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Old 05-02-2001, 03:13 PM
Dartasaurus Dartasaurus is offline
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My 67 Dart came with a 273 4bbl
I put a new purpleshaft 284 cam in it, and it ran fairly decent until that just wasnt enough power. (you know how it is.) So I pulled out the engine and trans and put in a 68 318/ 727 and used my 284 cam with new lifters, crane pushrods and crane 1.5 adjustable rockers. BAM lifter float at 3500 rpm. I then pulled out the 318 had it bored 30 over, everything new back in it (except the cam, wich looked brand new still) BAM lifter float at 3500 rpm. I just replaced the lifters with new anti-pumpups and tried every conceivable rocker adjustment. BAM lifter float at 3500. What the heck is happening? Help
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Old 05-02-2001, 03:35 PM
451Mopar 451Mopar is offline
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What about the Valve springs?
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Old 05-02-2001, 03:40 PM
Dartasaurus Dartasaurus is offline
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Oh, thats one thing I forgot to mention. The heads were new ported heads from Oakland dodge, and worked great on the 273. They have heavy springs with damper, and stainless valves.
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Old 05-02-2001, 04:26 PM
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MOPARMANJAMES MOPARMANJAMES is offline
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Question Hmmmm.....good question.

How's your oil pressure? Some folks forget to put the plug in the lifter gallery and they will never pump up, it happened to me when I built my first smallblock years ago!
If you don't already know, this plug is located in the block next to the intermediate shaft bushing.
Other than that, what does it do at 3500 to make you think it's lifter float? Have you checked your ignition?
A friend of mine couldn't start his car one time and learned that the rev limiter was on zero! If you have one, I would check it or the ignition components.
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Old 05-02-2001, 10:02 PM
Billydelrio Billydelrio is offline
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It seems unlikely that you are experiencing lifter float.

If it is lifter float at such a low rpm with such a mild cam, I would have to say "Broken Valve Spring." It could also be a really tight valve guide. Have you experieced any bent pushrods? A rocker arm could be tight on the shaft.

This is a strange one!

Billy
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Old 05-03-2001, 05:32 PM
Dartasaurus Dartasaurus is offline
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Maybe Im not understanding what everyone is calling lifter float. At 3500 rpm and higher, it begins to sound like a diesel. I mean every lifter in it rattles. I had a high pressure pump put in with the overhaul, presure is above 45 lbs after warmup. Here is a clue. The stock 318 didnt do this at first, then I put my purpleshaft cam in with the crane rockers and pushrods, then it started this strange phenomenon. After that I tried to use the stock rockers and pushrods, and they never snugged up. They stayed flopping loose. I had to go back with the adjustables. Could there be a difference between a cam for a 67 273, and a 68 318? I was always told they were the same. By the way, thanks guys for the input.
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Old 05-03-2001, 10:23 PM
Mach Manny Mach Manny is offline
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are you running adjustable pushrods? if not what kind are you running? hopefully they are one piece welding pushrods.

are you running shims under your valve springs? maybe vavle seat pressure per the manufacturer's recommendations is a good place to start.

also, you might want to get your lifter jounrals in the block machined for smoother motion.
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