Header glows orange on dyno

[Diz]

I'm just getting my car running and it's been on a chassis dyno twice. The first time, the header glowed bright translucent orange under any kind of heavy load. The A/F ratio was about 11.7:1 using their O2 sensor. I was using race gas. The second time I had a totally different fuel management system and the pipe stayed cool-looking. The A/F showed about 13.5:1 but i'm sure the sensor these guys were using was bad. I subsequently took it to the track (at 4000' lower elevation) and instantly melted a piston, blew the head gasket and blew the ends off of 2 plugs.

I have now invested in a pyrometer and an MSD knock alert.

Is the header glow indicative of excessive leanness? Is there a certain amount of glow that is "normal".

From reading all your posts, I asssume I should tune for an EGT of about 1450? Yes? Are the guys with alcohol injection getting much lowered temps? (I can't use any kind of non-stock liquid injection or even an intercooler).

Thanks..any and all help is most appreciated!

 

[10SV6]

Header glow has a lot to do with timing. I wish I has the pictures that my budy took when I was breaking in the cam on my stock block. Flat tappet hydraulic - 2500 +/- 300 rpm for 20 minutes. Both headers were glowing blood red. His jaw was dropping, didn't bother me. Steel goes blood red (deep red / maroon) about 1000 degrees F. With the WOT EGT's that turbos run the headers are going to be glowing.

 

[Reggie West]

The only time I have seen headers glow is on a water brake dyno. They seem to put quite a load on the motor in general.


That said, yes you should tune for EGT in the 1400 range. If you are using a wideband O2 that is also a good tuning tool.


If you are killing pistons that may be because of a lack of fuel. At 4000 feet lower elevation I can tell you that you are running a much denser air charge in the motor. All other things being equal you had too much air and not enough fuel.

good luck

 

[TurboJim]

11.7 is too lean to be pushing it. 13:1 is death city as evidences by the destruction of your motor..

In my limited experience, it seems the fast guys run 11.0-11.3:1. My buddy is running 11.3:1 and has EGT's of 1650-1680. When tuning, start RICH and LOW timing and work it from there.

I'll be re-tuning my car all over shortly and will see what it likes.

Oh, to answer your question, headers will glow, but at lower that full tilt loads, its indicative of too lean and/or retarded timing. Like the guy said above, if metal glows at 1000* and our EGT's are 1500*, it will be glowing.

 

[Chuck Leeper]

Fuel/Air/timing

I guess I missed something here.
11.7 is going to the fat side, not lean? 13.5 is the LEAN side??

At 4000' alt. the air goes thinner, not denser. Therefore, the fuel has to be adjusted, [less fuel] to bring the A/F back to an area for safe operation A/F wise and also to bring the power back up.[engine was too fat]

Being the engine was pulled on a chassis dyno, then the time to make the pull, as in a few seconds, there should not have been the red headers unless, the fuel was too low, the timing was either too high or way too low. It sounds to me as tho there was waay too much fuel going thru the motor and being burned in the headers, thus causing the "code red".[Or as you thot, the A/F gauge on the dyno is FUBAR!!]
When you changed fuel mgmt, the 13.5 was waay too lean and thus the engine went away.

An example: My engine has a FAST system dialed for 12.5 A/F.
Given a good fuel system, the EGT'S are consistently in the 1575- 1600*, while the A/F hovers at 12.2 to 12.7. Makes good power there and the engine is happy. Timing is at 22* once boost goes over 10psi. Keep in mind, my engine is intercooled, thus I can use a higher EGT. Yours at 1400 1450 would seem to be in the ballpark.

We should see the following to go further w/ the diagnosis:
1. Timing?
2. Base fuel pressure, and at boost. Does it keep up w/ rise in boost?
3. Injector size?
4. Boost level?
5. EGT readings.
6. Is the dyno at a different altitude than where you raced?

HTH,

Jim, are U REALLY going to the "new engine"?? Is that why you are "retuning"???

 

[Diz]

I'll start at 25-degrees total timing and keep an eye on the EGT. This time I'll give it some gradual driving and testing instead of making a full run right away...

 

[TurboJim]

Re: Fuel/Air/timing

Originally posted by Chuck Leeper


Jim, are U REALLY going to the "new engine"?? Is that why you are "retuning"???

Any day now

 

[Buicksx2]

Re: Fuel/Air/timing

Originally posted by Chuck Leeper

Jim, are U REALLY going to the "new engine"?? Is that why you are "retuning"??? [/B]

Chuck,

Look out the Testa Terror motor, it's gonna be one of if not the quickest 3.8 in New Jersey.......lol. He is taking applications right now for a driver cause he doenst like going that fast.....lol.

His motor is being worked on as we speak and as soon as Jimmy takes that 500 pounds of stereo equipment out of his trunk I am sure his car will pick up a few tenths.....lol. Jimmy when we going rollbar shopping?????

