My Head and Cam build Adventure!
04-05-2017, 01:54 PM
#41
Race Director
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2021 C6 of the Year Finalist - Modified
If you want to be real sure you are using the correct length of pushrod during an aftermarket cam install, you will need both the stock cam your pulling out of the engine and the aftermarket cam your going to install in the engine right there side by side and take a couple of measurements with a digital caliper ...
_____________________________
Determining Pushrod Length . . . . (easy peasy)
As with any engine that uses hydraulic valve lifters, the lifter requires a certain amount of 'preload' to operate correctly. On some engines, lifter preload is adjustable, however, on the LSx engines, it is not adjustable and can only be changed by varying the pushrod length.
On almost all aftermarket cams that have a greater valve lift and valve open duration than the stock cam, the aftermarket cam's Base Circle will be smaller than the OEM cam. And because the Base Circle is smaller, then the cam's Centerline to Heel distance will also be shorter (see photo below).
Depending on how much smaller the Base Circle on the aftermarket cam is (which results in a shorter Centerline to Heel distance), longer pushrods may be needed in order to achieve the correct lifter preload.
The easiest way to determine what pushrod length you need is to first measure the Base Circle of one of the lobes on your stock cam with a digital caliper. The last LSx engine cam change I did was on an LS1. The OEM cam had a base circle of 1.552". To figure the Centerline to Heel distance, you simply need to divide the Base Circle distance in half ... So, the Centerline to Heel distance was 0.776".
The Comp Cam that we had purchased had a Base Circle of 1.502". That gave use a Centerline to Heel distance of 0.751"
Subtracting the Centerline to Heel distance between the stock cam and the aftermarket cam told us that the aftermarket cam's Centerline to Heel distance was .025" less than the stock cam (0.776" - 0.751" = 0.025")
So, in order to get the correct lifter preload, we need to replace our stock LS1, LS2 or LS3 7.400" pushrods with a set that are 7.425" in length.
Or, for an LS7, we would need to replace our stock 7.750" pushrods for a set of 7.775" pushrods.
Stock LSx Base Circle: . . . . 1.552”
Centerline to Heel: . . . . . . .0.776”
Comp Cams Base Circle: _ . 1.502”
Centerline to Heel: _ . . . . . 0.751” . . . . (.025” shorter than stock) . . . . . (requires a .025" longer pushrod)
.
_____________________________
Determining Pushrod Length . . . . (easy peasy)
As with any engine that uses hydraulic valve lifters, the lifter requires a certain amount of 'preload' to operate correctly. On some engines, lifter preload is adjustable, however, on the LSx engines, it is not adjustable and can only be changed by varying the pushrod length.
On almost all aftermarket cams that have a greater valve lift and valve open duration than the stock cam, the aftermarket cam's Base Circle will be smaller than the OEM cam. And because the Base Circle is smaller, then the cam's Centerline to Heel distance will also be shorter (see photo below).
Depending on how much smaller the Base Circle on the aftermarket cam is (which results in a shorter Centerline to Heel distance), longer pushrods may be needed in order to achieve the correct lifter preload.
The easiest way to determine what pushrod length you need is to first measure the Base Circle of one of the lobes on your stock cam with a digital caliper. The last LSx engine cam change I did was on an LS1. The OEM cam had a base circle of 1.552". To figure the Centerline to Heel distance, you simply need to divide the Base Circle distance in half ... So, the Centerline to Heel distance was 0.776".
The Comp Cam that we had purchased had a Base Circle of 1.502". That gave use a Centerline to Heel distance of 0.751"
Subtracting the Centerline to Heel distance between the stock cam and the aftermarket cam told us that the aftermarket cam's Centerline to Heel distance was .025" less than the stock cam (0.776" - 0.751" = 0.025")
So, in order to get the correct lifter preload, we need to replace our stock LS1, LS2 or LS3 7.400" pushrods with a set that are 7.425" in length.
Or, for an LS7, we would need to replace our stock 7.750" pushrods for a set of 7.775" pushrods.
Stock LSx Base Circle: . . . . 1.552”
Centerline to Heel: . . . . . . .0.776”
Comp Cams Base Circle: _ . 1.502”
Centerline to Heel: _ . . . . . 0.751” . . . . (.025” shorter than stock) . . . . . (requires a .025" longer pushrod)
.
Last edited by Turbo6TA; 04-05-2017 at 03:16 PM.
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CammedC6520 (04-21-2017)
04-05-2017, 04:57 PM
#43
Drifting
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If you want to be real sure you are using the correct length of pushrod during an aftermarket cam install, you will need both the stock cam your pulling out of the engine and the aftermarket cam your going to install in the engine right there side by side and take a couple of measurements with a digital caliper ...
_____________________________
Determining Pushrod Length . . . . (easy peasy)
As with any engine that uses hydraulic valve lifters, the lifter requires a certain amount of 'preload' to operate correctly. On some engines, lifter preload is adjustable, however, on the LSx engines, it is not adjustable and can only be changed by varying the pushrod length.
On almost all aftermarket cams that have a greater valve lift and valve open duration than the stock cam, the aftermarket cam's Base Circle will be smaller than the OEM cam. And because the Base Circle is smaller, then the cam's Centerline to Heel distance will also be shorter (see photo below).
Depending on how much smaller the Base Circle on the aftermarket cam is (which results in a shorter Centerline to Heel distance), longer pushrods may be needed in order to achieve the correct lifter preload.
