If the hood has a passage from the underside to the back of the raised area, it is possible to pull air from the high pressure region at the base of the windshield. The change of angle between the hood and the windshield makes for a higher pressure region at the base of the windshield. The hood would have to be sealed against the top of the firewall as to not vent hot engine bay air. The intake would then have to be sealed against the opening to the passage to the back of the hood.

It would take some customization to make it work properly. Cowl hoods look nice on the blazers though!

 

indeed they do. I love the look of a subtle 2" cowl on trucks in general. Anything more is just too much IMO. That seems a bit complicated though swart. Would it be easier to pull in fresh air from the front of the vehicle (the grill) and use the cowl as an escape for the hot air? (similar to opening windows on either side of your house to get a cross breeze).

 

Depends on the design of the hood. If you already have a round air cleaner, then all you have to do is seal it to the underside of the hood.

 

Hm Good info. I think Im going to give the CAI a shot if I can find the proper TBI bonnet at a junk yard and if I can find room under the hood. I could always relocate the battery. So swart, would it be safe to say that I can just stick a crank case filter in place of the pre heater hose in conjunction with the CAI? Do you foresee any issues?

 

Doesn't the preheater hose just go down to the heat shield on the driver side exhaust manifold? That is where it went on my old '85 S10 2.8L.

As far as the crank case vent goes, yeah, you should be fine to just put a filter onto it. The PCV valve should still draw off of intake manifold vacuum.

 

Yes on the preheater hose.

For the cranck case vent you can put a filter on it and it will work but every 2.8 I've went that route with it spits oil out bad. I've found it to run a bit better with the vent being helped by the suction on the incoming air also.

 

I thought it went directly to the engine, but it could be the exhaust manifold. So Do I just plug it then? I guess my ultimate question is what do I do with the enigine side of the preheater hose and the vacuum line (for the flapper) if I go the CAI route?

 

If you are not keeping the stock intake with the snorkel tube, then you don't have to worry about it at all. It doesn't open up into the exhaust, just is a heat riser. Air gets heated between the exhaust manifold and the heat shield. The hot air rises and gets sucked into the intake helping the engine run properly while it warms up.

You could cut off the snorkel between the round part where the filter sits and the flapper, then take it to your location of choice for cold air.

 

so I can just leave the end on the exhaust manifold open or should I somehow fabricate a heat resistant screen to place over the hole so nothing gets trapped inside?

 

If you were worried about stuff falling down in between the manifold and the shield, you could just make a metal cover for the opening and either rivet it in or sheet metal screw it in. I really don't think it is necessary though.