Timing question. Other than a loss of HP, how would....July 27 2012 at 7:03 AM
|ford-boy (Login ford-boy)|
26* of total timing affect the engine when used hard, ie racing? I understand the late burning will cause more/higher heat to exit past the exhaust valve. Would this also have an impact on spark plugs? Cuase them to run hotter and shorten life?
|July 27 2012, 4:29 PM |
Hey how is it going ?
So I just wondered, no offense at all intended, why would you want to pull this much lead out of this race engine I wondered? And how is this FE built ?
Many guys here have seen guys like Jon Kaase develop fast burn heads that can make around a 1000 HP with one dominator, and 30 degrees total timing, like with P51's on a 429-460 based build. But the compression can be really up there for race gas only.
It is true that if you can redesign the combustion chamber to burn faster and make peak BMEP with less lead (advance),reposition the spark plug, and run small chambers. You sure can gain power from less advance but not with stock FE heads. The piston, on compression, has to overcome less counter rotational pressure so there is less parasitic load on a fast burn, small chamber, hig compression race engine in many circumstances. So please explain the combo further.
It is very true that many 10,9 and 8 second drag cars can pick up significant MPH out the back door(on the top end) by retarding the total advance,2,3,4 degrees. But not as much as you want to, so I am just wondering. Different ideas for nitrous. Is this guy getting heavy nitrous? If so, you better take away some lead..hee hee
Kaase, and others, also do 10.5 to 1 engines, big inch, with 32 degrees total and Boss Nine fast burn special hemi heads, and can make around 800 HP. What a guy. But I am not seeing state of the art fast burn chambers for the best Ford engines, the mighty FE. There is a Yates style head, I see some of the awesome guys here making the big numbers with less lead, but not WOT and 26 degrees. What is the situation I would ask again.
I was working on a huge Shotgun Hemi a while back, 709 inches, 15.4 to one or there abouts, and it only wanted 32 degrees in cool air, or 30 when the density altitude climbed or the track got greasy. So what is this going on in this case ?
If you retard a basic HP FE from 38-42 total on race gas, or with less compression and pump gas, say for instance,you watch the power fade and the EGT rise. So you want to pull out 12 to 16 degrees of lead(advance, ie, leed) away. Will you or would you re jet it here to compensate for the fuel that you are not burning, and thus after burning ?
That is going to get really soggy, quiet,and doggy, build a lot of heat and probably glow the headers red in short order.
I have had a fast big block for a girlfriend back when. She didn't know it, but I would pull lead and jet out of her car to try to save the engine....LOL. It was a 4 speed car and she was insane. But like 2, or 3, maybe 4 degrees, and some jet steps. Then I'd add it back for a race, go faster myself, and tell her that she needed more driving lessons....LOL
Are you trying to slow the car down a ton? Adjust the throttle to open less, take away some fuel, a little lead, turn down the rev limiter ? You have safer ways to save the engine or slow the car probably?
Let us know. Interesting question. I cannot recall a tuned , trick FE at 26 total mechanical with original style chambers.
Are you running a lot of vacuum advance or something?
Without more facts, we are kind of punching in the dark ya know.
Have fun. I personally would not do it, no offense intended in the slightest.
Maybe if you ran 'White Gas'? LOL
|This message has been edited by HolmanMoodyStroppeVet on Jul 27, 2012 4:52 PM|
I needed to lock out timing to see if.....
|July 27 2012, 5:25 PM |
my bracket car was more consistent. LOL My reason is VERY humble and not nearly as exotic and intelligent as all that you put forth. I settled on 26* because the car was easier to start. Thanks for your in-depth responce. It wasn't such a good idea after all. Plugs got fouled, of course it lost power. Oh well. Just a test.
You're too kind
|July 27 2012, 6:13 PM |
Well, right back at you and thanks kindly, but I was just scratching my head, like a typical monkey...trying to 'hep'.
So maybe there is more power, or 60 foot there for you ? Maybe tailor the curve to the launch.
You can put the ultra light springs on the centrifugal advance to get it to crank better, and go to full advance real low, like 1500 RPM or less. Just a thought.
But taking some timing away on the big end is worth exploring some day if you want more MPH or are trying to clip some guy in the lights.
But for sure, if you want to hit the tire at full advance, I get it. And it is no fun to crank it hot and slowly go, wahh, wahh, wahh against a bunch of lead.
Cool, thanks, now I understand
Have a blast !
