Anybody have any experience with these? Good or bad
http://www.westcoastcorvette.com/p-4...3-z06-ls7.aspx

 

From experience it makes the valvetrain a little stronger I would find out who has used them on there cars. Its a little pricey but it is nice layout. Just make sure when they slide on that the holes are a snug fit. I had shaft mounted rockets on my 97 ramair.

 

Do you have an LS7 the LS3 uses off set rockers,not like those in the pick.I had them on my race car, only way to go but takes work to set them up right,may need to change pushrods also.

 

i have them on my ERL 454 LS3 with Z06 heads. yes pricey as you will need machine work to the heads to accept the config. you also have to change your valve covers as stock are too short to fit Ktek has a great set that fit on these with proper baffles you can attach a catch can to. good luck

jerry

 

I've been researching them pretty intently:

1. Shop around for a much better price.

2. They've had some failures with the 1.7 versions, but they've also had some upgrades over that time. Also there seems to be an unwritten rule that the 1.7's are not recommended with much or any over 400 lbs open spring pressure.

3. There have been reports of a few bolt failures as well. Were they torqued, were they installed correctly, was the spring pressure reasonable, was there any coil bind, nobody knows/reports that info. Just that they sometimes break.

4. Clearance with the stock rocker cover is marginal even with the thicker gasket. I'd recommend a UMI 1/2" spacer. Lots of outfits make taller rocker covers but I doubt many include the same OEM baffling inside (unfortunately nothing seems to be simple these days, including the lowly valve cover).

5. No head machining should be needed.

6. They will be heavier on the nose than the OEM rocker, so either additional spring pressure (one cyl. head guru told me 30# seat and open, but I don't know if that was off the cuff or the the result of any specific testing) or other lighter components will be needed to offset/compensate. How much heavier is unknown, but I'm looking into that. If you're running a fairly wild cam and a lot of spring, these rockers may be too light for that task.

If cost is no object, the Crower stainless steel setup is the way to go... stronger and not as much valvetrain weight. About $1300 plus maybe $300 in machine work prep (the head needs extensive work... the OEM pedestals are machined off).
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Anybody else?
https://sdparts.com/details/yella-terra/yt6670
I'm installing these Monday. Should I stop now? I had someone tell me these make more noise than the stock ones

 

i have noticed some valve ticking at idle with the hood open, with it closed and inside the car you don't hear any noise. i suspect it is more in the final valve adjustment as some clearance is needed to prevent valve float from hydraulic lifters at higher rpm. i think you have made a good choice as it is a stronger setup. you can just look at the rockers and see how beefier they are over stock. i have 1.7 ratio rockers with 12,000 miles and no issues.

jerry

 

They are absolutely a well engineered and good looking set of rockers. You need see thru valve covers to show them off. They come with shims to get the geometry right....and sometimes those don't get it right. They're non adjustable. I never could get mine to run quietely. Probably would have taken a different set of push rods. Patience isn't one of my better virtues. I got tired of the noise and fooling with them. Sold them and replaced them with trunnion upgraded stockers. Happy now

 

what brand did you use? because mine have adjustments...when carteck installed mine they used a shorter pushrod and set the adjustment to take up the space, for valve cover clearance.

jerry

 

Mine were Yella Terra 1.8's for the LS3 motor.

 

What?

The Yella Terra rocker does not 'adjust'. You set pushrod length for lifter preload and shims for the contact pattern on the valve stem and bolt them down, they are known as 'zero or net lash adjustment'.

As for the valve cover, you can use a spacer or a Yella Terra extra thick gasket.

Comp, Crane and PRW make 'adjustable' rockers for the LS family and you adjust them like the Gen I/II/III engines.

 

This might be of some help. http://forums.corvetteforum.com/c6-t...g-pushrod.html

BJK

 

1. You might want to slightly clearance the inside of the head near the pushrod end of the YT's. You'll see once you test fit them that it is a pretty tight fit there. I'd also be concerned about whatever is in the valve cover directly above that area too (unless a true spacer is used).

