I am about to install a 5.3 gas burner

[3000gt]

I am about to install a 5.3 gas burner with a hotter cam that's around 400hp. My theory is it will be the perfect combo with the turbo 400. To **** with the stock diesel motor. I paid 700 dollars for a 5.3 vs 3000 dollars for a turbo diesel.... no thanks I will post my results shortly.

 

[Retiredwarhorses]

I am about to install a 5.3 gas burner with a hotter cam that's around 400hp. My theory is it will be the perfect combo with the turbo 400. To **** with the stock diesel motor. I paid 700 dollars for a 5.3 vs 3000 dollars for a turbo diesel.... no thanks I will post my results shortly.

And in the end you need run to run your gasser as what RPM to get the same torque from that old diesel?
these aren't race cars, they are military vehicles.....plus, real trucks don't have spark plugs.

 

[3000gt]

Spark plugs.... lol. I like that. Only other option is a Cummins. Too much work to install. 5.3 will bolt up with a flex plate. My goal is to keep the turbo 400. So I will be able to run 80mph no problem. I may be wrong but with geared hubs I will have a beast!

 

[3000gt]

Who needs torque. I am not pulling anything and that is what low range is for. Like I said it's an experiment but a 6.5 is a Turd

 

[patracy]

I would be concerned about those gearboxes and heat. I've driven my HMMWV at 65+, things get a little sketchy to say the least when it comes to braking and suspension. 80mph will mean you'll need to turn that 5.3 at 4134rpm with a TH400. Which makes me scratch my head why you'd go through a 5.3 swap. I assume you'll keep it FI. And not swap in a 4L80e.

 

[3000gt]

My bad, I CAN go 80 but will cruise around 60-65 and not have a motor pegged at redline while doing it.

 

[Retiredwarhorses]

I sure as heck don't want to go 80mph in a Hmmwv, I can do 75 in my 98 H1...but I don't and won't.
Your hmmwv was not built for those speeds...but folks are going to do what they want to do.
Being i do this everyday, I find just the addition of the 4L80E is night and day for drive-ability, but once you add a turbo diesel, or even one of the take out GEP's....no comparison. I have a cummins equipped truck here at the shop right now, the owner drove his buddies truck that I converted to 6.5NA with 4L80E, his words to me were "if I knew it had that much power and smoothness, I don't think I would have gone cummins.

 

[springbok]

This does not seem like something I would want to even try doing 80 mph in. 6.5 NA is fine for what they are, The trans upgrade is even better.
I am not sure I understand why people want to try to make race cars out of these...

 

[Stalwart]

On the civilian side AM General stopped offering a gasoline option after a very short period of time. The 5.7L 350 Chevrolet was unsuitable for the weight and demands of the truck. GM decided not to offer further warranty coverage on new units, too high of a failure rate and warranty costs to GM.

 

[AndyT]

5.3 is a terrible engine. And 400hp just from a cam swap? ....no.

 

[3000gt]

I'll keep my ideas to myself. Never seen so many people beat my Dick in the ground.

 

[3000gt]

5.3 is a terrible engine. And 400hp just from a cam swap? ....no.

What?? Terrible engine. U probably worship a 6.5.

 

[patracy]

5.3 is a terrible engine. And 400hp just from a cam swap? ....no.

I'd have to disagree with you. 400hp is however a tad much if that's the ONLY thing being swapped. But with rod bolts, cam, a GOOD tune, 243 heads and a good intake/exhaust, 400hp is easily done.

 

[3000gt]

On the civilian side AM General stopped offering a gasoline option after a very short period of time. The 5.7L 350 Chevrolet was unsuitable for the weight and demands of the truck. GM decided not to offer further warranty coverage on new units, too high of a failure rate and warranty costs to GM.

Mine weighs in at 5300 lbs. Most suvs weigh more than that. What engine do you think people run if off road buggies.

 

[Carrera911]

Mine weighs in at 5300 lbs. Most suvs weigh more than that. What engine do you think people run if off road buggies.

I agree that a cammed 5.3 is definitely an upgrade to the boat anchor 6.2. Stock it has another 100 hp and almost as much torque. Personally I would go with a 6.0. The 6.0 vortec has 320hp and the same torque as the 6.2. An ls3 would be even better but that's at a lot higher price point. The price between a 5.3 and 6.0 isn't much though. That paired with a 4l80 would be a pretty B.A. setup. My H2 has a 6.0/4l65 and it has plenty of acceleration at 7000 pounds. Don't forget that the LSX motors have twice the redline of the diesels too. And a 300k mile+ lifespan.

Are the LSX motor mounts different than the small block/ Detroit mounts?

 

[patracy]

I agree that a cammed 5.3 is definitely an upgrade to the boat anchor 6.2. Stock it has another 100 hp and almost as much torque. Personally I would go with a 6.0. The 6.0 vortec has 320hp and the same torque as the 6.2. An ls3 would be even better but that's at a lot higher price point. The price between a 5.3 and 6.0 isn't much though. That paired with a 4l80 would be a pretty B.A. setup. My H2 has a 6.0/4l65 and it has plenty of acceleration at 7000 pounds. Don't forget that the LSX motors have twice the redline of the diesels too. And a 300k mile+ lifespan.

Are the LSX motor mounts different than the small block/ Detroit mounts?

I'd disagree about it being an "upgrade". Sure, power and perhaps top speed it's an upgrade. But I'm not driving my HMMWV for racing purposes.

LSX motor mounts are completely different.

 

[RDUKW]

I think the ultimate motor swap is a 4bt Cummins. My 96 H1 will be getting one as soon as the 6.5td hiccups. You can easily add 20% more power (along with better fuel efficiency), with the advantage of easy to work on and the factory cooling is way more then enough. As far as the gas versus diesel debate goes, there is a bunch of gasser H1's that the owners are very happy with and swear by the gas motor. Me personally I prefer the diesel, besides adding to the character of the truck they are a more efficient power plant.

 

[Retiredwarhorses]

I think the ultimate motor swap is a 4bt Cummins. My 96 H1 will be getting one as soon as the 6.5td hiccups. You can easily add 20% more power (along with better fuel efficiency), with the advantage of easy to work on and the factory cooling is way more then enough. As far as the gas versus diesel debate goes, there is a bunch of gasser H1's that the owners are very happy with and swear by the gas motor. Me personally I prefer the diesel, besides adding to the character of the truck they are a more efficient power plant.

These can all be argued....I have worked on and Driven Dmaxx, I have a Cummins equipped truck here in the shop as I type. Everyone one of these has its own set of issues....beleive me.

 

[jrpontiac]

Please post your progress. I have a 5.3l on a stand in the garage and have thought if the 6.2l takes a dive would the 5.3l be a viable option. Fortunately my 6.2l is running great. LS series of engines are a fantastic motors.

 

[jeffy777]

Don't let anyone get you down.

Well I'd like to say, good luck. There are a lot of little issues with moving away from any vehicles original design. I hope you take a lot of pictures and teach me a lot. You are venturing into an area I wish I felt good about going.

Enjoy it!