6.2-6.5 long block or short block questions?

[Drock]

So after a 200 mile trip with blow by it's now good & fried. So it's bottom end time. My question is should I go with a short block or a whole long block? My current heads are 6.5 new replacements and only have about 20,000 miles on them. I've found several long blocks on line just no short blocks and the prices are all over the place? Also what's the best company to trust?

 

[MarcusOReallyus]

Also what's the best company to trust?

Not Jasper.


Best to find a local machine shop and do the work yourself. Then you know what you have. OR find a local rebuild shop that has a good reputation.

 

[Chaski]

Time is a real pain sometimes. I'm also of the opinion that you should assemble it yourself or find a reputable shop. I know that eats up a bunch of time, and if that is time you don't have maybe roll the dice on a used engine?

Finding a reputable shop can be a bit of a black art. Ask around with folks who race, and see what names get mentioned. Also ask at your local independent diesel truck parts retailers. See if both toss out the same name.

If you can't afford the time loss of a month plus to rebuild search your local self service yards and craigslist. I'd want to ability to do a compression test on any used engine I'd consider. Other option is a used one from one of the MV retailers, but those are spendy enough that you could rebuild the bottom end for the price of one... and have known good.

 

[Matt5]

Depending on budget you might be able to just slap a set of rings in... you have something else wrong if your killing a motor in so quick... I would find the issue first before doing anything. Your NOT frying a motor that just got blow by in 200 miles... and what is "good and fried" truck is going to run with blow by to the point of not starting...

Really should give way more details on the problem and post a picture of the blow by along with anything you done to diag where it is coming from.

Why do you say its "good and fried"

 

[royalflush55]

I would check the heads. The bottom end gets the blame a lot of the time when valve guides are worn out. I have seen "new" heads not be any good from day one. New valves not fitted to new guides properly can be in really bad shape in 20,000 miles.

 

[Drock]

https://www.youtube.com/watch?v=1GcQPwwIubk So this is from a cold start. You can hear the air rushing into the oil pan when it's cold like this. And you can see the blow buy build up.

 

[MarcusOReallyus]

Is that a 6.2 diesel or a steam locomotive????




But I think some diagnosis is called for rather than jumping into a full rebuild.

 

[microjeep]

Hi, just a few items to think about, If you can find a newer HMMWV 6.5 go for it, bottom end is stronger but there's a few things about putting them in a CUCV
1 oil pan, HMMWV pan is real close to the axle, 6.2 2 pc rear seal 6.5 1 pc, can't use old pan, got correct from rockauto.com with little research
2 oil cooler lines are smaller on 6.2 but a threaded adapter works perfect and the 6.5 block is recessed at this point so the adapters come out even with where it was on the 6.2
3 need 6.5 flex plate
4 made need old style water pump if new motor has serpentine belt
5 the 6.5 IP on the motor I bought had a different spring in the upper housing and looked/felt like the shutoff would bind so I took parts from the old and new covers and made one that worked better in my opinion, I posted this up in a thread somewhere,
6 and of course you will need 12v sending units for your gauges

Good luck and if you decide to go this way PM any questions, it's been a couple years but I might be able to help

 

[cucvrus]

If it were mine I would put a stock 6.2 in it and call it fixed. I know you need it everyday and that would eliminate the problems IMHO.

 

[Drock]

Yeah getting this done ASAP is a must. My business is virtually shut down without this truck. That being said I think the smart move would be to just bite the bullet, buy new, and call it done for the rest of my life. Money's tight right now so I was hoping to find just a short block sense my heads a new. But I'm not finding them on the interwebs? Maybe they like to machine them to fit together?

 

[cucvrus]

If you were closer I would be able to hook you up. I still have a couple not cheap ready to go in from HMMWV's. My experience has been the stock form CUCV seems infallible. Good Luck. I have 6.2 engines.

 

[gimpyrobb]

Its hard to arm-chair this from a computer.

Guessing its a stock 6.2 with the banks kit added? How old are the injectors? Have they seen any attention? Could one have gone bad and put a hole in a piston? Seems to me with the truck starting so easy, its just one cyl. The puff kinda confirms that.

I'd get comp numbers first. Might just need a piston and injector.

 

[cucvrus]

Might just need a piston

That was easy. Just is the key word.

 

[Drock]

I had a thought? Is my engine hoist going to be able to lift the engine high enough to clear the radiator support? This truck has a 4" lift on 31" tires. I guess I could take the front wheels off and bow the front a little?

 

[gimpyrobb]

Might just need a piston

That was easy. Just is the key word.

When guys are talking about building a whole motor, swapping a piston doesn't seem that bad.

 

[cucvrus]

My Son' has a 6 " lift. I hate it but I took all 4 wheels off and set it on stock rims only with plywood under them to roll back and forth. Worked great. Or unbolt the entire front end and make a project out of it. That was easy. One Saturday in at 7AM and drove out at 5PM. 3 of us with cordless tools. Pulled from a rolled M1009 and into the M1028 A1 all in one day. Fluids in both were drained the week before and left sit open all week. The M1009 had a brand new engine in it. Rolled from rail car when being loaded.

 

[MarcusOReallyus]

Might just need a piston

That was easy. Just is the key word.

Looks to me like "might" is the key word!

 

[Ilikemtb999]

I had a thought? Is my engine hoist going to be able to lift the engine high enough to clear the radiator support? This truck has a 4" lift on 31" tires. I guess I could take the front wheels off and bow the front a little?

I’d say either pull front wheels and put the axle on some car jack stands or pull the core support and radiator.

 

[Drock]

Okay so over the past few days I've bin Emailing questions to the Ebay retailer I bought my heads from (Bostic Motors) about their Optimizer Navistar 6.5. And they say my 6.2 flex plate is the same, but I'll need to have my 6.2 injection pump rebuilt and re-calibrated for the 6.5, and 6.5 non turbo injectors? I don't see why the 6.2 injection pump & injectors wouldn't work? I have their 6.5 heads on my 6.2 now, with original pump & injectors.

 

[Bighorn]

Drock,
Just run it.
There is a little blow by.
How much oil you burning?
My 400 sbc in a k5 burns a quart every 200 miles.

I would wait.
Accumulate the parts over time.
But wait.
That looks like condensation in the morning air to me.
Yea, above normal.
Dude, millions of Mexicans have driven these trucks with a broken rod.
You have plenty of time.