H1 vs HMMWV noise?

[broylz]

I ended up parking my HMMWV right behind an H1 at dinner the other night. was a restaurant that had outdoor seating so i noticed when they left that they seemed to have the 6.5 turbo motor but theirs was much quieter than my 6.2.

I do realize that i bought a military vehicle and really do appreciate it for what it is. That said, my wife has mentioned that if it were a bit quieter, she would also replace her expedition with one.

Is the 6.5 engine that much quieter than a 6.2? is it a sound deadening material issue that the HMMWVs dont have?

Would a 599 block with the 6.2L bore size and 6.5 upper end be quieter?

I guess my real question really is does the engine make the same noise and its a matter of insulation or is the 6.5 somehow inherently quieter?

 

[mdainsd]

Inherently quieter. I have had an H1 with the 6.5L and it was quieter by far, due to more insulation and the engine being buried under more accessories and emissions gear (I would guess). I still have an H1 with a transplanted 502 gas motor and transmission in it, and that is QUIET! Easy to converse in even at 100MPH.

Is your wife concerned with the exterior noise or internal noise? What top style is on yours?

 

[broylz]

My hmmwv has an arctic 4 man soft top on it. It is quilted so I imagine quieter.

The engine is a bit louder when cold. You can hear the change when the temp gets to about 120. Not as sharp sounding. I also know a lot of the noise is tire noise but if I let off the throttle, we can talk normlly. When I'm on the throttle going 55mph, we are yelling to talk.

One side benefit is the hum and inability to talk effectively puts my 4 year old daughter to sleep like it did most soldiers I know.

 

[Action]

You should have had your wife go to the hmmwv and start it while you stayed at the table. Then compare the noise. Then you could compare in the same situation. Insulation wont affect noise across a parking lot.

 

[broylz]

thats very true. I guess the concern is interior noise for her. i cant imagine people paying that kind of money for an h1 if they cant hold a conversation in it. maybe i am wrong as ive never ridden in one.

plan is to add some sound deadening to the passenger compartment and maybe inside the doghouse if thats possible.

 

[dhaumann69166]

H1 is much quieter inside. They have insulation and carpet and some sound deadening to keep it quiet inside. They also have under hood insulation. If you want to make your HMMWV quieter inside (still not H1 quiet) use bed liner on the underside of the body and inside the doghouse. For the interior use Lizard Skin sound deadener and heat reducer. Put a smooth top coat like Durabak 18 Smooth on it in what ever color you want and you still have the tough interior and a big drop in heat and noise. If you have hard doors you can coat them also for more sound reduction. You could probably coat soft doors but I have never seen it done.

 

[JoeJrTheBarber]

I have a buddy with a 2002 H1 with the 6.5L turbo diesel and his truck is like a Cadillac interior / exterior sound wise compared to my 1988 M998.
I plan to do as said above and insulate both underneath the body and inside with a host of insulations and such which I am sure will make a huge difference.

Also have to remember weather it be a M998 or a H1 these are never "quiet" trucks.

 

[mdainsd]

Another difference. H1s have two dog houses over the engine access in the cabin, both are well insulated.

 

[ken]

I replaced my 6.2 with a GEP6.5 NA. IMHO there is a big difference in noise. Mine too is louder when cold. Most likely fuel not burning completely from lack of heat. But once it gets hot it is smoother and quieter than my GM6.5 in my CUCV. Don't get me wrong. It isn't close to gasoline quiet. But I am happy with it. You can get sound insulation that you cut to fit from places like summit racing. You should be able to make a difference with products like that.

 

[riderdan]

Install a VIC with noise cancelling headsets. Cheaper than most other options and if your passenger is talking your ear off, you can turn down the volume or just switch it off

 

[patracy]

I'm going to add some stall mat from tractor supply to the rear of mine to see if it helps any.

 

[NormB]

Install a VIC with noise cancelling headsets. Cheaper than most other options and if your passenger is talking your ear off, you can turn down the volume or just switch it off

I got a 4-place noise-canceling AVCOM unit from Marv Golden that allows me to plug in my iPhone/iPod and use aviation headsets. Listen to music, handle calls, pretty sweet.

Don’t know how legal this is, but I’ve passed a handful of our guys in blue and other than a few waves, no one’s turned around in hot pursuit. Heck, I see people driving with iPhone earbuds every day, so headsets are a bit over the top, maybe it looks like princess Leia buns from a distance.

I’ll take my chances.

 

[Skrilex]

I got a 4-place noise-canceling AVCOM unit from Marv Golden that allows me to plug in my iPhone/iPod and use aviation headsets. Listen to music, handle calls, pretty sweet.

Don’t know how legal this is, but I’ve passed a handful of our guys in blue and other than a few waves, no one’s turned around in hot pursuit. Heck, I see people driving with iPhone earbuds every day, so headsets are a bit over the top, maybe it looks like princess Leia buns from a distance.

I’ll take my chances.

how bad i$ it to set this system up?

 

[NormB]

how bad i$ it to set this system up?

Faulty memory.

It’s THIS unit: http://www.marvgolden.com/pilot-usa-pa-400st-4-place-stereo-intercom-with-cell-interface.html

The headset is this: http://www.marvgolden.com/mg-anr-headset.html

You can also find ANR inserts for standard aviation headsets for about half that price if you shop around, and ePay sellers often have the ANR headsets for sale for half price.

Worth looking into.

If you don’t want to go the time, trouble, expense of finding the pieces for a milspec setup, this is a good way to go.

 

[Skrilex]

Excellent thank you.

 

[broylz]

I'm going to add some stall mat from tractor supply to the rear of mine to see if it helps any.

That was my initial thought as well. My cj5 has it and it helps but it allows moisture to rust the jeep tub. not an issue on the aluminum though...

 

[broylz]

Install a VIC with noise cancelling headsets. Cheaper than most other options and if your passenger is talking your ear off, you can turn down the volume or just switch it off

I have considered these. Any place that sells a complete kit? ive only been able to find pieces here and there.

 

[broylz]

I got a 4-place noise-canceling AVCOM unit from Marv Golden that allows me to plug in my iPhone/iPod and use aviation headsets. Listen to music, handle calls, pretty sweet.

Don’t know how legal this is, but I’ve passed a handful of our guys in blue and other than a few waves, no one’s turned around in hot pursuit. Heck, I see people driving with iPhone earbuds every day, so headsets are a bit over the top, maybe it looks like princess Leia buns from a distance.

I’ll take my chances.

My brother in law is a commercial airline pilot and this is what he recommended as well. at least similar but has a different brand preference as most do.

I am still trying to wrap my head around Humvee costs vs old jeep costs too...

 

[snowtrac nome]

Back to h1 vs 998 if you have a 6.5 with an electronic pump engine noise will be les because of the timing changes made in the electronic pump the early model 6.5 with a db-2 pump on it will clatter just as much as the old 6.2.

 

[NormB]

Back to h1 vs 998 if you have a 6.5 with an electronic pump engine noise will be les because of the timing changes made in the electronic pump the early model 6.5 with a db-2 pump on it will clatter just as much as the old 6.2.

“Clatter.”

Is that the ticking noise that sounds like a header gasket leak?