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GMT400 6.5 Swap Help

Pulled one up at the front of the engine that was accessible. Looks like it's worn thru the matte silver coating (still visible on the edges) but doesn't look too bad to me?

Applied more wd40 rust release spray on the pistons and will let that soak overnight.

I did see some of the rust on the cylinder walls start to wash away with this last spray round.




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I would have to see in person because pictures and reflections can be deceiving.
But I see to bearings on their way out. The first one from a piece of contamination.
Red circle then follow the mark across the bearing.
F718E899-A9D8-4B00-AE02-2730E73D7D53.jpeg
But you notice the general wear a ross the bearing is equal on that first one you posted other than that drag mark.
The second one pictured says the big end of the rod isn’t true. It would last 180,000 miles on new bearing with everything else ok. But that uneven wear you show is gonna continue and eventually drop pressure by allowing oil bleed out. And at the same time be susceptible to the 3rd layer of the bearing giving up. The added wear of the first layer in that 3 layer bearing that is wearing away- looks exactly like what got caught in the first bearing picture.

and again in the second bearing pic is contamination embedded into into the bearing.
It ran along the 2 lines and stuck into the bearing in the circled area.


would the engine get an ok life like that- yeah most likely. But that is not how to get 300,000 miles from an engine.

I have a hard time with doing too much inside an engine. I have heard more than once “Will, it is not a Swiss watch.” But the difference of it running forever is those fine differences.


DB60122D-700A-4640-910B-0FB32B6C305B.jpeg
But this contamination doesn’t look like bearing material coming apart.
This looks like cast iron flashing- a good example of why it should all be removed.

the trimetal bearing did its job in absorbing the micro pieces. They are designed to trap run away material and not damage the crankshaft. The issue doesn’t occur until the trapped piece leaves a protruding edge or when a second piece finds its way to the first partial.

Ceramic coated trimetal is now the premium for longest engine life because the coating is still softer than the crank so it will allow the piece to inbead if required but is less drag so that piece when tiny like the second bearing pic shown will allow ejection and the filter can pic it up.
 
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I’m doing a little study from the ring and piston manufacturers on how to properly break in chrome top rings.
Doing a top end rebuild on this 1974 Triumph T-150 Trident and I want to get this process absolutely correct. I will be searching other manufacturing companies and see if their procedures are similar to what is prescribed in this rebuilders mag.
 
I started a thread about pistons, rings and etc.
Instead of muddying Your engine thread.
I thought it would be interesting to read some on what is, and what is not proper, for installation and break in procedures.
 
Got her all broke free. Between soaking with the wd40 and smacking the tops of the pistons with a wood block, it finally popped.
Cylinder number 1 was the most stuck. Had to leave that one in the block until the crank was out of the way so I could give it a real solid "tap" lol

That said..... I don't want to use these rods and pistons, or the crank. Few of the pistons popped out unexpectedly and fell on the floor. Probably fine. But I ain't risking it.

Does anyone sell a complete balanced rotating assembly for one of these? That would really help me out.
I'm gonna take this block to local machine shop tomorrow and have them look it over. I think the cylinders will clean right up with a good honing. Will see.

If I can buy a balanced assembly from a vendor or a reputable machine shop, I'll be able to assemble the short block in my garage. Least I'll know how it was done, right or wrong o_O



Here are pics of the main webs and also cylinders 7 & 8. Those are the only ones that I've wiped down so far, but I know those were the main ones susceptible to cracking (I think).




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Do what AK dieseldriver said.

Remove and examine that camshaft very closely. I see rust on it- hopefully that all just wipes off and is “spilled” from somewhere else. Knock the cam bearings out, remove the oil plugs everywhere and flush them all. You will need to do it again just before assembly, but expect to get our rust this first time.

