djc2004 Posted December 16, 2005 Share Posted December 16, 2005 a couple of months ago I bought a hybridz - a sbc 350/th350 in a 75 260z. the unit was built in 1999 and has travelled about 1000 m since being built. I'm slowly waking it up again. the engine is a 4 bolt unit imported as a short block from the states and fitted with brodix track 1 heads, roller rockers, hydraulic lifters and projector 4 TBI. it was fitted with a 'sports' cam in the US as part of the short motor. My concern is that the TBI needs tuning as starting the engine is very difficult - it fires and dies instantly and only runs after 5/6 attempts. I understand this is indicative of too rich idle setting and is washing the oil from the bores and doing damage. I'm told that before i set up the TBI I should adjust the valve clearances. I dont have any information about the cam duration/lift and am told i'll have to measure the lift before setting the clearances. is there an approximate clearance i can set? I don't know how the measure the lift. any suggestion would be very helpful. cheers David Quote Link to comment Share on other sites More sharing options...
skipzoomie Posted December 17, 2005 Share Posted December 17, 2005 You mentioned hydraulic lifters. The correct way to adjust them is as follows. Warm the engine. At a slow idle, loosen each rocker nut (only one at a time) until you hear a loud ticking sound. Tighten the nut until the ticking sound stops and tighten it only 1/4 turn more. Be prepared to have some oil squirt from a few rockers. It makes a small mess but that's just a part of doing the job. Good luck. Quote Link to comment Share on other sites More sharing options...
A. G. Olphart Posted December 17, 2005 Share Posted December 17, 2005 Skip's got it right... a hydraulic lifter engine has no "clearances" or valve lash. The procedure he outlined works well if the engine is brought to operating temperature (as specified), and leaves very little of the lifter's travel to "pump up" should the engine be over speeded. As long as none of the lifters are clicking (and the engine isn't missiing due to a valve hanging open- VERY unlikely), this step may be omitted for your tuning purposes. You may want to go to the fuel delivery forum for more info on your injection: http://forums.hybridz.org/forumdisplay.php?f=74 Quote Link to comment Share on other sites More sharing options...
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