Running rich?

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BracketNova
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Running rich?

#1 Post by BracketNova » Sat Oct 16, 2010 9:26 pm

After I let up on the throttle after my pass, when I give it some pedal to come around to the return road I have to play with the throttle to get it to go...it tries to die on me. It doesn't back fire or anything like that which is why I believe it's flooding. EGT maxes at 1275° on e85. My jets are 96/98 on an 800cfm Holley. I'm thinking that's kinda huge on the jetting but I get 1300° if I go smaller. Timing is at 40° currently, egt is the same if I'm at 38°...it gets up on the converter better w/ 40°. I run delco R44T plugs. 8.0:1 compression steel heads larger valves.
"I always compare drag racing to lighting $100 bills on fire, only it's more expensive." - Craig W.

Check out my website...
http://www.findmoneyraces.com


'71 Nova E85
6.69 @ 100.2 MPH 9/6/14
1.4257 60'
1700' DA

13:1 439 BBC
3330 lbs

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jmarkaudio
Posts: 278
Joined: Fri Oct 26, 2007 4:22 pm
Location: Florida

Re: Running rich?

#2 Post by jmarkaudio » Mon Oct 18, 2010 2:16 pm

I was going to tell you you were way rich, until I saw E85. Where did you get the carb? And at 8 to 1, you will probably need the hottest plug you can get. DON"T use the EGT's to jet by, look at your MPH, go up until it slows then back to where it MPH's the best. E85 is a different animal when tuning the carb and you are probably better to use pump gas at that compression.
Mark Whitener
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BracketNova
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Re: Running rich?

#3 Post by BracketNova » Mon Oct 18, 2010 5:43 pm

It's a Mark Sullens carb. He told me to go hotter on the plugs as well, amongst other things.
"I always compare drag racing to lighting $100 bills on fire, only it's more expensive." - Craig W.

Check out my website...
http://www.findmoneyraces.com


'71 Nova E85
6.69 @ 100.2 MPH 9/6/14
1.4257 60'
1700' DA

13:1 439 BBC
3330 lbs

User avatar
jmarkaudio
Posts: 278
Joined: Fri Oct 26, 2007 4:22 pm
Location: Florida

Re: Running rich?

#4 Post by jmarkaudio » Tue Oct 19, 2010 9:09 pm

The carb from Mark should be fine, but with low compression you will have to work to get enough heat in it. Hotter plugs is a start, raise the starting line temp 5˚ at a time, maybe a little more timing. Learn to read plugs, E85 will make it harder, there is a good plug read here. http://www.dragstuff.com/techarticles/r ... plugs.html

You need to understand that gas has different blends of components that vaporize starting at around 100˚ and end between around 220˚ to 270˚. Ethanol boils at around 173˚, even though it has a little gas in it, it isn't much. So to get sufficient heat to vaporize enough before it hits the cylinder is important.
Mark Whitener
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Good work isn't cheap and cheap work can't be good.

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BracketNova
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Re: Running rich?

#5 Post by BracketNova » Thu Oct 21, 2010 10:54 pm

Yeah I'm putting my old plugs back in. They're one step hotter with an extended tip. They never gave me any problems, I just seemed to get a wild hair that if I got the egts lower I'd go faster :oops: . We'll see If I make it back to the track or not. On top of rain threatening my tracks last weekend, I had my appendecs out last week. Thinking about having a friend run the car, I just want to see if I can improve things anymore before before I put it away. That and last time out was a fastest pass at 2700 ft altitude. I'd like to see what it can do if I get better air.

Mark also suggested turning the idle screws out some more. If I recall I was only 2 1/2 turns out so I should have room to play yet. I shot some fuel in from the squirters and the engine didn't speed up or bog so I figured I was in the ballpark. I guess if I wasn't soo lazy I would have hooked up the vacuum gauge. :-)
"I always compare drag racing to lighting $100 bills on fire, only it's more expensive." - Craig W.

Check out my website...
http://www.findmoneyraces.com


'71 Nova E85
6.69 @ 100.2 MPH 9/6/14
1.4257 60'
1700' DA

13:1 439 BBC
3330 lbs

User avatar
jmarkaudio
Posts: 278
Joined: Fri Oct 26, 2007 4:22 pm
Location: Florida

Re: Running rich?

#6 Post by jmarkaudio » Sun Oct 24, 2010 11:50 am

If you are at 2.5 turns on the mixture screws it may need a little larger IFR. Yours is probably in the .040-.045 range, add .002 and reset the mixture.
Mark Whitener
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Good work isn't cheap and cheap work can't be good.

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BracketNova
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Re: Running rich?

#7 Post by BracketNova » Sun Oct 24, 2010 3:12 pm

I believe they are .042. I was able to get back to the track this weekend. Turned the idle scews out another half and put my R45XLS plugs back in, that sloved my hesitation. Turned the rear float back down two flats and that solved the wanting to die after the stripe.
"I always compare drag racing to lighting $100 bills on fire, only it's more expensive." - Craig W.

Check out my website...
http://www.findmoneyraces.com


'71 Nova E85
6.69 @ 100.2 MPH 9/6/14
1.4257 60'
1700' DA

13:1 439 BBC
3330 lbs

want-a-be
Posts: 189
Joined: Tue Feb 05, 2008 11:04 pm
Location: Southern Illinois

Re: Running rich?

#8 Post by want-a-be » Tue Dec 28, 2010 10:37 am

Running the floats too high is a very common problem that I have alot when trouble shooting problems like this. Any more recent feed back on how your car is now doing?

Don

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BracketNova
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Re: Running rich?

#9 Post by BracketNova » Thu Feb 10, 2011 7:36 pm

If I remember right it was in the timing. Thought I had 38°, but looking more closely, since I just have a stock tab, it was more like 36° So I moved it up to 38°. Before I switched to E85 the engine liked 42° the best. I will start moving the timing up some more when we get going again this spring. Some others at the track claimed my engine will really like timing being only 8:1.

But, last time out it was running really good. I didn't make it too far though. WE have concluded I need some new slicks

Run | #1 | #2 | #3 | +/-
Lane | R | L | L | --
60 FT | 1.5558 | 1.5701 | 1.5654 | .0143
60/330 split | 3.0752 | 3.0786 | 3.0731 | .0055
330/660 split | 2.6224 | 2.6248 | 2.6247 | .0024
et | 7.2534 | 7.2735 | 7.2632 | .0201
mph | 93.23 | 93.26 | 93.26 | .03
air alt. | 2250 | 2319 | 2247 | 72
egt | 1318 | 1305 | 1309 | 9


You'll have to excuse the burnout...my dad came out and it was the last run of the year...it's not reflected in the chart above :)
"I always compare drag racing to lighting $100 bills on fire, only it's more expensive." - Craig W.

Check out my website...
http://www.findmoneyraces.com


'71 Nova E85
6.69 @ 100.2 MPH 9/6/14
1.4257 60'
1700' DA

13:1 439 BBC
3330 lbs

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