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| What's the most anyone has milled the head? http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=81523 |
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| Author: | Mountainman [ Mon Mar 09, 2015 4:46 pm ] |
| Post subject: | What's the most anyone has milled the head? |
Well, it's gone from one to three heads that I'm going to get checked at the machine shop. Long story there, but anyhow, I think someone wrote that they milled a head 2or3 thousandths? I know some have said zero, but who all has experience with any milling on these? Thanks for any replies, I'm afraid the machine shop with be asking me how much to shave any day now 
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| Author: | flman [ Mon Mar 09, 2015 5:11 pm ] |
| Post subject: | Re: What's the most anyone has milled the head? |
Mountainman wrote: Well, it's gone from one to three heads that I'm going to get checked at the machine shop. Long story there, but anyhow, I think someone wrote that they milled a head 2or3 thousandths? I know some have said zero, but who all has experience with any milling on these? Thanks for any replies, I'm afraid the machine shop with be asking me how much to shave any day now How did you go through 3 heads already? |
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| Author: | SargeIndustries [ Mon Mar 09, 2015 5:38 pm ] |
| Post subject: | Re: What's the most anyone has milled the head? |
The machine shop where I brought mine said they milled off .040" in order clean up the repaired weld area in the fire ring zone. |
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| Author: | diesel_guy86 [ Mon Mar 09, 2015 6:24 pm ] |
| Post subject: | Re: What's the most anyone has milled the head? |
Mine was shaved 2-3 thou to clean up the surface. It's gotten abused with over 30psi of boost and 260hp, pulled a trailer, 10hr road trips up an down mountains. Not a single problem with 20k miles clocked on it, also used ARP studs too. |
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| Author: | Mountainman [ Mon Mar 09, 2015 9:05 pm ] |
| Post subject: | Re: What's the most anyone has milled the head? |
flman wrote: Mountainman wrote: Well, it's gone from one to three heads that I'm going to get checked at the machine shop. Long story there, but anyhow, I think someone wrote that they milled a head 2or3 thousandths? I know some have said zero, but who all has experience with any milling on these? Thanks for any replies, I'm afraid the machine shop with be asking me how much to shave any day now How did you go through 3 heads already? 3 of the 4 CRD's I have have head problems. Well, number 4 is also a possibility  One I bought that way, one is my daily driver and I earned it since I boiled it over once (it barely leaks, just tiny bubbles, and loses about a cup every 100-150 miles), another one had the rockers go and I was on a long grade so by the time I could get off the road it boiled over. The latest one is hopefully just a leaky EGR or other hose, but I sure hope it isn't a cracked block, or head gasket, because 4 for 4 is ridiculous!
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| Author: | Mountainman [ Mon Mar 09, 2015 9:06 pm ] |
| Post subject: | Re: What's the most anyone has milled the head? |
SargeIndustries wrote: The machine shop where I brought mine said they milled off .040" in order clean up the repaired weld area in the fire ring zone. Wow, 40 thousandths. I wonder if we can get away with that on all of these? 
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| Author: | Mountainman [ Mon Mar 09, 2015 9:09 pm ] |
| Post subject: | Re: What's the most anyone has milled the head? |
diesel_guy86 wrote: Mine was shaved 2-3 thou to clean up the surface. It's gotten abused with over 30psi of boost and 260hp, pulled a trailer, 10hr road trips up an down mountains. Not a single problem with 20k miles clocked on it, also used ARP studs too. I wonder what's safe, and if I get within 2-3 thou if I could just clamp it down with ARP's without cracking it? hmm, thanks for all of the replies! I definitely feel good with a few thousands anyhow. |
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| Author: | flman [ Tue Mar 10, 2015 7:08 am ] |
| Post subject: | Re: What's the most anyone has milled the head? |
Mountainman wrote: SargeIndustries wrote: The machine shop where I brought mine said they milled off .040" in order clean up the repaired weld area in the fire ring zone. Wow, 40 thousandths. I wonder if we can get away with that on all of these? Per the FSM Quote: The minimum cylinder head thickness is 89.95mm (3.541 in.).
