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Optimizer 6.5

grader6.5td

grader6.5td

Member
Messages
12
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34
Location
Wyoming
Well I pulled the trigger and Leroy ordered me a new Optimizer 6500. Looking forward to this new engine. Specs say that these are 20.2:1 compression ratio, just a bit down from a normal 6.5 at 21.5:1 right? Curious if that'll be noticeable as far as cold startup and overall performance? I would guess probably not really.
These don't come studded from what I see, I'm only running 12psi boost max on my quadstar tune and I've been happy. This pickup is mainly used for light occasional towing and empty highway travel, so I like my mpgs.
That being said, while the engine is still out do you guys think studs are worth it for the long term reliability, or for my usage don't worry about it?
Also what water pump do you all recommend? AC Delco balanced flow probaby??
 
I'm pretty sure they are NOT studed, mine was not. If yours turns out to be please let us know. I wouldn't worry about adding studs. I also thought about head studs and I was talked out of it unless I was going to add more than 12lbs of boost, which I do not intend to do. Enjoy your new engine!
 
cant tell a difference in starting.
If you dont want studs for higher pressure don’t bother.

My suggestion is pull it apart and go from good new engine to ideal new engine.

clean up flashing from the rods, measure gap of rings and asjust as needed to get them perfect. Mark 8 ziplock bags numbered and send the rings of for gapless alterations. Fine sand the piston wristpin holes to get clearance perfect and their oil holes. Verify main and rod bearing clearances. Send in the lower rotating assembly for balancing. Be 100% clear they are to modify the crankshaft NOT the balancer or the flywheel. Sand don't drill the rods.

remove flashing from block and heads, clean up oil return flow areas.
next decide about coatings. Imo minimum is main/ rod bearings and camshaft, pistons are next inline.

There is always more you can do like head work, roller rockers, better valves/ valve springs etc thats up to you.

New head gaskets, head bolts and main bolts.

Now the last thing to consider is cryogenic treatment. Expensive but you are buying time from metal fatigue and wear.
 
grader6.5td said:
Well I pulled the trigger and Leroy ordered me a new Optimizer 6500. Looking forward to this new engine. Specs say that these are 20.2:1 compression ratio, just a bit down from a normal 6.5 at 21.5:1 right? Curious if that'll be noticeable as far as cold startup and overall performance? I would guess probably not really.
These don't come studded from what I see, I'm only running 12psi boost max on my quadstar tune and I've been happy. This pickup is mainly used for light occasional towing and empty highway travel, so I like my mpgs.
That being said, while the engine is still out do you guys think studs are worth it for the long term reliability, or for my usage don't worry about it?
Also what water pump do you all recommend? AC Delco balanced flow probaby??
Click to expand...

Don't touch anything. Just run it. DS4 pumps worth a damn won't be around as long as that engine. If you go into the valve covers, buy new valve covers, else you will never get them sealed again. See where this is going? You open it and you open an expensive can of worms.
 
I don't know where folks got the idea lower compression made for harder cold starts.

Few weeks ago it was -4 here overnight and I didn't plug the truck in, was planning on taking the Jetta to work.

cold killed the Jetta battery (turned out it was from 2013) so I had to start the truck cold, lots of smoke but fired right up like normal, no extended cranking time or anything. And yes I have an 18:1 engine.

Granted I have a powermaster starter and batteries that are only a few months old, but even I was impressed by how easily the truck started.

With regards to what mods to do, depends on whether you will want to change truck's use in the future, or stay happy with what you have now forever.

Lowering compression will decrease MPG

If never running high boost, then head bolts are fine

Balancing the assembly is a good idea, optimizer blocks still have the potential to crack and it's a relatively small expense to do with longevity in mind

Gapless rings are another good investment in terms of low cost/ high return on longevity

Last I spoke to Leroy timing gear sets are a few months out, but if you can wait that long I'd say timing gears are worth the wait. Eliminate chain slop and its effect on injection timing forever.

Opening up the engine does indeed open the proverbial can of worms. You'll definitely spend less going for longevity over power.

There are also non- engine supporting mods to be done for longevity and MPG, like a 4" exhaust after your 3" downpipe and a better turbo
 
It is true the suggestions I make are if you are planning on crushing the 300,000 mile mark. And there is more to do once in. Clear tube on ip return line, hydraulic hose in place of the factory junk oil hoses, fuel pressure gauge tapped at the ip inlet. The harmonic balancer it comes with is good for 100,000 miles. Replace it with fluidampr now and sell the new one it comes with (after the balance job is done) or run the original and replace it with new AC Delco ones every 100,000 miles.

