Can you reverse the intake manifold?

[w70442]

I just heard that the LS1 intake manifold was symetrical and that you could install it backward and the engine would run just fine.

Anybody know about this or ever try it? I have an application that I think this may help with if it's true.

[whitels1]

This is true.

[Billett]

No $#!?. huh, never even thought about doing that before... might make a remote turbo setup easier. You would need to redo some wiring though and run the fuel lines to the front of the engine

[GCncsuHD]

Yes you can reverse the intake. I know of several guys running this setup in offroad trucks/buggys for various reasons-clearance, intake protection, dust/dirt/water protection (sucking fresh air from the passenger compartment).

[Wasted Income]

I did it on my jet boat. Ran great.

[w70442]

Originally Posted by Wasted Income

I did it on my jet boat. Ran great.

COOL! Bet that boat's bad A$$.

Since you've had first hand experience with fitment of the breather etc, what would you say would be the minimum distance from the firewall the passenger head would need to be?

[Billett]

Just an estimate, but I'd give yourself at least 6" so you can put a 90 on their and run the filter to wherever you need. I ran a short squat filter off the nose of mine when it was facing the right way and it was too turbulent for the MAF to handle. Even without a MAF I think it's too small for the engine.

[Wasted Income]

It's hard for me to give you a dimension, since I never measured...didn't need to. had plenty of room on my setup. sorry man.

[w70442]

Cool. I don't have an elbow hear but looking at some catalog pics, it looked like it was going to require at least 8 inches of space between the pass head and the firewall. 2 inches doesn't sound like much but when people are used to seeing the rear of the engine right up next to the firewall, even a 6 inch gap would probably look odd.
Thanks for the info.

[Warrens69GMC]

If you had enough room you could make a cowl induction hood functional.

[Billett]

I wouldn't be able to measure my setup until tomorrow, but I have a 90 right off of the TB. would at least give you a decent estimate.



This was the shorter filter

[w70442]

Will,
Thanks for taking the time to post the pics.

Warren,
Yeah, that's kind a what I'm hoping to do except the hood I'm wanting to modify never came with cowl induction or ram air scoops. It's a 49 Chevy pickup. Tons of space height wise. Just not sure if I will have enough space front to rear. The engine sits so low in these old trucks that I could go into the firewall some and come back out and up but that would add a lot of turns and reduce the "ram air" effect somewhat. It would still be pressurized air though.

[Billett]

There was a member on here who made a unit to fit a traditional style round filter on top of the intake.

http://67-72chevytrucks.com/vboard/s...=594769&page=3

[BR3W CITY]

I should probably toss in the fact that in a car application (or truck, anything that is on-road), the intake isn't just flipped around. Its flipped around and run THROUGH the firewall. No need for 6" of clearance, its strangely more common to just cut a 5" hole in the firewall.

Why? Because 98.5% of people running a flipped intake in a car/truck are doing so in a VERY high performance application. They either need to keep the filter inside the cab because it would get destroyed (baja truck, mud truck), OR they are trying to reduce the length of piping from an A2W, Ice system, cool tank etc.

[w70442]

Originally Posted by BR3W CITY

I should probably toss in the fact that in a car application (or truck, anything that is on-road), the intake isn't just flipped around. Its flipped around and run THROUGH the firewall. No need for 6" of clearance, its strangely more common to just cut a 5" hole in the firewall.

Why? Because 98.5% of people running a flipped intake in a car/truck are doing so in a VERY high performance application. They either need to keep the filter inside the cab because it would get destroyed (baja truck, mud truck), OR they are trying to reduce the length of piping from an A2W, Ice system, cool tank etc.

This raises a question I had about even recessing the firewall into the cab some to make room for the intake tubes. Even though there would still be a sheet metal firewall between the tubes and the passenger compartment/cab, I was wondering if there would be any noticeable air noise associated with the air going through the breather and tubes in such close proximity to the passenger compartment. This would be a street driven truck. Prob won't even see the track.

[w70442]

Guess I should also ask the guys who have put an LS1 on an s10 frame with a 47-54 Chevy truck body how much room they had between the front accessories and the radiator and how close the engine was to the firewall to determine how much room there is to play with. Anyone with this setup looking on?

[Wasted Income]

Originally Posted by BR3W CITY

I should probably toss in the fact that in a car application (or truck, anything that is on-road), the intake isn't just flipped around. Its flipped around and run THROUGH the firewall. No need for 6" of clearance, its strangely more common to just cut a 5" hole in the firewall.

