Top End Miss

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THINK....He had NO issues till he went from 3.91s to 4.88s.I will stick by my gear change screwing with his combo.THINK about it.His combo wont support 4.88s.Told him that before he went that way.Pulling my 4.56s and putting in 4.30s.Will loan him my 4.56 spool and I will bet anyone any amount he will pull just over 6.000 without any issues with my 4.56s.I am so sure of this I will put a grand on the table.Guzzi Mark
 
I agree with you Mark, but there's areason the combo can't support it. I know straight sixs have some weird crank harmonic issues. Leo's for years hit a wall at 6200. That's running big boost too, and methanol, so it's not a fuel/ignition thing. It just is. His approach was more boost and less gear...
 
The Shocker said:
I still think your problem is in the valve train ,but like mentioned read your plugs after a pass to see where everything is at.For the record i have no idea what my timing is set at on my 408 (as i have never put a lite to it) .I set the timing by reading the plugs and did the jetting on the 750 by reading the mph on my time slips...
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dam I'm glad you said this I have always wanted to tell people this but for the sake of the argument I haven't.I could see you and I do things allot alike..and I still think 805s car is still lean and with the fuel PSI Iv read I'm sure I always turn the PSI up till it dribbles out then back it off a 1/4 turn and it is usually around 9psi.I learnt that from a pro stock racer.........Artie
 
godfatherofchry said:
dam I'm glad you said this I have always wanted to tell people this but for the sake of the argument I haven't.I could see you and I do things allot alike..and I still think 805s car is still lean and with the fuel PSI Iv read I'm sure I always turn the PSI up till it dribbles out then back it off a 1/4 turn and it is usually around 9psi.I learnt that from a pro stock racer.........Artie
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We are a dead breed ,lol.I have told many that i set the timing on my race car by reading the plugs ,and they always tell me your gunna burn the pistons with too much advance ,since i dont know how much timing im running not using a lite ,and how they would never make a pass in a car that they didnt know how much timing was in it.At nearly 200 passes on the motor im still waiting for the burnt pistons.Usually the guys that tell me this have a car that pings going down the track ,or is lacking timing and runs slower than it should ,lol.I adjust valves by feel and carbs by ear also .Vacume gauges to set carbs are for newbies .Plugs will tell you everything about a tune .I set the fuel pressure up and up until it tries to over power the needle and seat ,then back off 1/2 psi on race motors.I run a gauge on mine just to makes sure it never changes .Im running 8 1/2 psi on my 750 Demon ...
 
Have you tried just slowly bring your engine up to the 6000 rpm? In other words, have you simulated the same rate of RPM increase as it would have been with the original gear set? I bet it's showing a lack of "something" in your setup because it can not keep up with the new rate of increase in RPM,,,, How about that fuel PSI reading when running it all out?
 
TXDart said:
Just throwing out some ideas for you.
Like others have said,You need to read your plugs and while you have them out gap them a little tighter and see what happens.
What model number MSD are you running ? (Some earlier boxes had a problem with 6 cylinders odd fire and even fire,,,If it is a 6200 you are good)
Check the ground connection for the MSD ignition box, If the Heavy Black wire is not connected directly to the battery negative terminal it can cause a breakdown in the ignition at higher RPM.
I know you had the problem before but what if the Valve springs fix the original problem and now you have a high rpm cross fire....
Good luck and curious to see what is wrong ?
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its a brand new box, its an MSD street fire, the the ground is connected to the same firewall ground on the motor... best place i have...

i pulled the cap and there was no "dust" in there so i dont think its cross firing...
 
madmax/6 said:
THINK....He had NO issues till he went from 3.91s to 4.88s.I will stick by my gear change screwing with his combo.THINK about it.His combo wont support 4.88s.Told him that before he went that way.Pulling my 4.56s and putting in 4.30s.Will loan him my 4.56 spool and I will bet anyone any amount he will pull just over 6.000 without any issues with my 4.56s.I am so sure of this I will put a grand on the table.Guzzi Mark
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will see today... might be the last thing left lol...

godfatherofchry said:
dam I'm glad you said this I have always wanted to tell people this but for the sake of the argument I haven't.I could see you and I do things allot alike..and I still think 805s car is still lean and with the fuel PSI Iv read I'm sure I always turn the PSI up till it dribbles out then back it off a 1/4 turn and it is usually around 9psi.I learnt that from a pro stock racer.........Artie
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im not running a reg as its not needed with the holley red...

