S30Z Bushido Posted December 10, 2002 Share Posted December 10, 2002 i bought an 81 L28ET a few months ago thinking it only needed a head gasket and new freeze plugs. i was planning on disassembling it, replacing all the wear parts, reassembling it, then installing it into my 76. i removed the cylinder head a few days ago and brought it into the shop to get a basic freshening up, valve job, and plane job, etc. well, the shop gave me a call before they started working on it and told me that the head is warped beyond planing and there is a water leak that needs to be welded up, the price for the work $300 when i removed the water pump from the water pump housing on the front cover of the motor, i found that part of the finned piece of the housing had broken off, i found those broken peices when i removed the oil pan... what does this mean? how would these pieces get into the oil pan? and do you think they have caused damage on thier way there? Basically what i'm wondering is, is it even worth trying to rebuild this motor? if there is damage to the head there will most likely be some damage to the internals of the block...correct? Thanks for any help you can give. -Domenic Quote Link to comment Share on other sites More sharing options...
fl327 Posted December 10, 2002 Share Posted December 10, 2002 would you have rebuilt the motor either way? i would completely dissassemble the bottom end and do a good investigation, if you can get away with a re-ring and .010 bearings thats normal i think, and worth it to me to get the motor rebuilt, at any extent, you should tear that sucker down and see whats really going on. Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted December 10, 2002 Share Posted December 10, 2002 I think that is called water pump osmosis, the diffusion of waterpump fins through a cast iron block. Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted December 11, 2002 Share Posted December 11, 2002 I got a feeling that you'll find that the broken pieces aren't water pump parts (unless the front cover is damaged), but probably piston skirts or ring lands. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted December 11, 2002 Share Posted December 11, 2002 From what I know of biology (very little, granted) osmosis is the passage of water through a membrane, not aluminum. If this is true, there is no way it could be osmosis of the (aluminum) fins through the (iron) membrane. I think this is much better explained by a theory of random teleportations and dislocations of matter, into other solid matter. Bushido, tear it down and be sure. These engines are pretty stout, so likely you won't be too far behind anyway. They also aren't that hard to come by, so don't fret it its messed up. Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted December 11, 2002 Share Posted December 11, 2002 If the block checks out-then dont worry about it. I spoke to an import salvage yard owner whose yard I frequent often enough that the owner & I always chew the fat for about an hour everytime I visit his yard (just setting up what I'm about to tell you), as I feel he is about 85% trusworthy. Anyway-I always try to pick his brain about the Z's and Z parts, since that is what I'm usually there for, while talking about their inline 6's he admitted that for the entire 16 years he's been in business he has never "AS IN NEVER" sold an entire engine assembly. He networks w/other import salvage yard owners nationwide, who were always calling him looking for Inliner 6 Cyl.Heads. He always hated to separate the engines & finally asked them one time why are they always looking for the cyl.heads & never their blocks. Their answer was that the Datsun Inline 6 is almost bulletproof and that the cyl.heads, being alluminum, are the weak link. He told me this was a hard lesson learned as when he took over the salvage yard he purchased a couple dozen Z's thinking their engines would sell like hotcakes-but all he's ever sold were their cyl.heads. So, just have them check your block out-and if its good to go-then slap another cyl.head on it if your cyl.head is to far gone....and feel good knowing that Z's blocks are pretty much bulletproof. Anyways-just my .02c's worth: acutally-it was the salvage yard owner's .02c's worth Kevin, (Yea,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
Guest joeyhammer Posted December 11, 2002 Share Posted December 11, 2002 damn even i feel better after that..of course i alerady knew that but i will sleep better tonight.. on another not(not to be a therad pirate) i once left my z running with the electrical fan disconnected for about an hour.. the street was filled with smoke and it was whistling like all hell.. i still have no problems with that motor..didnt even blow theheadgasket Quote Link to comment Share on other sites More sharing options...
Len Posted December 11, 2002 Share Posted December 11, 2002 In the last month I've seen 3 to 4 P-90 (one p-90a solid lifter) heads on E-bay. They sold from $75 to $125. Right now in this space in time the Datsun 280z/zx/zxt are sleepers! They are cheap to make mucho mas power . Don't know what I could say a few years from now when all you lead foot hot rodders (me included)use up all our cheap parts! Quote Link to comment Share on other sites More sharing options...
S30Z Bushido Posted December 11, 2002 Author Share Posted December 11, 2002 thanks for the replys guys, now i have to figure out wether to try and find another cylinder head or to fix the one i already have...anyone have a P90 for sale? Quote Link to comment Share on other sites More sharing options...
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