162 6.2 heads on a 6.5

[Snowbound98]

Need a little advise here. I'm rebuilding my 6.5, only had about 30k on it when it developed a bad vibration. Found the balancer had turned on the crank and sheared the key way and took chunk out of the crank. Other than that everything was ok. Long story short, it's a 95 block and a 929 casting number. No piston squirters, no main web cracking, and has the 12mm bolts throughout. Of course the heads have the typical cracking between the valves but no head gasket issues or no pressure in coolant or white smoke. Appear to be superficial. I bought a scat crank, ARP main and head studs, fluid dampner, and am balancing the rotating assembly. But my question is: can I use the 162 heads off a 6.2 that I have laying around? Injector thread pitch is the same as the 6.5. I have fuel lines for both heads. But my main concern is the precups. The 6.5 have 2 square dots on them and the 6.2 have 1 square dot on them. The 6.2 heads have no cracking between the valves and I seen somewhere that they have bigger valves then the 6.5 heads. Is this true? Can I benefit from this? Either way I go I will be putting that upgrade in the heads between the valves. K-line has a kit I think it's KL3900 and it inserts a valve guide between the valves in the water passage to allow coolant flow without cracks being an issue. So the cracks on my 6.5 heads wouldn't matter much to me but if I can run a head with bigger valves and port and gasket match them to the intake and exhaust manifold why wouldn't I? I know replacing the precups isn't cheap and then I would have a head shop do the work for me which would all start to add up. Or should I just stick with the 6.5 heads and do the upgrade and porting? Any help and or info is greatly appreciated. Thanks.

[mrwilecoyote]

I certainly don't know everything but I'll take a shot at it. I went through this recently with my 6.2. There are going to be fill in the blanks here . But
the short answer is yes you can use them. However if they are the angled heads then you will have to bend the inj lins alot and they will damn near touch the turbo side manifold. If it's a DB2 equipped truck you can just use 6.2 lines.
As far as the 162 casting, that doesn't mean boo as I found out. That casting number covers a wide variety of heads and valve configurations.
I found this out the hard way when trying to match a head for my 6.2
It really doesnt matter which heads you use as long as they match.
As far as precups the diamonds are the latest turbo cups. I run 3 dot 6.2 ones with a turbo. No issue. I had a long talk with Bill Heath about precup and he seems to think people put way too much into believing that one kind has a more dramatic effect over another. You can swap them yourself but make sure you put a straight edge on the head. They should not stick up or be recessed more than .002.
as far as sleeving the passages that is a repair for cracked heads. My head guy showed me the kit. I would not do it if there is nothing wrong with the heads. they all crack sooner or later on the 6.5's and most of the time don't effect the engine. I don't think I have pulled a 6.5 apart yet that wasn't cracked. 6.2's tend not to crack as easy because less heat from lack of turbo. If you had no problems with your 6.5 heads use them.
just my .02
Like I said, I left some blanks here. This knowledge was attained whilst on the hunt for a matching 6.2 head for my CUCV after I ...oops...with a 5 lb hammer.
As far as ARP studs, I love 'em but make SURE you clean them well and use a good sealan on the threads. I am sure there is alot of different opinions on what to use. Personally I have had the best luck using Aviation Permatex.
I saw a guy o ring the bolt holes. If the heads are off...not a bad idea.

[Snowbound98]

Yes this does have the DB2 pump and I have both sets of injector lines. Thanks for the info. It helps. I figured the 6.2 heads didn't have cracks because the lack of the turbo also. If you say having different precups won't really make a difference then going to a head with bigger valves would. Should that be enuff reason to use the 6.2 heads? I'm just concerned because I know that my 6.5 heads have cracks but were not an issue. If I use these 6.2 heads because I want the bigger valves and they crack using a turbo or the precups aren't good for the bigger bore or something, they could be an issue. I'm sinking a lot of hard earned money into this engine and don't want to pull it out again or remove heads because of such a small gain with the 6.2 heads. Either way I go the heads will be ported, gasket matched, and the coolant passage upgrade. I'm not taking any chances. I have a marine injection pump, marine injectors, holset turbo, and water injection. I plan on getting as much as I can outta this engine and haven't cut any corners. I just need to know if anyone has seen any gain out of putting 6.2 heads with bigger valves on a 6.5 turbo.

[sctrailrider]

The larger valves will help the motor breath, with that said, they are prone to crack between the valves. I doubt you would know the difference between the heads. I would be sure and have them pressure checked for sure !!!

As for the cups, just swap them out for the 6.5 cups, most cups will have small hair line cracks, used ones anyway, the cracks don't hurt anything as long as the crack doesn't go past the fire ring on the gasket. You will need the larger cups with the turbo you are going to use.

[Snowbound98]

Thanks sctrailrider. I just didn't know if the cups would be that much different. I do know that when the 6.2 came out they were after economy more than power and as they introduced the turbo and bored out the engine fuel economy dropped but power increased. And so did all the problems. I heard if u want better mileage on your 6.5 go with the 6.2 cups. But by me thinking
bigger valves, more air flow along with porting and gasket matching, maybe the precups won't be that big a deal(compared to my 95 6.5 cups). I'll try punching them out and see if I can do it without damaging them. If I end up having to buy a set I think I'll go to the newest design diamond shape precups. And my head guy told me to pressure test them too so I'm sure it'll happen. They try to sell you on everything. But I just like to hear from people out there that have been down this road b4. Thanks guys for all the input.

