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Head gasket

G

Goose57

Active Member
Messages
92
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Location
Eureka Mo.
Hi all it’s being awhile since I’ve been here. Since then my truck has 166xxx miles on it. Oh also a blow head gasket🤯. White smoke coming from tail pipe. Unfortunately I drove it awhile before the white smoke came out the tail pipe and the head gasket may have been starting to leak (Low heat, temp gauge going up and down).😂 it’s my own fault😩. I was told that driving it with a leaky head gasket could do damage to the block deck, cycl. walls. or the top of pistons. I haven’t ripped the heads off yet. But I’m am looking into some motor suppliers. Any suggestions on suppliers. I looked in to Unique Diesel and BMI both offering Optimizer (AM GEP blocks and heads). Supposed to be beefed up block and heads etc.🤔. Thoughts. I hate to get rid of my truck😂 thanks Gus.
 

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Goose57 said:
Hi all it’s being awhile since I’ve been here. Since then my truck has 166xxx miles on it. Oh also a blow head gasket🤯. White smoke coming from tail pipe. Unfortunately I drove it awhile before the white smoke came out the tail pipe and the head gasket may have been starting to leak (Low heat, temp gauge going up and down).😂 it’s my own fault😩. I was told that driving it with a leaky head gasket could do damage to the block deck, cycl. walls. or the top of pistons. I haven’t ripped the heads off yet. But I’m am looking into some motor suppliers. Any suggestions on suppliers. I looked in to Unique Diesel and BMI both offering Optimizer (AM GEP blocks and heads). Supposed to be beefed up block and heads etc.🤔. Thoughts. I hate to get rid of my truck😂 thanks Gus.
Click to expand...
Nice truck Gus
 
Others here will chime in I'm sure, there is nothing new or upgraded with a new optimizer motor. They are the same thing that has been produced in the past with the same flaws. Beware of BMI, do your research before you buy. A top quality build will give you much more than just a rebuild for the cost of a new motor, and a new motor from GEP doesn't come with a warranty, a professional blueprint builds does .
 
Goose57 said:
Hi all it’s being awhile since I’ve been here. Since then my truck has 166xxx miles on it. Oh also a blow head gasket🤯. White smoke coming from tail pipe. Unfortunately I drove it awhile before the white smoke came out the tail pipe and the head gasket may have been starting to leak (Low heat, temp gauge going up and down).😂 it’s my own fault😩. I was told that driving it with a leaky head gasket could do damage to the block deck, cycl. walls. or the top of pistons. I haven’t ripped the heads off yet. But I’m am looking into some motor suppliers. Any suggestions on suppliers. I looked in to Unique Diesel and BMI both offering Optimizer (AM GEP blocks and heads). Supposed to be beefed up block and heads etc.🤔. Thoughts. I hate to get rid of my truck😂 thanks Gus.
Click to expand...
Thank you very much
 
Mighty fine looking rig there. iirc Leroy also sells engines and heads too. I would say pull the engine and do a good inspection on the top and bottom end to see if it's worthy of a rebuild. let Chris have it to build one for you.
 
Thanks guys, I will have to pull the heads to see where I’m at, There are so many engine suppliers out there, all kinds of info, new and redesigned , different metals , p400 blocks, 50something blocks, China knock offs, etc. A lot to digest🤯. Thanks again.
 
If you find someone advertising a P400 Please post the info here. to my knowledge there are no more in production and are one of the most desired engines in the 6.5 platform. New - not gonna find it, Used - maybe....
 
dbrannon79 said:
If you find someone advertising a P400 Please post the info here. to my knowledge there are no more in production and are one of the most desired engines in the 6.5 platform. New - not gonna find it, Used - maybe....
Click to expand...
From what I’m reading on the web AM General makes the supposedly new block. Navistar ( the foundry ?) markings on the block. Look for a date code after 2001. AM General website list two suppliers of their engine , Unique Diesel out of Texas and Leroy,s. Unique Diesel offers the supposedly new long block with a 1 year warranty and they don’t want the core🤔. Why only a 1 year warranty on a new engine? Unless they think the 6.5 is a high maintenance engine💁. You can’t even phone them with questions. I’m a little suspicious.
 
