Picked up a 2015 Z/28

[Stefano]

Congrats, truley a great track capable package. GM has some issues with the valves in their LS 427 engines. The issue
was not resolved for the Z28s. Just something to be aware of. A bit of old school cam, headers and head work and your @ 700 hp Naturally aspirated, which transforms the car to "amazing" Super Car status. The white with all the black accents works real well.

[x77-69z28]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Stefano</div><div class="ubbcode-body">Congrats, truley a great track capable package. GM has some issues with the valves in their LS 427 engines. The issue
was not resolved for the Z28s. Just something to be aware of. A bit of old school cam, headers and head work and your @ 700 hp Naturally aspirated, which transforms the car to &quot;amazing&quot; Super Car status. The white with all the black accents works real well. </div></div>
I thought they corrected the valve problem. I thought it was bad castings on the heads?

[Stefano]

No it was never &quot;fixed&quot;. GM has never conceded to the issues. There is a lot of incorrect and conflicting info, even amongst engine shops.

Wegner Motor Sports found, that the coating on the valves as spec'ed by GM from Del West its way too course and wears the valve guides in short order. So we fix the worn guides and send the valves to be stripped and re coated with a non abrasive coating. We have not seen a single valve guide related issue, since, on our custom engines. We spin the LS7s to 7200 rpm. This is really an awesome engineered engine considering the basic design goes back to 1955 for GM.

Here I'm testing a line lock / Barker Button in the parking lot prior to delivery of a 700hp Stage III NicKey Z28.


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[68camaroz28]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Stefano</div><div class="ubbcode-body">No it was never &quot;fixed&quot;. GM has never conceded to the issues. There is a lot of incorrect and conflicting info, even amongst engine shops.

Wegner Motor Sports found, that the coating on the valves as spec'ed by GM from Del West its way too course and wears the valve guides in short order. So we fix the worn guides and send the valves to be stripped and re coated with a non abrasive coating. We have not seen a single valve guide related issue, since, on our custom engines. We spin the LS7s to 7200 rpm. This is really an awesome engineered engine considering the basic design goes back to 1955 for GM.

Here I'm testing a line lock / Barker Button in the parking lot prior to delivery of a 700hp Stage III NicKey Z28.


<object width="425" height="350"> <param name="movie" value="https://www.youtube.com/v/5L3XQ4tIIGg"></param> <param name="wmode" value="transparent"></param> <embed src="https://www.youtube.com/v/5L3XQ4tIIGg" type="application/x-shockwave-flash" wmode="transparent" width="425" height="350"> </embed></object> </div></div>

Wow, quite a remark concerning GM. Interesting as I'm not aware of this and we and several that I know own a 2014/15 Z/28. When did this issue come about, with the LS7 in Z/28 or when still being used in C6 Z06's. Need to review but had not heard of this either on Camaro5 Z/28 forum and quite a lot of those guys are tracking their cars.