Older Rig Updates: Cooling and Power

[parker_rowe]

I thought I would post my latest updates to our Suburban. Had some nice weather yesterday and got some work done.

In my last post, I had regeared from 3.73's to 4.56's. My truck and trailer specs are in that post.

3.73->4.56 Regear Results

I am still super pleased with the change, even in daily driving. Towing was vastly improved. Towing fuel mileage also improved.

However one thing we ran into on our test trip was cooling on big grades...we pulled a few hills (11% grade when I looked them up later) that still required 2nd gear, and the temperature would start creeping past 230, so I started looking for solutions.

Fan and Clutch

The later model trucks had a much improved 11 blade fan. I happen to get a super cheap parts truck that had this fan and a brand new severe duty clutch. So I swapped them out.

Here is my old "HD Cooling Package" 5 blade fan with hd clutch vs the new setup.



There is a huge difference in the air moved by the new setup. Should help the AC function at lower speeds as well.

Exhaust Mid-Pipes

The second change I wanted to make for a long time is the mid pipes. The Vortec 5.7 1500 trucks had tiny 1 7/8-2" pipes that were crush bent, so they were as small as 1 5/8 at the bends.

The 3500 trucks with the same 5.7 had huge 2 3/4 pipes even though they had the same power rating. Seems that this might help reduce heat under sustained high rpm high load pulls.

Jeg's sells a 2 1/4 mandrel bent set that bolts in. My cats are already deleted in the tune so no worries there.



I also took the opportunity to replace my 138K mile 23 year old o2 sensors.

I got stainless steel so hopefully they don't give me any rust issues.

Payload guys will be happy to hear this shaved at least 20lbs off the truck, so I can carry more snacks and beer. 😄

I still have the factory muffler and tailpipe so the sound output is only slightly louder. I do have a cat back exhaust for it but I don't want to be fighting drone while pulling the trailer.

The pipes cost $160 on sale, normally $230. The fan and clutch would have run me about $100 if I didn't have the parts truck. Less then a single payment on a base model new truck so I'm not to disappointed with that.

We have a few long trips planned this summer, so I will be sure to update with the results. First short trip is in 2 weeks, but its all flat roads. If I still have cooling issues on challenging grades I will move up to a 2 core radiator.

Love this old truck!

[parker_rowe]

Just wanted to make a small update, since a lot of time these threads never get updated with results to help future searchers.

In short, the changes I made seemed to have fixed the cooling issues.

We made a long trip out to IL and back this summer to visit friends, during the killer heatwave that was going on.

A big bummer though, I had to go back to a factory 3.73 rear and the factory computer tuning. Not because I didn't like the 4.56's, but because there were some setup problems with the gears that would could not resolve in time for our summer trips. I have a parts truck here that happened to have 3.73's so I swapped them out.

I had a few long steep hills where the fastest the truck would go was 45mph in second, with my foot to the floor for minutes at a time. So full power at 3500rpm, with the AC on max. There were also other hills that required second, but I could go as fast as I was comfortable spinning the engine.

The highest the truck got was 210F...before the changes in this thread it would hit 230 with no indications of stopping, even with the AC off and the heater running to get us to a pullout where we could let it cool down.

So being able to motor up hills without everyone sweating and being generally miserable, was huge.

Personally, I feel the exhaust changes are the big player here. I'm not sure how much the fan does at 45mph, but engine is trying to move a lot of heat out the exhaust under full power for minutes at time, not just a few seconds fo quick acceleration unloaded.

The fan and HD clutch did great things for the AC at idle, and at low speeds, but it is LOUD! Fine with me though, if it does the job it is suppose to do.

I am currently shopping for a deal on a big block suburban or crew cab though. Wanted one for a while, and as we do more and more long trips it seems like a good time!

[parker_rowe]

BenK wrote:
Thanks Parker !

That is from my Suburban forum...closed down due to lack of funds and Andy who was instrumental in helping with hosting the data on his server. He passed away after a heart attack dealing with the Houston floods this January. Andy was a very young 88 year old. Wished I’d given him the 4 gallons of my BBQ sauce he asked for last year...gave him 1 qt when he visited...then he asked for a gallon...then 4 gallons...’Andy, you can’t possibly be eating all that your self...are you selling the stuff?’....silence...so just sent him a gallon...

