sprayed99 Posted August 16, 2011 Report Share Posted August 16, 2011 Does anyone have a factory cam out of a 5.3l or 6.0l they can mic the base circle and report back? I'm curious of the actual size difference between it a LS6 cam and a few other popular camshafts... I have a LS6 to measure and have a measurements from a few other aftermarket cams.... just don't have a stocker to measure up. I see too many posts where people assume that a 7.4" pushrod is the correct length because that is "what everyone else said". I want to put together something that proves this theory wrong, and could possibly help others in the future. Thanks Quote Link to comment Share on other sites More sharing options...
zachm89 Posted August 16, 2011 Report Share Posted August 16, 2011 My stock cam is sitting on the shelf in the garage, I'll take it to work with me and get you a measurement. Quote Link to comment Share on other sites More sharing options...
sprayed99 Posted August 16, 2011 Author Report Share Posted August 16, 2011 My stock cam is sitting on the shelf in the garage, I'll take it to work with me and get you a measurement. do you know how to measure it? Quote Link to comment Share on other sites More sharing options...
malibutwins Posted August 17, 2011 Report Share Posted August 17, 2011 How is it measured? Valve Lift is the amount (usually in inches) that the valve is lifted off of its seat. It is usually measured with a dial indicator at the tip of the valve. Lobe Lift is the amount (usually in inches) that the cam lobe increases in radius above the cam base circle. Tip: To quickly find maximum lobe lift, measure the base circle of the cam and subtract it from the thickness across the cam lobe’s highest point (see the diagram below). Tip: Maximum valve lift can be calculated by multiplying the maximum lobe lift times the rocker ratio. For example, a 0.310" lobe lift cam yields 0.496" of valve lift when using a 1.6 ratio rocker arm. Formula: valve lift = lobe lift x rocker ratio Quote Link to comment Share on other sites More sharing options...
bruiser04 Posted August 17, 2011 Report Share Posted August 17, 2011 i just measured my stock lq9 cam and base circle is 1 1/4 inches Quote Link to comment Share on other sites More sharing options...
Cramer Posted August 17, 2011 Report Share Posted August 17, 2011 (edited) I just measured my old one and it came out to be between 1.547" and 1.552". Most of the lobes were at 1.549". This was with a caliper, as my mics what go this big are at work. BTW this cam had approx 130k on it too. Still looks fresh!!! Base Circle Dia.: ’97-’04 LS1 = 19.7mm / 0.776″ = 1.552" ’01 LS6 = 19.3mm / 0.760″ = 1.520" ’02 -’04 LS6 = 19.0mm / 0.748 = 1.496" This brings the stock LQ9 cam in my measurements to Low- 0.7735 Median- 0.77475 High- 0.776 Edited August 17, 2011 by sinr98 (see edit history) Quote Link to comment Share on other sites More sharing options...
Cramer Posted August 17, 2011 Report Share Posted August 17, 2011 I can also get the measurements off "The other cam" if you want. And If I can find my cam install papers, I will have the measurements of the TR224 that's in my truck. Quote Link to comment Share on other sites More sharing options...
sprayed99 Posted August 17, 2011 Author Report Share Posted August 17, 2011 I can also get the measurements off "The other cam" if you want. And If I can find my cam install papers, I will have the measurements of the TR224 that's in my truck. I'm looking more for comps specific lobe profile measurements... Like the LSK, XER, and XE base circle dimensions I will be measuring my lunati voodoo cam when it gets here so I know what the voodoo cam base circle size is Quote Link to comment Share on other sites More sharing options...
sprayed99 Posted August 17, 2011 Author Report Share Posted August 17, 2011 How is it measured? Valve Lift is the amount (usually in inches) that the valve is lifted off of its seat. It is usually measured with a dial indicator at the tip of the valve. Lobe Lift is the amount (usually in inches) that the cam lobe increases in radius above the cam base circle. Tip: To quickly find maximum lobe lift, measure the base circle of the cam and subtract it from the thickness across the cam lobe's highest point (see the diagram below). Tip: Maximum valve lift can be calculated by multiplying the maximum lobe lift times the rocker ratio. For example, a 0.310" lobe lift cam yields 0.496" of valve lift when using a 1.6 ratio rocker arm. Formula: valve lift = lobe lift x rocker ratio good post... my above question was me asking Zach if he knew how... Zach reported back with 39.43" or 1.552" Quote Link to comment Share on other sites More sharing options...
sprayed99 Posted August 17, 2011 Author Report Share Posted August 17, 2011 This way we can put something together that will have the recommended pushrod length for the actual aftermarket lobe being used with factory heads. This gives the end user an idea where they should be with factory heads if they don't have the proper knowledge or tools to actually measure for correct pushrod length. Ex. Stock for the 4.8, 5.3, 6.0 and the 5.7 (non Z06) would be 7.4" for the 01 Z06 cam you would use 7.425" 02-40 Z06 you would use a 7.45" and so on.... Quote Link to comment Share on other sites More sharing options...
sprayed99 Posted August 17, 2011 Author Report Share Posted August 17, 2011 I can also get the measurements off "The other cam" if you want. And If I can find my cam install papers, I will have the measurements of the TR224 that's in my truck. This would be helpful but please post the specs of the cam and who it is from. If it is comp I have a listing of their lobes and can determine what lobes were used. Quote Link to comment Share on other sites More sharing options...
zachm89 Posted August 17, 2011 Report Share Posted August 17, 2011 good post... my above question was me asking Zach if he knew how... Zach reported back with 39.43mm or 1.552" 39.43" would be a little big for any vehicle ive ever seen, lol Quote Link to comment Share on other sites More sharing options...
sprayed99 Posted August 17, 2011 Author Report Share Posted August 17, 2011 39.43" would be a little big for any vehicle ive ever seen, lol Yeah Yeah Yeah smart guy.... its a typo.... you deseve a swift kick in your dinky sausage for that find! Quote Link to comment Share on other sites More sharing options...
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