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Head Gasket time!

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Old 10-30-2008, 08:02 PM
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Default Head Gasket time!

I am new to the forum, and thought Id introduce myself with my current land rover problem. After prolonging the inevitable. I finally admitted to myself, "My head gasket is blown" My coolant hoses were over-presurizing, and there was brown gunk in my reservoir. I got the heads off and sure enough, the driver side rear cylinder had blown the gasket into the rear coolant passage. I got the heads resurfaced for about $90, the guy at the machine shop said my heads look fine except they were .008-.009" warped, which he solved by milling .010 off the surface. I ordered the full composite head gasket / intake set, including head bolts from Atlantic British for $200, and more intake bolts that have the sealer on them. My order will be here tommorow, so this weekend I will be re-installing it all. I got my 98 Disco 1 about 2 months ago for $4000. It has 104,000 miles on it. I was told it had been overheated, now I know why. Luckily, I found that all of my cylinder liners were nice and flat even with the block. I dont think that any of them slipped. Thank God. Wish me luck guys!
 
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Old 10-30-2008, 08:39 PM
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Default RE: Head Gasket time!

Welcome to our humble little forum.
Good luck with your head job, it sounds like you have it well under control.
 
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Old 10-30-2008, 11:44 PM
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Default RE: Head Gasket time!

My disco looks pretty much like yours Spike, alpine white. I will have to post some pics once the head gasket job is done. I did have the simbars brush guard on it, but I got stuck on some farmers field access road after it had been raining for 4 days straight, the road was severely crowned "rainbowshaped" so I kept slamming right into the ditches, I was driving on what seemed like elmers glue that was 10" thick...lol Anyways, a buddy of mine tried pulling me out and I thought he tied to my tow hook on the front frame, but he tied to my simbars guard and I said "GO man", so he did, along with my brush guard....lol Good times man. Anyways, Head gaskets here we come!
 
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Old 10-31-2008, 11:08 AM
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Default RE: Head Gasket time!

Dave, You may have some problems soon to show up. You shouldn't have let this problem go as long as you did. The warage your heads had are over limits and milling .01 may raise your compression too high as well as clearance issues.
You might want to check with a real experience Rover tech to see for sure.
 
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Old 10-31-2008, 11:53 AM
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Default RE: Head Gasket time!

I think you deserve a price for posting this title with a happy face !!!
 
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Old 10-31-2008, 03:49 PM
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Default RE: Head Gasket time!

Well Disco Mike. I got my head gasket kit in today. I was reading some of the material that came with it, and it states that a composite head gasket will reduce compression slightly, due to them being thicker gaskets. It also states that this drop in compression will be negated by having the heads resurfaced .005-.010. I might be at the top of the tolerance. but I am hoping that all goes well. As far as the "smiling" about the head gaskets. I guess I see it as an improvement. I will no longer have a LR with a blown head gasket, and hopefully one that runs great. Along with the head gaskets, I am replacing thermostat, power leads, spark plugs, serpentine belt, and reservoir pressure cap (just incase). I will post back once its all together and running. Wish me well guys!
 
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Old 10-31-2008, 04:35 PM
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Default RE: Head Gasket time!


Approximate gasket thicknesses are as follows:
Standard (tin) gaskets 0.5mm
Composite gaskets 1.2mm
Typical effect on compression ratio:
Standard (tin) gaskets 3cc
Composite gaskets 10cc

 
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Old 11-01-2008, 02:00 PM
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Default RE: Head Gasket time!

What does the effect of the thicker gasket means exactly ??? My HG was done a year ago, and I used composite gaskets also. Was it a mistake to use composite or an improvement?? What is 10cc compared to 3cc ??? 7 more is the first thng that comes to mind[8D]but what does it mean ???
 
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Old 11-01-2008, 04:39 PM
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Default RE: Head Gasket time!

It means that your compression ratio probably dropped, but in such a small amount, that it really wasn't noticeable. You added 7cc to the combustion chamber, which means when the piston is at top dead center, it now has 7 more cc's than it did before. Your cramming the same amount of air into a larger chamber, which means less PSI. The stock ratio is 9.4:1, you may have dropped yours to 9.3:1 or 9.2:1 at worst. You did no harm in using a composite gasket. They supposedly seal better too. The main issue that Disco mike was concerned about is clearance. If I shave .010" off the head surface, it is possible that the valves could contact the piston. But I am thinking it wont be a problem, especially with the thicker composite head gasket. Some hot rodders will actually shave .020" off their heads to further DECREASE their amount of cc's, which means MORE PSI...lol and hence a little more power. There is a threshold though, about 13:1, then your approaching pre-detonation, and the gray area between a gas motor and a diesel...lol
 
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Old 11-03-2008, 05:40 PM
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Default RE: Head Gasket time!

Well guys, I got the heads on, and engine back together again. Filled the coolant and fired her up. I was really hesitant to turn the key, but then said" screw it" and did it. She fired up fine and idled high for a few seconds. then settled right back down, I got a flowmaster 40 on it, so it just set there and burbled happily. I finished bleeding the coolant system while it idled, and did some last minute checks. After 45 min. of idling and a few bumps of the gas pedal from me, I noticed no leaks, no knocks or pings, and an idle as smooth as glass. I then took it for a gentle cruise around our farm section. I am happy to say that it ran great, almost seemed spunkier. I let it set over night to see if it leaked. This evening I checked again, no leaks. Fired her up and then took a more aggressive spin around the section. Revved her up to 4000 a few times, and made a few fast take offs. Ran great!! I parked her a few minutes ago, still no leaks, and my coolant hoses were only normally pressurized, not about to burst like before. YAY!!!! Also I smelled the exhaust, it smelled like clean, properly catalized fumes YAY!!!!
 


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