He is right ds4 is done for. Many places like Nv where I live people with ds4 are stuck with them. But in Wyoming you can swap to db2 once the ds4 are all dead and gone. They don’t go through the inspections like we do here or California. The ds4 and electronic nonsense that goes along with it is not used in military rigs, but the only reason that optimizer is made is because they and the hmmwv they go in are in production for the next 13 years guaranteed.

Now, like the ds4 which stopped being made just recently - they were made in production for new vehicles only until 2000, AM General/ GEP is going to be producing parts to support those new 2035 hmmwvs that will be built. And db2 sitting on top of them are included. I have a bias against the ds4 because db2 gets more power or more mpg by operator choosing. It lasts longer and is more plentiful. For manual transmission rigs absolutely no electronics is needed and 4l80e there is tons of aftermarket controllers. There is a couple advantages like it’s already in the truck- and if you use wmi the control of it is done better. Outside of those two- nothing.
So dont give up on a long term, better engine just because the ds4 isn’t gonna be around as long as the engine.

There is a technique to removing the valve covers without distorting them. Same one used on sbc from the 50s-90s. Full metal tang 1” or 2” puddy knife. Sharpen the edge a little on a grinder. Drive it with a hammer all the way around. I know some here, the 6.5 is the first engine they get Inside of- but using this technique isn’t because of the 6.5 unique design. Many engines need valve covers, oil pans, etc removed properly or replaced.

the improvements I am talking about are north of a grand not counting roller rockers and the headwork to be considered. Determine the cost on each item and ask about why and what is worth doing and what isn’t by your use and determination.

The low compression = hard starting thing is this:
Rings & cylinder wear gets blowby and compression falls. Eventually the engine gets hard to start. So people relate the lower compression to hard starting. But it isn’t accurate. Look at the stock compression of a duramax. The air and fuel mixture being proper ratio, and all that energy going into the compression lets it work fine. But when an engine has blow by- it ruins the air to fuel ratio with that air going into the crank case.

Then there is this- think of a new 6.5 but with really low batteries. It cranks so slow it barely starts, or maybe won’t start. You can’t start a 6.5 with a ratchet on the balancer bolt because you can’t turn it fast enough. 21.5:1 or 20.2:1 or 18:1- the lower compression means the heat created is lower, but the crank speed is faster. So getting the air to fuel correct and the speed of crank is faster means you create the heat easier to ignite.
 
Any hope for the DS4 rebuilds like Quadstar is doing?
I do want to keep my truck, especially considering my investment in the new engine. I will start to keep my eye out for a mechanical pump and footpedal just for the future. What is the recommended db2 pump number for a turbo 6.5?
 
Even when people can’t get junkyard throttle pedals- there are so many aftermarket pedal/cables for hot rod and racing... but low cost bolt lt in is always nice.

Find out if your dmv stops it is all. Only places I really know that did is Cali, Nv, and part of NY. I can’t imagine anything in Wyoming limiting that.

Then if auto trans- get an aftermarket controller if you cant find the van/ hummer/ tcm.

Idk what resell value is of good ds4 with pmd kit, app, and all that stuff is. But I would imagine most of the cost of new db2.
 
Just on a curious note for the inspection stations. how do they do it in Cali and other places so it won't pass if it's had modifications? switching to a db2 and removing the PCM for a TCM. can they actually tell? I know the PCM on my rig has no record of a vin that I have seen when reading the data on it, I thought only odb2 had that capability of storing the vin.
 
In nevada every year you have to go to a smog station (private owned). There is a check list the huy goes through like fuel cap, pcv valve, vacuum hoses not plugged off, muffler & cat in place etc. gas engine rigs just sits parked but diesel is up on dyno rollers to load the engine. Then they plug into obd2 and run it at idle a little, then at speed, something like 35-40 mph on the dyno- gas engine just rev it up and hold around 3,000 rpm.

Older cars that don’t have obd2, that just have a probe in the tail pipe and it monitors parts per million of nox, carbon monoxide, hydro carbons, oxygen. Also noting if too much visible smoke comes out. There is an optic tester if too much smoke, but that is almost never used.

Because obd2 can have codes be reset, it has to be in the ready state. You can’t just clear the codes- you have to complete the drive cycle for them to be gone legitimately. Trouble codes related to emissions are automatic failure.

So the moment you have an obd2 rig, it has to have emissions read through the ecm. This was the entire purpose the ds4 was built. A creative individual could get away with removing the obd2 plug and installing an obd1 in its place- then they would do the tail pipe test, which any db2 truck even with blowby passes no problem. But the computer system knows that gm trucks had obd2 before the 1996 mandatory year. I forget what hear it is 1994 that gm had obd2 and ds4 in all their trucks? So when you are missing the required obd2 ability to monitor emissions here- automatically fail.

