What did you do with your GMT400 today...or yesterday....

[MrMarty51]

Pour Me another cuppa coffee, head to the shed, fire up that truck enjun, warm it some then step up the idle and let it run for a good long while.
I imagine a half an hour to an hour should be enough time.
Buzz on over to Oriellys or walmart, get some sort of an oil dying substance and let it run with that in the cranking case. Then get out the UV light and see if anything shows.

 

[Big T]

Thats what I like to hear.
I fired it up with the bare essentials hooked up. Check to make sure rocker covers is sealed.
After it sat running for a short time, I goosed the throttle, came a sort of a loud chirp noise, like in time with rocker arms. Realizing that possibly the washers to rocker arms was seeking a centering.
After twice more of revving the engine the noise went away and never returned.
I’ll be running this for an hour or two without the intake manifold and just the bare minimum hooked up.
I want to make sure that there are no rocker cover leaks and that that noise will not return.
Just a real good preassemble shake down.

You won’t know if the valve covers leak until after a couple long drives.

Once again, there is more uncertainty with unproven design on the valve retainer bolt solution. Owner feels good with “over engineered bolt solution,” but has not idea what additional issues have been introduced. Stock retainer buttons are $2 apiece and easily go 200K miles with no unknown design issues. You just ground up some metal washers which introduced metal filings to your lubrication system.

 

[MrMarty51]

You won’t know if the valve covers leak until after a couple long drives.

Once again, there is more uncertainty with unproven design on the valve retainer bolt solution. Owner feels good with “over engineered bolt solution,” but has not idea what additional issues have been introduced. Stock retainer buttons are $2 apiece and easily go 200K miles with no unknown design issues. You just ground up some metal washers which introduced metal filings to your lubrication system.

I was afraid of such.
I was installing some of the new plastic spacers and two of those broke off on the nails.
That was when I pulled the rocker arm assemblies and tried the steel washer components.
The rocker arms and shafts are both hard steel and dont wear out in sometimes 300,000 miles and more.
I cant see where the hardened steel washers could be different.
I do realize there will be a break in cycle but once those surfaces seek their break in cycle there should be no more filings or grindings.
Thats just My theory.
Is there still anyone that came up with this idea, or tried it, still active in the forum to comment ?
If it is a bad plan the speak out, I’ll remove the injector pipes and any components thats in the way, pop the rocker covers and undo the bolts and warshers.

 

[MrMarty51]

No crank case oil dye to be had in town.
NAPA was on back order.
They did have five 1 oz bottles over in Baker so I told them to get me two of them.
I imagine a 1 oz bottle would be for about a five quart system and seeing as how the parts store could find no instructions for use I feel it safe to add two bottles for a richer mixture.
We shall see.
Maybe if I fast idle the engine at about 1300 rpms for about 3 hours, I hope that will be enough of a run for any oil to seep out, if them rocker covers are going to leak.

 

[Will L.]

We’ve done similar in the fleet.

@Big T the comment of “Stock retainer buttons are $2 apiece and easily go 200K miles with no unknown design issues” shows only he hasn’t seen enough miles worth of 6.5s running.

We had rocker buttons fail ALL THE FRICKIN TIME starting around 100,000 mile range.
It isn’t like I have personal copy of records for what all we did back then - but if I had to guess I would say 1 in 20 engines had a failure before the 200,000 mile mark. 1 in 75 had a failure before 100,000 miles. Not rebuilds- factory engines.

Look up what the WARRANTY TIME was. Note that it was a corrected time- meaning enough dealership mechanics REFUSED to do it for the amount of time it paid.
Now think this through carefully- what was the warranty on the internal engine back in 1998?

Your opinion is duly noted, but experience tells those of us with a lot more experience that your opinion is incorrect. You don’t have to like every modification- but you are misleading him with your opinion. Could he install a bolt, washer and nut SO WRONG that it does damage? Yup. But it’s easier to crack a plastic retainer installing it wrong.

@MrMarty51 - dude- your rocker retainer mod is fine. I’ve seen a bunch of ways, done several ways. Let me count the failed mod ways reported- so far my count is ZERO.
Anyone have pics/ videos of fail #1?

