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Discussion Starter · #1 ·
Just wanted to know what the best distance is for mounting 8 EGT bungs on the headers? BBC n/a injected 496 on alcohol. what is a good temp, starting point? Thanks
 

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1" to 1-1/2" from flange.
1050-1150 deg.
The water temp should be approx 170* when you stage the car and increase no more than 10-15* at the end of the run.

This is where I had placed my single EGT on #7 tube and where the exhaust temps ran on my 406 sbc w/ Enderle Hat Injection. I also ran a high-speed lean out as well.

Hope this helps.
 

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.

About where mine are also. Not a big deal, but don't forget tilt, on the bends.

.
 

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I agree with Horndog on the 1 to 1 .5 inches from the flange. I put my car in the water box at 140 and depending on outside temp things go from there. That has proven to be the most consistant way to run my car. Last Sat at 95 degrees I was going thru the traps at 180 and getting back to the trailer at 195 to 200 degrees
 

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One thing to note is try and put all of them the same distance and in the same position from the flange and same depth when you put them in. That should give you the tighest readings across the board.
2x with the temps, 1100 exhaust and 170 water seem to be pretty universal on methanol motors.
It is fun to fatten up the barrel valve and have the motor really crisp off idle but than you can't get any heat in it and in this nice humid weather the manifold sweats.
 

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My junk is on gas, I missed the alcohol part of the post......LOL. DUH! RM
 

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If I was a little younger I would switch. Probably don't have many years of this left in me so I stay what has worked and I know. I think the couple numbers I need to be competitive in the 5.30 index class would just be there with alcohol. I'll probably piss away lots more time and money looking for those numbers with head porting and camshafts.......LOL. RM
 

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Discussion Starter · #9 ·
Do any of you all ever get false readings, like when you do a pill change & the egt's don't respond? I tried running an egt before & had that problem all the time. Ended up tunning it off engine temp, but the egt was about 2-2.5" from the flange. They tould me it might still be burning the fuel & that is why I could not get the egt's to change. I only ran one, now I bought a data aqusion kit with 8 egt's & all these other bells & whistles. Thank You Everyone
 

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I run gas but get different readings from different cylinders. The odd thing is the cylinders on the dyno that were hotter or colder are not the same ones when checked in the car during a race. That just further proved that we don't race dynos. And weather conditions also effect the EGT temps on mine. RM
 

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Do any of you all ever get false readings, like when you do a pill change & the egt's don't respond? I tried running an egt before & had that problem all the time. Ended up tunning it off engine temp, but the egt was about 2-2.5" from the flange. They tould me it might still be burning the fuel & that is why I could not get the egt's to change. I only ran one, now I bought a data aqusion kit with 8 egt's & all these other bells & whistles. Thank You Everyone
2 -2.5" from the flange is a mile away. Figure that would be like 5+" from the exhaust valve and at that point it has seen enough surface area to cool and radiant heat loss. Try and keep them close for best readings.
The other thing is if you are running a mechanical fuel injection system with a High Speed By-Pass you might not see any EGT change with your pill change as the highest EGT is after the high speed takes over.
 

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Do any of you all ever get false readings, like when you do a pill change & the egt's don't respond? I tried running an egt before & had that problem all the time. Ended up tunning it off engine temp, but the egt was about 2-2.5" from the flange. They tould me it might still be burning the fuel & that is why I could not get the egt's to change. I only ran one, now I bought a data aqusion kit with 8 egt's & all these other bells & whistles. Thank You Everyone
Sure, if you're not using flowed jets/nozzles, you can sometimes change from a 90 to a 95 main, and not change a damn thing. It just depends how far off the main jet flows from it's stamped number.
 

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I run gas but get different readings from different cylinders. The odd thing is the cylinders on the dyno that were hotter or colder are not the same ones when checked in the car during a race. That just further proved that we don't race dynos. And weather conditions also effect the EGT temps on mine. RM


RM hit on a good point.
The better the air, the higher the exhaust gas temperature.
 

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Sure, if you're not using flowed jets/nozzles, you can sometimes change from a 90 to a 95 main, and not change a damn thing. It just depends how far off the main jet flows from it's stamped number.
Say it isn't so.
We know all the fuel injection racers on YB only used flowed nozzles and jets simply because that is the correct way. :cool:
 

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Discussion Starter · #16 ·
When would you all recomend a high speed by-pass? I've been told that I didn't need one. BBC 496 N/A 7400rpm. How much does it help? After a pass when I shut it off , under full throttle alcohol fumes are real bad,even if I just lift & shove it into neutral. would a high speed help this, or should I put one in? how much ET/MPH?
 

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Better exhaust routing would help.

Think about it this way...

When you're standing on the throttle, you have all of this exhaust pressure blowing the fumes out, and probably away from the vehicle.

When you're idling, that shit is rolling around under the car/truck, finding it's way into the vehicle through every crack it can, fumigating you in the process.

A high speed, or multiple high speeds are used to control the fuel curve, not cure fume issues within a vehicle. Even with one, it will probably still do it.
 

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chevette, you need to install turn-outs on the collectors if you have the room. I had to on my Beretta and I had to install some sheet metal deflectors between the bottom of the rocker panels and the top of the turn-out to ensure no fumes would enter the car. My Beretta is a tube chassis car and the rocker was open where the lower main bar was positioned.

A HS lean out is always good to run but they won't help with any fumes. You need turn-outs. My 406 only saw 6800 in the 1/8 and 7400 in the 1/4.
 

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Discussion Starter · #19 ·
Thank You guys, I can let it idle, drive around pits & no problems with fumes , but I will be building a new set of headers or having a new set made this winter, with a new engine combo. Thanks for your replys again.
 

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When would you all recomend a high speed by-pass? I've been told that I didn't need one. BBC 496 N/A 7400rpm. How much does it help? After a pass when I shut it off , under full throttle alcohol fumes are real bad,even if I just lift & shove it into neutral. would a high speed help this, or should I put one in? how much ET/MPH?
I ran a 496 n/a BBC on methanol with a Kinsler fuel injection for 3 years and always used a high speed by-pass, tweeking the pill is where you get peak torque, tweeking the high speed is where you get peak horse power and mph gains.
http://www.kinsler.com/Cat_31_Web_HTMLs/0201234_screen42.html
As far as fumes like the other guys said do something with your headers. Once you lift unless something is wacky with your system all the fuel gets routed back to your fuel cell. I would suspect that without a high speed by-pass you motor is really fat on top end which will give you low EGT readings. What system are you running?
 
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