1994SEV6 Posted December 12, 2011 Share Posted December 12, 2011 My studs were gone, and even if they weren't, I definitely wasn't going to reuse them. I didn't feel like getting the revised studs from the dealer, and I thought bolts would be easier and cheaper. Tell me what you guys think This is showing the grade of the only studs the hardware store had. They had the proper size in stock, but it was low grade. stud with price prices of various studs. pretty expensive, especially for 5.8 grade. The price of bolts. 10.9 grade at $.65 and 8grade at $.55 They only had 7 10.9 in stock. Got 5 in the 8grade. I just took some picture to show how expensive (or cheap) these are, and to make sure I got the proper ones. Link to comment Share on other sites More sharing options...
sewebster Posted December 12, 2011 Share Posted December 12, 2011 Personally I would upgrade the size, but if I were to stick with M8 I'd definitely use the best grade possible. Probably I'd buy the Z ones from the dealer. Link to comment Share on other sites More sharing options...
Precise1 Posted December 13, 2011 Share Posted December 13, 2011 Yep, that looks right. IIRC 25mm long works and you might need a washer/spacer with the 30mm ones. Too bad they didn't have enough 10.9 grade but the 8.8 equate roughly to grade 5 standard bolts so I'll bet they will work just fine. It could be an interesting test. It couldn't hurt to put the grade 8.8 bolts in the easy to access holes... B Link to comment Share on other sites More sharing options...
1994SEV6 Posted December 13, 2011 Author Share Posted December 13, 2011 Personally I would upgrade the size, but if I were to stick with M8 I'd definitely use the best grade possible. Probably I'd buy the Z ones from the dealer. What do you mean "upgrade the size"...? m8 is the diameter of the bolt, right? The diameter of the bolt has to match the head. I can't go around changing that stuff. Yep, that looks right. IIRC 25mm long works and you might need a washer/spacer with the 30mm ones. Too bad they didn't have enough 10.9 grade but the 8.8 equate roughly to grade 5 standard bolts so I'll bet they will work just fine. It could be an interesting test. It couldn't hurt to put the grade 8.8 bolts in the easy to access holes... B Sorry, I keep getting grade and class confused, but you know what I mean. I didn't intend it to be a test or experiment, but I guess it will turn out to be. It might be kinda fun. Apparently, they only stock 7 10.9 at a time. I was a little ticked off that they had about 40 of some M6 bolt. Link to comment Share on other sites More sharing options...
Tungsten Posted December 13, 2011 Share Posted December 13, 2011 (edited) What do you mean "upgrade the size"...? m8 is the diameter of the bolt, right? The diameter of the bolt has to match the head. I can't go around changing that stuff. VG33E engines use 10mm studs instead of 8mm studs. He wanted to say that you could drill the heads out to fit 10mm studs instead. I think you can leave the heads alone and should be fine with 8mm studs or bolts, they were never an issue for me. The original studs probably broke because they weren't strong enough. Edited December 13, 2011 by Tungsten Link to comment Share on other sites More sharing options...
1994SEV6 Posted December 13, 2011 Author Share Posted December 13, 2011 VG33E engines use 10mm studs instead of 8mm studs. He wanted to say that you could drill the heads out to fit 10mm studs instead. I think you can leave the heads alone and should be fine with 8mm studs or bolts, they were never an issue for me. The original studs probably broke because they weren't strong enough. drilling out the head unnecessarily? Um..yeah. No thanks. I'm good. It was definitely because they weren't strong enough. Link to comment Share on other sites More sharing options...
Tungsten Posted December 13, 2011 Share Posted December 13, 2011 yeah nissan used some of the weakest fasteners possible in some areas exhaust studs could have been one of those but they were revised later on anyway Link to comment Share on other sites More sharing options...
1994SEV6 Posted December 13, 2011 Author Share Posted December 13, 2011 yeah nissan used some of the weakest fasteners possible in some areas exhaust studs could have been one of those but they were revised later on anyway I agree. Some of the fasteners are pretty flimsy sometimes. Especially the ones in the interior. Oh boy. I heard the 10mm studs didn't really help much? From the factory at least. Link to comment Share on other sites More sharing options...