My hummer is a 95. The last year of hummer obd1 with db2. Wanna guess why it was specifically chosen even though they were n/a and turbo only option on ds4 hummers?

So you go pay the smog inspection owner each year (now like $84) it takes about 15-20 minutes plus waiting in line sometimes for an hour, usually 15 minute wait, and they gove you a slip of paper saying you passed. The computer is linked to dmv, so you can either go in person with the paper or go online and type in your information along with a big serial number of that inspection that just happened and pay with a card that years registration fees. A late 90’s diesel pickup is probably in the $55 dollar range is my guess. Used to be about $40. This is on top of the smog fees set by the county. Smog fee is maybe $20 less in Northern county where Reno is but registration is same. Then extra for personalized plates if you want them.

I will let others from NY, Ca and Az @WarWagon tell theirs because it might have changed since ai last seen their system.
 
The only reason it wasn’t done federally (national) is because there wasn’t funding for it when the laws were passed before the gmt400 was on the drawing board. Now with green initiatives- it has been pushed foreword more. The only thing that is holding it back now is California, and all of GM going to electric only in 2035.

to make it happen anywhere- all it takes is two different multi millionaires to be willing to build the smog places in an area and go to the epa showing funding is in an escrow account for it. Then the epa enacts the law in that county and the county has to conform. The county and state dmv like it because they get a percentage of profit from every single smog done.

Diesel smogs were not done here at all, then two competitors of regular smog shops (emissions testing stations) that were friends both agreed to put in the dyno required to do the testing. And since two different companies were willing to invest- they start enforcing.

My hummer being full time all wheel drive was exempt because the first places only had one set of rollers (one axle at a time). But then another business realized he would be the inoy game in town- and put in a dyno with dozens of rollers so now a semi truck could be all wheel drive and dyno-load the drive axles. So then all light diesels have to smog. Has to be over 20,001 lbs to not be required here.
 
‘94 and most of ‘95 GMT-400s were OBDI. ‘96 and later we’re all OBDII.

CA is inspection every two years for ‘98 and later. Total PITA as I had to reinstall the stock turbo and vacuum pump. The vacuum lines to the solenoid were breaking and AFAIK you can no longer buy them. I had a Heath flashed PCM and it smoked on heavy acceleration, the combination of the tune and marine injectors. I bought a stock PCM for the same year Suburban and swapped that in for my final tests in CA and that cleaned it up. I never flashed the PCM with the VIN # from the vehicle, so they must not pull the VIN # from the PCM when they plug into OBDII because it is different from the vehicle. Thank god those days are gone.
 
There are some guys in Cali that had a problem with stickers on the valve covers for emissions inspection. The GEP sticker says “emissions exempt” and they made the mistake of leaving that on there. But then when removed and flagged already- they had to “buy” a whole new engine -but lucky the new engine had the gm factory stickers on there-

Because you know, putting a GM compliant sticker on a GEP exempted engine is not acceptable. And luckily GM doesn’t make and sell those stickers so a person can’t just buy stickers and install them.

On a different topic, I met a person in 7-11 the other day who said he was a graphic artist. I wonder what he actually does for a living... he said something about making things on computers, but I didn’t understand. But he had a cool Honda - thats why I brought him up!
 
Maybe if a person is scrounging the auto salvage yard and happens across a sticker on a valve cover, might be worth nabbing that cover.
I dont know though if it could work like that, by just switching the covers.
 
MrMarty51 said:
Maybe if a person is scrounging the auto salvage yard and happens across a sticker on a valve cover, might be worth nabbing that cover.
I dont know though if it could work like that, by just switching the covers.
Click to expand...

I have never seen a 6.5, let alone a diesel, any brand, in a pick a part boneyard. I think the 6.5s were grenaded in Obama’s cash for clunkers program, while the other diesels were handled by salvagers.

 
WOW! so I guess with all this epa madness my 95 obd1 truck would never pass up there if it was converted to db2.

there has been talk here in Texas about the smog testing, some cities actually have the capability, but there is an inspection station at just about every mechanic shop now. at my work we inspect our own trucks, no emissions testing. I know here if a person owns a said amount of acreage, they can put farm tags on their trucks and drive on the roads. only they are not supposed to be on the freeway, they do it anyway though. several farms in the area the only way in or out is a major freeway into town.
 
Big T said:
I have never seen a 6.5, let alone a diesel, any brand, in a pick a part boneyard. I think the 6.5s were grenaded in Obama’s cash for clunkers program, while the other diesels were handled by salvagers.
Click to expand...
I did see a square body with a 6.2 setting on a rack in one of obummers crash for klunkers. I could have bought the whole truck but didnt have money for that. I did talk the guys in the yard into letting me take the grill and bumper. There was vehicles in there that’d make a sane person cry.
 
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