6.9 Rebuild Parts Advise Please

[Garbage_Mechan]

Hello 6.9 experts! My dailey driver 86 F250 is in serious need of some help before I run it out of oil and burn it up. It has 500,000 miles on the pistons, however I did a re-ring overhaul on it 200,000 miles ago due to a failed lifter roller and flat cam. At that time it got a valve job, rings, bearings, cam, lifters, and the block and heads decked. The pistons were cut to compensate. It has run great for many miles but is begining to put away 3-4 qts of oil every 500 miles. It only smokes blue after extended idling or when cold. I is probably valve guides but I have decided to go all the way because I'm pushing it by now on the pistons.
Rebuilding diesel engines is not new to me (I'm a diesel fleet maintenance mananger) but I would like some opinions on what parts and where to gert them. I may turbo this engine in the future but I can't get too carried away since it is a company truck.
Here is what I have in mind.

What valve guides to run? any specific info on the valve job?

I have seen reference to converting to 7.3 rockers?

Best vendor for headstuds?

Preference on headgasket brand?

Where to buy engine rebuild kit? I will insist on Mahle pistons I beleive. I may be able to use fleet pricing at International.

Preferred piston clearance?

Cylinder hone specs? (surface finish, pattern etc)

Preferred piston protrusion?

There are probably more but lets get the conversation started.

Not to slight anyone else who I have neglected to mention, but I hope to hear from Typ4, Icanfixall, HESutton, AGNEM and a few others who have put some thought into this.

John

 

[Garbage_Mechan]

Updated My Sig!

 

[rhkcommander]

Not one of those preferentials but i might be able to lend a hand.

ARP headstuds 150-4069, plus ARP thread lube applied lightly.

Victor reinz or fel pro head gaskets - either works just fine

Engine rebuild kits are often junk but a few look ok. Probably better ordering pieces separate.

Rockers are all 7.3 style now, same deal with oil cooler centers.

Probably overdue for IP rebuild and fresh injectors. Cam grind and turbo would give a nice performance boost too.

 

[hesutton]

Precision Engine Parts makes some quality valve guides. They have Manganese Bronze and hardend cast iron guides. The MGB guides are supposed to be the bee's knees, but require some special tooling to machine properly, they are supposed to last for ever, but heat transfer can be a concern. The HCI guides are better than the stockers and heat transfer is not a concern. The biggest factor in the quality of the guide replacement is going to be the machineshop doing the work. If they screw it up, it can ruin the heads or cause big problems in a few short miles of operation. Choose your machine shop carefully.

Victor Reinz and Felpro have a good reputation. Hypermax may.......... I stress may have a "high performance" option for headgaskets down the road that doesn't require machine work on the block, but, you'll still need gaskets and seals for the rest of the motor.

I like Clevite 77 bearings (main/rod) and at the time I needed mine, Hypermax had the best price I could find.

Mahle pistons are a good choice. With the deck and the heads being milled, it'd be a good idea to go with their reduced compression height (by 0.010) pistons. Shop around and see who has the best price on a set.

Same is true on the ARP studs. I looked at 10 or more places before I found a set on sell. Steve (spg) is a member and had a good price on them recently.

The engine specs are in my manual and I don't have it with me at work. Sorry. Gary may have that posted up before long.

Please ask more questions when you need to or if I've been to general, ask specific things that need clarity. You can always call me too. Just shoot me a PM.

Heath

 

[Garbage_Mechan]

RHK, thanks for your post! The more experiences the more I know.

Heath, your right, I need to norrow it down to a few items at a time.

So as far as the heads go, first is making certain certain they are flat and not cracked if the first thing.

I do recall the shop that did them about 7 years ago put bronze guides that screw in or are a spiral design (I seem to recall, which is a dangerous excercise)

Also, to reepair cracks between the intake and exhaust seats, he used a kit to install a liner in the water port which goes between the seats. The proceedure was to remove the ball plug in the water jacket on the outside of the head, use a precision reamer (part of the kit) and install a brass sleeve in the water port through the seat area. Anyone else had this done? Any problems?