[sctrailrider]

The small cups will be smokey with a turbo and hurt both mileage & performance but you can use them if you want, there is a reason GM changed them for a turbo.

If you change them, use a BRASS rod through the injector hole to knock them out, do not use steel!!!! And if your machine shop decks the head, they should be out when that is done, there is a chance the machine will pull them out while cutting and kill the head & machine...

The diamond or turbo cups would be best I think, they will be better for mileage than smaller ones... I get 20+ easy with much more work done to my setup....

[Snowbound98]

Well, as it turns out these 162 heads have the same size valves as the 567 heads. I cleaned up the 6.5 heads to see if I could get the cups out without damaging them but noticed that some of the cracks on the cups go right up to the fire ring on the head gasket so I'm getting new cups regardless. And then said to myself " self, those look like the same size valves". So I pulled one intake and one exhaust and sure enuff. Same size. I was told that the 162 head had bigger valves than the 567. I know better than this but didn't check it out before going thru all this aggravation. So my 567 heads will go in to get heads checked, that k-line kit installed, and cups put in. Also gonna set all my spring pressures, and 3 angle valve job. I'm gonna do all porting and gasket matching myself. I see you have the holset 40 turbo. How do you like it? What kind of boost pressure do you see? I have the hx35w. Should I have gone with the 40? I just wanted a less restrictive turbo and saw the holset 35 and 40 but thought bigger isn't always better. I wasn't sure if this engine would benefit from that. What other kind of mods did you do to your engine? Are you happy with it? Are you running an air charge cooler? I'm gonna water inject it to try to stay cool. Did you put on thicker head gaskets? I'm thinking about it but I need to check my piston to deck clearance to see if this deck has been cleaned before. I'm still in pieces, so you think I should shave the pistons and go with thicker gaskets or don't bother? I see a lot of people dropping compression a bit but is it worth the cost? Gaskets aren't much but shaving pistons could add up. I try to get as much info before I do something so it's only one time. I can't balance crank rods and pistons and then go back and shave the pistons. What ya think?

[sctrailrider]

here is my build thread here, I don't remember if I finished posting all the info here or not but it will give you a idea if what was done, some out of the box things I did and such...

http://www.thedieselpageforums.com/tdpforum/showthread.php?t=40794

As for the turbo, it was custom built by a member on this site not a off the shelf turbo at all and I will not give the specs of it other than it is a true Holset and is just as he described it to be and more.... not cheap but nothing is these days.

If you need more details, pm me and I will try and help you if I can.

Maybe Ron Schoolcraft will chime in, he built the turbo.

[sctrailrider]

I didn't shave them, I used Kennedy Diesel 18:1 pistons.

I am installing a CAC now & water injection also, my IP was built and it is set at 95cc now, I love the setup, very fast spool up and more than enough fuel.

I haven't dynoed it yet, only 4500 miles on it so far, when I get everything else installed I will try it on the rollers and see how it does, but from the few times I have towed with it, 19,000 - 20,000 lbs, it is as strong as I had hoped for, turbo will light around 1300rpm and keep on going, at road speed of 65-70 in OD (5th - nv4500) boost is instant with a cruse rpm of 2200 - 2300 @ 70mph.

[Snowbound98]

Gotta tell ya, you really out did yourself on that build. Took that to a whole new level and it looks really good. I really don't wanna get down to 18:1. I'd rather stay around 19.2-19.5 range just so I can add a little more boost and do it safely. I live in Chicagoland area and these things are hard enuff to start in the cold. I found a machine shop to do the machine work to the pistons and I too am having them ceramic coat the tops and moly graphite coat the sides. But one thing I can't seem to resource is rod bolts. Where did you find yours? I read a couple post but never saw a conclusion. Does ARP make them now? I refuse to reuse these rod bolts. No way not happening. Any how I have time. I need to get my heads, block, and pistons back before I can balance rotating assembly and recondition rods with new bolts. But a push in the right direction would be appreciated. I tried to pm you but I don't know how. There was no link or private message area. But it is 4 am so it could be me. Thanks for all your help and I'm sure I'll be talking to ya soon. Also message me or email me a quote to coat my pistons if you want to. Machine shop doesn't do it at their facility they have to send them out. I saw what you can do and it looks good. I could ship them to you when they are done and you can work your magic on them if its something you do or want to do. Thanks.

[sctrailrider]

For the rod bolts, no one sells new ones that we can find, ARP doesn't yet and may never sell them...

I couldn't PM you either, might be because you are new here or something...might ask the mods about it...

I could do them for you but I don't think the mods here want me posting those kind of things posted out in the open, not sure???

I am on other diesel sites with the same user name tho... and my email is in my sig below...

thanks for looking at the build, I love the new motor...

We all here will help anyway we can..

[Snowbound98]

Hey trailrider, I sent you an email. Thanks again.

[sctrailrider]

Hey trailrider, I sent you an email. Thanks again.

reply sent...