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| Author: | Mountainman [ Tue Mar 10, 2015 12:20 pm ] |
| Post subject: | Re: What's the most anyone has milled the head? |
Thank Flman, I'll have to let the machine shop know that. I'm really curious to see how thick they are now 
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| Author: | gmctd [ Wed Mar 11, 2015 2:15 pm ] |
| Post subject: | Re: What's the most anyone has milled the head? |
An aluminum cylinder head conforms to the cast-iron block surface when head-bolts are torqued to spec - meaning, the block surface level is most important, here - normal requirement for milling aluminum head is not warpage, but large nicks and gouges in the surface between the combustion chamber and bolt-holes, water passages, and cylinder-to-cylinder which require welding operations - this requirement for milling an aluminum head is to bring welded repair areas back to surface level, then very minor cleanup resurfacing the entire head if necessary, due to induced local warpage from welding heat - other than that, don't get carried away, here: aluminum head warpage will conform to flat cast-iron block surface after torquing to spec, will re-settle during repeat heat\cool cycles during normal engine operation - soft aluminum does that, where cast-iron is un-yielding and cannot - key is hardened flat-washer necessary to reduce twisting resistance and evenly distribute applied torque\tension around the bolt-hole surface - you can mill a warped head deck to flat, but what do you do about the still-warped surface that the head-cover with camshafts mates with? - the cylinder deck surface may now be flat, but the head-cover surface still conforms to the original warpage which will not now even\settle out during torquing - head cover surface must be in plane with the cyl surface to prevent warping the camshaft carrier, with it's precision camshaft bores, hydraulic lifter bores, etc - resultant induced warpage ain't even good for this assembly |
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| Author: | Mountainman [ Wed Mar 11, 2015 9:00 pm ] |
| Post subject: | Re: What's the most anyone has milled the head? |
gmctd wrote: An aluminum cylinder head conforms to the cast-iron block surface when head-bolts are torqued to spec - meaning, the block surface level is most important, here - normal requirement for milling aluminum head is not warpage, but large nicks and gouges in the surface between the combustion chamber and bolt-holes, water passages, and cylinder-to-cylinder which require welding operations - this requirement for milling an aluminum head is to bring welded repair areas back to surface level, then very minor cleanup resurfacing the entire head if necessary, due to induced local warpage from welding heat - other than that, don't get carried away, here: aluminum head warpage will conform to flat cast-iron block surface after torquing to spec, will re-settle during repeat heat\cool cycles during normal engine operation - soft aluminum does that, where cast-iron is un-yielding and cannot - key is hardened flat-washer necessary to reduce twisting resistance and evenly distribute applied torque\tension around the bolt-hole surface - you can mill a warped head deck to flat, but what do you do about the still-warped surface that the head-cover with camshafts mates with? - the cylinder deck surface may now be flat, but the head-cover surface still conforms to the original warpage which will not now even\settle out during torquing - head cover surface must be in plane with the cyl surface to prevent warping the camshaft carrier, with it's precision camshaft bores, hydraulic lifter bores, etc - resultant induced warpage ain't even good for this assembly Wow, thanks for that! Sounds like it should be left alone if it's within the factory .004" spec then? The machine shop told me today that it's 3-4 thou out, but said that "it's not all that exact checking it with a feeler gauge, and there could be a dip that's worse"... Would you have them shave 3 thou and call it good, or leave it alone? I will be using ARP's and this motor has the 2 hole gasket. When it overheated it blew the fluid out of somewhere fast. I was too pissed to even see strait (stranded in a remote area), so I can't remember where all that fluid exited, but he said the water jacket and combustion chamber have no cracks. I shut it down the moment I saw the temp skyrocketing. |
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| Author: | gmctd [ Thu Mar 12, 2015 3:26 am ] |
| Post subject: | Re: What's the most anyone has milled the head? |
Apologies for the delayed response: Broadchurch, Sherlock, Blood,Sweat, and Gears, and What Could Possibly Go Wrong? had me tied up for the evening - I'm a glutton for funishment............................ Yeah, if .003"-.004" will clean it up fer sure, but have them legibly stamp the head in a visible location such that the next guy doesn't think he has .003"-.004" to clean up, and the next guy doesn't think he has .003"-.004" to clean up, and the next guy doesn't think he has .003"-.004" to clean up, and etc |
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| Author: | GreenDieselEngineering [ Thu Mar 12, 2015 5:53 am ] |
| Post subject: | Re: What's the most anyone has milled the head? |
As gmctd alludes to...don't mill it. This head is weak enough as it is. Buff any bad areas with a scuff pad or very fine sandpaper and slap it back on. Having the deck surface very clean on the block is a good idea. We have used scuff pads on a drill to make sure teh old gasket material is all gone. This engine is like a roll of the dice sometimes... |
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| Author: | Mountainman [ Sat Mar 14, 2015 2:54 am ] |
| Post subject: | Re: What's the most anyone has milled the head? |
Thanks Gmctd and Keith! Makes me wonder if they even come out of the factory any better than within spec (.004"). Sounds like I better run these for a good number of miles before I sell them so I don't hand someone a time bomb... |
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