Visit The Dirt Forum for More Information

Author Topic:   Glowing headers help
mdsteacher
Dirt Maniac

Total posts: 145
posted August 28, 2005 07:49 PM  
Need help diagnosing problem . . . headers get cherry red hot at 4 & 6 and sometimes 3 & 5. This has just started past few weeks. Spark plugs look great, so we figure it isn't running lean. Strong 358 with well ported heads on gas.
Engine generally doesn't run hot.
Any input would be helpful.

racer19x
Dirt Full Roller

Total posts: 26
posted August 28, 2005 08:50 PM  
check your timing, my gear had worn bad, and this was happening to me. Turned out my oil pump drive shaft was notched off center, bent, and wore the gear sideways.

sc1 racing
Dirt Freak

Total posts: 419
posted August 29, 2005 01:06 AM  
what kind of intake are you running? with just the centers glowing could be vacum. if no vacum it will be timing or carb settings/jets..

mdsteacher
Dirt Maniac

Total posts: 145
posted August 29, 2005 08:32 AM  
We run the Speedway Pro Performance hi rise intake with extra cooling lines to the heads. Intake matched to heads.
The timing is set at 36 degrees with MSD HEI ignition (new module and coil) and the distributor gear still looks new.
We thought the carb jetting might be the problem but the spark plugs look just fine. I know little about carbs, but this is a top line Blake carb. Maybe I'll give them a call.

[This message has been edited by mdsteacher (edited August 29, 2005).]

Kromulous
Dirt Forum Champ
Total posts: 796
posted August 29, 2005 03:13 PM  
If its not lean, its got to be timing.

Put a light on it and double check it.

sc1 racing
Dirt Freak

Total posts: 419
posted August 29, 2005 03:40 PM  
how are you reading the plugs?and did you run engine at low rpms before checking them.
it sounds like fuel isnt being distributed evenly to me which may be a vac leak, or a cracked intake..

racer17j
Dirt Forum Champ
Total posts: 5390
posted August 29, 2005 06:38 PM  
We'll check the intake.

TEAMPCR
Dirt Freak

Total posts: 238
posted August 30, 2005 06:24 AM  
Had the same problem last year. Turned out we had some ba plug wires and the fuel was burning in the headers. We also had some leaks in the headers, making the problem somewhat worse.

streetstock82
Dirt Forum Racer

Total posts: 81
posted August 30, 2005 09:17 PM  
put timing light on it and rev it around the same rpm your having this problem. sounds like your timing is retarding. also cam walk could be an issue.

mdsteacher
Dirt Maniac

Total posts: 145
posted August 31, 2005 06:48 PM  
We time it weekly, but don't necessarily rev it over 5K. We run it around 7-7500K. We've got a new MSD module and coil in MSD HEI with Moroso Ultra 40 wires. The distributor has the springs in it to stop it retarding. The cam is roller and has a cam button.
We think it might be something else as others have described.

streetstock82
Dirt Forum Racer

Total posts: 81
posted August 31, 2005 09:16 PM  
check the front of your timing cover too. just because you have a button, don't mean it can't walk. i had one this year that had a nice set up with a jack screw on the water pump and it still moved 1/4 in and had the same symptoms as your describing. always worth another look.

akadirtracer7
Dirt Freak

Total posts: 217
posted September 01, 2005 06:08 AM  
Sounds like and air leak Put a vacum guage on the crankcase and see if its pulling any vacum. I have seen a few intakes with porosity problems to but not to frequent.

[This message has been edited by akadirtracer7 (edited September 01, 2005).]

mdsteacher
Dirt Maniac

Total posts: 145
posted September 01, 2005 02:36 PM  
I don't know if this makes a difference or not, but the heads we use have been extremely ported, so much so that the water jackets (or whatever you call them in a head) leak a little water out of the header bolts. We put gasket seal on the header bolts and it solves any water leaking issues. Our engine builder (he didn't port the heads) said it should be fine. When you do take the header bolts out, the water will pour out.

Mr. Badboy
Dirt Full Roller

Total posts: 29
posted September 03, 2005 10:23 PM  
For what it is worth, MSD says their timing light is the only one which will accurately check timing on a race car with the type of ignition you have. Those aren't my words.

Sounds like tight valves. If valve lash is changing dramatically on the cylinders in question in relation to the non problem cylinders, the cam may be going flat.

mdsteacher
Dirt Maniac

Total posts: 145
posted September 05, 2005 06:00 AM  
No problems this weekend this time. Ran nearly 60 laps this weekend without any glowing headers. We did put on a different set of headers (larger tube and collector diameter and shorter length). Engine was strong.

Back to the Archives