2. I did a test fit of these with the 1/2" UMI spacer I spoke about earlier, and the spacer would have to be clearanced for the YT pushrod end as well. Heavily clearanced on the outside rockers (where the valve cover mating surface curves), and then probably pinned somehow to keep that clearancing in the proper place (the spacers were not exactly a snug fit laterally).

3. There has been a couple of reports of pushrod clearance also being tight (where the pushrod passes up thru the hole in the head). Might want to give that a good close look too.

 

1. You might want to slightly clearance the inside of the head near the pushrod end of the YT's. You'll see once you test fit them that it is a pretty tight fit there. I'd also be concerned about whatever is in the valve cover directly above that area too (unless a true spacer is used).

2. I did a test fit of these with the 1/2" UMI spacer I spoke about earlier, and the spacer would have to be clearanced for the YT pushrod end as well. Heavily clearanced on the outside rockers (where the valve cover mating surface curves), and then probably pinned somehow to keep that clearancing in the proper place (the spacers were not exactly a snug fit laterally).

3. There has been a couple of reports of pushrod clearance also being tight (where the pushrod passes up thru the hole in the head). Might want to give that a good close look too.


Can anyone translate all that crap I just read? (Quoted above here) I think sometimes peeps over analyze things a bit. Whew!!!!

 

That was real good, thanks a bunch 07!!!!

 

my suggestion would be to make sure the shaft rockers you install have the ability to be adjusted. any form of wear will cause clearance which will become valve noise. as motorhead said the noise made him take them out. either way i wish you luck.

jerry

 

I'll add my .02 since we've been through hell & back with every set of rocker on the planet.....

For those of you still running a stock GM castings, I would not personally spend the money on an aftermarket rocker. So many people underestimate the value and capability of a stock rocker and it's really a shame. The stock rocker is an amazing piece once fitted with an aftermarket bearing kit (Comp trunion). As long as you stay below .630 lift and are using a stock valve angle cyl head there's absolutely no need to run an aftermarket rocker.

Guys like myself, BTR, and several other well known shops known for being very **** about valvetrain geometry have no issues out of a stock rocker and will even use them on a Trick Flow cylinder head as long as the cyl head has the correct parameters to do so.

It's also nice to have the piece of mind of a stock rocker not breaking and/or needing adjustment after a certain amount of mileage.

If you're dead set on using an aftermarket, I would go with something like a Jesel or Crower. I am not positive about Crower but I know for a fact Jesel makes a 1.7 fixed roller rocker (Sportsman series) that is compatible with the stock valve angle. Most of what Crower makes is going to be adjustable so you'll need to both know how to set them up, and how to readjust them after certain mileage intervals.

YT rockers are alright if you never plan on installing an aggressive set of valve springs and/or camshaft in your engine. YT's break under heavy spring load.

Hope this helps.

 

Josh,

I think the LS7 guys are looking at the roller tipped rockers because valve stem side load is a possible culprit or contributor in the valve guide wear issue.

A few shops I've talked to think that the YT is a little too heavy 'over the nose', at least over 6500 RPM and especially compared to the OEM rocker, and from looking and weighing and tinkering I tend to agree.

 

Well they went in today and I had a chance to put about 50 miles on them so the results so far are in..........................
Much quieter than the stock rockers with the trunnion kit. I really think this is because I've got a bigger cam installed. I'm guessing that trunnion kit is only good for stock applications. I know some guys are saying they're making 800 HP with CCTKit, but how far are they driving? I also noticed a definite increase in the climb up of the RPM's, seemed to rev much faster and smoother. So far they've done exactly what I wanted them to do, happy for now. One other note... I had to loosen the valve covers a bit to provide clearance for the rockers, they come with a big fat gasket but not quite good enough with the cam I have. Stock cam would clear easy. My lift is .625 so go from there. I'll report back in a few days.