DIY: LS3 Camshaft Install (a lot of pictures, may take a moment to load)

[East Coast Supercharging]

Originally Posted by robertway

Hey, thanks for helping me remember I don't have the money to do the kit. I could probably sell one of the kids but I would get killed in the divorce that would most definitely come afterward. Believe me, it is on the list, eventually.... in line after some safety, suspension, and track time line items.

Oh man! I didnt mean to get you thinking about selling one of your kids..



On a side note but your "track items" reminded me, ECS is going to be sponsoring a GM EFI 8.90 index class, and bracket class at Raceway Park with the 5th gen Camaro guys in mind!

It will be an eight race series this year on the following dates;

April 23
May 21
June 11
July 23
Aug 20
Oct 22
Oct 29
Nov 4

These are on the same dates as the ECS Corvette challenge, which is Raceway Parks largest race series for years now, and were are putting this together for all of our Camaro customers to come out and have some fun while being supported by your builder. (although you certainly do not have to be an ECS customer to come)
Stock or heavily modded works for the bracket class, so hopefully we will see you there Rob.

[RSS77]

Wow....I looked forever on trying to find a somewhat detailed view of this job. Detailed doesn't do justice for this kind of patience!! I'd say you had as much time doing the pictures and videos as you did in the install if not more. I'm getting ready to add a complete American Racing Headers exhaust to my car and can't get myself to pull the trigger on the cam install yet. I don't have a garage.....YET ;-). I do however have storage for the car at least. A garage would turn my attention to a cam easier no doubt. I have mechanical abilities, but this install is more in depth than I figured . It would definitely be an at home, garage job for the winter. I'm use to putting cams in trucks of 1986ish. So much simpler!! I have never seen a LS3 tore down before this. I am going to bookmark the post juuuust in case. I may say the hell with it and go supercharged, who knows. Thanks so much for all the details and pics. Excellent post, robertway

[Bell040]

Step #55

The methods I used for checking pushrod length were to find the pushrod length with a rocker torqued down and at zero lash then adding my targeted lifter preload to the length checker and verifying its length by bolting the rocker just down to zero lash and then getting 1.5 turns out of the rocker pedestal bolt to get to 22ft/lbs.

Some things are better explained by watching them so here is a video of the entire process I went through to measure and then verify the pushrod length I was going to use.



So after all my measurements I came up with a 7.325" base pushrod length, added 0.075" preload (GM spec on the stock lifters is 0.060" so I erred slightly on the high side of spec) and came up with a 7.4" pushrod which makes sense as the new cam's base circle was about 0.033" smaller than the stock intake cam lobes and 0.055 smaller than the stock exhaust cam lobes (base circles on the stock cam are different for intake and exhaust yet all the stock pushrods were the same length so the exhaust lifters were carrying about 0.020" more preload than the intake lifters). I picked up some Comp Cams Hi-Tech 5/16" diameter 7.400" length hardened pushrods after having determined the proper length I needed.

I figured I should add some information that I found. The stock intake valves are actually 0.024" longer than the stock exhaust valves to keep the valve train "geometry optimized" because of the difference in the cam base circles. http://www.camarohomepage.com/ls3/page4.htm

So I am pretty sure that the comment of your's that I bolded is not true.

Therefore, to keep the exact same preload as the stock system (whatever it may be... you noted a GM spec of .060") you would need to go from 16 of the 7.375" pushrods (@ stock cam base R=.748" int and .760" exh) to 8 intake pushrods of 7.392", and 8 exhaust pushrods of 7.403". I assumed that the difference in base circle that you measured (of .033" and .055") were diameter measurements, therfore your cam had R=.732" on int and exh.

I used this EQN:

cam base radius + valve deltaL/rocker ratio + pushrod length + C = the LS3 valvetrain constant, where C = other valvetrain stuff that isn't changing.

the stock intake valvetrain formula would be .748" + (.024/1.7)" + 7.375" + C = 8.147" = stock distance that matters
... for the exhaust, the formula would be .760" + (0)" + 7.375" + C= 8.135"

add your cam that has R=.732" into both equations, leaving pushrod length as a variable:

int pushrod = 7.392"
exh pushrod = 7.403"

if I am correct, do you did pretty good ... but maybe unknowingly if you were trying for .075 preload, and didn't account for the longer intake valves.

