help with getting pushrod size (VIDS)
help with getting pushrod size (VIDS) Hey guys I need help please. So using my comp cams pushrod checker and following the link from vettesnut I measured a lil different from intake to exhaust. Maybe I did something wrong?
I'm on tdc using a lil flathead through the spark plug hole and turning the crank I'm as good on tdc as I can be, I put the rocker on intake and exhaust and snug it down and barely getting any up and down movement I got these readings using the formula at 0.075 preload
I:6.800+9.75x0.050=7.3...7.375
E:6.800+10.0x0.050=7.2875..7.3625
Did I do something wrong or should I just go 7.375 or can I add more preload and use 7.4?
Mods are 243 heads no milling with gm MLS gaskets. Ls7 lifters and eps 222/230 596/600 117+4
Thanks I'm out here putting her back together hopefully I can get a response asap.
I'm on tdc using a lil flathead through the spark plug hole and turning the crank I'm as good on tdc as I can be, I put the rocker on intake and exhaust and snug it down and barely getting any up and down movement I got these readings using the formula at 0.075 preload
I:6.800+9.75x0.050=7.3...7.375
E:6.800+10.0x0.050=7.2875..7.3625
Did I do something wrong or should I just go 7.375 or can I add more preload and use 7.4?
Mods are 243 heads no milling with gm MLS gaskets. Ls7 lifters and eps 222/230 596/600 117+4
Thanks I'm out here putting her back together hopefully I can get a response asap.
Last edited by 408Maro; Jun 21, 2011 at 03:30 PM.
Good question, I know PatG recommended 7.425 for me with EPS 226cam, LS7 lifters, PRC 2.5 LS6 unmilled GM MLS gaskets on my 02 C5. But I've seen a couple threads where 7.4 seemed to work best cuz the height of the pushrod cup offset the base circle difference once pre loaded correctly, or something like that. I'm nervous cuz I already paid quite a bit more for the 7.425's. Good luck I hope someone can help you get it right.
Thanks he said 7.4 should be fine but wanted to measure to make sure. I have new 7.425 sitting aswell as 7.4 from the last set up but guess ill have to put on on maybe smaller? Hopefully we can both get our issues solved
I'd just go 7.375" on both. The pushrods are typically available in .025" increments, and 7.375" is closer than 7.350" on that exhaust side (7.350" would also be a bit light on preload IMO).
I would NOT go as long as 7.400" on either side....and definitely not 7.425"!
I would NOT go as long as 7.400" on either side....and definitely not 7.425"!
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Good question, I know PatG recommended 7.425 for me with EPS 226cam, LS7 lifters, PRC 2.5 LS6 unmilled GM MLS gaskets on my 02 C5. But I've seen a couple threads where 7.4 seemed to work best cuz the height of the pushrod cup offset the base circle difference once pre loaded correctly, or something like that. I'm nervous cuz I already paid quite a bit more for the 7.425's. Good luck I hope someone can help you get it right.
LS7 lifters will require about a .050" shorter pushrod than if you were using the stock LS1 lifters that came in a 4th gen F-body.
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Verdad Gallardo Wow, ok so 7.350 or 7.375 is what I need? I'm really puzzled why PatG would recommend this length? I even double checked with him after I ordered the cam from EPS and Geoff asked why I was going with 7.425 instead of 7.4?
Not sure why he'd recommend that length. Your measurements with the proper tool and method confirm this length! 7.375" would be the way I'd go!
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How would you all explain the OP's combo, where the person who spec'd the cam and has tested the cam on stock lifters recommends 7.425", yet with a simple swap to the LS7 lifters it CLEARLY needs 7.375"? This is not a new thing, we've been dealing with the LS7 lifters for several years!
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COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
POWERBOND - ASP - AND MORE!
Largest Stocking Distributor of LS-x Engines / CHECK OUT OUR NEW WEBSITE!
COMP - FAST - PACESETTER - DIAMOND RACING - EAGLE SPECIALTY PRODUCTS - CALLIES - COMETIC GASKETS
RAM CLUTCHES - MOSER ENGINEERING - KOOK'S HEADERS - ARP - GM BOLTS AND GASKETS - MSD - NGK
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Another question. I got my 7.375 pushrods in and installed them. I torqued to 22 then turned her over a few times by hand and this is how the valve tips looked since I colored in the tips with a sharpie. The intake looks centered but not the exhaust. Any thoughts or am I ok? Thanks
How would you all explain the OP's combo, where the person who spec'd the cam and has tested the cam on stock lifters recommends 7.425", yet with a simple swap to the LS7 lifters it CLEARLY needs 7.375"? This is not a new thing, we've been dealing with the LS7 lifters for several years!
(Since I am running Morels I don't have a dog in this hunt.)
ok nevermind on the sharpie question for the moment, I think I measured the wrong size pushrods.
so today once i got the new 7.375s in i wanted to make sure so i got a straw this time and put her all the way in and turned the crank till i felt it was at the highest spot and i believe this time its accurate as its going to be.
i measured at 9.75 turns aswell as 10 turns as before and now it feels even better to me at 9.5 turns which would make it 7.350 the better fit?
please take a look at the vids i took and lmk what you think is the best..thank you
http://www.youtube.com/watch?v=FINpWgt-8Oc
http://www.youtube.com/watch?v=P2UUudXVww8
http://www.youtube.com/watch?v=PTa1TPCF2bQ
http://www.youtube.com/watch?v=hzil_meT_gs
http://www.youtube.com/watch?v=jOVh9gtntnk
http://www.youtube.com/watch?v=PSvbEEjtA9c
so today once i got the new 7.375s in i wanted to make sure so i got a straw this time and put her all the way in and turned the crank till i felt it was at the highest spot and i believe this time its accurate as its going to be.
i measured at 9.75 turns aswell as 10 turns as before and now it feels even better to me at 9.5 turns which would make it 7.350 the better fit?
please take a look at the vids i took and lmk what you think is the best..thank you
http://www.youtube.com/watch?v=FINpWgt-8Oc
http://www.youtube.com/watch?v=P2UUudXVww8
http://www.youtube.com/watch?v=PTa1TPCF2bQ
http://www.youtube.com/watch?v=hzil_meT_gs
http://www.youtube.com/watch?v=jOVh9gtntnk
http://www.youtube.com/watch?v=PSvbEEjtA9c
Last edited by 408Maro; Jun 21, 2011 at 03:39 PM.
Its hard to tell from the video but one observation, the 10 turns looks like you are forcing it a bit and in the process pushing down with some force on the pushrod/lifter, which will give a bit. Be very very gentle when you move the tip up and down so no force is transferred through the rocker to the pushrod (like you are lifting the tip with a feather).
Looks to me like either 9.5 or 9.75 is in the ball park.
One other note, if you need to alter the wipe by shimming or reducing the rocker height, this will also change the pushrod length. So if you plan to alter the wipe pattern at all do that first then measure.
Looks to me like either 9.5 or 9.75 is in the ball park.
One other note, if you need to alter the wipe by shimming or reducing the rocker height, this will also change the pushrod length. So if you plan to alter the wipe pattern at all do that first then measure.
Thank you. Yes forgot to mention that the 10 is very hard like it looks. So think ill be ok with the 9.75 turn 3.75 pushrods? Or would you rather get some 7.350s in my situation? Thanks again. And don't want to shim or change anything besides get the correct size. Thanks again