jlozinsk Posted August 22, 2008 Share Posted August 22, 2008 Hi, I am going to completely refurbish my hydraulic lifters (new tops balls etc) then send them to Rhoades Lifters so they blead down. I plan the cam to turn 6,500 RPM with 15 lbs boost on a blower but I suspect I could up the power band if I uped the revs to 7,000 and max power to 6,800 RPM. Currently my cam will peak at 345Hp at 6,300 RPM. Has anyone run a hydraulic set up to 7,000 RPM? Thank you John Quote Link to comment Share on other sites More sharing options...
z-ya Posted August 22, 2008 Share Posted August 22, 2008 Hey John, I would not try to rebuild the lifters, just gather a bunch of used ones in case you need to swap one or two out. I've got some spare used ones if you need a couple. I've heard that when you try and rebuild them, they are never the same. You can also convert your P90A to solid too. My L28 turbo pulls strong right to 6000 RPM with hydraulic lifters. Stock turbo cam. Another thing to keep in mind is that if you purchase an aftermarket cam for you hydraulic head, it needs to have the correct profile for hydraulic lifters. All aftermarket cams that I have seen are for solid lifter heads only. I'm in NH, we should hook up. Pete Quote Link to comment Share on other sites More sharing options...
jlozinsk Posted August 22, 2008 Author Share Posted August 22, 2008 Hi Pete, My cell is 305-762-2460 I have a BRE 1970 race car I am converting to the street. Regards John Quote Link to comment Share on other sites More sharing options...
(goldfish) Posted August 22, 2008 Share Posted August 22, 2008 What kind of cost is it to have those suckers rebuilt? Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 22, 2008 Share Posted August 22, 2008 Is any modification required to run the hydraulic pivots to 7000? My 83 ZXT seemed to tolerate 6500 without much ado. Is the extra 500 rpms that critical? Is it a hydraulic regrind or a mechanical regrind---as from my understanding the ramps on the two different cams are quite different. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted August 23, 2008 Administrators Share Posted August 23, 2008 I too am quite interested in just how many RPM can hydraulic lifters/adjusters go before they “pump up†or hit whatever limit/issue hydraulic lash adjusters run into? I haven’t really dug into this topic myself, though I am curious if this is a universal issue/limit or dependant on lifter design/manufacturer or is it a myth masking the issue of possibly weak valve springs? We read about it all the time regarding domestic V-8,s. Some sources will claim as low as 6000, others claim as much as 7500, others claim it depends on the lifter and manufacturing tolerances in the clearances, others claim it is related to how much valve spring pressure, others claim how much oil pressure feeding the lifter, others say it depends on where in the “adjustment range†the lifters are set to.. etc etc etc… Not sure of the relevance regarding the L-6 hydraulic lash adjusters, but I’ll share my later model Nissan hydraulic experiences. My ’96 Infiniti Q-45, VH45DE, has hydraulics lash adjusters and the factory rev limiter limits RPM to 7100 RPM. It ran great, never missed a beat all the way to the rev limiter. My ’93 Z-32 with VG30DE, hydraulic lash adjusters, recently replaced the factory ECU with a WOLF 3-D V-500, programmed the new rev limit to 7300 soft cut, 7400 hard cut, runs great all the way up, the WOLF rev limiter is MUCH smoother and virtually seamless as compared to the OE rev limiter. No noticeable hydraulic lash adjusters pumping up or valve float. Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted August 23, 2008 Share Posted August 23, 2008 I know this is on a different car, but my '03 Mitsubishi Evo which has 9.8'ish stock lift cams and 7k stock rev limit was running around with 12.5 mm cams and they held fine until about 9,500~10k. They all blew their seals out. Quote Link to comment Share on other sites More sharing options...
BurnoutZ Posted August 23, 2008 Share Posted August 23, 2008 Solid lifters seem to have better aftermarket support but hydraulic lifters seem like the better option. Little to no adjustments and silent operation with the same performance. Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted August 23, 2008 Share Posted August 23, 2008 with the same performance. Not sure I'd say that, but it all depends on your priorities, I suppose. After having tinkered with quite a few vastly different cars, I'd prefer solid. Especially on something as easy as the L-series to adjust. But then, silent is very low on my list of priorities. Quote Link to comment Share on other sites More sharing options...
jlozinsk Posted August 23, 2008 Author Share Posted August 23, 2008 hi, Normaly 6,000 is it but Rhoads bleed down (which do make noise) add 500 RPM and i talked to crower they recomended not to try for 7,000 RPM and i will believe them. John Quote Link to comment Share on other sites More sharing options...
jlozinsk Posted August 23, 2008 Author Share Posted August 23, 2008 What kind of cost is it to have those suckers rebuilt? The cost is $40 for the rebuild and $160 to make them bleed down lifters at Rhoades. I have the addresses is you want. My email is jlozinsk@yahoo.com Quote Link to comment Share on other sites More sharing options...
jlozinsk Posted August 23, 2008 Author Share Posted August 23, 2008 Is any modification required to run the hydraulic pivots to 7000? My 83 ZXT seemed to tolerate 6500 without much ado. Is the extra 500 rpms that critical? Is it a hydraulic regrind or a mechanical regrind---as from my understanding the ramps on the two different cams are quite different. Crower is giving me a billet cam and they seem to think 7,000 is not practical. Quote Link to comment Share on other sites More sharing options...
jlozinsk Posted August 25, 2008 Author Share Posted August 25, 2008 Hi, At 5,800 RPM with 15 lbs the motor would makes 325Hp at 6,300 RPM the motor will make 345 HP so the extra 500 RPM could increase HP to 365 HP or better. John Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 25, 2008 Share Posted August 25, 2008 More Boost achieves the same horsepower without trick parts and one-off components... Not as snazzy when it comes to benchracing, but from a practical standpoint 'horsepower is horsepower' and from an engineering standpoint I would think the lower the rpms it's achieved at, the better as reversal loads go up as speeds go up... Is there a particular reason you need to turn 7000 rpms (i.e., Bonneville Top Speed Trials, Trap Speed due to gearing, etc) or what? If it's simply horsepower you are after, turning up the boost will achieve the same results far cheaper. Quote Link to comment Share on other sites More sharing options...
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