The Shocker said:
We are a dead breed ,lol.I have told many that i set the timing on my race car by reading the plugs ,and they always tell me your gunna burn the pistons with too much advance ,since i dont know how much timing im running not using a lite ,and how they would never make a pass in a car that they didnt know how much timing was in it.At nearly 200 passes on the motor im still waiting for the burnt pistons.Usually the guys that tell me this have a car that pings going down the track ,or is lacking timing and runs slower than it should ,lol.I adjust valves by feel and carbs by ear also .Vacume gauges to set carbs are for newbies .Plugs will tell you everything about a tune .I set the fuel pressure up and up until it tries to over power the needle and seat ,then back off 1/2 psi on race motors.I run a gauge on mine just to makes sure it never changes .Im running 8 1/2 psi on my 750 Demon ...
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i havn't got to play with timing much becasue the time i went out to the track and was my balancer was slipping (OEM original 40 yr old one) so i couldn't keep track of where it was...

i have a new set of plugs im gonna make a run and shut off with the vacuum gauge and wide band on it to...

67 B-body said:
Have you tried just slowly bring your engine up to the 6000 rpm? In other words, have you simulated the same rate of RPM increase as it would have been with the original gear set? I bet it's showing a lack of "something" in your setup because it can not keep up with the new rate of increase in RPM,,,, How about that fuel PSI reading when running it all out?
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no i have not tried reving slowly... before i was only trapping 5 grand...

psi was just climbing slowly through out the run after the launch... never got below 5.5... besides it wouldn't jst be from 5800 to whatever in ever gear... it wouldn't catch up...
 
805moparkid said:
its a brand new box, its an MSD street fire, the the ground is connected to the same firewall ground on the motor... best place i have...

i pulled the cap and there was no "dust" in there so i dont think its cross firing...
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Sounds like you got that covered.Maybe you are experiencing Spark Blowout.it is more of a problem with turbo cars but it does happen on NA cars as well.If it still does it with new plugs,set your old plugs .010 tighter than you have been and see what that it does,a lot of the turbo guys are running .020-.028 gap...
Google Spark Blowout and on UTUBE and see if that is what you are experiencing.
Good luck.
 
TXDart said:
Sounds like you got that covered.Maybe you are experiencing Spark Blowout.it is more of a problem with turbo cars but it does happen on NA cars as well.If it still does it with new plugs,set your old plugs .010 tighter than you have been and see what that it does,a lot of the turbo guys are running .020-.028 gap...
Google Spark Blowout and on UTUBE and see if that is what you are experiencing.
Good luck.
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well they are only set to .037, almost stock lol... and with only 10:1 dosn't seem likely... but will check...
 
madmax/6 said:
THINK....He had NO issues till he went from 3.91s to 4.88s.I will stick by my gear change screwing with his combo.THINK about it.His combo wont support 4.88s.Told him that before he went that way.Pulling my 4.56s and putting in 4.30s.Will loan him my 4.56 spool and I will bet anyone any amount he will pull just over 6.000 without any issues with my 4.56s.I am so sure of this I will put a grand on the table.Guzzi Mark
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I'm in agreement....but what I am saying is the gear change is NOT the cause. It uncovered a problem that already existed. That's all I'm saying.....and I think you too. Gears won't cause one to shoot ducks. They might contribute to it happening, but they cannot cause the problem. The gear change made the problem noticeable. Now he needs to find the cause. I am still holdin onto the fuel thing.
 
DUH. your pump and his may be as different as day and night. yours may have more clearance and turn slower. go find a holley blue or black in used condition and it will still keep up with the demands of your engine.
 
That red pump was working perfectly and got me 6 records on a higher compression engine,more hp than Eds,,,,,Then ya got me thinking,,,My car is alot lighter???Only reason I changed out pump cause I will bee spraying in Vegas.Guzzi Mark
 
Now really thinking,,My red pump was enough for a 2300 lbs car,,,not enough for a 3000 lbs car??? Just got me thinking.Guzzi Mark
 
madmax/6 said:
Now really thinking,,My red pump was enough for a 2300 lbs car,,,not enough for a 3000 lbs car??? Just got me thinking.Guzzi Mark
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Would be interesting to find out if you were on the absolute ragged edge of that pump not being enough and Ed found it's limit because of his weight difference. He's fatter than you too so he's gotta haul all that around as well. If that works out to be true, that means yours should have possibly sped up with the pump change. Did it? I'm stickin by fuel on this one. Whether it's the pump or not is difficult at best to diagnose online, but I think it's fuel somewhere. The pump is the source of the pressure though. All us hollerin fuel could be slam wrong.....but I'm old school and like to stick with the tried and true first and eliminate that and then move.......and that hasn't been done yet.
 
