Michael Posted December 9, 2003 Share Posted December 9, 2003 Doubtless this one came up before, but our trusty “search” function uncovered only peripheral mention of timing covers (for example, http://www.hybridz.org/phpBB2/viewtopic.php?t=24353&highlight=timing+cover). My 454 is getting a “mild” hydraulic roller (221/227 deg, 0.557 lift). Hence, issues of thrust buttons, Torrington bearings, all that good stuff - and how the timing cover holds everything in place. The question is, is a cast aluminum timing cover – a > $200 item – so greatly superior over a stamped-steel timing cover (a $20 item, if that) with a thrust button? Does the stamped steel timing cover need reinforcement (welding) – and if so, is that mostly a matter of avoiding spark scatter as the cam dances back and forth, pulling the distributor drive gear along with it? Granted, a 2-piece timing cover sounds very useful. And in the Chevy big block world, there are 2-piece and 3-piece timing covers (the latter a $270 item) – so what are the benefits of the 3-piece over a 2-piece? Trouble is, I’m only familiar with the concepts and terminology from catalogs and books – I’ve never seen a roller cam installed. Quote Link to comment Share on other sites More sharing options...
jt1 Posted December 9, 2003 Share Posted December 9, 2003 The trick timing covers have two benefits over the stamped steel ones. They control cam movement better; the two piece ones let you adjust cam timing without breaking the oil pan loose; the three piece ones I have seen allow cam changes without disturbing the oil pan. A reinforced steel one will work fine, just not as fancy. Some water pumps have a boss on the pump housing to put a bolt in and use as a support for the timing cover, eliminating the need for any reinforcement. So, a steel one will work fine, but the aluminum pieces do have advantages, at a cost. John Quote Link to comment Share on other sites More sharing options...
Mikelly Posted December 9, 2003 Share Posted December 9, 2003 First, A BIG BLOCK Zcar project, Then a Beautiful wife falls into your lap, and now a NEW CAM and fresh rebuild on the bigblock???? Lucky man... Spring for the three piece unit and listen to your wife and I... You can't take it with you! Mike Quote Link to comment Share on other sites More sharing options...
denny411 Posted December 9, 2003 Share Posted December 9, 2003 The three piece would be great if you plan to make numerous cam/cam degree adjustments,but may be of little use depending on what your plans for the engine are. If you know what rpm ranges and hp expectations you have,most cam manufacturers will give you a recomended cam timing spec. In any case I suggest using some type of cast aluminum cover when using a roller cam and thrust button. Here are two of them on ebay for less than 40.00 http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2446000725&category=33625 http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2447223066&category=33625 And here`s a gear drive set for a big block for 90.00 that you may be interested in. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2446991306&category=33625 Quote Link to comment Share on other sites More sharing options...
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