Regards,

 

[Chuck Leeper]

Testa's testas!!

Rich, are you saying he needs to lose some wt??
Where does the famous floor jack come into this thread???

Back to plumbing ol BART for a BBQ

See you guys at BG.

 

[Buicksx2]

Re: Testa's testas!!

Originally posted by Chuck Leeper
Rich, are you saying he needs to lose some wt??

>>>> Chuck Jim needs to lose some weight in his nose, theres 2 tenths right there.....lol. If he lost some nose weight and lots of hair he might just start to look like me.....lol.....jeez not another Brad Pitt look alike....lol.


Where does the famous floor jack come into this thread???

>>>> Chuck rest assured the RCA Floorjack will have a hand in lifting Jimmys car up from the pumpkin so he can change his tires, the Jack is the mainstay upon which Richs Custom Auto/JT Performance is built. Jim and I would be nowhere with our jack and chips......lol.

Back to plumbing ol BART for a BBQ

See you guys at BG.

>>>> Unfortunately Jim and I arent welcomed in BG (not being members and all among other reasons) however we will be at Bristol at the Hoilday Inn so stop by our EZ UP for a nip of courage......as Groundskeep Willie would say...lol. Stay well.

 

[Diz]

1. Timing was 25 to 30. It was at 30 when it grenaded. It worked great on the dyno there. I run a distributor with the timing locked.
2. Fuel pressure was around 45 psi.
3. 35# injectors.
4. I had it at 23# boost.
5. I haven't finished installing the EGT gauge.
6. The dynos were at 5500' elevation--the track was at 1600'. I assumed that the MAP sensor would adjust for altitude changes.

I'll start with the boost set at 17psi now and go from there...

 

[cool 84]

Not that it matters but my headers, my dad's, and a friend's all glowed when breaking in the cam. When racing my friend's car I can see his headers glowing bright orange by the top of first gear through the fenderwell. He said the same about mine. Neither of us have ever had any problems with melting stuff and my 02s were in the 840 range. Since every GN I've ever raced has glowed I consider it normal. I don't know why but the three cars with aftermarket headers (ATR and KB) glow sooner and brighter than the ones with stock headers. Might just be coincidence.

 

[Chuck Leeper]

Glowing headerz

Diz, what kind of HP and TQ readings did you get on the dyno pulls??
Tuning the car on the dyno at 5500' then going to 1600' caused the engine to go lean. The fuel requirenents at 5500 are far less than at 1600, thus the engine went to a "reversed" tuning requirement. IE: @5500 you needed less fuel due to less air. @1600, this requirement reversed itself. You have more air, thus you needed more fuel. [This is assuming you were looking for the same A/F target] The engine would most likely be close to "happy" at about 12.5 A/F [+/- a couple tenth's] at max torque.

As for the timing, I'd look at an MSD retard system and tie it to boost. You can run more at the low end and taper it off to somewhere in the low 20's. [No intercooler doesn't help here]

Another tuning tool would be a weather station and keep a record of density altitude at the various locations you do dyno pulls and racing. Tie this info to the tuneup and then as the conditions change, you can baseline the tuneup using current density altitude readings.

HTH, and Good luck w/ the project...

 

[Chuck Leeper]

RICH AND JIM

I bet you two do make a real "pair to draw to"!! Sorry to hear you guys are not members of "King Richards" court!!
I too have let my subscription lapse.. $35.00 buys 2 nites at the track and since this damned ol BUICK never stays together longer than that, I get in a whole season for $35.00

As for B@B, I'll be there. Hope to be at the HI also. Guess I'd best get a res. in and soon.....

Am looking forward to seeing the floor jack do it's "thing".
As for noses and hair.. not going there!!

Cu later,

 

[Buicksx2]

Re: RICH AND JIM

Originally posted by Chuck Leeper

I bet you two do make a real "pair to draw to"!!

>>>> Chuck, yeah we do draw people to us, maybe it's cause we smell like s&%$.....lol.....well Jim does really not me....lol.


Sorry to hear you guys are not members of "King Richards" court!!

>>>> I stopped my subscription a couple years ago and my last nats was in 98, I wont rehash past history but some here in Jersey have had some problems with some in the gsca....no biggie.


I too have let my subscription lapse.. $35.00 buys 2 nites at the track and since this damned ol BUICK never stays together longer than that, I get in a whole season for $35.00

>>>> Chuck $35 buys me 12 years worth of shampoo so I can relate to your way of thinking.

As for B@B, I'll be there. Hope to be at the HI also. Guess I'd best get a res. in and soon.....

>>>> Sounds good, look for us in the Holidayy Inn parking lot.

Am looking forward to seeing the floor jack do it's "thing".
As for noses and hair.. not going there!!

>>>> The Jack will be there doing it's thing which will be holding the cooler full of adult beverages.....lol.

See ya there,