Here is a longer version and more comprehensive version of how I arrived where I am today when I was faced with a decision on where to buy:

'95 Engine build

I guess I'll start one of these. I don't guess this will be nearly as useful as Hink's website or some others, but maybe it will help someone, as well as myself to try to keep track of some information. Here it is with a broken crank diagnosis, to start with.
www.thetruckstop.us
 
The manufacturer of the engine only offers a one year guarantee because their main customer is the US DOD (military) and unless one comes through dramatically wrong, they don’t eat the cost. They really don’t mind if civilians stop buying it.

The foundry (company actually casting the main engine parts -block /heads) was navistar from 2001 and recently changed. The name of the new foundry escapes me.

But when the 2001 castings are compared to the 2023 castings there has been no improvements made on the regular 6.5 engine aka 6500 optimizer.

There was an available variant of the engine known as the p400. Basically that one solved almost every flaw in the 6.5 that could be fixed and still be mass produced. It is the dream version but nla to the public. They only do limited manufacture runs for militaries buying in large quantities at this point.

As to buying from Leroy Diesel & Unique diesel- they are both reputable companies with good service.

Because modifying the new engine is only voiding a one year warranty- and these engines have weak points in them still- that is why I recommend tearing down the new mass produced engine and investing a bit more seems worth while to the long term investment.

Balance the lower rotating assembly. Biggest expense depends on your area.
Clean up flashing- your free labor with 1/8” die grinder and 6 hours.
Ceramic coating bearings
Main girdle
Gapless rings are a nice low cost extra that will extend oil life.
Then putting back together will be new gaskets, head bolts and some main bolts.
Extra care needed to remove valve covers to be able to reuse them.

This all is not required, but helps. But like any project has the ability to get out of hand with “while Im there…”
 
Will L. said:
Then putting back together will be new gaskets, head bolts and some main bolts.

This all is not required, but helps. But like any project has the ability to get out of hand with “while Im there…”
Click to expand...
Based on a recent conversation with a known 6.5 voice, I would recommend only studs for the mains, not bolts. I was told that the bolts have been measured to induce a torsional effect on the webs and that the Detroit 6.2 was originally designed with studs and that it was GM which decided to use bolts.
 
Yeah all main studs are better. It is always a question of how much $ does one keep “investing”. Some guys worry about what the proper mainstud torque should be if not getting it align honed. Some guys will get the coated bearings but stay with stock main bolts (provided they get replaced) and do the same with head bolts. While studs are better when applied properly, any back yard mechanic can replace main and head bolts with new ones doing the basic couple of improvements and use factory torque specs- then expect 350,000 from the engine no worries if not working the dog-snot out of it.
 
Will L. said:
The manufacturer of the engine only offers a one year guarantee because their main customer is the US DOD (military) and unless one comes through dramatically wrong, they don’t eat the cost. They really don’t mind if civilians stop buying it.

The foundry (company actually casting the main engine parts -block /heads) was navistar from 2001 and recently changed. The name of the new foundry escapes me.

But when the 2001 castings are compared to the 2023 castings there has been no improvements made on the regular 6.5 engine aka 6500 optimizer.

There was an available variant of the engine known as the p400. Basically that one solved almost every flaw in the 6.5 that could be fixed and still be mass produced. It is the dream version but nla to the public. They only do limited manufacture runs for militaries buying in large quantities at this point.

As to buying from Leroy Diesel & Unique diesel- they are both reputable companies with good service.

Because modifying the new engine is only voiding a one year warranty- and these engines have weak points in them still- that is why I recommend tearing down the new mass produced engine and investing a bit more seems worth while to the long term investment.

Balance the lower rotating assembly. Biggest expense depends on your area.
Clean up flashing- your free labor with 1/8” die grinder and 6 hours.
Ceramic coating bearings
Main girdle
Gapless rings are a nice low cost extra that will extend oil life.
Then putting back together will be new gaskets, head bolts and some main bolts.
Extra care needed to remove valve covers to be able to reuse them.

This all is not required, but helps. But like any project has the ability to get out of hand with “while Im there…”
Click to expand...
that is why I recommend tearing down the new mass produced engine. Do mean getting a new Optmizer
and and getting inside to do the improvement?🤔
 
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