... I think the valve train can handle an 0.008" change (or 8 mils in engineer speak)


btw, I am printing your DIY to help me through the cam swap in a couple weeks (ordered all the parts, waiting for them to come in). Thank you for doing such a meticulous job on it!

[robertway]

Originally Posted by Bell040

Step #55

I figured I should add some information that I found. The stock intake valves are actually 0.024" longer than the stock exhaust valves to keep the valve train "geometry optimized" because of the difference in the cam base circles. http://www.camarohomepage.com/ls3/page4.htm

So I am pretty sure that the comment of your's that I bolded is not true.

Therefore, to keep the exact same preload as the stock system (whatever it may be... you noted a GM spec of .060") you would need to go from 16 of the 7.375" pushrods (@ stock cam base R=.748" int and .760" exh) to 8 intake pushrods of 7.392", and 8 exhaust pushrods of 7.403". I assumed that the difference in base circle that you measured (of .033" and .055") were diameter measurements, therfore your cam had R=.732" on int and exh.

Bell040, thanks for taking the time to lay that all out, you obviously put a lot of thought into it. Also thanks for the compliment and good luck with the install. As an aside, would you happen to have a calculation that would allow me to redo the kitchen for my wife but not have to pay for it

[Bell040]

Originally Posted by robertway

Bell040, thanks for taking the time to lay that all out, you obviously put a lot of thought into it. Also thanks for the compliment and good luck with the install. As an aside, would you happen to have a calculation that would allow me to redo the kitchen for my wife but not have to pay for it

lol...

we may have to start using imaginary numbers

[ScottieBlkSS]

I have to agree with everyone else, This is got to be the most intailed and best write up I have ever seen, But with seeing all of this it definately makes paying a professional worth it, My car would NEVER run again if I tried to do this..

[Bell040]

Originally Posted by ScottieBlkSS

I have to agree with everyone else, This is got to be the most intailed and best write up I have ever seen, But with seeing all of this it definately makes paying a professional worth it, My car would NEVER run again if I tried to do this..

lol... funny that you say that. Everyone I know thinks that I am going to be calling a tow truck just to get it out of the garage. Thank God for this DIY... I will be able to prove them all wrong.

[themossman]

Robert-

THANK you for your glorious DIY thread...it made me confident to dig in for an oil pump replacement (faulty bypass valve in OEM pump...so a melling is going in).

After getting the pump off....I noticed the tensioner didn't look quite right...

Sure enough...broken both at the top and bottom and I was missing the top piece. I found it behind the cam sprocket in a little void and went back inside to mull over next steps and do a little research. I had heard about this issue long ago and the hot debate over 'which goes first'...the timing chain or the tensioner....I guess I know in my situation the tensioner went first. After looking at some more pictures...I realized I hadn't found everything yet...I was missing the little piece of metal. See the video for it's 'new' location. I'm still trying to figure out how I'm going to get it out of there...

I'll be putting the in LS2 style dampner when I'm ready to button it back up.

One comment regarding your DIY...I too was searching for a suitable breaker bar. Turns out my neighbor had a conduit bender and that thing was MONEY for getting the crank bolt loosed...made it a pretty easy and quick job...

Thanks again for you time and effort on an INCREDIBLE DIY. Suggest mods also label it as 'oil pump' and 'timing chain' DIY.

[robertway]

Originally Posted by themossman

Robert-

THANK you for your glorious DIY thread...it made me confident to dig in for an oil pump replacement (faulty bypass valve in OEM pump...so a melling is going in).

After getting the pump off....I noticed the tensioner didn't look quite right...

Sure enough...broken both at the top and bottom and I was missing the top piece. I found it behind the cam sprocket in a little void and went back inside to mull over next steps and do a little research. I had heard about this issue long ago and the hot debate over 'which goes first'...the timing chain or the tensioner....I guess I know in my situation the tensioner went first. After looking at some more pictures...I realized I hadn't found everything yet...I was missing the little piece of metal. See the video for it's 'new' location. I'm still trying to figure out how I'm going to get it out of there...

