3500 upper intake

[alpinestar10]

Well i had a extra 3500 upper intake and someone told me that in the intake had a plate inside of it for cylinder five and six so i decided to cut mine apart and see for myself, Well he was right cylinder 5 and 6 dont get air right away why did they do this i can get pic if needed in a couple days just wondering

[pocket-rocket]

Even air distribution, I would imagine. That way all cylinders get around the same % of the air flow instead of the first two after the TB hogging most of it.

[alpinestar10]

I always thought that the cyliders only pulled the air they need in? Only reason i ask is the 3400 does not have this block off plate

[WrathOfSocrus]

The cylinders do PULL in air, but the more restriction there is, the less dense the air will be. Since the oxygen sensor only measures a mixture of exhaust from all cylinders, the one(s) with least restriction will end up leaner and hotter. I'm sure the oil squirters only being on cylinders 5 and 6 in the 3500 is no coincidence. Back when I took the 2.8 out of my Cutlass it had a major carbon buildup going to cylinder 6 from the EGR and cylinder 5 spun a rod bearing. Since I bought the car 'as is' for next to nothing from a high school kid I think there was more in play than just a lean cylinder, but it must have contributed to the situation.

[neversleeps]

The rear cylinders can actually get more air than the others during situations where the air is really moving through and it piles up at the end of the intake due to inertia.