Why? Because 98.5% of people running a flipped intake in a car/truck are doing so in a VERY high performance application. They either need to keep the filter inside the cab because it would get destroyed (baja truck, mud truck), OR they are trying to reduce the length of piping from an A2W, Ice system, cool tank etc.

I've been thinking about doing that, but doubt I have enough room with the Vintage Air HVAC box under the dash...not really a fan of turning the passenger seat base into an ice tank/A2W either.

[BR3W CITY]

A local racer has a REALLY cooler fabbed ice tank that fits like a center console. Ice in one side, water in the other.
Besides Wasted, then I'd have to copy and paste all of my pm's to you about running an intercooler!!

As to whether or not you can hear the air noise from the intake/tubing.....well....lets just say I've never been in a 900+hp car in which you could hear much of anything.

[w70442]

Thanks for all the info so far guys. I'm not against going into the firewall some but, even going into the firewall, flipping the intake is going to cause some clearance issues up front between the radiator fan and the water pump and accessory drives.
I've read that you can use vette accessories and water pump but that only gains you 3/4" and the cost is quite high for such a small gain. Granted, it might be worth it if you HAVE to have the space. Do you really only gain 3/4" of clearance going from 2000 firebird accessories to vette accessories?

I'm looking at moving the radiator forward. There looks to be room behind the 49 chevy truck grill but I may have to lower the radiator some. So anyone know if the radiator has to be a certain height compared to the engine.
I have read that, because the truck uses a closed system, the upper hose needs to be above the engine. Is this the case with the firebird steam vented engine/radiator?
Thanks again,

[BR3W CITY]

All of these LS's are steam-lined, meaning they have the crossover tubes to move the steam out of the heads and hot-spotting. Generally, its accepted that the high point on the radiator (inlet) be higher than the high point on the engine....so basically ya, what you already knew is correct.

How bout puttin on a seperate fan cooler for the tranny, divorcing it from the engine radiator, and putting the regular coolant radiator in the bed with a fan....Baja style.

I mean it would only require a good, heat compatible fluid pump and a good amount of hose...and more coolant.

Seriously though, someone has done the swap your looking at before, and I really don't think they went to these lengths.

[w70442]

Originally Posted by Wasted Income

I did it on my jet boat. Ran great.

Hey Wasted,
I finally got a chance to get out tot he garage and work on the truck some.
I flipped the intake and found out that the throttle body hits what I believe is the oil pressure switch. Did you have to relocate the oil pressure switch? If so, where?
I also noticed that the steam tubes look like they could be flipped along with the intake so that the steam tube connection will be next to the throttle body when they are both flipped. It looks like the steam tubes are symetrical anyway. Is this right?
Then I noticed that the pcv hose and vacuum hose for the brake booster also need to be rerouted. Can I simply swap valve covers side to side?
One pic is of what I believe is the oil press sw. The second pic shows the switch in my hand above a spot on the block that looks like it could be tapped for the oil pressure switch. This looks like it would involve some dissassembly of the engine in order to catch filings from drilling and tapping. Is this where you put yous or is there a better spot?
PS. Where's your mass air flow sensor? The one on this firebird is a whole nother unit almost the same size as the throttle body.
Thanks for your help,

[Wasted Income]

That is just the oil pressure sender. It doesn't do anything but send an oil pressure signal to the gauge on the cluster. If you REALLY need to have it, you could tap the aluminum cap down by the oil filter on the side of the pan, or several other spots.



I just did away with mine completely, and plugged it. I REALLY would lean away from drilling and tapping the block for it...

Yes the steam lines are symmetrical, and you can flip them around if need be.

The valve covers can also be swapped side to side with zero issues. Room around the oil filler may be tight around your brake booster though.

I was not running a MAF. I tuned it with an EFI Live custom operating system, open loop, speed density.

[w70442]

Thanks for the quick reply.

I'm doing a street rod so I'll be running aftermarket gauges. The piece you showed a pic of....I assume that bolts onto the oil pan. Is that a piece that can be bought. I think mine just has a flat piece of metal on the oil pan above the filter. I bought the H3 oil pan by the way.

I just read that you could put a 90 degree elbow on the block and screw the switch to that to clear the throttle body. Do you see any issues with that?

Oh, And I am planning to use a frame mounted street rod brake booster set up so I won't have any space issues with the filler cap if I flip the valve covers. I think the only reason I was thinking of flipping the valve covers was to simplify the vacuum line routing. Basically flip everything attached to the intake.

Thanks again,