I'm not questioning anything you've said about flat tappet push-rod engines. I was simply pointing out that many OHC designs have similar characteristics. I wasn't intending to belittle your statements. My primary point was this should affect engines other than traditional flat tappet designs. That they are no longer used in current manufacture makes them obsolete for sure, but as you noted, only recently not used at all. There are way more flat tappet engines on the road than roller right now in everyday use -- especially if you include flat OHC types. One thing I just thought of... because of the rocker arm ratio, pushrod flat tappets may develop more pressure between the tappet and cam lobe than an OHC follower and cam lobe. Don't forget that this board is dedicated to "buggy whips"!! ;> I wasn't aware of the new diesel fuel standard details. I did know that new formulation would have less sulphur and catalytic converters would be used on some, but not that there would be two incompatible blends. That's interesting! Two totally different diesel fuels will complicate the infrastructure and impact used vehicle sales. I guess fueling stations will have to dedicate some pumps to one fuel or the other. Doesn't sound like it wouldn't work well with dual pumps such as used for different grades of gasoline, but mixing a small amount (what's left in the hose) might not matter. I wonder what this will do to the bio-diesel advocates -- limit them to older engines (pre 2008) most likely. -----Original Message----- From: Larry R. Daum [mailto:mramc@xxxxxxxxxxx] Sent: Saturday, March 03, 2007 1:20 AM To: Swygert, Francis G MSgt 436 CES/CECM Subject: Re: [Amc-list] new lifters old cam Gee, Frank you act like I shot your dog! According to my Hot Rod engine article of the 5 companies that made hydraulic flat tappets , 4 went bankrupt and the 5th is General Motors. Of the 4 other companies only one got out of bankruptcy and reorganized. And china rushed in with low quality crap flat tappet replacement lifters. <snip> There several styles of OHC engine setup, but you can debate wether they any thing like a traditional hydraulic flat tappet. My point is no more traditional hydraulic flat tappets, BUGGY WHIPS , Frank , Buggy whips, obsolete, no longer used in any new car of truck for 2007. GM still makes flat tappet REPLACEMENT engines, and ZZ crate motors, but no new cars or trucks with them. The oil standard changed as of January 1st. I went to an oil seminar on this just before I left Illinois. The 2007 diesel trucks have catalytic converters, limited zinc and moly because of it in the new oils, a new diesel fuel that hates air or water and a new ultra high pressure common rail fuel injection system. You can't use the old diesel fuel in the new 2007 trucks or new fuel in the old diesel trucks. Yes, they were trying to sell $6 moly/zinc oil additives , but the diesel truck guys, your semi truck long haul guys are very concerned about all this, but it's a federal mandate, no choice. So, as Jan. 1 , they took almost all the moly and zinc out of even the diesel oil, gone Frank , Federal mandate, no choice . But they left open a small place for additives and specialty oils like Bull Tears. thanks , LRDaum _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list