Need advise in fixing a block

[PHeadings]

Talked to a certified mobile mechanic today and I was told to use JB Weld on the low area between the cylinders and sand it smooth. Does anyone else have any other Ideas in repairing the low spot. Was thinking of making a long board with 300 or 400 grit and sand the whole block unit the low area is undetectable with the hand. I know the best way is to pull it and have the block decked but I am trying to avoid that. If you look at the pictures you can see that the groove is the same depth as the bridge marks left by the OEM gasket. The bridge marks are the inch and a half lines between the cylinders. Each cylinder has four darker marks on the outer corners that are lower that the top surface. The corners come together down the center which leaves less surface area for the head. Not Good!

 

[TBurow]

not good, but how many times do you want to take that head off? the first time it gets hot the metal will expand and the jb weld will melt and you will be right back where you started. i would have the deck surfaced, why ruin a good engine with backwoods fixes. if that is not an option, the only permanent repair i can think of is to heat the block to 350 degrees and weld a small bead across the low spot and carefully file/sand it flat and smooth. if no welder is available you could try using a brazing rod, but it is your engine and like i said is it worth screwing it up if done wrong? pull it out and have it decked or pull it out and replace it if you screw it up, i would take the cheaper way and have it decked, and not need a new block.

 

[nps]

As much as I love JB Weld, it won't even hold the pressure of a radiator. No way will it hold the cylinder pressures if the gasket won't.

 

[JHardwick]

Deck it and forget it!

 

[GWoody]

Decking would be the best way to fix it, but keep in mind the valve to piston clearance is already pretty close so you may need to have valve reliefs cut into the piston or if it's available a thicker headgasket. I had heard at one time that Cometic was working on some.

 

[JFaughn]

How do you know this , or did you just not tell us the the gap , between a long enough machinist straight edge & deck .
I would have to check spec. , but the gasket will take up some , about . 02-. 04 .

 

[Vaughn MacKenzie]

Decking would be the best way to fix it, but keep in mind the valve to piston clearance is already pretty close so you may need to have valve reliefs cut into the piston or if it's available a thicker headgasket. I had heard at one time that Cometic was working on some.

You can actually shave quite a bit off the head before piston-valve clearance becomes a concern, somewhere on the order of . 030", so I wouild think taking . 005 -. 010" off the deck wouldn't be a big deal.



Vaughn

 

[WUnderwood]

I agree, JB Weld wont hold up to the heat/pressure. If you have access to a TIG welder, weld a small bead and then sand it smooth.

hope this helps

 

[PHeadings]

Anyone use Belzona 1111 super metal? At 1500. 00 dollars a pint it has got to be good.

Belzona 1111 (Super Metal)

 

[betterthanstock]

Talked to a certified mobile mechanic today and I was told to use JB Weld on the low area between the cylinders and sand it smooth. Does anyone else have any other Ideas in repairing the low spot. Was thinking of making a long board with 300 or 400 grit and sand the whole block unit the low area is undetectable with the hand. !

Are you saying the low area is undectable by hand, or you'll sand until it is undetectable by hand?



How deep is the low spot, with a dial indicator?



You could cut a piece of aluminum or copper foil, or coke can, file it to the exact shape of the low spot, and use very thin epoxy or crazy glue just until the gasket clamps it down.



BTW, don't sand. Where is all the abrasive going to go? in your cylinder ring grooves, oil passages, coolant passages?



I would just put on a new gasket, tighten with new bolts, or maybe get those ARP ?? high strength bolts, and tighten it up. If it fails again, then take it all apart and resurface it properly.

 

[rbattelle]

I would just put on a new gasket, tighten with new bolts, or maybe get those ARP ?? high strength bolts, and tighten it up. If it fails again, then take it all apart and resurface it properly.

This might be the best advice so far. We're all speculating about how you might try to fix that imperfection, but the truth is nothing so far sounds very promising.