 

[Big T]

We’ve done similar in the fleet.

@Big T the comment of “Stock retainer buttons are $2 apiece and easily go 200K miles with no unknown design issues” shows only he hasn’t seen enough miles worth of 6.5s running.

We had rocker buttons fail ALL THE FRICKIN TIME starting around 100,000 mile range.
It isn’t like I have personal copy of records for what all we did back then - but if I had to guess I would say 1 in 20 engines had a failure before the 200,000 mile mark. 1 in 75 had a failure before 100,000 miles. Not rebuilds- factory engines.

Look up what the WARRANTY TIME was. Note that it was a corrected time- meaning enough dealership mechanics REFUSED to do it for the amount of time it paid.
Now think this through carefully- what was the warranty on the internal engine back in 1998?

Your opinion is duly noted, but experience tells those of us with a lot more experience that your opinion is incorrect. You don’t have to like every modification- but you are misleading him with your opinion. Could he install a bolt, washer and nut SO WRONG that it does damage? Yup. But it’s easier to crack a plastic retainer installing it wrong.

@MrMarty51 - dude- your rocker retainer mod is fine. I’ve seen a bunch of ways, done several ways. Let me count the failed mod ways reported- so far my count is ZERO.
Anyone have pics/ videos of fail #1?

Will you were observing fleets where the drivers abused the vehicles and arguably you were doing limited preventative maintenance by virtue of your claims here that they never even bothered changing the transmission fluid.

Between the three 6.5s I’ve owned, I have seen a combined 250K miles under my watch and total mileage of 185K, 236K, and 296K with no valve retainer button failures. You are encouraging weekend warrior mechanic improvements which have not been proven and could be detrimental. These nylon plastic valve retainer buttons are used in any number of cars and trucks and you are the only voice I’ve seen on the internet who’s claiming repeated failures and/or problems.

 

[Will L.]

Incorrect
You said not been proven.
Absolutely proven. I didn’t ONLY work for fleet trucks and not all were abused. Outside of regular shops and dealership…

I have probably built 250 6.2/6.5 engines for private individuals. About two dozen I have done different retainer mods. A couple of those are for hot shotters and they are over 300,000 miles with no issues.
One guy did report the death of my 100% never an oil leak unfortunately, But it might be front main seal so I wouldn’t feel bad for that. Haha.

It is interesting that you think the abused ones in the fleet we modified should be excused because being driven hard and the plastic failing- but no credit for the modified ones that haven’t failed.

So please- show me the failed modified ones? Even one?

 

[Big T]

Incorrect
You said not been proven.
Absolutely proven. I didn’t ONLY work for fleet trucks and not all were abused. Outside of regular shops and dealership…

I have probably built 250 6.2/6.5 engines for private individuals. About two dozen I have done different retainer mods. A couple of those are for hot shotters and they are over 300,000 miles with no issues.
One guy did report the death of my 100% never an oil leak unfortunately, But it might be front main seal so I wouldn’t feel bad for that. Haha.

It is interesting that you think the abused ones in the fleet we modified should be excused because being driven hard and the plastic failing- but no credit for the modified ones that haven’t failed.

So please- show me the failed modified ones? Even one?

Your sample size is extremely small on the modified. Just waiting for a nut to back off on one of these mods. There is minimal load on these to break the OEM plastic retainers, but there is plenty of vibration to loosen up a nut and bolt assembly, particularly since there is all sorts of give with the space created by the round rocker arm vs a flat nut cinched up against it.

Meanwhile, I have a ‘94 with 296K miles and the valve covers have never been pulled, so it has the OEM plastic retainers and they are are the least of my current concerns with the truck.

 

[Will L.]

Ok, and like I said- not everyone needs to do every mod.
But you sound like the guys 30 years ago saying never mod the turbo or exhaust or oil pumps or the timing chain.
Here is another one- the 6.2 rocker shaft system- they had boat loads of problems and we would modify those in the mid 80’s because of it. 85-90% would run a bazillion miles and no issues. But the ones that did fail did so in a grandiose style. And naysayers would abound.