I'll be putting the in LS2 style dampner when I'm ready to button it back up.

One comment regarding your DIY...I too was searching for a suitable breaker bar. Turns out my neighbor had a conduit bender and that thing was MONEY for getting the crank bolt loosed...made it a pretty easy and quick job...

Thanks again for you time and effort on an INCREDIBLE DIY. Suggest mods also label it as 'oil pump' and 'timing chain' DIY.

Thanks very much for the compliments. Sorry to see you had the break with the tensioner but at least you found out when you opened it up and not when something major happened. I know there is a possibility that it will break as there have been others and I know some chains can go with the LS2 style after they stretch a bit and slap around so it is a double-edged sword. The breakages seem to be isolated incidents from my poking around. Good luck putting everything back together.

[Camarodriver]

OMG that was incredible! Watching your install process, so detailed and so clear. I must commend you on a fine instruction manual and pure info-tainment for this Camaro and all things V8 enthusiast! WOW! The fine work is much appreciated and I want to thank you for taking the time and quality effort. Good luck with the car, I will certainly keep checking in on things. eB

[themossman]

Robert-

I owe you a couple of beers...well...probably quite a bit more than that. Everything buttoned up successfully and easily...and upon start up...NO ISSUES!!!

I've had her through a minor shakedown and everything appears to be good...I'll be watching for leaks over the next couple of days. As you mentioned...the pic below was a beautiful sight! And how I got that tensioner band out of the oil pan is a story in and of itself...

I have a couple of points that you could add to the DIY...primarily in the putting it back together section. Not a criticism in the least, it will just put the polish on one of the best DIYs I've ever seen. I'll write them up in the next week or so and post.

Also...I would suggest the mods also label this thread as a DIY for oil pump and timing chain replacement...it's obvious to me now...but wasn't prior to this issue.

Again...THANK YOU.

[Bell040]

Originally Posted by themossman

Robert-

THANK you for your glorious DIY thread...it made me confident to dig in for an oil pump replacement (faulty bypass valve in OEM pump...so a melling is going in).

After getting the pump off....I noticed the tensioner didn't look quite right...

Sure enough...broken both at the top and bottom and I was missing the top piece. I found it behind the cam sprocket in a little void and went back inside to mull over next steps and do a little research. I had heard about this issue long ago and the hot debate over 'which goes first'...the timing chain or the tensioner....I guess I know in my situation the tensioner went first. After looking at some more pictures...I realized I hadn't found everything yet...I was missing the little piece of metal. See the video for it's 'new' location. I'm still trying to figure out how I'm going to get it out of there...

I'll be putting the in LS2 style dampner when I'm ready to button it back up.

One comment regarding your DIY...I too was searching for a suitable breaker bar. Turns out my neighbor had a conduit bender and that thing was MONEY for getting the crank bolt loosed...made it a pretty easy and quick job...

Thanks again for you time and effort on an INCREDIBLE DIY. Suggest mods also label it as 'oil pump' and 'timing chain' DIY.

I cant figure out what you are doing in the video... please explain

...I was missing the little piece of metal. See the video for it's 'new' location

... what peice of metal?

[themossman]

Originally Posted by Bell040

I cant figure out what you are doing in the video... please explain



... what peice of metal?

The video shows the metal strap from the stock LS3 timing chain tensioner as I'm moving it with a magnet. The view is looking inside the oil pan from the drain plug.

Here's a pic of what the piece looked like outside the oil pan...

[blake-b]

This might help with the pickup tube bolt. I left the front driver's oil pan bolt in but backed it out most of the way. Every other oil pan bolt I completely removed. That allowed me to be able to push down on the passenger side of the pan and I wedged a roll of 1" tape in there to hold it down. That gave me plenty of room to stick my fingers in and hold onto the bolt as I turned it with the 10mm ratchet end wrench. I had to stop shortly after that so when I reinstall the pickup tube, I will do the same thing.