Warped Head: Mill it or Replace it?
#1
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Warped Head: Mill it or Replace it?
So, I am finally getting around to fixing my 4Runner, the last time it got looked at, my cousin: Toyota mechanic and general Toyota guy, said the head is warped to the maximum allowable, so I was wondering if i should get my head milled/machined and pop a thicker gasket on it, or just save for a new rv head from engnbldr.
#3
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If the old is warped to the max allow'd spec, I would save for a new head. I know I would only want to do the job once, ya know?
#5
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It all depends on what your plans for the truck are...
If you have the money and want to do the job the best you can then do the new head with maybe a better cam and oversized valves. If you're on the cheap, there's nothing wrong with milling the one you have and putting it right back on. If you do mill it, be sure to get a thicker head gasket so you don't bump the compression too much if you can.
Either way you'll be back on the road.
If you have the money and want to do the job the best you can then do the new head with maybe a better cam and oversized valves. If you're on the cheap, there's nothing wrong with milling the one you have and putting it right back on. If you do mill it, be sure to get a thicker head gasket so you don't bump the compression too much if you can.
Either way you'll be back on the road.
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max allowed warpage does not necessarily mean milling the head will take the head out-of-spec. But I am always weary of 'thicker' (or shimming) head gaskets. The best head gasket is the thinnest one you can use. If you need a thicker gasket, it's usually because so much has been milled that the combustion chamber is too small and has raised the compression ratio too much and you need to compensate.
If you're okay with retarding the timing and not having as much power as you should, then do what you're going to do. If you shim the head, it is more likely to fail again, unless you detune the engine.
If you're okay with retarding the timing and not having as much power as you should, then do what you're going to do. If you shim the head, it is more likely to fail again, unless you detune the engine.
#7
when mine were warped i was going to get them resurfaced. sent them off to the machine shop and come to find out the heads were cracked.. so i got a pair for 515 bucks but thats for a v6 and the 22r heads are alot cheaper.
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#8
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Thanks a lot guys.
Money is the biggest issue at the moment, do not really have enough to even do the milling yet. This all came about because I found a head gasket that was .020" thicker.
I would really rather do it right, but I need a real job before I can afford that. LOL
Money is the biggest issue at the moment, do not really have enough to even do the milling yet. This all came about because I found a head gasket that was .020" thicker.
I would really rather do it right, but I need a real job before I can afford that. LOL
#9
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If you put it in the shop and told then to fix it, they'd mill it and put in a thicker head gasket.
There's nothing wrong with fixing it that way, it just isn't what's considered the "best" way to do it...
There's nothing wrong with fixing it that way, it just isn't what's considered the "best" way to do it...
Last edited by ovrrdrive; 11-10-2008 at 08:19 AM.
#10
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One of the reasons why thick gaskets are not a good idea is heat transfer.
The heat of the block is different than the heat of the head, so if you have a thick gasket in between there, the gasket takes all of the heat and becomes somewhat deformed because of unequal heat on both sides.
A thinner gasket will allow the heat transfer from block to head a little more easily.
Thats one part of gasket theory. I have more in one of my boilermaker books.
The heat of the block is different than the heat of the head, so if you have a thick gasket in between there, the gasket takes all of the heat and becomes somewhat deformed because of unequal heat on both sides.
A thinner gasket will allow the heat transfer from block to head a little more easily.
Thats one part of gasket theory. I have more in one of my boilermaker books.
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