And so it begins...

[Primer]

Captain's Log.
Stardate: August 13nd, 2008..err...sorry...

I'm excited! Today I found a block for my engine buildup!

I went to look at a block this place had listed as a "Hummer" block. He described it over the phone to me has being "new" looking, having smaller oil cooler jets, and being overall a heavier block.

I showed up there today to look it over. We look at it a bunch and finally flip it over. To my surprise right in the center of the valley there's a diamond with a road through it. I'm very happy! I've found myself a Navistar cast 6.5L!

It looks like it was cast on 11 28 00 and looks to have next to no miles on it. It's been sitting in storage since 2005 or early 2006.

This begins my 6.5L build! Now all I have to do is start ordering stuff!

 

[TurboTahoe]

Good for you!

BTW, I talked to the boys over at Heath, and they think you should definitely stay with the single thermostat housing. The reason is that the single is a 'blocking' design, which means that when the thermostat is open, it FORCES the coolant to go through the radiator before coming back into the engine. The dual design doesn't do that. The dual design does have a little higher flow, but their theory is that since the non-blocking type thermostats leave the ability for the heated coolant to go either to the radiator OR back to the engine, it kinda defeats the purpose of having higher flow. Their view is that the SINGLE thermostat when used with the higher flow water pump and a scrupulously clean radiator is the best mix.

Rob

 

[matuva]

---The dual design does have a little higher flow, but their theory is that since the non-blocking type thermostats leave the ability for the heated coolant to go either to the radiator OR back to the engine, it kinda defeats the purpose of having higher flow---

:confused5:
So, as an upgrade, we better ger rid of the dual T-stats, keep the HO water pump and install the single stat :confused5:

 

[North Maine]

There are many different opinions on single vs. dual. My dual works fine.

 

[nvmtnlion]

I did the hi-flow/dual stat upgrade and it made a huge difference on my 94.. Funny how schools of thought change :biggrin5: Newer isn't always better

 

[Ratman]

I just did the dual stat 130 GPM pump on mine, -and it never cooled so nicely.

Unless the gauge lies.

It's been hot here in Portland the last week or so, -and getting hotter this week (supposed to be 103 tomorrow).

With the AC cranked, sitting in traffic, -never above 185-190.

So, single stat is the way of the future, eh?

I have one I'll give to somebody for free (it's being used as a door stop right now). I don't plan on going back.

 

[TurboTahoe]

I had a chance to call the good guys from Heath. They explained that according to their thinking, the bypass-blockoff concept has merit, which is why they like it. I am going to try and paraphrase what I heard, but I do NOT claim to speak for them. I'm just trying to add to the body of knowledge here.

Here's the thinking, if I understood it properly:

* The block-off thermostat sends coolant to one of two places - either bypassing the radiator and directly into the input of the water pump, or through the radiator.

* By employing a block-off strategy, it ensures that when the thermostat is fully open (i.e. the coolant is up to operating temperature) 100% of the coolant is being forced through the radiator.

* Some of the 1996 side-mounted thermostats were also of the block-off type, and worked the same way as the 94-95 thermostat crossovers.

* The concern they have is that the constant-bypass type of crossover, which is what is used on 97+, does have greater flow capabilities leading to the radiator, but since GM went away from the 'forced bypass' design, the coolant (when up to operating temps) has two places to go - bypass back to the inlet of the water pump AND/OR to the radiator. They claim to have some people who have done the 97 cooling upgrades, and STILL have cooling problems. Their theory (which makes sense to me) is that since there is nothing "forcing" the hot coolant to take the trip through the radiator to have heat removed, that coolant will simply take the path of least resistance, and if the path of least resistance is back to the water pump inlet, this will simply send hot coolant right back through the engine again, without having been cooled, thus exacerbating the cooling problem, not fixing it.

*They say that their fix for '97+ cooling systems that are still overheating has been to put a restriction into the path leading to the water pump inlet, thus making the path to the radiator the 'path of least resistance', thus solving the cooling problem.

* They claim that use of the single bypass-type thermostat crossovers with the HO water pump, coupled with the HD fan clutch and HD fan has provided the most consistent cooling performance, even over the '97 systems.

* They claim to not have seen any evidence of over-pressurized systems nor 'blowing frost plugs' when retrofitting an older 6.5 with the HO water pump.

My personal analysis of it is that this makes a lot of sense, and I will likely put the HO pump on my Tahoe as a result, and NOT change the crossover.

Sincerely,

Rob

 

[Matt Bachand]

It must force it somewhat because if it didn't it would overheat in a hurry.

Probably cheaper for just the HO Waterpump also, give her a go.

 

[Dave12]

If you're going to be in the market for new heads I have a set of dressed heads that are aftermarket castings that have about 500 kms on them. They were put on my engine only to find out the block was cracked. I'm just waiting to get them back from the guy that bought my truck. He's putting in a used longblock and giving me back my old one with the heads on it. I paid $900 for them but would sell them for $700 shipped (shipping will probably be close to $100). Let me know if you're interested.

