David K Posted October 15, 2003 Share Posted October 15, 2003 Now that they are clean, do you think the adjuster would benefit from a bigger oil passage? Will the oil lose pressure from the new width? Im thinking i should keep it stock size, since any widening of the adjuster would probably require i widen the passages in the head also. Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted October 15, 2003 Share Posted October 15, 2003 Try things one step at a time. See how they do and then if they are making any noise, we'll go from there. Quote Link to comment Share on other sites More sharing options...
Guest ZmeFly Posted October 15, 2003 Share Posted October 15, 2003 id love to know the answer to both questions. i did the same thing dave did to his lifters. i had one that was a clacky lil bitch, and it was more annoying then anything. i went threw the same as david did, minus the boiling of course. all has been well since the cleaning with the exception of the one lifter. it seems to have started making noise again. its about at 20% of the level of noise as it was before, this is after 5k miles. this one particular lifter was completly compressed. the bottom spring. no telling how long it had been like that as well. i think that the spring is worn as it seems to be the only part that would wear. my lifters with 180K on them looked just as good as davids after cleaning. the oil passage enlargement would be a good or bad thing. maybe allowing more oil to flow in and fill the lifter faster?? not sure, but please in respect to heavier springs and redrilling the hole please keep it alive im very interested in the results Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted October 15, 2003 Share Posted October 15, 2003 Well, I don't really see how drilling the hole would hurt...and I think adding stiffer springs would help, too...especially with low rpm noise. Quote Link to comment Share on other sites More sharing options...
David K Posted October 15, 2003 Share Posted October 15, 2003 Going to an industrial hardware store tommorow to find some springs. I dont see how it would hurt anything to add a little stiffer spring. If anything, its just securing the rocker arm to the lobe. Quote Link to comment Share on other sites More sharing options...
Guest jt240z Posted October 15, 2003 Share Posted October 15, 2003 I've done this very same process to a set of lifters with very good success. The Chem-Dip does work well, but there are actually two different formulas on the market. One is like a kerosene solution while the other is a more volatile solution that smells like moth balls. The moth ball solution works like a dream. The kerosene solution is total crap and doesn't clean anything. I used a sonic cleaner with the moth ball solution and the lifters came out just like new. After the lifters were installed, they were loud for a few seconds and then calmed down. It took two startups to get everything in order, but once they were set they were totally quiet. I'd say the rebuild process was successful based on those results. The one question I've never been able to get answered was if the factory lifters came primed with oil or if they were installed "dry". When I assembled my lifters I used a small amount of ATF in the lifters for initial startup. I'd still like to know if the lifters should be fully pumped up or not when assembled. The springs may be a weak link in the rebuild process. I'll try to source out a set of new springs to see if they can be bought easily. One other issue may be that the head must be cleaned before the "new" lifters are installed. Any sludge buildup in the oil lifter passageways could cause the new lifters to clog again. I'd figure if your lifters are in bad shape from sludge, then the head should probably be rebuilt anyway. All said and done, I see no reason that the P90a heads can't live a long second life once the head and lifters have been rebuilt. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted October 15, 2003 Share Posted October 15, 2003 15-20hp loss with the hydraulic lifter head??? Please tell me that isn't true..... Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted October 15, 2003 Share Posted October 15, 2003 Bastaad 525, I wouldn't worry about the "loss" of HP with the P-90A head they guy that told me that has been wrong about so many other things that I don't hold much faith in whatever he told me. I just wanted to ask to see if anyone on here had experienced the same thing or knew about it at all. I must have the "moth ball" forumla for Chem-Dip. The stuff I used made me think it might even eat some of the metal. When I did my engine last summer I cleaned everything I could with the stuff and it all came out looking like new or better. This stuff works great on old bolts that are dirty and need to be cleaned before going back into a new engine and stuff. They smell is just crazy to. When I was using the stuff alot I would have to come in the house and put my clothes in the washer right away or it would smell up the house. Certainly one of those use in well ventalated area chemicals. Quote Link to comment Share on other sites More sharing options...
Afshin Posted October 15, 2003 Share Posted October 15, 2003 15-20hp loss with the hydraulic lifter head??? Please tell me that isn't true..... Your wish is granted. It's not true. There is no reason I can think of to have power loss on hydraulic lifters, and certainly not 15hp. Also the power output on the 83 ZXT turbo was identical to previous ones without hydraulic vales at the same boost.... I personally prefer hydraulic, either works just fine. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 15, 2003 Share Posted October 15, 2003 How about if the HLA bleeds down at max lift on the cam basically robbing you of .010 or .020 lift? Don't know that this happens, but I'm sure that is the reasoning behind the theory that it loses hp versus solid valvetrain. Jon Quote Link to comment Share on other sites More sharing options...
