Falls on it's face!

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sverbus
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Joined: Tue Dec 27, 2005 10:03 am

Falls on it's face!

#1 Post by sverbus » Sun Jul 25, 2010 10:10 pm

Posted in the chassis section about my rack & pinion, but also have an issue with the car's performance. I've not really ran it hard yet, but if I ease into the throttle it wakes up REAL fast till about 4000rpm and then just falls on it's face and pops a little through the pipes. It will NOT drive through it...just stays there. Feels as if someone put a tow strap on the bumper and hooked it to my truck.

The carb guy, Jesse at Bigs Carbs, who built my 950 thinks that the metering blocks are gunked up and need a cleaning. So, I'm soaking them in carb cleaner now. But, in case that's not it, I figured I'd get some idea's here of what some other people might think. I've got 36* of timing, and the carb is squared off at a very conservative jetting of 77's all the way around. That's not nearly enough jet for racing the car, but it's a great start to make sure that I don't wash out the rings. I DID have to change the air bleeds though as it was fat as hell as soon as I got over 1500rpm. went from 35's on the mid-range to 40's and it seemed to clean up nicely.

Thanks guys...hey, at least it's running again.

Scott
'70 Nova
434 small block
Best so far of 10.51 @ 131mph with a best so far 60' /1.46

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BracketNova
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Re: Falls on it's face!

#2 Post by BracketNova » Mon Jul 26, 2010 12:13 am

Have you checked the valves lately?
"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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wikd69
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Re: Falls on it's face!

#3 Post by wikd69 » Mon Jul 26, 2010 1:13 am

Yeah that really sounds like valves...

Or maybe you have your two-step wired wrong ? Does it ceiling out at 4,000 ?
1969 ProStreet Camaro RS Best 9.75@139 1.46 60'
Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

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sverbus
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Re: Falls on it's face!

#4 Post by sverbus » Mon Jul 26, 2010 8:20 am

Valves wouldn't do what this is doing...I've felt horribly adjusted valves and these are actually freshly adjusted. It just hits around 4 and you can just hear the motor struggling. Tonight I'll put the carb back together after cleaning the metering blocks out and see what happens.

Here's to crossing my fingers! :)
'70 Nova
434 small block
Best so far of 10.51 @ 131mph with a best so far 60' /1.46

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sverbus
Posts: 418
Joined: Tue Dec 27, 2005 10:03 am

Re: Falls on it's face!

#5 Post by sverbus » Mon Jul 26, 2010 2:31 pm

Yes, it was timing and carb. finally checked the timing a 3rd time and for whatever reason, the damn dist. was tight and so it moved, only had about 32* timing in it. Fattened it up with new jets and air bleeds in the carb and put 36* timing in it and it was like a different car. Not yet enough though..as it's still acting lean and the plugs are pretty white. SO, more jet is incoming.
'70 Nova
434 small block
Best so far of 10.51 @ 131mph with a best so far 60' /1.46

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wikd69
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Joined: Sat Feb 23, 2008 12:42 pm
Location: Rocklin, CA
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Re: Falls on it's face!

#6 Post by wikd69 » Mon Jul 26, 2010 4:14 pm

sverbus wrote:Yes, it was timing and carb. finally checked the timing a 3rd time and for whatever reason, the damn dist. was tight and so it moved, only had about 32* timing in it. Fattened it up with new jets and air bleeds in the carb and put 36* timing in it and it was like a different car. Not yet enough though..as it's still acting lean and the plugs are pretty white. SO, more jet is incoming.
My first T-brake launch at Fontana last month was pretty wild and then the damn thing almost broke my neck falling off RPM...

Got back to the pits and found the fricking thing was only running 16* of timing. And that was with a locked out distributor, so that was total timing. Sheesh. I'm not even sure how the damn thing was running, much less picking the front wheels up at the lights. I don't have a clue as to how it ended up so far out of time.

Image
1969 ProStreet Camaro RS Best 9.75@139 1.46 60'
Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

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BracketNova
Posts: 618
Joined: Sat Apr 25, 2009 6:46 pm
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Re: Falls on it's face!

#7 Post by BracketNova » Mon Jul 26, 2010 11:12 pm

Glad you got it figured out. Probably gets up on the converter alot better now no?
"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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cad
Posts: 4
Joined: Wed Oct 01, 2008 8:03 am

Re: Falls on it's face!

#8 Post by cad » Tue Jul 27, 2010 1:14 am

Dont rely in the plugs being "white". The only thing you should look for is detonation on the ceramic, and the fuel halo way down in the plug, but you cant see that with the naked eye.
If you are just driving the car around and have anything like a MSD, your plugs will remain white for quite a while.
The jetting is read off the base of the plug. Your best plug reading would be after a WOT pass on the strip, and shut it off immediately, pull to the side and pull a plug. Otherwise, get an O2 sensor and you will no longer be guessing.

http://www.dragstuff.com/techarticles/h ... plugs.html

Clark

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