95' Junker Drag Truck

Your pictures look exactly the same as mine with the same symptoms, it had a crack in the cylinder about half down split in a circle you could barely see. Water in the oil never happened when it blew a head gasket in the past with mine anyway. I hope you have good luck with it.
 
USARMY12V said:
...Wouldn't be surprised if the coolant isn't the culprit of your scuffed walls. But could be other factors.
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I can see that being a possibility.

Blue, as of right now, what's your train of thought/game plan? Bigger and better internals w/head work, swap in a known good long block with studs and call it good or...?
 
In a turn of fate, perhaps, I believe I am dealing with this same issue... Clear coolant, clear oil, but hazing at idle. Coolant disappearing someplace. Will did you start this?!?!? You gypsy witch doctor! My game plan is o-ring, HG as deemed necessary by head decking or not, finally put in my studs. Clip my waterpump (Blue I suggest same if you haven't done so already) and valve job if necessary, then also port possibly. Would love to do a runner intake, but that's out of the question right now. Which sucks because why yank off something twice. But when you consider the ~2000 difference at best it quickly becomes a non-issue haha. Waiting it is.
 
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USARMY12V said:
In a turn of fate, perhaps, I believe I am dealing with this same issue... Clear coolant, clear oil, but hazing at idle. Coolant disappearing someplace. Will did you start this?!?!? You gypsy witch doctor! My game plan is o-ring, HG as deemed necessary by head decking or not, finally put in my studs. Clip my waterpump (Blue I suggest same if you haven't done so already) and valve job if necessary, then also port possibly. Would love to do a runner intake, but that's out of the question right now. Which sucks because why yank off something twice. But when you consider the ~2000 difference at best it quickly becomes a non-issue haha. Waiting it is.
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Joker fab does a runner for ~800. I'm sure you could get machining done for a few hundred.
 
The machine work for P&P is high too unless you get a quickly done botch job but then you risk more harm than good. Perhaps one thing you cannot rush on our engines. I'm on the fence on what I wanna do and when. So much stuff I want to do. Luckily this is my last semester in college so the truck budget will go up. I guess theoretically I can be looking at anywhere from roughly ~300 for o-ring machining and deck if necessary plus headgasket all the way to a few thousand if its worst case scenario. Won't know til I yank the head.
 
A true port and Polish does cost a ton. But some cleanup and bowl work with a back cut on the valves, is fairly inexpensive (like 100 bucks if you do the work yourself and farm out the valve work..) And rather effective. While not full out race it helps a lot over stock.
 
No real updates, still trying to figure out how the get the head o-ringed on a Junker shoe-string budget.

Another idea...... Has anyone tried modifying a common rail MLS head gasket to fit a 12 valve? I know 12 valve head gaskets have been modified to work on a common rail so they can't be that different. If I get the block and head both machined with the proper RA finish for an MLS gasket, I don't see why it wouldn't hold up. I know in the past MLS gaskets have been nothing but premature failure on these 12 valves.
 
I am quite interested in that as well because I've seen claims of no o ring or fire ring holding a lot of boost. But as you say, simply failures on 12V. Wonder if this question of ours wouldn't be better served in engine tech perhaps.
 
Pick up a lapping block. Lap the block in the truck, and the head on the bench. Can achieve the ra finish needed, without cost of machine shop. But they can make it really flat if there is any warpage.
pick up a cr gasket and hold it up to a 12v, make sure coolant and oil holes line up right, use a drill to make em right.

Extreme studs has a set of h13 tool steel studs for around 600 bucks.
 
My concern is the documentation of MLS failures on 12V's for some reason. I don't understand why they haven't caught on in 12V applications when CR's seem to use them with good success. And not just CR's but all other types of engine applications from import 4 CYL to high performance V8's. Ozone how deep does your tool cut? I wouldn't mind trying it but my 285k head probably needs to be decked if I had to guess... And perhaps a valve job.
 
Big Blue24 said:
No real updates, still trying to figure out how the get the head o-ringed on a Junker shoe-string budget.

Another idea...... Has anyone tried modifying a common rail MLS head gasket to fit a 12 valve? I know 12 valve head gaskets have been modified to work on a common rail so they can't be that different. If I get the block and head both machined with the proper RA finish for an MLS gasket, I don't see why it wouldn't hold up. I know in the past MLS gaskets have been nothing but premature failure on these 12 valves.
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I just bought a Cincinnati j head milk with power feeds and all for $500 something to think about
 
I got the head cleaned up and checked it for flatness and warping.

Running lengthwise with the head, there is a low spot between cylinders 4 & 5 that is 0.003" deep.

CylHeadCheck1.jpg


CylHeadCheck2.jpg


When I checked the head lengthwise along the exhaust and intake sides, there was less than .0015" anywhere.

I then checked the head at a diagonal from exhaust side of cylinder # 6 to the intake side of #1 and that small low spot between #4 & #5 measured to .004".

CylHeadCheck.jpg


CylHeadCheck3.jpg


CylHeadCheck4.jpg



According to the factory service manual, that maximum allowable overall difference is .012" so my measured .004" is well within tolerance.

HeadSpecification.jpg


For those who have experience with high performance head work and specifically flatness, would you worry about this .003" to .004" dip in the head? Because this truck is and has been built on a shoestring budget, I'm leaning towards running it rather than spending the money only to err on the side of caution.

I have not yet checked the block but the tolerance looks to be much more stringent for the deck at 0.003" allowable difference. I'm really curious to see if there is a corresponding high point between cylinders #4 & #5 on the block deck.

BlockSpecification.jpg
 
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Finally read through the whole thread and its damn impressive.

Sent from the recliner butt naked
 
So when you say you can't get .0015 anywhere along the length but can get a .004 dip between cylinders is telling me that's too much over a short distance.

I can respect a budget but I'd get it surfaced.
 
If its going to the machine shop, might s well get valve job done, and back cut valves, anything to increase low lift flow numbers...
 
Port and do bowl work before it goes, do they can fix the valve seats you mess up. O ringing should not be that much more at the time
 
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