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By idaho211 - 15 Years Ago
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I bought some new high ratio rockers from a guy on ebay. The number on them is ECG6564-B2. The question I have is are there some cheaply made rockers I should be concerned with? I don't want to put a inferior part on my ECZ-G heads. The sealed bag they came in had no name. It came with black adjustable studs for the push rods. Thank you.
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By Glen Henderson - 15 Years Ago
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I have never seen the ebay rockers, but I am sure they are off shore items. I heard of one guy that said the adjusters galled in the threads. Sorry thats all I have, maybe someone else has more info.
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By lowrider - 15 Years Ago
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One company on ebay advertises high ratio rockers for a y-block, but I couldn't get them to verify they were high ratio rockers or where they were from. I heard y-block rocker made today are all low ratio. The only place I know to get high ratio rockers is from Mummert's. Not cheap but at least you know what your getting. I found some good used ones on ebay after a couple tries bidding for them. The bidding can get crazy sometimes.
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By DANIEL TINDER - 15 Years Ago
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I bought some a few years back, and noticed the latest versions (had to obtain some replacement parts) are a bit different, and have heard of trouble with them. Though the use of white grease is frequently discouraged for internal engine parts, I assembled my adjusters with it and have had no problems to speak of. You may be lucky also, but you should keep regular track of lash clearance for awhile to be sure.
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By Ted - 15 Years Ago
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Be cautious of some of the newer ‘no name’ rockers as being advertised as ‘high lift’ doesn’t necessarily make it so. I have a set here that I received as a tradein on some aluminum roller rockers and was told at the time that they were advertised as the high lift variety. In reality they measure 1.40:1 but this was only figured out after running them on the dyno engine and then checking the lift at the valve just prior to changing them out. Picked up another 3HP by switching out to a real set of 1.54:1 rockers and then another 2½HP switching out again to some Dove 1.6:1 rockers. This is all on stock unported G heads.
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By DANIEL TINDER - 15 Years Ago
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Ted,
Any way you can think of to ID which ECG6564-B2 repro is which (aside from measuring pushrod & valve lift at zero lash, and doing the math)? Were ANY of the earlier repros to original OEM specs, I wonder?
I guess it is time to finally get off my butt and measure mine. Never bothered before since motor seemed to definitely run better after swapping with original '55 jamb-nut/slotted screw rockers, but I suppose it COULD just be wishful thinking on my part.
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By DANIEL TINDER - 15 Years Ago
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OK. Just finished measurement of #2 exhaust valve lift (.390") at zero lash (P&G gapper):
MADDOG ECG6564-B2 1.54:1 ratio eBay-sourced forged repros. (manufactured 2005) with adjuster in mid-position, which (according to Ted's Y-Block Mag. article) should produce an approximate 1.5:1 ratio. My original '55 ECK cam is rated (shop manual specs.) at .292" exhaust lobe lift. So, .292" X 1.5 = .393". Allow for 110,000 miles of lobe wear (it's unlikely the cam has GROWN since 1955), and I would say the MADDOG rockers were "as advertised". Since I know the T-Bird's repair history (original factory cross-drilled cam), I don't see any need to push the rocker aside and actually measure pushrod lift (?). Getting the damn dial indicator & stand in just the right position to measure valve lift was enough trouble.
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By DANIEL TINDER - 15 Years Ago
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Oops. It occurred to me that there could still be some variation between the individual rockers, since they are forged and not likely cast from the same mold? I will wait though, until time for reinstallation & geometry adjustments to measure/compare them for consistency.
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By Ted - 15 Years Ago
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The quick and dirty method I use for checking rocker arm ratios is measuring the overall length. 2.9” and the rockers are the 1.54’s while 3” and longer has the rockers being the 1.43’s. After they are sorted out this way, then they go on the dual dial indicator setup to determine the exact ratios as manufacturing variances still seem to sneak their way in.
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By idaho211 - 15 Years Ago
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I did measure the overall length and they are under 3 inches (about 2 7/8 inches) and compared to the original rockers (1.43) the are shorter. I think I will go with some original rockers either from Mummerts or have some reconditioned. Thanks for your help.
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