Any experirnce with installing replacement intake seats when the cast iron original seat is pouunded out?

I would love to talk to or ship my heads to a proven shop. Anyone have a reccomendation?

Suggestions on valve guide seals?

Porting?

Thanks,

John

 

[rhkcommander]

No problem, glad to help as best I can.

Porting: exhaust side needs it more. Most people match the exhaust ports to mani as i recall. Intake can be smoothened since we arent gassers (thus we dont need to swirl air/fuel in like they would. )

 

[RLDSL]

You are far better off with the Victor Reinz gaskets ( they also make the gaskets for the factory , along with most of the other high end engine manufacturers in the world ) and a little trick to assure leak free installation , shoot the head gaskets down with about 3 light coats of spray hylomar on each side
If you are going to be running dino oil stick with the standard umbrella seals on the exhaust valves, but if you are going to run a high end synthetic on the full rebuild, you can consider picking up an extra set of positive valve seals for the exhaust valves. THe 7.3 heads came this way but they had problem with them eating guides on dino oil but i ve been quite confident of teh extra lubrication with the synthetic to be able to go back to the positive seals all around and it cuts down on consumption a bit.
If you have guides that are just a little bit out, you can have them drilled and inserts put in called false guides by a good diesel machine shop that will save a minor fortune over the cost of having complete guides replaced and they are of a very high quality material.
Ive got a real good diesel machine shop here nearby, they even make cams and cranks for locomotives needless to say, my iddy biddy engines are some of the smallest things they ever see, but they do all the machine work for the local IH dealer ( and the pete dealer , and KW dealer and the... well you get the picture

 

[hesutton]

The old seats certainly can be machined out and new sets pressed in, but again, the long term outcome will depend on the quality of the machine work. I can't stress that enough. The machine work can make or break any build.

As far as valve seals..... I'm trying something different on my heads. The machine shop that did my head work (the third one, 1st two couldn't do it correctly), Haas Machine in Louisville, Ky, suggested a positive seal with a teflon insert to go with the new Precision Engine Parts hardend cast iron guides they installed. He had really good experience with them and I'm giving them a shot.

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Heath

 

[Garbage_Mechan]

Thanks everyone for your contribution. I love how people on this site are truely helpful .

RDSL the machine shop your talking about, is it Chrome Crankshaft? I beleive the rebuild complete locomotives for resale too. (somewhat of a railfan but mostly steam)

I have to get moving on this because my last 2 tanks of fuel went about 500 mile and went through 3 quarts of oil to go with the fuel. Funny thing is it runs great! Only smokes if left idling too long.

On the engine kit anyone have any leads on a kit with Mahle pistons? I need the reduced height one since the block had to be cut last time. Had to cut down all the stock pistons on that re ring job.

I have expererince valve guide failure on my 7.3 turbo'd engine back in the 90's. After the rebuild I noticed something wasn't right and had one or two exhaust guides really loose, one would have fit 2 valve stems through it! When it went back to gether the 2nd time I didn't put seals on the exhaust valves, no more failures and I don't recall it using a lot of oil.

Anyone had any experience with the repair I mentioned on head cracks between the seats?

John the Garbage Truck Mechanic

 

[icanfixall]

Mahle is the oem piston maker for all 6.9 and 7.3 engines. Buying parts instead of a rebuild kit. Boring a 6.9 is not an issue like it is in the 7.3 engines so bore away and be sure its not an issue. Never ever use an oil pan gasket even if your gasket kit comes with one. The factory used an RTV and its stil the best gasket. No cork crushing and leaking. Replace the front and rear main seals with the speedi sleeves. If you don't install a sleeve the new seals will leak. All these cranks and dampners have a seal groove worn in them so they need the sleeves. Ford sells a rear seal with a sleeve as part of it. Its around $40.00. ARP studs are the real only way to go too. All these idi engines had the two rear cylinders bored 1/2 thousands larger than the front 6 for the oil that collects in the back cylinders from the CDR valve. VR gaskets are the best. Then felpro. The intake valley pan gasket can be either one also. I like the Mahle bearing but as posted above, those are