rockers were set. Car seems to run good except sometimes it has a slight stumble on a rare occasion (carb needs adjusting) and this missing at 3500 or so rpms. Motor has been setting for a few yrs but it has approx 4-6k on rebuild.
The guy that helped me is a pretty good mechanic and said it most likely a wore out distributor. He said to get the MSD Corvette Pro-Billet Tach Drive and a MSD 6A capacitive discharge. I wanted to try to reuse my tach so thats why I went with this model since mine has a bad gear and I could use it again after all these yrs.
Anyone have this setup did you notice any gain in performance? I'm sure there is a gain but is it worth $450?
I guess if thats not my problem I'll have something thats good or so I can say it is. 
The guy that helped me is a pretty good mechanic and said it most likely a wore out distributor. He said to get the MSD Corvette Pro-Billet Tach Drive and a MSD 6A capacitive discharge. I wanted to try to reuse my tach so thats why I went with this model since mine has a bad gear and I could use it again after all these yrs.
Anyone have this setup did you notice any gain in performance? I'm sure there is a gain but is it worth $450?
I guess if thats not my problem I'll have something thats good or so I can say it is.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Unless you have significantly increased cylinder pressures and/or the rpm range over stock, that very capable ignition system will not improve performance. It may cure the effects of a defective distributor, but it won't give you a gain over a properly operating stock system. I have my doubts that the distributor is at fault. Especially in light of acknowledged carb problems. $450.00 is an expensive way to find out.
RACE ON!!!
RACE ON!!!
Thread Starter
Instructor
Joined: Jul 2004
Posts: 210
Likes: 0
From: Missouri
Well I'm going to have a much stouter engine before its all over. 
I figured I would need these anyway.
Well if it was in the carb what do you think it would be? The wrench head that helped me said he didn't think it was the carb and I can assure you this guy knows engines. He did say we need to adjust it a little to lose the slight stumble and from what I have read a lot of guys are having this stumble with 650 dp carbs.
He told me I would notice the differance in a stock dis. and the one I got. I believe him I just wanted to throw it out to the crowd here. Never hurts to get input from others.
I figured I would need these anyway. Well if it was in the carb what do you think it would be? The wrench head that helped me said he didn't think it was the carb and I can assure you this guy knows engines. He did say we need to adjust it a little to lose the slight stumble and from what I have read a lot of guys are having this stumble with 650 dp carbs.
He told me I would notice the differance in a stock dis. and the one I got. I believe him I just wanted to throw it out to the crowd here. Never hurts to get input from others.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by BatManFire
I figured I would need these anyway....
The wrench head that helped me said he didn't think it was the carb and I can assure you this guy knows engines....
He told me I would notice the differance in a stock dis. and the one I got....
I believe him ....
The wrench head that helped me said he didn't think it was the carb and I can assure you this guy knows engines....
He told me I would notice the differance in a stock dis. and the one I got....
I believe him ....
RACE ON!!!
Thread Starter
Instructor
Joined: Jul 2004
Posts: 210
Likes: 0
From: Missouri
Really what I wanted to know is if someone here has that distr. and what their thought of it were. I already purchased it so no going back now.
Not trying to be a smartazz or anything like that. My expertise is starting and charging systems not engines itself but I'm trying to learn and I will. I got hosed by a shade tree guy and am doing pretty much everything myself with help from others local and on the net.
Matter a fact before its all over I will know how to do everything so i can be self sufficient. I'm going to learn how to even paint my car too.
Sorry if I came off the wrong way I wasn't intending to do that.
Not trying to be a smartazz or anything like that. My expertise is starting and charging systems not engines itself but I'm trying to learn and I will. I got hosed by a shade tree guy and am doing pretty much everything myself with help from others local and on the net.
Matter a fact before its all over I will know how to do everything so i can be self sufficient. I'm going to learn how to even paint my car too.
Sorry if I came off the wrong way I wasn't intending to do that.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by BatManFire
I already purchased it so no going back now.
Originally Posted by BatManFire
Anyone have this setup did you notice any gain in performance? I'm sure there is a gain but is it worth $450? I guess if thats not my problem I'll have something thats good or so I can say it is.
Thread Starter
Instructor
Joined: Jul 2004
Posts: 210
Likes: 0
From: Missouri
Oh and I did ask YOU what your thoughts were or could be causing the slight stumble. You never replied about that. Search the forums for "stumble" and see how many others are having that problem. It seems no one can pin point it.
A stumble imo could be caused by getting TOO much gas or even too little. That kinda tells me it could be jetting or air mix. I have tried air mix w/o any change so its almost down to jetting.