I went back and read both posts... Did I miss where you posted what the fuel pressure went back up to during the run? I thought I read where you posted it started at 5.5, and dropped, then never really recovered. But I don't see where you said "In high gear at the traps my fuel pressure is xxxxx"
 
StrokerScamp said:
Would be interesting to find out if you were on the absolute ragged edge of that pump not being enough and Ed found it's limit because of his weight difference. He's fatter than you too so he's gotta haul all that around as well. If that works out to be true, that means yours should have possibly sped up with the pump change. Did it? I'm stickin by fuel on this one. Whether it's the pump or not is difficult at best to diagnose online, but I think it's fuel somewhere. The pump is the source of the pressure though. All us hollerin fuel could be slam wrong.....but I'm old school and like to stick with the tried and true first and eliminate that and then move.......and that hasn't been done yet.
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you know thats a very good point...

moper said:
I went back and read both posts... Did I miss where you posted what the fuel pressure went back up to during the run? I thought I read where you posted it started at 5.5, and dropped, then never really recovered. But I don't see where you said "In high gear at the traps my fuel pressure is xxxxx"
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no no... started at 7.5, dropped to 5.5 and slowly climbed... i can only get into thrid before i have to let off...
 
Ditch that red pump...lol
It should maintain the volume for 7.5psi under wide open throttle. If it can't (which is what it sounds like) you need more pump to push it. Switch to a blue and regulator.
 
I ran that red pump tru a regulator on a 625 Holley vacume secondaries carb at 5.5 lbs..NO issues with my close to 1,000 lbs lighter car.My carb was a 600 but has been worked.He is heavier and running more carb on lesser engine,with more gear.I hate to admit it,,butt he might need more pump.Black pump with a REGULATOR set a 6 lbs running will just tell me I was at the brink with that red pump,and not enough for his car.VERY CURIOUS.Btw my car ran the same with my new black pump at 6 psi as it did with with the red at 5.5. Mark
 
Blue or black I think flow the same,I went black cause I read somewhere that once you go black you will never go back????Actually went black just in case i want to go for Alky records.Guzzi Mark
 
madmax/6 said:
I ran that red pump tru a regulator on a 625 Holley vacume secondaries carb at 5.5 lbs..NO issues with my close to 1,000 lbs lighter car.My carb was a 600 but has been worked.He is heavier and running more carb on lesser engine,with more gear.I hate to admit it,,butt he might need more pump.Black pump with a REGULATOR set a 6 lbs running will just tell me I was at the brink with that red pump,and not enough for his car.VERY CURIOUS.Btw my car ran the same with my new black pump at 6 psi as it did with with the red at 5.5. Mark
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Whether the engine can use it or not, it may be that HIS red pump just can't fight the inertia in HIS car. Either way, I dont think 5.5 is enough at the gage, and if the gage is at 5.5, the carb needles wil be slightly lower.
 
I've read through all the responses & opinions, even have seen Ed's car run in the past (fun to watch, BTW) & while I generaly agree with most all the responses, the "glaring" problems that seem to catch my eye is wiring & the fuel delivery issue.
Now assuming the valvetrain is all correct & the new gears only amplified an existing problem, we're bac k to fuel issues & wiring. Many enthusiasts add to existing wiring instead of re-engineering their electrical system for the rigors of racing. IF IT WERE ME, I'd find someone I know & respect to go through the entire car to assess its wiring. Sure it can get expense, but a "third eye" might find something you overlooked or simply wasn't familiar with. WE all have our "gurus" in the hobby, but I'd find a veteran, different source, just to ease my mind. Anyway, with that done, I'd first get rid of that red pump (NEVER saw one on a racecar, always blue or another brand), set the pressure to 7-8 psi, as the fuel has to overcome inertia going downtrack, and perhaps consider a carb in the 550-650 range.
Of course don't make ALL the changes at once otherwise you'll never know what cured the problem (besides it's expensive). He's operating his motor in a range alot of strret big-block guys do & they don't have the sort of problem he's describing. My suspicion is the problem is one of assembly & not necessisarily componentry
 
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