How does a Grill Block help with engine warmup?

[oil pan 4]

It sounds like you really want warm air before the engine gets up to full operating temperature.
If you really want air warmed by coolant before the thermostat opens then plumb in a second heater core off your exixting heater core plumbing and build an air intake for it.
Then your intake air temperature will rise along with your coolant temperature.

[RedDevil]

Originally Posted by oil pan 4

It sounds like you really want warm air before the engine gets up to full operating temperature.
If you really want air warmed by coolant before the thermostat opens then plumb in a second heater core off your exixting heater core plumbing and build an air intake for it.
Then your intake air temperature will rise along with your coolant temperature.

A radiator feed for the WAI does have some benefit in the transition. The effect of grill blocking/winter fronts however slows down the air entering the engine bay, That air will get heated up by the exhaust etc.; so if the intake feeds from the bay the temperature does rise more quickly, as was proven in earlier posts.

[wmjinman]

I'm thinking of rigging a movable "snorkel" (maybe the wrong term) that, in one position, pulls intake air from around the exhaust manifold, but then when warmed enough, can be moved away so it doesn't get too hot. Roughly similar to the cowl flaps on some airplanes. I'm thinking a metal tube extension that's hinged. The "heat" position would put the opening right next to the manifold, but the other position moves it a few inches away where it's just getting engine compartment air, not as severely heated by the exhaust.

[olds455]

wmjinman...that sounds neat. I picture a y shaped plenum. WIth one end close to the manifold, the other a bit away. Remember the old carburator warm air valves on the air cleaner snorkels...that amy be an automatic valve for your design.

Your idea certainly got me thinking. Now to find an old air cleaner...

[RedDevil]

I had plans for a rWAI that takes air heated by the rad but uses a ventilator and a heat switch to get fresh air from the OEM air duct (snorkel).
I think I may switch that around; draw air from around the exhaust with a vent until it gets too hot. But coming the hot season there's no hurry now.

[wmjinman]

Olds455 ... Whoa, yeah - just use one of those, maybe!!

My thought was a pipe with another movable pipe on the end of it hinged on a pin through the middle. The hinged pipe could be moved via a cable, like a "choke cable", to swing it closer to the manifold for more heat, or farther away for less heat. The pipe's open end would probably be cut on an angle too, so it could snuggle-up closer to the manifold.

I realize homemade moving parts in an engine compartment are asking for trouble though,, so the conventional warm air intake from an older car might just be the ticket!!!

[oil pan 4]

Originally Posted by wmjinman

I'm thinking of rigging a movable "snorkel" (maybe the wrong term) that, in one position, pulls intake air from around the exhaust manifold, but then when warmed enough, can be moved away so it doesn't get too hot.

I have seen something like this before in cars that strugled to meet emmissions that were built as late as the 1990s.

[t vago]

Sunday (no WAI) - 288.4 miles / 13.637 gallons = 21.1 MPG
Wednesday (WAI)- 363.9 miles / 15.292 gallons = 23.8 MPG

More realistic than what that UltraGauge junk reported out.

Originally Posted by wmjinman

I'm thinking of rigging a movable "snorkel" (maybe the wrong term) that, in one position, pulls intake air from around the exhaust manifold, but then when warmed enough, can be moved away so it doesn't get too hot.

What is "too hot?"

[wmjinman]

Originally Posted by t vago

What is "too hot?"

Not entirely sure, but it seems I read on here somewhere that there's an "optimum" intake temperature (for that person, at least), and I'm thinking it was like 90 to 115 deg. F. I'm pretty sure you don't want the intake air to get TOO hot - detonation problems, etc. And I'm guessing air right off the exhaust manifold could easily get to 300 degrees F or more, which would probably be too hot.

Now, it could just be permanently positioned far enough away that it doesn't get that hot, but my thought is for fast warmup, have it so it can really snuggle up close at first, then be backed away. I would watch the "intake air temp." on the ScanGauge & move it away once it hits - whatever - 115, or??

Probably do some "A-B-A testing" to fine-tune it. . . .

[t vago]

Originally Posted by wmjinman

Not entirely sure, but it seems I read on here somewhere that there's an "optimum" intake temperature (for that person, at least), and I'm thinking it was like 90 to 115 deg. F. I'm pretty sure you don't want the intake air to get TOO hot - detonation problems, etc. And I'm guessing air right off the exhaust manifold could easily get to 300 degrees F or more, which would probably be too hot.

Good points, all. I do not remember reading about any "optimum" temperature, as such, but pre-ignition / detonation are things to steer away from.

Preventing overly hot temperatures was one reason I went with a heater core-based heater, as opposed to an exhaust manifold-based heater. It'd be near-impossible to get 300 F out of coolant (and if you're getting that high a temperature out of coolant, you've got other issues...) Another reason was that it was easier to route coolant hoses than it was to route air hoses.

As for the actual temperature? Your guess is as good as mine. I do know that my truck seems to love 130 F as its intake temperature. I would go higher, except that might start wandering into pre-ignition / detonation territory.