The easiest way to determine what pushrod length you need is to first measure the Base Circle of one of the lobes on your stock cam with a digital caliper. The last LSx engine cam change I did was on an LS1. The OEM cam had a base circle of 1.552". To figure the Centerline to Heel distance, you simply need to divide the Base Circle distance in half ... So, the Centerline to Heel distance was 0.776".
The Comp Cam that we had purchased had a Base Circle of 1.502". That gave use a Centerline to Heel distance of 0.751"
Subtracting the Centerline to Heel distance between the stock cam and the aftermarket cam told us that the aftermarket cam's Centerline to Heel distance was .025" less than the stock cam (0.776" - 0.751" = 0.025")
So, in order to get the correct lifter preload, we need to replace our stock LS1, LS2 or LS3 7.400" pushrods with a set that are 7.425" in length.
Or, for an LS7, we would need to replace our stock 7.750" pushrods for a set of 7.775" pushrods.
Stock LSx Base Circle: . . . . 1.552”
Centerline to Heel: . . . . . . .0.776”
Comp Cams Base Circle: _ . 1.502”
Centerline to Heel: _ . . . . . 0.751” . . . . (.025” shorter than stock) . . . . . (requires a .025" longer pushrod)
.
_____________________________
Determining Pushrod Length . . . . (easy peasy)
As with any engine that uses hydraulic valve lifters, the lifter requires a certain amount of 'preload' to operate correctly. On some engines, lifter preload is adjustable, however, on the LSx engines, it is not adjustable and can only be changed by varying the pushrod length.
On almost all aftermarket cams that have a greater valve lift and valve open duration than the stock cam, the aftermarket cam's Base Circle will be smaller than the OEM cam. And because the Base Circle is smaller, then the cam's Centerline to Heel distance will also be shorter (see photo below).
Depending on how much smaller the Base Circle on the aftermarket cam is (which results in a shorter Centerline to Heel distance), longer pushrods may be needed in order to achieve the correct lifter preload.
The easiest way to determine what pushrod length you need is to first measure the Base Circle of one of the lobes on your stock cam with a digital caliper. The last LSx engine cam change I did was on an LS1. The OEM cam had a base circle of 1.552". To figure the Centerline to Heel distance, you simply need to divide the Base Circle distance in half ... So, the Centerline to Heel distance was 0.776".
The Comp Cam that we had purchased had a Base Circle of 1.502". That gave use a Centerline to Heel distance of 0.751"
Subtracting the Centerline to Heel distance between the stock cam and the aftermarket cam told us that the aftermarket cam's Centerline to Heel distance was .025" less than the stock cam (0.776" - 0.751" = 0.025")
So, in order to get the correct lifter preload, we need to replace our stock LS1, LS2 or LS3 7.400" pushrods with a set that are 7.425" in length.
Or, for an LS7, we would need to replace our stock 7.750" pushrods for a set of 7.775" pushrods.
Stock LSx Base Circle: . . . . 1.552”
Centerline to Heel: . . . . . . .0.776”
Comp Cams Base Circle: _ . 1.502”
Centerline to Heel: _ . . . . . 0.751” . . . . (.025” shorter than stock) . . . . . (requires a .025" longer pushrod)
.
Got it all done I noticed I forgot to put the oil pressure sensor so I turned the car off already heat cycled it. Tune tomorrow at 10 synergy motorsports
04-21-2017, 12:46 AM
#46
Drifting
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What are you gonna do when a neighbor complains and the township comes and tells you to move it all NOW?
Did you find the noise yet? No air tools?
I'll give you credit. At least you got it off the ground.
You do know that it's going to pour down rain again soon don't you?
Good luck.
Did you find the noise yet? No air tools?
I'll give you credit. At least you got it off the ground.
You do know that it's going to pour down rain again soon don't you?
Good luck.
Update car was dropped off at synergy 2 days ago they are getting it back to me by next week. Changing battery oil and starter and crank sensor and she's good to go.
04-21-2017, 05:03 AM
#48
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C6 of Year Finalist (appearance mods) 2019
I wonder if previous owner used the wrong battery oil? The starter and crank sensor is not known to be a problem. Curious as to why it's being changed also.
04-21-2017, 08:48 AM
#49
Le Mans Master
Might as well replace harness smoke fluid too. Made in England by Lucas, reliable stuff.
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CammedC6520 (04-21-2017)
04-21-2017, 09:30 AM
#50
Drifting
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I said they are changing starter and crank sensor but he said he thinks this was from a bad battery. He said other then this.... you did a good job man!
04-21-2017, 09:31 AM
#51
Drifting
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It's being changed just incase and the oil because the car was running so rich has got into the oil so they changed it. Needed to be changed anyways for starter.
04-21-2017, 09:53 AM
#54
Le Mans Master
Improves conductive fluid characteristics forming a strong earth ground for composite cars. This is because non metal car bodies do not have sufficient earth grounds to maintain good battery and electrical connectivity. Show the mechanics this picture they should be able to obtain and install it.
04-21-2017, 11:14 AM
#56
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Improves conductive fluid characteristics forming a strong earth ground for composite cars. This is because non metal car bodies do not have sufficient earth grounds to maintain good battery and electrical connectivity. Show the mechanics this picture they should be able to obtain and install it.