Upgraded lift pumps- heck even the guys I used to argue with that swore the mechanical lift pump was fine. SMH. There is still today a company promoting the mechanical lift pump as an improvement! And trying to feed ds4 with it!
And most of them ran a long life back in the 80’s. But the ones that failed were massive failures. Enough dealerships were adding the electric lift pump themselves so corporate finally jumped on board in 88 iirc.

There is a TON of modifications that work well, but because some people don’t experience the short comings, they shoot it down.

I feel like walking away and just calling out the mods that were bashed by so many that proved good later…
ATT
remote mounted pmd
Improved fan clutch
9 blade fan
Repositioning the cam bearings
Trimmed flashings
Lowering compression
Head studs
(This is a long walk, remember to read quieter and quieter as to replace the Doppler effect)
Fill & tap smaller outside main bolts
File edges of tooling marks from oil squirters
Balance flow serpentine water pump
Replace balancer every 100k (my personal discovery)
Securing oil pickup tube
Tim’s FTB
Fender Air flow mod
High idle mod
Ops relay mod
Blah blah blah…

 

[jrsavoie]

Ok, and like I said- not everyone needs to do every mod.
But you sound like the guys 30 years ago saying never mod the turbo or exhaust or oil pumps or the timing chain.
Here is another one- the 6.2 rocker shaft system- they had boat loads of problems and we would modify those in the mid 80’s because of it. 85-90% would run a bazillion miles and no issues. But the ones that did fail did so in a grandiose style. And naysayers would abound.

Upgraded lift pumps- heck even the guys I used to argue with that swore the mechanical lift pump was fine. SMH. There is still today a company promoting the mechanical lift pump as an improvement! And trying to feed ds4 with it!
And most of them ran a long life back in the 80’s. But the ones that failed were massive failures. Enough dealerships were adding the electric lift pump themselves so corporate finally jumped on board in 88 iirc.

There is a TON of modifications that work well, but because some people don’t experience the short comings, they shoot it down.

I feel like walking away and just calling out the mods that were bashed by so many that proved good later…
ATT
remote mounted pmd
Improved fan clutch
9 blade fan
Repositioning the cam bearings
Trimmed flashings
Lowering compression
Head studs
(This is a long walk, remember to read quieter and quieter as to replace the Doppler effect)
Fill & tap smaller outside main bolts
File edges of tooling marks from oil squirters
Balance flow serpentine water pump
Replace balancer every 100k (my personal discovery)
Securing oil pickup tube
Tim’s FTB
Fender Air flow mod
High idle mod
Ops relay mod
Blah blah blah…

What's the fender air flow mod?

I argued or ignored idiots comments about diesel exhaust sizing for a few different vehicles.

How many times have you heard "they need the back pressure to run right"?

 

[Husker6.5]

The fender airflow mod was for the old, small rectangular air filter box. It had a very small intake throat hole into the inner fender. The mod opened up both the fender and the box's opening to allow more air flow into the box and through the filter.

Some of the 94-95 models with that airbox also had a long, small diameter snorkle that snaked between the inner and outer fenders and picked up "cool" air from behind the headlight. Many of the airbox mods also included a much shorter, larger diameter "scoop" snorkle to help direct air into the larger, modified opening.

 

[Big T]

Ok, and like I said- not everyone needs to do every mod.
But you sound like the guys 30 years ago saying never mod the turbo or exhaust or oil pumps or the timing chain.
Here is another one- the 6.2 rocker shaft system- they had boat loads of problems and we would modify those in the mid 80’s because of it. 85-90% would run a bazillion miles and no issues. But the ones that did fail did so in a grandiose style. And naysayers would abound.

Upgraded lift pumps- heck even the guys I used to argue with that swore the mechanical lift pump was fine. SMH. There is still today a company promoting the mechanical lift pump as an improvement! And trying to feed ds4 with it!
And most of them ran a long life back in the 80’s. But the ones that failed were massive failures. Enough dealerships were adding the electric lift pump themselves so corporate finally jumped on board in 88 iirc.

There is a TON of modifications that work well, but because some people don’t experience the short comings, they shoot it down.

