Dual Snorkel Air Cleaner Housing

[Zeb]

Once I get the more pressing issues on my m1008 addressed, I'd like to give the 6.2 a little more air. Last time I towed a heavy load uphill, the truck was crawling. Since then I've put in a rebuilt injector pump and and injectors in it, but hoping that feeding more air along with adding some 2.5" exhaust pipes might help a little.

Looking at the options for increasing air intake, it doesn't seem like there are a whole lot. I like the idea of a dual snorkel on the air cleaner housing, maybe with some tubing to the front of the truck for cooler air intake (something like the picture below). But it seems like the CUCVs I'm seeing online with dual-snorkels on the air cleaner housing were custom-fabricated by the driver. Are any of yall aware of after-market products that would be a simple swap out for the current air cleaner housing? Or would I be forced to cut a hole and install my own snorkel? If I'll have to do it myself, is it worth the trouble?

I know dual-cold-air-snorkels plus bigger exhaust pipes won't change a whole lot on this truck, but in a few months I'll be moving my house and farm an hour north, on top of a mountain...so the m1008 will be pulling many heavy loads up long inclines over the span of a week or so while we are moving. I figured any little bit I can help the 6.2 might make the process somewhat easier on the truck and me.

Another [perhaps easier] option I was considering was the 4 inch tall performance K&N air filter, however I’m not sure how that is supposed to fit into the stock air cleaner housing... considering the stock housing allowance is for a 3 inch tall air filter. I read somewhere on this site that there are aftermarket housing covers that would allow the extra inch, but I haven’t had any luck finding one online

 

[Skinny]

I doubt it will make any difference. I'm guessing the easiest way of adding anything would be changing to the uppper elbow style like the turbo model has. Then feed that to a real snorkel that has outside air.

Sent from my SM-T380 using Tapatalk

 

[cucvrus]

You are not going to gain anything. These 6.2 are gutless when towing. Even when these trucks were new, we had townships at the GM dealership I worked at return the trucks and complain that they could not use the K30 cab chassis with a dump body loaded and pull a trailer to and from job sites within the borough up the mountains at a safe speed. The next contract sale they switched and bought Ford's with 6.9 diesel engines and had a slight but not desired improvement. Speed and uphill towing with 135 HP don't go well together. Keep in mind the 6.2 diesel was supposed to be a diesel model that was a diesel equivalent to a 305-gas engine. Nice thing about the 6.2 is - even though its maximum torque is lower than a 350 and equal to a 305, the 6.2 will hold its torque at lower RPMs and you will go slower also. You wouldn't be the only one to do it. People have been towing stuff that is way too heavy for one of these trucks ever since they came out. You'd be much happier with something more powerful, though... Good Luck. Be Safe. The CUCV is not known for speed on the highway especially uphill. It is best known for simplicity and durable reliability.

 

[Zeb]

Wasn't what I was hoping to hear, but I appreciate the straight shooting. Avoiding wasting time and money on fruitless "upgrades" is always a good thing. Wondering though, would it at least help on gas mileage? Or is the air intake & exhaust upgrade a complete and total waste of time?

the uppper elbow style like the turbo model has. Then feed that to a real snorkel that has outside air.

You referring to the snorkels that stick up vertically above the hood, like a literal recreationally swimming snorkel?

You'd be much happier with something more powerful, though...

Maybe one day. For now the m1008 will have to do. I don't tow heavy often, and after this move I should be done for a while.

 

[Skinny]

The filter is never the limiting factor. Maybe the point of air intake especially on older stuff but modern cars pull air usually between the headlight and radiator.

Porting the heads and intake will have a better outcome. Next step is turbo.

The only hidden power in a 6.2 is whatever adjustment in the fuel screw you are currently at to the engine starting to puff some black smoke. That's it.