Dave

 

[bison]

Captain's Log.
Stardate: August 13nd, 2008..err...sorry...

I'm excited! Today I found a block for my engine buildup!

I went to look at a block this place had listed as a "Hummer" block. He described it over the phone to me has being "new" looking, having smaller oil cooler jets, and being overall a heavier block.

I showed up there today to look it over. We look at it a bunch and finally flip it over. To my surprise right in the center of the valley there's a diamond with a road through it. I'm very happy! I've found myself a Navistar cast 6.5L!

It looks like it was cast on 11 28 00 and looks to have next to no miles on it. It's been sitting in storage since 2005 or early 2006.

This begins my 6.5L build! Now all I have to do is start ordering stuff!

what makes you so sure its a navistar! look up my post "is this an AMG block. I hope for you it is.

 

[Primer]

If it's not, then it's a perfect fake. It's got typical 6.5L serial numbers stamped all over it.

It was actually taken out of a Hummer that destroyed a piston. It has one scored cylinder and some damage to the pan rails, I'll know for sure when the engine shop finishes the Magnaflux on it to ensure no cracks are present.

 

[bison]

If it's not, then it's a perfect fake. It's got typical 6.5L serial numbers stamped all over it.

It was actually taken out of a Hummer that destroyed a piston. It has one scored cylinder and some damage to the pan rails, I'll know for sure when the engine shop finishes the Magnaflux on it to ensure no cracks are present.

Here is a perfect fake,100% chinese

 

[chrisk1500]

bison - what is the date code on that fake block?

 

[bison]

bison - what is the date code on that fake block?

man i dont know,this pic i got send from china, DSG is using them.I did however imported one from an other factory there,who where willing to modefy it for me. See bottom of my sig

 

[chrisk1500]

DSG told me that their blocks are brand new AMG blocks. They sent me to Reviva - Reviva said that they are using AMG blocks as well....could they have been lying?

 

[bison]

DSG told me that their blocks are brand new AMG blocks. They sent me to Reviva - Reviva said that they are using AMG blocks as well....could they have been lying?

they are lying,I have covered this issue before last year on the place,when i was digging in to it with a hole,s JR performance Claim.and others about these [AMG]blocks.
matter of fact,when i asked the chinese factory sales manager for a adress in the states to buy a block He said

Due to our contract with the importing company we are not at liberty to disclose that information,end Quote,

now if that ai'nt a snake under the grass then what is

 

[chrisk1500]

Interesting.

Now it looks like the owner of the 'page' is incorrect in stating that DSG uses AMG blocks. No wonder they haven't changed their advertising to read 'AMG blocks' instead of the slightly skewed 'Hummer style' blocks.

Someone is going to get sued......

 

[chrisk1500]

Here is an email I have kept from the guy at Reviva:

From: [email protected]
To: ********@hotmail.com
Date: Tue, 22 Jan 2008 08:40:49 -0600
Subject: RE: 6.5 diesel engine inquiry

Chris,

We use the same block that is utilized by AM General. The blocks are casted by International Trucks on behalf of AM General. There are other new blocks being used by other companies that are being cast in China. We do not use these.



Thanks.



John Hudson

Technical Sales Consultant

Reviva,Inc.

5130 Main St. NE

Minneapolis,Mn 55421

Phone-763-971-6251

Fax-763-390-3722

[email protected]

 

[bison]

trouble is trying to figure out wich of these outfits is telling the truth,I think that most of the blocks made avalable to the civillian market comes from overseas and the millitary blocks stateside.I tell you these chinese blocks and heads look very good,at least the ones i have have a very good finnish.
they have been on the market since 1996.

Believe me that the chinese did not cast these blocks on a whim,Cummins, caterpillar and a host of other brands are cast overseas as well by the same factory's

 

[Turbine Doc]

I would not get all wrapped up over China being origin of material many big name companies get stuff made in China, there is good and bad from there, GE/Siemens/Rolls Royce get material from there, I've worked for all 3 of companies last 28 years. I paid premium price last year for a brand name (Jet) chain fall only to find after it arrived on site it was made in China.

I have a China AMG cloned block, still trying to find time to install it, but when I had it machined for splayed mains, machinest said it was great cast & metal cut/drilled like any he ever cut/drilled of US manufacture, he owns a 6.5 and says he would have no reservations installing into his if it ever quit.

Slim & I are running a Chinese A-Team turbo, very similar to the TD07-22A Mitsubishi turbo, quality work, Japan was once junk now is considered quality stuff, where did they learn how to build quality, US & other nations teaching them how to do it, China stuff is inproving all the time. I don't like trade going to China one bit, but it is a fact of life, now once China begins to have a robust middle class as japan did, and have to conform to standard of safety and environmental regulations their cost to produce will go up, as have Japan and Korea.

Some China stuff is good some isn't got to be wary of what you are buying, what would bother me though is paying premium price for "genuine" article, possibly AMG has figured how to sub out to China so you might be getting a AMG block cast in China machined to AMG specs, I don't know that to be the case with all of them, but the one I used was that way, it was not marked per typical AMG style markings.