Clean the cylinder walls, especially 7&8 and post pics of each. We can’t see the critical area near the deck surface in those pictures.

how much $$ you want to spend makes decisions on crankshaft, rods, pistons, wristpins, rings, and balancing. Best option is going to be p400 parts. Your call if worth the $. If I had gobs of money to spend, I would run p400 rods and pistons in a heartbeat, and a scat crank

You need to have cylinder checked to make sure they don’t need bored out because of rust, pitting, scratches before you buy pistons. And obviously have to but the pistons and rings before having it all balanced. Buying pistons and having it balanced to later find out the block needs bored and those pistons are not going to work—ouch.

Do you know how to file rings to gap them properly? My suggestion is total seal gapless rings. With gaps at 3/5 th to 4/5th loose end of the specification because the gapless will keep it sealed well, yet leave collapsing room for overheating error space since you are not going for big power, but long life.

Because you are ordering new parts and possibly the best ones-then having machine work done to them- I would expect payment up front to them. This is special order items at their most expensive.
I suggest you contact Chris @Twisted Steel Performance for this, as he can buy the components direct from GEP/ AM General and is working with machine shops that have solid experience in this.
 
Will L. said:
how much $$ you want to spend makes decisions on crankshaft, rods, pistons, wristpins, rings, and balancing. Best option is going to be p400 parts. Your call if worth the $. If I had gobs of money to spend, I would run p400 rods and pistons in a heartbeat, and a scat crank
Click to expand...

Why would you use a "scat" crank, it's CAST not forged, in china no less.... GEP/AMG "forged" are US made and machined....
 
Will L. said:
Do what AK dieseldriver said.

Remove and examine that camshaft very closely. I see rust on it- hopefully that all just wipes off and is “spilled” from somewhere else. Knock the cam bearings out, remove the oil plugs everywhere and flush them all. You will need to do it again just before assembly, but expect to get our rust this first time.

Clean the cylinder walls, especially 7&8 and post pics of each. We can’t see the critical area near the deck surface in those pictures.

how much $$ you want to spend makes decisions on crankshaft, rods, pistons, wristpins, rings, and balancing. Best option is going to be p400 parts. Your call if worth the $. If I had gobs of money to spend, I would run p400 rods and pistons in a heartbeat, and a scat crank

You need to have cylinder checked to make sure they don’t need bored out because of rust, pitting, scratches before you buy pistons. And obviously have to but the pistons and rings before having it all balanced. Buying pistons and having it balanced to later find out the block needs bored and those pistons are not going to work—ouch.

Do you know how to file rings to gap them properly? My suggestion is total seal gapless rings. With gaps at 3/5 th to 4/5th loose end of the specification because the gapless will keep it sealed well, yet leave collapsing room for overheating error space since you are not going for big power, but long life.

Because you are ordering new parts and possibly the best ones-then having machine work done to them- I would expect payment up front to them. This is special order items at their most expensive.
I suggest you contact Chris @Twisted Steel Performance for this, as he can buy the components direct from GEP/ AM General and is working with machine shops that have solid experience in this.
Click to expand...



I did end up stripping the block the rest of the way down last night. Pulled the cam, lifters, oil pump drive, etc. Cam did have a few rust spots on some lobes. I'll buy a new one if required.
Dropping the block off at local machine shop today so that they can look at it and let me know what all the cylinders will need. They can also hot tank it which I much prefer to me trying to clean it myself.

Now this next part is the balancing act on wants/needs/wishlist/timeline.
As mentioned in my first posts, I would have loved to have found a complete new P400. Would have snatched it up for sure just for peace of mind and the fact that it was available.
So yes, I'd love to be able to build this thing up with P400 parts (I didn't even know you could use P400 parts in a standard 6.5 until now), but I've also got to prioritize timeline. This whole project is fairly large and complex. If I start having to wait months for parts, my mind automatically starts figuring out other options. I could have had a complete 6.2 LS with 6L80e in this thing and driving by now (see how my mind works lol).
That, coupled with the fact that I'm absolutely fine with the performance of my 3500HD shop truck (98 model 6.5 bone stock 216k miles) tells me that going with all P400 parts probably isn't worth the wait for my application.