 

[cucvrus]

My experience has been when you hook a trailer to anything the mileage suffers severely. And a CUCV truck variant I experienced low fuel mileage with highway speed greater then 55MPH. I never drove a truck for fuel mileage. I used every one of my CUCV's hard and serviced them harder. The M1028 was my workhorse. I tow barred many CUCV's back to my place and hauled a lot of rocks and firewood with the trusty truck in the 18 years I had it. It never failed. I always think that trying to improve something that is already proven to be reliable is counterproductive. Spending money on trying to improve fuel mileage on a reliable vehicle is fruitless. Just keep the truck operational, maintained and you can use the cash your were going to spend to save money to buy fuel and it will all even out in the end. Do the math. Spend $1000. to get 3-5 MPG increase buys a lot of fuel. Have a Great Day. The TM 9-2320-283-10 States the M1008 M1028 A1 A2 all have a maximum safe towing capacity of 3100 lbs. with a 300 lb. maximum tongue weight. take that with a grain of salt. I have cross the US towing an M1010 with my M1028A1. Be Safe. Stopping the truck and load is always the problem so consider adding brakes to the loaded trailer and be careful. You will be held liable in todays world for any negative results.

 

[Zeb]

My experience has been when you hook a trailer to anything the mileage suffers severely. And a CUCV truck variant I experienced low fuel mileage with highway speed greater then 55MPH. I never drove a truck for fuel mileage. I used every one of my CUCV's hard and serviced them harder. The M1028 was my workhorse. I tow barred many CUCV's back to my place and hauled a lot of rocks and firewood with the trusty truck in the 18 years I had it. It never failed. I always think that trying to improve something that is already proven to be reliable is counterproductive. Spending money on trying to improve fuel mileage on a reliable vehicle is fruitless. Just keep the truck operational, maintained and you can use the cash your were going to spend to save money to buy fuel and it will all even out in the end. Do the math. Spend $1000. to get 3-5 MPG increase buys a lot of fuel. Have a Great Day. The TM 9-2320-283-10 States the M1008 M1028 A1 A2 all have a maximum safe towing capacity of 3100 lbs. with a 300 lb. maximum tongue weight. take that with a grain of salt. I have cross the US towing an M1010 with my M1028A1. Be Safe. Stopping the truck and load is always the problem so consider adding brakes to the loaded trailer and be careful. You will be held liable in todays world for any negative results.

Understood. I appreciate that perspective! After throwing a few belts when I first bought the truck a few years ago, I never take it above 55mph anymore (loaded or unloaded).

I should have been more specific though with that last question, as I was more so asking about gas mileage unloaded, since I'm now using the truck as a daily driver (50miles roundtrip to/from work everyday) and won't be able to afford purchasing a more fuel-efficient daily driver until after our big move in July. Even if the answer is yes, MPG will improve, I don't think I'll bother making those changes after reading everything else above. More so just asking out of curiosity at this point.

 

[Barrman]

Injection pump timing might gain you a hair of performance. But, as has been written. Once you get to where you are pushing the pedal down further and nothing is changing. Just back off to where you can make changes and keep it there as the speed goes down. If smoke is coming out of the exhaust, back off until it is clear. That is your max speed for that hill on that day.

 

[Zeb]

Injection pump timing might gain you a hair of performance. But, as has been written. Once you get to where you are pushing the pedal down further and nothing is changing. Just back off to where you can make changes and keep it there as the speed goes down. If smoke is coming out of the exhaust, back off until it is clear. That is your max speed for that hill on that day.

That's another things I was considering, but I've heard that messing with the IP timing can be risky, especially if you don't know what you are doing (like me).

 

[Barrman]

Fair enough. You wrote that the injection pump had been replaced by you. Did you line the lines up even or is the pump to one side of the engine line a little? If you turn it one line width to the drivers side. You won't cause any problems and probably get a performance pick up. Not much, but enough to feel during normal driving. Just do the adjusting with the engine off.

 

[nyoffroad]

I think you will get a bit of extra power with a snorkel, but you'd be hard pressed to measure it let alone see it. Where it might (key word) help would be cooler air when going up hill loaded it might (there's that word again) help keep the engine cooler. I did the snorkel to the core support and about the only thing I noticed was the engine seemed quieter. I also tried a taller air filter without a taller housing for one very loud trip around the block, I never got around to cutting up the housing and adding an inch to it. YMMV

 

[Skinny]

I have a snorkel on my Burb with an 8.1 engine. The intake air temp is always nice and low. But noticeable power gains... probably not.

