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Engine Specific Info and Questions => IDI Engine => Topic started by: Darkness_is_spreading on May 15, 2006, 09:27:11 pm
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The thought was to integrate a complete iron head and block and be able to have the ultimate engine, this would be manily for Reliabilty more than anything.
Has this been done on our VW diesel's, what would be other problems one would face with having a eaiser metal to work with over harsh and tough iron?
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The block is already cast iron but I don't see any advantage to a cast iron head.
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The block is already cast iron but I don't see any advantage to a cast iron head.
Easier to rebuild??? :)
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same expansion rate as the block.
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same expansion rate as the block.
Maybe that'd be worth it if you used the engine in a tractor pull or something....If I were going to go to the trouble to cast a new cylinderhead for my diesel it would still be aluminum but have 16 valves. :D
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the aluminum head is also used for and is really good at it for absorbing heat.
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Ummm, absorbing heat is a distinct downside and the #1 cause of inefficiency in a diesel motor.
Andrew
so far we have a few pro's to this idea. Doesn't absorb heat like aluminum does, and easier to rebuild. Cons: where do you get one? must be made custom. Will add significant weight to the motor. Removing injectors won't be so difficult either - no more soft aluminum to deal with.
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I think weight and availability are the main concerns here.
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Topline Automotive makes their own aluminum castings which is where I got my new head. I'm set for another decade.
I always wondered why they aren't cast iron. I've seen a mercedes straight 6 diesel head that was cast iron. It was really big and heavy. It just seems like it would last longer and have less head gasket sealing problems.
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If you're having that much trouble with head gaskets, perhaps you should rethink your source and type of fasteners?
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My big problem with head gasket sealing was 1. POS rebuilt heads and 2. Bolts that protruded too far as a result of problem 1.
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Head studs would probably solve that problem.
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Topline Automotive makes their own aluminum castings which is where I got my new head. I'm set for another decade.
I always wondered why they aren't cast iron. I've seen a mercedes straight 6 diesel head that was cast iron. It was really big and heavy. It just seems like it would last longer and have less head gasket sealing problems.
probably why the mercedes diesels are bullet proof. Some of the mercs in the warm climates in africa are driving with more than a million miles on them. Cast iron seems to be the way to go for longetivity :)
merc diesels arent really noticed much for being THAT great on fuel though... just extremely reliable. 32-35 mpg on diesel, highway or not.
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Cast iron often won't allow the level of casting detail that aluminum provides, aluminum flows well in a mold, iron not as well. Cast aluminum also makes a very good bearing surface, the camshaft and lifters can run directly in machined bores in the head. Iron bearings of the same size would require bearing inserts.
Iron is much more stable, but is more expensive to machine and would require additional parts. The patterns for a head and the core patterns for the cooling jackets would be expensive to initially produce, probably why no aftermarket companies have tried. The patterns and cores for aluminum will not work with iron due to the lower shrink and different material flow.
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Yeah the diesels in the w123 MB's were bomb proof. I used to wrench for MB as their diesel guy, haha I didnt have to do squat, just oil changes and valve adjustments, my daily beater benzo has 513,000kms on it never had a head gasket just 2 or 3 timign chains, valve adjustments and oil changes. Indestructible. We had one longtime customer, the mechanic I worked beside had been working on it since it was brand new in 82, an 82 SD, and it had 827,000kms on it, no rebuild no headgaskets, just valve adjustments, t chains and oil changes, this guy was super anal, his car was mint. My personal car has pretty low compression, probably wont make it much over 600,000kms likely due to the previous owner not taking as good of care of it as I do. But I cant complain i have put about 45,000kms on it since last year and I bought it for about $1600CAD and I havent done anything to it, they are so reliable, its funny cause I build vw diesels for all my customers and they always ask why I dont drive a vw diesel, i just laugh and say "cause I want a relaible car" :lol:
Holy goat trail, ok the purpose of all that was, that the MB 617 mb motors are bomb proof largely because of their cast iron head, I have never seen or heard of fromm all the mb mechs I know replacing a head gasket on those engine from normal use. ANd yeah the fuel mialge is good for the weight of the car, they arent fast or anything but man if you want an ultra reliable car with all the options you could want in the 80's those old w123's are the best cars you can buy.