This is an old copy. There were a couple of updates showing the filter box mods. I’ll post them later after the below...

Am out of commission for a while...took the backup hard drive and was transferring pictures to be downloaded. While waiting for it, looked up my text file for automotive stuff and found the original tinypic url’s.

Used that link to check the image of ‘my’ picture and ransomware popped up... computer is now at the shop where they will nuke the drive and check the backup drive and cleansing if needed

Warning...DO NOT ever, ever click on tinypic url’s...trusted by me, as it was ‘my picture’...guess tinypic.com has many url’s taken over....

Oh no, thats a pain!

[time2roll]

I am not a fan of removing emissions equipment.

[BenK]

Thanks Parker !

That is from my Suburban forum...closed down due to lack of funds and Andy who was instrumental in helping with hosting the data on his server. He passed away after a heart attack dealing with the Houston floods this January. Andy was a very young 88 year old. Wished I’d given him the 4 gallons of my BBQ sauce he asked for last year...gave him 1 qt when he visited...then he asked for a gallon...then 4 gallons...’Andy, you can’t possibly be eating all that your self...are you selling the stuff?’....silence...so just sent him a gallon...

This is an old copy. There were a couple of updates showing the filter box mods. I’ll post them later after the below...

Am out of commission for a while...took the backup hard drive and was transferring pictures to be downloaded. While waiting for it, looked up my text file for automotive stuff and found the original tinypic url’s.

Used that link to check the image of ‘my’ picture and ransomware popped up... computer is now at the shop where they will nuke the drive and check the backup drive and cleansing if needed

Warning...DO NOT ever, ever click on tinypic url’s...trusted by me, as it was ‘my picture’...guess tinypic.com has many url’s taken over....

[parker_rowe]

BenK wrote:
Photobucket screwed up my posting files...have to dig up the HDD from the safe and then search that drive

Mod's works on any GMT400 era, uses hardware store parts and now that I've done it...can do it in about 2 hours (you have to have the tools, but cando without the Greenlee punch...just more time with a jigsaw)

Will post them sometime this week, I hope...


IIRC, 4" dia x about 4 foot plastic drainage pipe, drainge pipe 90# elbow, HAVC floor duct/register, RTV, a few tubes of RTV and duct tape to cover the engine bay right fender holes that allows HOT engine bay air into the air box

Left the OEM intake run alone, just covering those fender holes with duct tape

Found it. The internet never forgets. Mostly. :B

Bens Air Box Archived

[FishOnOne]

Turtle n Peeps wrote:
The mods you made will make a huge difference in cooling ability.

A lot of people just think about the cooling system and not the exhaust system when dealing with cooling issues.

As with all things there is also a down side. As Ben states, the new fan will pull a LOT of HP away from the wheels. But I also think that it's better to finish your vacation a little slower than not finish it at all.

BTW I love the way your rig looks. Your Burb and trailer look great together.

Again, great job on your mods! 🙂

I recall reading many years ago when Chevy launched the 2000 model trucks with the new 5.3 that the fan was designed similar to a submarine prop that would move more air, but didn't require more energy to do it.

[BenK]

Photobucket screwed up my posting files...have to dig up the HDD from the safe and then search that drive

Mod's works on any GMT400 era, uses hardware store parts and now that I've done it...can do it in about 2 hours (you have to have the tools, but cando without the Greenlee punch...just more time with a jigsaw)

Will post them sometime this week, I hope...


IIRC, 4" dia x about 4 foot plastic drainage pipe, drainge pipe 90# elbow, HAVC floor duct/register, RTV, a few tubes of RTV and duct tape to cover the engine bay right fender holes that allows HOT engine bay air into the air box

Left the OEM intake run alone, just covering those fender holes with duct tape

[parker_rowe]

Turtle n Peeps wrote:
The mods you made will make a huge difference in cooling ability.