I also had one on a Jeep XJ. Could notice a slight bump on low throttle tip in but that's it. There was zero seat of the pants improvement.

Now make the engine choke super hot engine bay air under a load. Probably a decrease in power.

 

[2INSANE]

Back when I had a non turbo 6.2 in my M1009, I had every mod or tried every mod imaginable to get as much power out of the 6.2 without installing a turbo.

I added dual 3” stainless exhaust, advanced the timing on the injection pump which allowed more fuel, added an Oem civilian cold air pipe with resonator. Those simple mods gave a little more power.

Putting electric fans on and ditching the mechanical fan will give you some more power too!

Heck! I even cut up the sides of a 6.2 air box making it a full open air intake and all it did was add more noise. Lol

Your best bet is to just go to a junkyard and find a 6.5 diesel with turbo and install all its goodies on your 6.2.

 

[2INSANE]

A thought just occurred to me… If you are worried about restrictive air flow, why not install a 6.5 filter indicator on the steel 6.2 filter air box to determine if you really need to spend the time and money doing modifications? I’ve never seen anyone doing this, so you would get the honors of being the first

 

[Skinny]

I'm guessing the most restrictive part of the 6.2 is the engine

Personally I like to turn the screw up so it just starts to puff at WOT. I know I'm getting full fuel at that point. Then advance the pump by one line width. Anything short of a turbo is a waste IMO.

Sure you can port/polish, headers, etc. but forced induction really solves a lot of those problems and is probably far cheaper in the long run. I've seen those long tube headers for a 6.2 engine. They look to be about three times the money they should be and I question if they have turbo gains as they claim.

 

[Zeb]

Fair enough. You wrote that the injection pump had been replaced by you. Did you line the lines up even or is the pump to one side of the engine line a little? If you turn it one line width to the drivers side. You won't cause any problems and probably get a performance pick up. Not much, but enough to feel during normal driving. Just do the adjusting with the engine off.

Sorry, I see now how my post was misleading. I did not replace the pump myself. Due to an especially busy work schedule around the time that the old pump went out, and the luxury of an alternate daily driver, I threw the towel in on that project and had it done at a shop down the road…. which I really regret now, considering the other more difficult CUCV projects I’ve tackled since then and the absurd amount of money they charged me just to put the part on (that I supplied). I'm considering trying your suggestion though

 

[Zeb]

I appreciate all the feedback and suggestions! I think after reading everything yall had to say, I'll hold off on any of these mods until I'm in a better spot in terms of time, money, and more-urgent-truck needs (seems like once per week something that needs repairing rears its head on the M1008, now that its my daily driver). But once I have more time to play with non-essential truck repairs/maintenance/upgrades, I definitely plan to refer back to this thread...and may followup with more questions.

 

[Skinny]

That will change, once you get a lot.ofntje stuff dialed in the truck will become reliable.

I have gone through every system and sure it's expensive and time consuming. But for most of a decade it was basic maintenance and the occasional fail which was usually just something small.

Most of my downtime has been due to upgrades and not part failure. You just have to get to that point with an almost 40 year old truck.

 

[cucvrus]

 

[Zeb]

That will change, once you get a lot.ofntje stuff dialed in the truck will become reliable.

I have gone through every system and sure it's expensive and time consuming. But for most of a decade it was basic maintenance and the occasional fail which was usually just something small.

Most of my downtime has been due to upgrades and not part failure. You just have to get to that point with an almost 40 year old truck.

I'm looking forward to that day!

Don't get me wrong. I love this truck, and really enjoy working on it (just moreso when I'm not racing to put it back together before driving it to work on Monday morning). But I can confidently say that I 100% would not trade it for any other vehicle at this point. Sentimental value on this truck goes up every time I fix something, and with all the work I've been putting in lately that value has skyrocketed!