A Tip on advance curve , too Early no Good
|July 28 2012, 9:50 AM |
Having the advance all in before the rpm in which you leave is really of no help , BUT it can hurt , most drag cars leave above 2500 , if the advance is all in below that , plan on some day down the road NOT being able top start the car because the WEAK springs allowed the weights to stick out and no its like a locked out Dist , and you already know what that does, Just food for thought
|July 29 2012, 6:22 PM |
Happy Birthday and good luck with Blair, he is an awesome guy..
I had no idea what his combo was here, so I was also trying to help but there is a point, when you really start to fly, when locked out timing is fine. He told us about his combo later, so sure, he can probably use a smart strip curve, but...
A lot of smart tuners try to 'Back in' to their tune up,by starting very conservatively,and stepping toward max power carefully, not 'Back down' to the ideal tune up by starting with the tuning tools 'On kill' . You often save a lot of parts that way. I wondered if he was being super safe and trying to compensate for a ton of cylinder pressure maybe, and giving away too much.
Locked ignition systems can work though. I have run 42 degrees of mag, locked out, and helped go 6.0's with 1.06 60 ft times at over 230 MPH out the back door, high gear only ?? I didn't think he had a dragstter but many faster cars do not need a curve for a range of reasons, especially if you can also tune in the spark controller. There is a point where springs become irrelevant, or a marginal tuning tool. Simple point.
At first I thought he might be running a bunch of boost or nitrous maybe and trying to 'get brave', by adding lead, fuel and clutch maybe.
Think he needs more ignition timing, and sure, kill some bottom end with modest retard since he is a door car with a carb. But there are plenty of normally aspirated 4 bar cars, with big inch dual quad semi Pro Stock engines, that leave closer to where many street engines float the valves, and do so at full advance. Then they retard down track.
|This message has been edited by HolmanMoodyStroppeVet on Jul 29, 2012 10:32 PM|
|July 28 2012, 9:12 AM |
I run it in the race cars - 38 degrees in a closed chamber 351C, 34 in the 302. Too slow caused overheating, possibly burn exhaust valves. Why so slow? Set it where it make power and leave it. You can take a little out, but not a lot. If you have trouble starting then either get a 10 degree start retard or switch off the ignition until the engine is cranking then light it off. Set right, it will make the car more consistent.
1967 Falcon 4 door 351C-4V
1970 Mustang 351C-2V
Owner built, owner abused.
|This message has been edited by Falcon67 on Jul 28, 2012 9:14 AM|
If you have a Duraspark, you can use the white wire while cranking
|July 28 2012, 5:52 PM |
It is a retard for that purpose. If you hook up the red wire and put a normal curve you can run 36°-38° total at WOT, and while cranking only have 26°-28° cranking up. If you are running locked out,which works best at the strip. I have wired mine up to have the ignition dead while cranking by holding the cigarette lighter down by putting it in like a toggle that cuts out the coil while cranking. Once its cranked and got fuel and oil pressure, I have let off the cigarette lighter and had it light off. This is with locked out timing and no vacuum advance.
36°-37° running, none cranking while holding the lighter down. You can also kill it on the big end if you need to slow down a little to make your dial by hitting the cigarette lighter to kill the engine on the big end. You could use a two position switch that lowers the coil voltage and make it cut out a little, If using a single position switch or the cigarette lighter, don't let it out though to full voltage, it will backfire unless you can kill the ignition switch. Blow the mufflers off most of the time, or savvy officials will catch it and get you like for braking if your track frowns on it Pretty easy do though in a Galaxie, have your little finger on the lighter and your thumb on the key.
|This message has been edited by 65Galaxie394 on Jul 28, 2012 6:11 PM|
Love the pop
|July 29 2012, 6:36 PM |
I have always loved the pop a race engine gets when you crank it, let it build fuel and oil pressure, then pull the ground, or hit the mag switch and light it with a bang. The POP is unmistakable and cool to listen too.
This thread brings back memories of a misguided youth,,,hee hee
Way back when, Lion's Drag Strip had rollers. They were like a chassis dyno in reverse. The roller were spun for you to start the car with before reliable starters.
You would slip the dragster or flopper on to it first. Give the track guy a thumbs up and he would start the rollers. You kept the clutch in. You would hear them roll up and up to speed. Then the driver would dump the clutch and you'd hear the engine start revving up slowly. Once fuel began to mist out of the zoomies, you would hit the mag switch and POP !! Cackle cackle cackle. The ground would shake, your ears would bleed and all Hell would break lose. They would kill the rollers, and the driver dropped the clutch to drive off. Turn in to the groove and do a burnout. Often a bleach burnout. Sometimes a fire burnout.