I guess if you don't run a Holley 650dp or ever have you wouldn't know what I'm experiencing. If someone has ever had a 650 dp and had a slight stumble on a fast blip of throttle and you cured it what was your fix?
So let me define who I'm asking.
1) anyone that has this dist I purchased and their thoughts
2) anyone who has or ever had a Holley 650 dp and had or know of the cure for a slight stumble on a quick blip of the throttle.
Thanks
A stumble imo could be caused by getting TOO much gas or even too little. That kinda tells me it could be jetting or air mix. I have tried air mix w/o any change so its almost down to jetting.
I guess if you don't run a Holley 650dp or ever have you wouldn't know what I'm experiencing. If someone has ever had a 650 dp and had a slight stumble on a fast blip of throttle and you cured it what was your fix?
So let me define who I'm asking.
1) anyone that has this dist I purchased and their thoughts
2) anyone who has or ever had a Holley 650 dp and had or know of the cure for a slight stumble on a quick blip of the throttle.
Thanks
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by BatManFire
Oh and I did ask YOU what your thoughts were or could be causing the slight stumble.
Originally Posted by BatManFire
You never replied about that. Search the forums for "stumble" and see how many others are having that problem. It seems no one can pin point it.
Originally Posted by BatManFire
A stumble imo could be caused by getting TOO much gas or even too little. That kinda tells me it could be jetting or air mix. I have tried air mix w/o any change so its almost down to jetting.
Originally Posted by BatManFire
So let me define who I'm asking.
1) anyone that has this dist I purchased and their thoughts
2) anyone who has or ever had a Holley 650 dp and had or know of the cure for a slight stumble on a quick blip of the throttle.
1) anyone that has this dist I purchased and their thoughts
2) anyone who has or ever had a Holley 650 dp and had or know of the cure for a slight stumble on a quick blip of the throttle.
RACE ON!!!
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Melting Slicks
Joined: Nov 2002
Posts: 2,460
Likes: 5
From: Wheaton IL
Check your dwell at timing and free rev the engine to near red line and check the dwell again - if it changes significantly you have a worn out distributor. By 'worn out' I mean the upper and lower bushings are worn to the point where the main shaft wobbles and the points do not open and close properly. The next thing to do is map out your advance timing with the vacuum can disconnected. A miss could be a million things.
I am from the school of thought that thinks all the MSD and breakerless ignition stuff is snake oil. A properly functioning points system will perform sufficiently unless you are building a serious race motor. Same with 160 degree thermostats, ram air, and most of the other gack that is advertisied at 2:00 AM.
Brian
I am from the school of thought that thinks all the MSD and breakerless ignition stuff is snake oil. A properly functioning points system will perform sufficiently unless you are building a serious race motor. Same with 160 degree thermostats, ram air, and most of the other gack that is advertisied at 2:00 AM.
Brian
Thread Starter
Instructor
Joined: Jul 2004
Posts: 210
Likes: 0
From: Missouri
Sorry I didn't update on what has happened but the forums went south for me for a while.
The dist fixed my high speed miss so I'm alright there. I started trying to get the off idle stumble fixed after I had the dist problem solved and what I found I guess was the front/rear float was set a little to low. I adjusted them so there is more fuel and my car now runs like a champ.
The car even before the carb fix seemed to run very smooth nothing like it did before. I was in need for a new dist. The MSD unit I got for the engine I have is overkill but I plan on having about 500+ hp before its all over so some day it will come in handy.
Thanks for all the ideas and help
The dist fixed my high speed miss so I'm alright there. I started trying to get the off idle stumble fixed after I had the dist problem solved and what I found I guess was the front/rear float was set a little to low. I adjusted them so there is more fuel and my car now runs like a champ.
The car even before the carb fix seemed to run very smooth nothing like it did before. I was in need for a new dist. The MSD unit I got for the engine I have is overkill but I plan on having about 500+ hp before its all over so some day it will come in handy.
Thanks for all the ideas and help
Drifting
Joined: Apr 2002
Posts: 1,736
Likes: 37
From: Stockton Ca
Did you replace the ign wires along w/dist? I have seen new plug wires cure many problems. Mine were burned through where I couldn't see it. If you changed both dist and wires, it could have been one or the other or both! I haven't heard many complaints about stk HEI on mild engines.
Rick
Rick
Thread Starter
Instructor
Joined: Jul 2004
Posts: 210
Likes: 0
From: Missouri
I put a set of 8mm wires on a week prior to installing the dist. the wires didn't solve the problem of my 3500-4000 rpm miss. I did have a new set of cheapo wires on but they got into headers and burnt a few almost thru. I really thought the new good set would take care of the problem but they didn't.
