LN2 valve spring broke, what to replace it with?? - Performance Forum

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LN2 valve spring broke, what to replace it with??
Saturday, September 24, 2016 10:27 PM
So, back in 2004/2005, I got some valve springs from jbody performance (toronto) long since out of business. My car has only put 10,000 miles on it since then, but today, while driving in stop and go traffic, the spring on an exhaust valve broken, and cause the car to run like crap, obviously. It's been a while since I've done the research on valve springs, but I've started again.
I've found this link for IPP valve springs: http://www.chevycavalierworld.com/ipp-springs-retainers.php
and another forum post talking about K-motion springs.
I guess I need to decide how much stiffer I want, but it's for a turbo, with maybe 14-20lbs of boost. So, I don't want the turbo to be able to push open the valve, and i guess from a rev point of view, 7000 would be nice (yes, i can re-program the ecu from a rev limiter POV)
A mechanic friend of mine, who deals a lot more with Honda, was suspicious if our cars needed valve seats (on the bottom of the spring) Mine appear to be sitting directly on the cylinder head. Is that right?
They also looked a bit "off-center" and kinda leaned to one side, and i'm not talking about canted valve springs(which our cars have), but the spring it self looked like it curved. Hopefully, some of these pictures help.
If any of the OHV/2.2 (LN2) guru's can help point a guy in the right direction, that would be appreciated. I'm kinda dead in the water now until I can decide on a replacement, and get something ordered asap.

brokenSpring.jpg (140k)
leaningValve.jpg (138k)
notCenteredValve.jpg (122k)

Re: LN2 valve spring broke, what to replace it with??
Sunday, September 25, 2016 5:52 PM
It looks like based on this post from MadJack, there is also an option from Comp Cams, #26981.
I guess what I need to figure out now, is which is good for my application, which has a reputation of being reliable. I don't know what my current install height is, so I guess I should go measure that... How should I measure that? dial calipers?

I have a patriot performance head, but I wonder if my valve spring height was never right from when it was first assembled. I'll admit I was pretty naive 10 years ago when I was building it, lol.
I just hope I don't have to pull the head, and machine the seats...

Re: LN2 valve spring broke, what to replace it with??
Wednesday, September 28, 2016 8:41 PM
So, I think i've settled on using the Comp cams #26981, since it won't require any machining, and I can get the car back and operational sooner, and based on the recommendation from MadJack. Based on Mad Jack's s10forum post, factory retainers and factory locks can be used with these springs. However, I haven't had factory components for 10 years, and I suppose I could get some,(if they aren't discontinued like everything else on my car from GM) but I was hoping to just get something that matches from Comp cams. I think the matching retainers are Comp Cams 795-16. They are for the beehive, they have very similar dimensions to the top of the beehive, summit point listed them as required for the #26981 springs. Here's my problem though. Using the comp cams website, all the locks that work with 10 degree retainers, none work with 7mm valves. I know the 94-97 engines used 7mm valves, but i'm actually not sure if mine are 7mm. They might be 8mm. I guess I should measure that, lol, because there is one lock that works with the 8mm valve, comp cam 632-16

If anyone has any thoughts, they would be appreciated.

Re: LN2 valve spring broke, what to replace it with??
Sunday, October 02, 2016 5:28 PM
So, good news is I replaced my broken valve spring with the parts I mentioned above. My j-body performance locks (what their specs are I have no idea) worked with the retainers I mentioned above from comp cams.
One weird thing I noticed is that the jbodyperformance valve springs were installed at a 1.8" height, (but their retainers were concave in such a way it made the spring height taller, without needing the seats machined, I guess. Anyways, there was a shim in place on the cylinder head seat on my broken valve spring, I left it in place, and the new springs installed at 1.72. I know they should be 1.7", so I may have to go back and add a different ship to make the install height less. I guess the only harm it will do is I might have valve float at high RPM.

Re: LN2 valve spring broke, what to replace it with??
Friday, October 14, 2016 1:14 PM
Here's some pics to liven things up. Showing the new springs and retainers.
Broken valve spring as I found it in the Cylinder head

After I removed it

Here are the new Comp Cams #26981 beehive springs, with their comp cams 795-16 retainers.

Re: LN2 valve spring broke, what to replace it with??
Friday, October 14, 2016 1:56 PM
My new issue is that my rocker rollers are not sitting correctly on the valve tips. It looks like the guide plates are not doing their job correctly.

Here's a few videos to show the point. The gold rockers are new, and they are better, but still not good enough. The comp cam rockers are just terrible, but that's also because it's rub and actually cut into (removing material) from the ARP rocker studs, allowing it to leak to the side even more than normal....
new gold rockers

prior rocker rollers

Isn't Slow-mo so cool?! hehe.

Re: LN2 valve spring broke, what to replace it with??
Tuesday, October 25, 2016 8:56 PM
In case anyone is wondering, I re-read the rocker thread, and learned about this thing called self-aligning rocker arms. The part number is just one less than the non-aligning ones(seen in the video above).
Self -aligning can 1.6 gold rocker roller: 10758-1
the non-self aligning one is 10759-1 (seen in the video, and still not perfectly aligned with my worn down pushrod guide plates....
So, since the guide plates on these 95-97 LN2 motors is all but impossible to find, I'm hoping I can get these self aligning ones working, and it won't even be an issue anymore.

I'll report back once I install them.

Re: LN2 valve spring broke, what to replace it with??
Friday, November 11, 2016 7:51 AM
Got the self-aligning rockers installed, and they are sitting nicely on the top of the valve during operation. not half off like the old rockers. I took out the guide plates, and used a spacer under the rocker stud. They seem to be running nice, but I do need to grind a little material off the valve cover. Thankfully, I have the 95-97 engine, which only needs minor grinding (so i've read) but the 97+ 2200 motor needs a valve cover spacer, which you'll probably need to get a local CNC shop to machine for you.

I'll update again once I get the grinding done.

Re: LN2 valve spring broke, what to replace it with??
Friday, November 11, 2016 2:21 PM
What are you spinning the motor to?

I was able to turn 7k+ with (i think 26915) springs (a little bit stiffer than the common swap guys do on the ln2). I was getting float at 25+psi on the first set of springs. i had the seats taken down a little on the head (which i think was unneeded)

but the thing didnt seem to mind banging the limiter all the time lol.

youre making me miss that car.

"A car just isn't a car without a little blood, sweat, and beers." -- Shadowfire
Re: LN2 valve spring broke, what to replace it with??
Sunday, November 13, 2016 9:07 PM
Matt, currently, the stock computer still does fuel cut at 6200 rpm. I need to burn a prom to increase that, but it may be a few more months/years. (don't work on the car too often)
But it did spend a few track days sitting at the rev limiter mostly for 30 minute session, 4 sessions in a day. it had no issue with it, and that was with the terribly mis-aligned rockers. I really feel like i got lucky, lol. Those things were just eating the valve tips away. oh well, these new ones should be a whole lot better. and quieter too

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