Tungsten Posted December 13, 2011 Share Posted December 13, 2011 yep they can still break you have to upgrade the tensile strength and not the size Link to comment Share on other sites More sharing options...
MY1PATH Posted December 13, 2011 Share Posted December 13, 2011 I agree. Some of the fasteners are pretty flimsy sometimes. Especially the ones in the interior. Oh boy. I heard the 10mm studs didn't really help much? From the factory at least. the reason they didn not help much on the 3.3 is because the 3.3 hangs the pre-cats right off the end of the manifold thus increasing stress. Without the wieght of the pre-cats the 10mm studs are plenty strong for plain headders. 10.9 10mm studs or bolts FTW if you want to go over kill. Link to comment Share on other sites More sharing options...
sewebster Posted December 15, 2011 Share Posted December 15, 2011 Yeah, I drilled and tapped my heads for 10mm. But some of the threads in my heads were stripped, so it was that or helicoil. I don't regret my decision at all, though I still need to grind one of the manifolds a bit to be able to get a socket on easily. Link to comment Share on other sites More sharing options...
1994SEV6 Posted December 15, 2011 Author Share Posted December 15, 2011 Yeah, I drilled and tapped my heads for 10mm. But some of the threads in my heads were stripped, so it was that or helicoil. I don't regret my decision at all, though I still need to grind one of the manifolds a bit to be able to get a socket on easily. I read several threads here and on other websites about replacing the exhaust manifold studs. I also saw a few videos on youtube. every single time, there was a warning about not drilling off center for danger of hitting a water jacket. If this is the case, then how are you willy-nilly drilling into the heads like that? Link to comment Share on other sites More sharing options...
Tungsten Posted December 15, 2011 Share Posted December 15, 2011 If I were to drill out the heads, I would remove them off the engine first and replace the head gaskets in the process. Link to comment Share on other sites More sharing options...
sewebster Posted December 16, 2011 Share Posted December 16, 2011 I read several threads here and on other websites about replacing the exhaust manifold studs. I also saw a few videos on youtube. every single time, there was a warning about not drilling off center for danger of hitting a water jacket. If this is the case, then how are you willy-nilly drilling into the heads like that? It's pretty hard to drill off center when you have the previous holes there to guide you... also, I don't think the water jacket is really THAT close. But it IS in there somewhere, so you can't just go drilling into your heads all over the place. Basically you're just removing 1 mm of material all around the hole. It isn't too much. I drilled with the heads on the engine after I rebuilt it, but the engine was on an engine stand. I did end up replacing the head gaskets again later due to some valve problems, but that was unrelated. You're going to want to have the heads attached to something solid when you drill them of course. Things could be more complicated if the engine is in the truck. Anyway, I'm not really trying to convince you to upsize your studs! I think it is a good idea because, for me, I'd hate to have to goof around with my studs and then do it again later, but I'm not sure if this is the best plan for you. As I said above, it was easier with the engine on the stand. Link to comment Share on other sites More sharing options...
1994SEV6 Posted December 16, 2011 Author Share Posted December 16, 2011 It's pretty hard to drill off center when you have the previous holes there to guide you... also, I don't think the water jacket is really THAT close. But it IS in there somewhere, so you can't just go drilling into your heads all over the place. Basically you're just removing 1 mm of material all around the hole. It isn't too much. I drilled with the heads on the engine after I rebuilt it, but the engine was on an engine stand. I did end up replacing the head gaskets again later due to some valve problems, but that was unrelated. You're going to want to have the heads attached to something solid when you drill them of course. Things could be more complicated if the engine is in the truck. Anyway, I'm not really trying to convince you to upsize your studs! I think it is a good idea because, for me, I'd hate to have to goof around with my studs and then do it again later, but I'm not sure if this is the best plan for you. As I said above, it was easier with the engine on the stand. yeah. you definitely make some really good points. I might do it down the road or something. I think I read somewhere that the threads on the heads are very vulnerable. If you put manifold studs in and out too many times the threads can be come weak? something like that..idk. At this point, I just want my truck back together in one piece. I love the idea of custom fabrication type stuff, but I don't have the means. I don't have any means to pull my engine and stuff like that. Maybe when I'm older, have more money, and most importantly, have space. I guess I wasn't thinking of how to enlarge the bolt holes though. Duh. Link to comment Share on other sites More sharing options...
