Everything you ever wanted to know about the LS7 engine

[froggy47]

Hi Hib, going to read your article, now have a 2013 z06 with 8k miles. Ddi/do you mention the rod/crank issue on the 12-13 ls7's. It's talked about on the other forum.



Finally joined the c6z club

 

[lgvenable]

Hi Hib, going to read your article, now have a 2013 z06 with 8k miles. Ddi/do you mention the rod/crank issue on the 12-13 ls7's. It's talked about on the other forum.

Finally joined the c6z club

The quick answer is yes...it also applies to the 2014 to 2015 Z/28.

I would say that you need to do the wiggle test and find out if there is any issue with the engine, as any high performance engine should be examined by a competent mechanic every year to two years to make sure there isn't an issue that would break your heart..since crate LS-7's are $16,000-$17,000 plus installlation. But hey- it is a 427 right..and a monster performer.

I have an '09 Z06 and a '15 Z/28..and LOVE my LS-7s. The only thing Hib doesn't mention is stud mounted roller rockers.Doing that eliminates any side loading of the valves, which eliminates the valve drop issue. In the build I'm also using Moldstar 90 guides -> which are the valve guides used in F1 engines. I'm in the middle of an American Heritage Performance build to eliminate any chance of a dropped valve. I've got a target of say 715 to 725 crank hp, so...~630 to 640 RWHP.

Kohle (at AHP) started his career at Cosworth in F1; so the Moldstar 90's were a logical $700 head upgrade, as well as the extra $2800 to machine the heads to accept stud mounts along with stud mounted roller rockers. On valve guides Moldstar 90 guides work harden, and have great innate lubricity. The normal guides do NOT work harden and can gall,and other upgraded guides increase in hardness slightly and will gall. But the Moldstar 90's perform at much higher RPM range than the LS7 is capable of;work hardening about 14 to 15%, and WILL NOT gall over the next 100,000 miles. Truly its the way to make this an issue that your heirs don't have to worry about.

 

[Iroc2Vette]

My 2013 no at 58Kmiles +, almost no oil consumption and no DTCs or oddball sounds from the valve train. And mine has 5 hours of track time, too.

 

[froggy47]

Thanks guys.

 

[Pacha]

Thank you Hib for the fabulous in depth article covering the LS7. I'm having the heads looked at next week and will have oil samples tested for each oil change going forward.

 

[Hib Halverson]

Post here and let us know what condition your heads are in.

Glad you liked the article.