for those with the 60 degree motor

[Shaun41178(2)]

For those running the stock v6 intake setup and the 2.8/3.1/3.4 This is some info about which cylinders run hotter then others.

it might seem common sense to some, but after looking at my plugs its obvious which cylinders are getting more air.

Cylinders 1 and 3 get the most. Cylinder 5 runs a tad bit cooler. Cyl 2 runs about the same as cylinder 5. Cylinder 4 is a tad bit cooler then 2 and 6 is the coolest being as how the air has to make a hard 90 degree angle to feed that cylinder

So from hottest to coldest 1,3,2,5,4,6

Not too sure what you can use this info for but figured I would post it up. If you had a stand alone that could control individual injector pw then this would be good to know I guess.

this is all of course with the stock upper and middle and lower intakes.

[p8ntman442]

your guessing from plug color? Infared thermometer on the manifolds?


I dont see how this is common sense, as the timing of cylinder pulse reverberations dictates more of how the air flow is affected than intake shape. As you have shown from your "data" 1 and 3 run similar, where as 1 and 2 should run closer as the manifold is more symetric about the x axis of the engine than the y. Origin being the center of the car, and y pointing to the nose.


Please elaborate more.


edit: ever heard of the 4-7 cam swap for sbc's?

http://www.thirdgen.org/techboard/tech- ... -swap.html

We could elaborate more on this and do some thinking and see if the option is available for v6's. I am not familiar with how the 4-7 swap works so I cant say if it could be modified for our firing order.

[The Dark Side of Will]

SBC firing order is 18436572. 5 & 7 are adjacent cylinders that pull from the manifold sequentially. The fear is that since 5 is in the last phase of its intake stroke as 7's intake valve is opening, that 5 will rob air from 7. The solution is to switch 4 & 7 in the firing order... but then 2 & 4 are adjacent/sequential and you have the same problem again.

Each bank of a square crank V8 is odd fire.

Because each bank of the V6 is even fire, swapping cylinders in the firing order would only screw things up.

[The Dark Side of Will]

Along the same lines as what Shaun said... Barry Grant recently came out with INLINE 4 barrel carbs. What these do is allow equal intake runner length to all cylinders. In an article about the setup in a magazine, Barry said that when he started testing the configuration, he thought his test equipment was broken at first because all the cylinders had EXACTLY the same mixture. This is a pipe dream with conventional carbed manifolds.

It goes to show how much EQUAL length runners matter when tuning an engine.

http://www.barrygrant.com/images/BadManImg.htm

[Pyrthian]

how's about injector flow & coolant flow?
kinda funny how this also closely follow ignition sequence
and - which rod bearings fail the most? and which piston burn the most when EGR is removed?