I feel like walking away and just calling out the mods that were bashed by so many that proved good later…
ATT
remote mounted pmd
Improved fan clutch
9 blade fan
Repositioning the cam bearings
Trimmed flashings
Lowering compression
Head studs
(This is a long walk, remember to read quieter and quieter as to replace the Doppler effect)
Fill & tap smaller outside main bolts
File edges of tooling marks from oil squirters
Balance flow serpentine water pump
Replace balancer every 100k (my personal discovery)
Securing oil pickup tube
Tim’s FTB
Fender Air flow mod
High idle mod
Ops relay mod
Blah blah blah…

Of all theee, only repositioning the cam bearings has anything to do with moving internal parts of the engine.

 

[jrsavoie]

The fender airflow mod was for the old, small rectangular air filter box. It had a very small intake throat hole into the inner fender. The mod opened up both the fender and the box's opening to allow more air flow into the box and through the filter.

Some of the 94-95 models with that airbox also had a long, small diameter snorkle that snaked between the inner and outer fenders and picked up "cool" air from behind the headlight. Many of the airbox mods also included a much shorter, larger diameter "scoop" snorkle to help direct air into the larger, modified opening.

I guess I was doing that mod starting with the NA 1989.

I was told them it wasn't a good idea to unrestrict the air intake

 

[MrMarty51]

Might be against My better judjement.
I removed the FFM, laid back wiring and items and got the intake manifold set atop of the heads. Did that late yesterday afternoon. When accomplished it was back to the recliner to ease some back pains.
Awoke about midnight and me and the little puppydawg trundled off to bed.
Just getting awokened and moving. See how much I csn get attached today.

 

[Will L.]

Of all theee, only repositioning the cam bearings has anything to do with moving internal parts of the engine.

Bro- you just wanna argue.
Wrong again.
I marked the 7 I Listed- yes cam bearings are inside.

Please show me the other 6 …how they are not inside the engine, how they couldn’t destroy the engine just as fast or faster?


And there is a BUNCH MORE I didn’t write
Girdles
Sizing oil bushing portals
Edging things like crank, rods, pistons, cam, lifters, etc.

Dude- apparently no one ever explains to you when you’re wrong.
Just swallow the pill man, you’re wrong. It happens. Get over it and let it go.

 

[Big T]

Bro- you just wanna argue.
Wrong again.
I marked the 7 I Listed- yes cam bearings are inside.

Please show me the other 6 …how they are not inside the engine, how they couldn’t destroy the engine just as fast or faster?
View attachment 81399

Did you read what I wrote? Talk about wanting to argue: "has anything to do with moving internal parts of the engine."

 

[Will L.]

Check my edit- there is some moving parts for ya. I hit post often when typing before reading my post and forgetting to add part that I meant to.

 

[MrMarty51]

Added a fitting for a fuel pressure sender unit.


And the FFM on its pedastol

 

[dbrannon79]

@MrMarty51 Make you a bracket from the intake to the FFM to limit some of the vibration for the FFM. this way it lessens the chance the pedastol you made coming loose down the road.

 

[MrMarty51]

@MrMarty51 Make you a bracket from the intake to the FFM to limit some of the vibration for the FFM. this way it lessens the chance the pedastol you made coming loose down the road.

View attachment 81422

Good plan. The center bolt for the upper intake manifold will be an excellent mounting position. A simple two hole tab and possibly an offset S kind of a bend and done.
The hose made for the oil pressure remote sensor is also some too long. It will work out good though.
Going to make a two hole tab to mount the underhood lamp connector too, a stud mounted to the firewall with a nut keeps that in place, mount the two hole tab to the mounting tab of that connector to drop it down about an inch and a half, then a wiring P clamp around the oil pressure sensor switch and that will have a secure mounting position high on the firewall and the OP sensor harness/connector will still reach it.
I had that remote hose made 24” long and that length is just right for this secure mounting position.
I do not know how long the hoses that Leroy sells is so I dont know what a good secure position would be for the sensor when using His remote hose.
I’ll post a pic when I get the OP sensor secured.