Das Ninjabot Posted February 12, 2017 Share Posted February 12, 2017 Opinions on that scratch? Can catch a thumbnail.. goes within 1-2mm of the water jacket. 1998 LGT 2.5 n/a. I'm using the 2.5T head gaskets. I'm thinking I need to have the block machined. Prior owner put new head gaskets on and I found the scratch when I was brass wheeling the old gasket residue off. Concerned but want opinions. Link to comment Share on other sites More sharing options...
Brighton96 Posted February 12, 2017 Share Posted February 12, 2017 Ooohh that's not good that you can feel it :/ You can get a section of 2x4 (the length of the block and like 300+ grit paper and do an even back and forth sanding. It'll even out the surface but it's not the same as having it machined. Link to comment Share on other sites More sharing options...
doublechaz Posted February 12, 2017 Share Posted February 12, 2017 I'm no engine builder, but that scratch is a deal breaker. Get rid of it one way or another. I've thought about that, but I would go get a chunk of 1/4 inch thick plate glass many inches bigger than the head and glue the paper to it, put it on a flat rigid desktop or some such and sand the head on that. Link to comment Share on other sites More sharing options...
Das Ninjabot Posted February 12, 2017 Author Share Posted February 12, 2017 After reading horror stories all night, I'll be sending the bottom end off to the machine shop Monday. Tempted to have him punch it .020 over since it'll all be apart anyways. Thoughts? Link to comment Share on other sites More sharing options...
Brighton96 Posted February 12, 2017 Share Posted February 12, 2017 If you are going to do rings and it's going to get machined anyway I would just have it bored out a little bit, mind as well make sure the chambers are all even and fresh too. Link to comment Share on other sites More sharing options...
Das Ninjabot Posted February 13, 2017 Author Share Posted February 13, 2017 I've thought about that, but I would go get a chunk of 1/4 inch thick plate glass many inches bigger than the head and glue the paper to it, put it on a flat rigid desktop or some such and sand the head on that. If this was on the head I might consider this option. As it's on the block, I'll be sending it out to be dealt with professionally. Link to comment Share on other sites More sharing options...
doublechaz Posted February 13, 2017 Share Posted February 13, 2017 Pro's is certainly a better idea. Did you source some pistons 20 over? Link to comment Share on other sites More sharing options...
Das Ninjabot Posted February 13, 2017 Author Share Posted February 13, 2017 Pro's is certainly a better idea. Did you source some pistons 20 over? I have not settled on any yet. I'm waiting to find out if they can machine the block without splitting it. I doubt they can but if I don't need to split it I won't. If I have to split the block then I'm going to do rings and bearings at a minimum. If I can keep the added expense of the overbore to under $200 then I'll have them punch it out. This project has suffered from major mission creep to this point and I need to start setting some limits or who knows what I'll end up at. Link to comment Share on other sites More sharing options...
Das Ninjabot Posted February 15, 2017 Author Share Posted February 15, 2017 So I showed the block to my machine shop today and his reply was, "I wouldn't worry about that. Take a wood block and some 400 grit to it, keep the shit out of the chamber and reassemble it. It looks worse than it is. Different story if it was boosted but should be just fine for n/a." He suggested rubbing some copper gasket filler into whatever scratch is left just before I put the heads on. Looks like I'm finally getting this damned thing assembled this weekend! Link to comment Share on other sites More sharing options...
doublechaz Posted February 15, 2017 Share Posted February 15, 2017 Like Permatex Ultra Copper? No kidding. That's great. Link to comment Share on other sites More sharing options...
Das Ninjabot Posted February 15, 2017 Author Share Posted February 15, 2017 Like Permatex Ultra Copper? No kidding. That's great. Yeah, I was very surprised and relieved to hear I can go this route without dumping more cash into it. Link to comment Share on other sites More sharing options...
Das Ninjabot Posted February 19, 2017 Author Share Posted February 19, 2017 Sanded the block down per my machine shop and it turned out pretty good. Started reassembly today. Got the heads on and the passenger side cams in. Then I got distracted by hockey and beer. Hit it again tomorrow. Link to comment Share on other sites More sharing options...
Das Ninjabot Posted February 20, 2017 Author Share Posted February 20, 2017 Apparently I forgot to attach the picture to the above post the other night. Here is a close up of the effect of sanding with 320, 400, 800, 1500 dry, and then 1500 grit wet (with wd40). Ended up with a much less scary scratch. Some copper gasket spray and the new gaskets and this thing should be golden. Link to comment Share on other sites More sharing options...
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