Exhaust header carbon build up question

[SilverXJ]

I took the exhaust header off my head today and the carbon build up was a bit odd.. i thought. The #1 and #6 cylinder tubes were black with carbon. #3 and #4 not so much so.... #5 and #2 even less, grey... should the carbon build up on the exhaust header be even, or is this just how it works? Before I put my engine back together I would like to make sure there are no hiding issues.

-Chris

[gremlinsteve]

how does the back of the exhaust valve look? kind like a burnt oil deposit??

steve

[SilverXJ]

Its on my list of things to check tomorrow... I was planning on checking the deposits on the head tomorrow to see how they correlate with the exhaust manifold any how. As of now I hadn't checked the back of the valves, but the face of the valves look all the same.. greyish on the exhaust and darker on the intake... but its all even on the valve face(side that faces the piston).

[gremlinsteve]

if its not oil deposits, then i would say its nothing more than poor distribution. either with tuning or with the intake design.

steve

[SilverXJ]

Its not oil deposits. I'm probably going to build a manometer and compare the different intake tracts. I don't think it is a tuning issue as all the ports on the exhaust manifolds would look the same. Its either air flow or fuel flow... and I don't know how to test a fuel injector.

[SilverXJ]

For your viewing pleasure. #5 is the one that is very concerning. #1 and #6 are the darkest. #3 and #4 are about the same. They seem to be paired with the intake tracts on the manifold.

[SilverXJ]

I made the manometer tonight. Here are the results I came up with. Here is the order of the way I had things set up: intake manifold ---> manometer ---> shop vac. Higher numbers are more resistance, less flow

Test 1 with all other ports sealed up but the one I was testing:
cylinder - inches H20:
1 - 6.5
2 - 6.5
3 - 7.5
4 -7.5
5 - 6.25
6 - 6.25


Test 2 with all ports open:
1 - 5.375
2 - 5.375
3 - 6.625
4 - 6.625
5 - 4.75
6 - 5.25

It does show that #5 does have less restriction than the others... however, #6 has more flow than #4 but yet #6 is still darker (i.e. richer). Same thing for #2 and #1... they both flow the same yet #1 is darker.