Hey guys,
Um got my car running today with new combo and was gonna break in my cam by 1500-2000 rpm for 30 min. But then I noticed after about 1 minute my brand new slp stainless headers with jet hot coating turned a bright orange color like they were melting. NOT GOOD! We think the fuel and timing are not quite correct but don't have the tools today to check. Could there be something else wrong? We dont want to run it for too long and ruin something because it was all very pricey. Any Ideas? Is this normal for slp headers? Thanks,
John

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• 84 Firebird w/ T/A gfx
• 350 4bbl (LM1)
• Automatic
• Non-leaking T-Tops (new rubber all around)
• Working headlights (new parts)

Mods: 14" K&N open element, 180* stat, ram-air hood, Accel cap & rotor, MSD Super Conductor Wires, 24mm solid rear & 36mm hollow front sway bar w/ PST polygraphite bushings & endlinks, Spohn SFCs, WS6 springs, SLP 1 3/4" Jet-hot coated headers, Hooker 3" cat-back, Catco high-flow cat, Comp Cams High Energy 268 cam, AFR 190 heads, Weiand Action+ intake, Comp Pro Magnum 1.6:1 Steel Roller Rockers, Moroso Oil Pan with trap doors, windage tray and crankshaft scraper, poly graphite motor mounts, K&N oil filter and Mobil 1 synthetic.

http://www.homepagez.com/350thirdgen/

 

I believe that can be caused by either running lean or your timing being off.

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'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
3" Hooker CatBack w/Aero Chamber muffler
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
3:73 Posi
Rebuilt 700R4
B&M Megashifter, 5" Autometer Tach w/shift lite

 

Ok, we have the jets and metering rods set up for the 305 H.O. motor and the timing set 4-6* advanced I think. Any recommendations guys on jets and rods? I guess I should check the carb board?
John

 

Had the same problem when I did my very first head/cam swap oh so long ago. Turned out the new balancer that I installed was marked differently and the timing was 20d retarded.

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

 

Bring the timing up to around 10-12 degrees initial.Either timing or fuel caused this,had it happen with my new motor.You probably will have to richen it up a little too to help out with the new cubes.

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1982 Z28:355,4 Speed,Lots of bolt ons

 

Ok Ive heard now from several sources that I should advance the timing and richen up the mixture a bit to stop the glowing. But why does my dyno 2000 program tell me that advancing it 10* will kill my top end to the tune of 40 peak Hp?!?! YES 40! and my peak torque by 4 ft-lbs? The whole curve just drops off like there was a cliff there. Before it was nice and broad. I really could use that extra power. Is this accurate or am I confusing something?

 

Although dyno2000 is a nice theoretical tool, it doesnt help with real life problem solving.... I dont know why these guys are saying lean makes headers glow...In my experience, if you are scavenging too much of the intake charge, and it is igniting in the headers...THAT is what causes them to glow. Try advancing the timing a couple degrees at a time and double check that TDC of the piston is really the same as the TDC mark on your balancer. What cam did you install, and what centerline was it installed on?

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Mike Metzler (Desert86Roc)[*] Check Out:SpeedWorldMotorplex.com[*] Check Out:Chevrolet F-Body Online Part & Illustration Manual[*] My 86 IROC 305 TPI Page (406 build in progress)

ET's @ 1250 ft[*] 14.28 @ 95.461 mph (uncorrected, NOS, no headers)[*] 15.362 @ 88.238 mph (uncorrected, headers, no NOS)
<><

 

The cam is comp cams high energy 268.

218*/218* duration @.050
.484"/.484" lift with my 1.6 roller rockers

I'm not sure what centerline it was on.
So you think it may be the opposite? Too much unburnt fuel in the exhaust? thats what popped into our heads first so we disconnected the A.I.R. tubes thinking they were giving the unburnt fuel the oxygen they needed. It didn't help and the air wasn't even pumping out of those lines anyway.

P.S. This is at part throttle for about 1 min in neutral at about 2000 rpm on a computer controlled carb car.

[This message has been edited by johns84bird (edited September 24, 2001).]

 

There's no option to advance ignition timing in Desktop Dyno 2000. You're advancing the cam timing.

[This message has been edited by Apeiron (edited September 24, 2001).]

 

ah..... thanks!! (im an idiot)LOL

 

Agree with ROC,fuel is burning in the headers. Started my motor with stock electronics,had no way to lean out the idle mixture in the tune and had the same thing happen.Be sure timing is right.

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91Z28 406,mini-ram,Track-1s,232/242 roller,Wiseco 9.5:1 pistons,6"Eagle rods,Callies crank,Speed Pro EFI w/ wide band,Weldon 2015,Nitrous Express 150,Turbo350 w/ 10"ATI,12-bolt 373s,Southside bars,Centerline Warriors,28x11.5 ET Streets Best N/A: 11.22,120mph...10.83/128 with 150 shot

 

OK guys,
played around with it again tonight. My uncle did something to the timing earlier this week when I wasn't there (so I don't know what) but it takes a bit longer to glow now. It seems the whole motor is getting WAY too hot. The heads didn't come with a coolant temp. sensor bung in the stock location, so we mounted the stock one in the water neck on the intake manifold. The temp gauge is not reading correctly now (very low even when motor is extremely hot) Would this affect the fan coming on? I have a manual fan switch and turned it on to try to keep the temps down but no luck. The EGR valve is also loose against the intake manifolf because like every other threaded hole on the weiand, they're too shallow. I know egr will help keep temps down. Would these two things contribute to it running very hot? The coolant does flow through the radiator, thermostat and heater core when warmed up and the level is correct. The heads and intake themselves are getting way too hot for my liking. Does this point to another problem? The cooling system worked fine before we modified.
John
P.S. the o2 sensor reads .645V-.800V most of the time when I am keeping it at 2k rpms. That is part throttle and only the primary side, when warming up initially (cold start), so I guess its supposed to be a bit richer like it is? I also had jets in there that were much leaner earlier (don't know o2 readings) but the headers glowed with them too.

[This message has been edited by johns84bird (edited October 02, 2001).]