I am building it to be reliable. But even still, the shop truck has 216k miles on it and has been reliable. If I'm honest with myself, this new engine will be lucky to have 25,000 miles put on it over the next 3yrs.

I guess my main point is, if good options/upgrades exist and can be purchased within a reasonable amount of time, I'm open to spending the money even if it's probably not needed.
 
Can you share the costs of machining and your parts list for the engine?

From a Frugal standpoint of restoring a classic, no matter it's book value, I would be interested in a cost comparison of rebuilding this engine vs. a new Optimizer longblock. Some would need to be punched OS to clean up so needing pistons is a fair example. Heads are a known expense so not quite the show stopper. And yeah some things like balance would be better, but, merely added to the longblock when one puts a gapless 2nd ring in it.

If you find some good insurance to cover a modified vehicle like this please also share. I looked at ins when dropping $10K into a Cummins engine and not much luck for coverage "if it was stolen the next day".
 
WarWagon said:
Can you share the costs of machining and your parts list for the engine?

From a Frugal standpoint of restoring a classic, no matter it's book value, I would be interested in a cost comparison of rebuilding this engine vs. a new Optimizer longblock. Some would need to be punched OS to clean up so needing pistons is a fair example. Heads are a known expense so not quite the show stopper. And yeah some things like balance would be better, but, merely added to the longblock when one puts a gapless 2nd ring in it.

If you find some good insurance to cover a modified vehicle like this please also share. I looked at ins when dropping $10K into a Cummins engine and not much luck for coverage "if it was stolen the next day".
Click to expand...



Yeah, I'm keeping track of everything. This is my list as of today. Doesn't include any internal engine parts or machine work, nor does it include the PCM tuning or lift pump setup that I will need:






Promax Heads $960.00
GM Headgaskets $90.00
Intake/Pump Gaskets $26.00
New Lifters $349.99
Pump Timing Wrench $54.99
Center Turbo Drain Blockoff $29.99
Ultimate Turbo Drain Kit $129.99
PTO High Idle Wiring Kit $8.00
ECT Fooler $14.99
Reman DS4 Pump $850.00
2.5" Exhaust Crossover $104.99
ARP Starter Bolts $19.99
Starter Bracket $14.99
Engine Wiring Harness $195.00
Fuel Inlet Upgrade Fitting $32.99
Valve Cover Stud Kit $32.00
Turbomaster WG GM-8 $119.00
Fluidampr $498.95
New Bosch Fuel Injectors $369.99
Billet Fuel Return Log $74.99
6L90e Swap Kit $2,549.99
Low Mile 2014 6L90e $1,200.00
ARP Head Studs $200.00
AC Delco Thermostats $37.42
AC Delco Waterpump $171.79
GM EV Fan Clutch $130.79
Fan Clutch Wiring Pigtail $12.54
GM EV Fan Blade $36.79
AC Delco Crank Pulley $99.79
GM Upper Radiator Hose $11.50
GM Lower Radiator Hose $36.89
GM Bypass Hose $11.02
Exhaust Flange Gaskets $13.78

CrewCab Parts Truck $2,000.00
Reg Cab Parts Truck $1,000.00
GEP Motor $2,000.00

Total $13,489.14
 
Twisted Steel Performance said:
@3bals is working to remove a P400 and will more than likely have it for sale...
Click to expand...


Looks like his rv is 6.5hrs from me.

I looked thru at his pics. Do you think the engine is still fine?
Also, would I need different heads for truck applications?

Realistically, Ive got a 45ft trailer with a winch. And also a couple of sky tracks here at the shop which would make quick work of the engine removal.

Just trying to get a grasp on if it's feasible or not.
 
It has side mount heads, and yes it's fine, the fire didn't even melt the plastic stuff on top of the motor... He has a thread from back when the motor work was done by Peninsular... don't know what was done to achieve the 18:1 as there are no "stock" 18:1 P400 pistons from GEP/AMG.
No harm in contacting Jody and inquiring...
 
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