I don't like the idea of trying to use a weld to fill in that patch. From what I've been told, welding is the worst thing you can do to cast iron. Besides, it would need to be preheated to at least 450°F before welding, and it won't be easy to do that to the block installed in the truck.



JB Weld is a horrible idea. And I'm no fan of betterthanstock's scrap aluminum piece, either.



You don't want to make the situation any worse than it already is. The lowest-risk solution for now seems to be "slap on a new gasket and see what happens".



The other thing you might consider is measuring the depth of the imperfection, then taking that over to a Cummins repair center and asking them whether they thing a new head gasket would hold.



Ryan

 

[PHeadings]

I got some Belzona (read about it post #9) from the shop that is remaning the head. I was told it works better than JB weld and expensive too. I was told to rough it up with 80 grit, but that would be uglier than it is. I will sand it with 200 grit leaving the grain running the opposite of the way it blew out. Wipe it down with thinner to remove the oil. The layer of Belzona added will be thin. Just want it to be level when the gasket is sandwiched down. I will be using ARP head studs. I bought a 30" piece of channel aluminum which I will attach 400 grit to and do a few light (blocking) passes before I blow it all out and clamp the head down.

 

[JFaughn]

Before you start doing some thing to the block [ that could make you take the block out ] a machinist straight edge long enough to have at least a 1" hang over on either end & measure .
Look at what your talking about spending [ $1,500 - pt. ] on a eng that is worth $2,500 used , $3,000-$4,000 rebuilt , and you haven't mentioned in your posts that you spent $100 for a tool to check spec. , just trying to keep you from hitting that guy in the street , while your looking at the babe on the side walk .

 

[Slingblade]

Several years ago I purchased a rebuilt engine from a parts store. When I turned it over for the first time it filled the no. 1 cylinder full of coolant on the power stroke. I pulled the head and found a deep gouge between the cylinder and the coolant passage. I called the shop that had built the engine and their advice was to pull it and return it too them or fill the gouge with JB Weld and file it smooth. (which is what they would do if I sent it too them for repair). I cleaned the block made the repair with the JB Weld, then filed it down smooth. I drove that truck for several years without any trouble. The JB Weld held up very well. If it were my engine I would deck the block and rebuild it, however I can say that the JB Weld does work if done correctly.

 

[PHeadings]

Before you start doing some thing to the block [ that could make you take the block out ] a machinist straight edge long enough to have at least a 1" hang over on either end & measure .

Look at what your talking about spending [ $1,500 - pt. ] on a eng that is worth $2,500 used , $3,000-$4,000 rebuilt , and you haven't mentioned in your posts that you spent $100 for a tool to check spec. , just trying to keep you from hitting that guy in the street , while your looking at the babe on the side walk .

Is this a text message? Can someone translate?

 

[B.G. Smith]

Text message, don't know?? Looks like he is saying keep things in perspective, spend a couple of dollars for some quality measuring equipment (machinists straight edge that will span the block from front to back, a depth micrometer or might be able to use dial indicator) and find out what you really are dealing with (depth of the path between the cylinders). Second paragraph says about the same thing only differently. Focus on finding out what the problem really is and not on trying to find a fix that may not work. Well, that's my interpretation, that should bring on some flames. bg

 

[PHeadings]

Thanks for the ideas guys, today I built a long block and sanded it out with 400 grit, seemed to be more of a carbon build up than a grove. I will post pictures later. Not so lucky on the head. They called and said they can't repair it, So for 1450. 00 (reman) I can wait 15 days and get one through Cummins or for 1850. 00 I can get a reman through Dodge (2 day wait). If any one has a spare head laying around PM me.

 

[MMeier]

So, are you going to with the '06 head or..... ?

 

[PHeadings]

Why would I go with a o6 head when I have an o4?

 

[JFaughn]

What made you use the 400 sand paper , I'm not sure if thats it or not , but the headgasket manufacture wants a very specific surface for the gasket , there is a surface grading system for machined surfaces , they do not want a surface thats either too soothe or too ruff .