A lot of people just think about the cooling system and not the exhaust system when dealing with cooling issues.

As with all things there is also a down side. As Ben states, the new fan will pull a LOT of HP away from the wheels. But I also think that it's better to finish your vacation a little slower than not finish it at all.

BTW I love the way your rig looks. Your Burb and trailer look great together.

Again, great job on your mods! 🙂

Exactly my thoughts. I would rather pull a hill slower and not have to micromanage engine temps. And, I had the power to go (slightly) faster, to be honest. Just not the cooling.

We'll see how it goes, one thing at a time. I still have a few more cards to play if needed.

Thanks!

1320Fastback wrote:
Love old trucks too, something about simplicity and being able to work on them yourself keeps me in mine!

Does your suburban have a single core radiator? You said you would upgrade to a 2 core?

I know with the old Dodges like mine the replacement radiators are much lighter even with the same amount of cores. The general feeling is it's better to get the stock one rebuilt as the weight difference is more metal that can absorb heat from the coolant. For us it's pretty drastic too, almost 9 pounds!

Also consider a coolant filter. It's not something you have to run all the time and is easy to Y it into the heater core lines. If you do run it all the time, like I do, it adds a little to the capacity and is another metal source than can absorb and dissipate heat, although minimal.

Yes, the current radiator is single core, but the wider version they offered in these trucks.

With a little digging I was able to find a 2 core model. I will eventually buy that either way. Just haven't pulled the trigger yet since this one is only a few years old.

It was an emergency purchase after I cracked a tank, so I had to take what the store had in stock.

[1320Fastback]

Love old trucks too, something about simplicity and being able to work on them yourself keeps me in mine!

Does your suburban have a single core radiator? You said you would upgrade to a 2 core?

I know with the old Dodges like mine the replacement radiators are much lighter even with the same amount of cores. The general feeling is it's better to get the stock one rebuilt as the weight difference is more metal that can absorb heat from the coolant. For us it's pretty drastic too, almost 9 pounds!

Also consider a coolant filter. It's not something you have to run all the time and is easy to Y it into the heater core lines. If you do run it all the time, like I do, it adds a little to the capacity and is another metal source than can absorb and dissipate heat, although minimal.

[ACZL]

When I had my 6.0 Powerstroke and wanted to add the Banks exhaust, it was told to me that you can make all sorts of power up front, but you need to get rid of the heat produced by it....hence the exhaust side of thing. Need to have a large or larger exhaust, much like OP posted in 1st post.

[Turtle_n_Peeps]

The mods you made will make a huge difference in cooling ability.

A lot of people just think about the cooling system and not the exhaust system when dealing with cooling issues.

As with all things there is also a down side. As Ben states, the new fan will pull a LOT of HP away from the wheels. But I also think that it's better to finish your vacation a little slower than not finish it at all.

BTW I love the way your rig looks. Your Burb and trailer look great together.

Again, great job on your mods! 🙂

[parker_rowe]

ACZL wrote:
Put a couple Cheery Bomb mufflers on it! LOL

Seriously tho, good looking rig

😄

My glass pack days are behind me. I have a 2 into 1 AFE exhaust that I could make fit, but its only a 17" body magnaflow style muffler and I don't think it will be enough. Maybe if I add 2 resonators before the muffler.

[ACZL]

Put a couple Cheery Bomb mufflers on it! LOL

Seriously tho, good looking rig

[parker_rowe]

BenK wrote:
Love that era too...albeit there were issues and solutions will touch oh below...

Dexcool is long gone. I flushed it all out and replaced it with regular antifreeze. But it was already gone when I got it.

I do plan on getting an HD filter when I replace this one next. It's still new so that will be a bit. They are pretty cheap though.

This fan is just the factory fan from a 98 Tahoe, so it fits the shroud perfectly. If I stepped up to the 21" duramax fan I would have to trim the shroud.

This one definitely roars when the clutch is engaged and moves a huge amount of air. I could never hear the old fan, even though the old clutch was good. I'm hoping its a good improvement.

EDIT: I can't seem to find the pictures of your airbox modifications. Do you still have those kicking around somewhere?