Captain_Crazy Posted March 2, 2014 Share Posted March 2, 2014 Yep, that looks right. IIRC 25mm long works and you might need a washer/spacer with the 30mm ones. Too bad they didn't have enough 10.9 grade but the 8.8 equate roughly to grade 5 standard bolts so I'll bet they will work just fine. It could be an interesting test. It couldn't hurt to put the grade 8.8 bolts in the easy to access holes... B 25mm is how long they are, Right?, I'll be dealing with this next on my 1991 3.0. I was also thinking of going with bolts Link to comment Share on other sites More sharing options...
Captain_Crazy Posted March 2, 2014 Share Posted March 2, 2014 It's pretty hard to drill off center when you have the previous holes there to guide you... also, I don't think the water jacket is really THAT close. But it IS in there somewhere, so you can't just go drilling into your heads all over the place. Basically you're just removing 1 mm of material all around the hole. It isn't too much. I drilled with the heads on the engine after I rebuilt it, but the engine was on an engine stand. I did end up replacing the head gaskets again later due to some valve problems, but that was unrelated. You're going to want to have the heads attached to something solid when you drill them of course. Things could be more complicated if the engine is in the truck. Anyway, I'm not really trying to convince you to upsize your studs! I think it is a good idea because, for me, I'd hate to have to goof around with my studs and then do it again later, but I'm not sure if this is the best plan for you. As I said above, it was easier with the engine on the stand. I'm gonna buy a right angle drill so I can do it while the eng is in the truck. You can't get a reg drill in the area Link to comment Share on other sites More sharing options...
Captain_Crazy Posted March 2, 2014 Share Posted March 2, 2014 My studs were gone, and even if they weren't, I definitely wasn't going to reuse them. I didn't feel like getting the revised studs from the dealer, and I thought bolts would be easier and cheaper. Tell me what you guys think Shoulds a slim washer be used or a lock washer on these?? This is showing the grade of the only studs the hardware store had. They had the proper size in stock, but it was low grade. stud with price prices of various studs. pretty expensive, especially for 5.8 grade. The price of bolts. 10.9 grade at $.65 and 8grade at $.55 They only had 7 10.9 in stock. Got 5 in the 8grade. I just took some picture to show how expensive (or cheap) these are, and to make sure I got the proper ones. Link to comment Share on other sites More sharing options...
k9sar Posted March 3, 2014 Share Posted March 3, 2014 I scrapped the idea of studs when I installed my headers and just went with a high grade bolt and lockwasher. Link to comment Share on other sites More sharing options...
Precise1 Posted March 3, 2014 Share Posted March 3, 2014 ^Exactly. Pros and cons to both, but the bolts are cheaper and more available... B Link to comment Share on other sites More sharing options...
k9sar Posted March 3, 2014 Share Posted March 3, 2014 biggest problem was that I had to hold the headers in place and try to get the bolts started where, if you use studs, you can slip the manifold on and then worry about the nuts. One of the pro's was that, by not having studs sticking out, there was more room to maneuver the headers to get them into place. Link to comment Share on other sites More sharing options...
Precise1 Posted March 3, 2014 Share Posted March 3, 2014 Yep, and I used some Permatex Copper to stick the gasket to the heads since there were no studs to hang it on. It works just fine both ways in my book... B Link to comment Share on other sites More sharing options...
Jarrod90p Posted April 16, 2014 Share Posted April 16, 2014 K9sar what was the exact size of bolt and washer you used. I just bought pacesetter headers Link to comment Share on other sites More sharing options...
k9sar Posted April 16, 2014 Share Posted April 16, 2014 I'll have to check. don't recall offhand Link to comment Share on other sites More sharing options...
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