David K Posted October 15, 2003 Share Posted October 15, 2003 No more bleeding down if we get stiffer springs for the HLA's. The piston in the HLA can only go down so far with a stiffer spring. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 15, 2003 Share Posted October 15, 2003 That makes me wonder if Comp oil pressure springs might help. Might also wear the cam and rockers faster... Jon Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted October 15, 2003 Share Posted October 15, 2003 No, alot of engines use HLA's...including Mitsubishi's 4G63T...and I've seen plenty of 400+hp 2.0L's using stock HLA's. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 15, 2003 Share Posted October 15, 2003 That doesn't mean that the HLA's don't bleed. Look at the V8 guys. They obviously understand the difference in solid lifter vs hyd lifter. You can make 1000 horsepower with hyd lifters in a V8. Does that mean that it does the same thing as a solid lifter? Jon Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted October 15, 2003 Share Posted October 15, 2003 So...you're telling me that by simply changing to mechanical style valve adjusters in an L28ET that has hydraulics will gain you 20hp? The main "problem" with HLA's is their rpm limits are lower than manually adjusted valves. However, I've seen DSM's that have been able to run more than 7500rpm with a stock HLA. The "lifter" that you are comparing to in V8's is a completely different animal and works in a completely different way than the lash adjusters that are used in the P90A head (which is the same style as the 4G63T). You may be meaning that you have a potential loss of 20 hp over a mechanical valve adjusted P90 head assuming the engine is completely built...or am I wrong? Quote Link to comment Share on other sites More sharing options...
David K Posted October 15, 2003 Share Posted October 15, 2003 HLA with stiffer spring would probably keep those rocker arms in contact with the cam at high rpms. I went to the industrial supply warehouse a few hours ago. I was playing with all kinds of springs. They were all too long, but i was able to come out of there with what seems like the perfect spring. 2134 x .047 or 850 x 1.194 Those are what was on the bag, make what you can of them. They are only the width and thickness of the spring, not the length. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 15, 2003 Share Posted October 15, 2003 It wasn't my 20 hp argument to start with (I don't know who came up with that #), but I was playing devil's advocate with Cody's post. I was trying to figure out how the HLA's would lose hp vs a solid pivot. I think the HLA's are run by oil pressure, and the spring just acts to keep it from totally collapsing and possibly even falling out when the car is not running. The spring in the chain tensioner does not provide the pressure, it just keeps the tensioner against the chain when the engine is off, so that the chain doesn't flop all over when you start the car. I don't think the spring pressure is what keeps it from bleeding down. I think its the oil pressure. I could be wrong. If I am right, more oil pressure would mean less bleeding, more lift. I think the lifter example is a good one because they still take up the slack in the valvetrain like a lifter does, and they are still subjected to pressure when the cam opens the valves. If they bleed, you would still lose lift. How much difference that makes is a question I can't answer. Mostly I'm just throwing ideas out to try and help. Jon Quote Link to comment Share on other sites More sharing options...
David K Posted October 15, 2003 Share Posted October 15, 2003 I don't think the spring pressure is what keeps it from bleeding down. I think its the oil pressure. You are right, but thats with the little tiny stock spring. If we were able to find the perfect spring to fit in there, and make sure its a nice stiff spring, then maybe if the HLA decides to wear out and bleed down, it wont have such as an effect as a collapsed lifter. It cant hurt with rocker arm to cam contact either Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted October 15, 2003 Share Posted October 15, 2003 I'll agree that in a highly modified engine (ie; fully built) that solid lifters may be advantageous for ultimate power output (because of ramp profiles at higher rpm's)....but, until about 7500-8000 rpm I don't think there will be a measureable difference between the two designs.... and...that's assuming that all vehicle owners keep their lash adjusted perfectly 100% of the time...if the valve lash is set incorrectly or neglected, then it swings toward the HLA design. In a normal street car, though, I think the HLA is more practical, as long as they work correctly. Quote Link to comment Share on other sites More sharing options...
Cody 82 ZXT Posted October 16, 2003 Share Posted October 16, 2003 I remember correctly the guy said that the loss of HP was on a built engine and it was due to the added volume that the oil pump must provide for the HLA's. I agree that it doesn't really make sence when the 81 car and the 82-83 cars had the same output and boost pressure. It must have been on the built motor where things can be dratically differnt. Really it was just something that I was told by a peson that I respected greatly at the time but, have later found some of his information to be bogus. About the springs and added pressure needed to keep them on the cam I think some springs that were just bearly greater in pressure would be good also I would certainly add the inner Nissan Comp spring to the oil pump at the least. The added oil pressure would certainly be a benifit in this application. I was looking at the Melling oil pump cataolg at work the other day and noticed that there is still a part # for a high pressure oil pump for our cars. The part # is M112. I have Part # M111 which is the Turbo Automatic pump that I've added the inner Nissan Comp spring to. During the summer I was running 20w-50 Mobil 1 oil and could get almost 90 PSI at first start up if the oil was cold and fresh. When it was hot I had 75 PSI by 3000 RPMs. I think this would be plenty of oil pressure for the HLA's and a cam with greater lift. Anyone have any thoughts on this also. It seems to me that to make the HLA's work correctly in an application like we aare talking about the oil pump should be considered aswell. Quote Link to comment Share on other sites More sharing options...
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