Recommend me machine shop for LS7 head work

addyyin

addyyin

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hi. I am new here

I got myself a used 09 z06 with 60k km. The motor was replaced once possibly due to drop valve in late 2013 and replacement motor was built Sep 27 2013. It currently has probably 20k or 25k km on 2nd motor now and this drop valve crisis really worry me. Can anyone suggest me a great cylinder Head machine shop that's familiar with ls7 valve guide issue, or valve seat runout problem. I like to have my head re-do ASAP

By the way I prefer within 604 BC local area.

Thank you.

Addy
 
Addy..
Welcome to the site.
congrats on the '09 Z06... Nice ride.
I've never had serious head work done myself...
I'll check with friends to find a good place that is local.

Graham
 
Call Manny at Dasilva Motorsports. You just cant go wrong with these guys, they know a lot about corvette. They are forum vendors.
 
When the original engine was replaced, was it rebuilt with new heads, etc or was the engine replaced with a factory engine (with the factory heads)?
If the engine was replaced with a stock factory engine, my only thought is for the cost of redoing the valve guides, have you thought or priced out the difference of getting aftermarket heads? I have no idea of the cost difference but just thought I would ask.
And as stated, although Manny is in Ontario, he's a good person to pick his brain about what work needs to be performed and if there are any other options. It's definitely worth getting in touch with him so you'll know you're on the right path and don't get any unnecessary work completed.

Oh! And sorry about being so rude! Welcome to the forum! I'm hoping our advice can help you out and get you some peace of mind with your gorgeous sounding car! I love the C6Z and although the chance of your car dropping a second valve is extremely rare, I can understand you wanting to get it inspected/fixed before anything else happens.
 
hi. All.

Thank you all for the quick help. I was an import guy had more than dozen popular imports before but I fall in love with corvette when I was in Bob Bondurant racing school in Arizona for their courses back in 2010, and it wasn't even z06 but z51 I had. It's astonishing the vettes are going thru that kinda continuous abuse under their ridiculous hot weather by all sort of skill level.

From my research before purchasing the used z06 I know the motor was replaced and had a head gasket job after replacement motor. Thru decoding the motor serial number sticker it's a factory GM long block replacement minus pulley, intake manifold, cover vs crate motor. I bought this particular one becuz I thought by 2013 GM is very likely had solved the valves train issue but after further research it seems GM had done absolutely nothing.

Ruthless Pursuit of Power: The Mystique of the C6 Corvette LS7 Engine - Page 18 of 26 - CorvetteActionCenter.com

After all my research thru Google, My idea of z06 is entirely stock except brake pads with reliability in mind first simply becuz the motor is just too expensive if anything on the heads fail on me.

Thank you for the shop suggest over in Ontario but I really prefer shop within 604 Vancouver area. I have thought about the new aftermarket heads that summit is selling but at current exchange rate it seems too pricy to go thru that route and there are very little feedback regarding long term reliability. I decided to have my factory head valve seat rework and new guides put in to run another -40k km and take it apart again to recheck or not. by time there should be more long term feedback towards aftermarket heads. Bronze guide longevity. Or a more proven solid fix. Thank you all.
 
Hello Addy. Welcome to the forum. Davenport Motorsports in Calgary has a good reputation around here. Have never been myself so would recommend checking them out yourself if you choose to come to Alberta. Lot closer than Ontario. Graham (nascar03) will likely get back to you with a connection in Van. though....good luck either way,
Eric

And by the way. Most Corvette drivers will tell you there's just something about a Vette. A cross between a sports car, muscle car, Saturday night cruiser.... or whatever, there's something there that just reaches into your soul and hooks you once you get behind the wheel. No matter what your age, you smile like a kid with his first candy... and you don't even know you're smiling until your cheeks start to hurt...... just my thoughts.....

Nothing wrong with imports either though. I have a 0-60 in 14.9 Rav4 that will set you back in your seat too.... pk.... that was a joke.... the 14.9 might be an exaggeration... :p
 
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Addyyin; Give Manny Dasilva a call before you do anything. I have dealt with Manny several times and He is a straight up Guy.

He probably has experience with the issue you are talking about, and will at least give you an honest opinion of what your options are. Whether you end up dealing with him or not is your business, but Manny will at least give you straight goods.

Good Luck and Welcome to the Forum
 
Bearly Flying said:
Addyyin; Give Manny Dasilva a call before you do anything. I have dealt with Manny several times and He is a straight up Guy.

He probably has experience with the issue you are talking about, and will at least give you an honest opinion of what your options are. Whether you end up dealing with him or not is your business, but Manny will at least give you straight goods.



Good Luck and Welcome to the Forum
Click to expand...
In the past Manny has posted about this problem with pictures so he is quite aware of it.
 
Hi sup. Some updated. I pulled my ls7 heads off on 2016 March myself. Had it sent to Alec machine shop in Vancouver. Remember the car is 2009 but the warranty replacement motor was built Sep 2013 with only 30.000 ish km on motor mileage After their inspection they told me my intake valve guides are more worn out over exhaust side. After bronze guide replacement and re-concentric/re seat the valve seats, decked and bolt back to get it running I notice much quieter valve tick noise from idle to 1800rpm range. After 5500km and 1 track day my valve train remains quiet.

Btw during head re-assemble I noticed my crank pulley bolt back out and completely loose, so I upgrade the crank pulley to 10% under drive ATI super damper and ARP crank bolt torqued to 250lbs and it hasn't move yet after 5500km and 1 track day.

The motor is still quiet from valve tick now except my front wheel bearing seems start to go south.

The ls7 valve guide issue is real, it seems earlier engine experience exhaust guide wear and later engine experience titanium dust issue on intake side, and maybe concentric problem on all of them.
 
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Thanks for the update! Glad to hear the issue has been resolved and now you can drive worry free. Shocking about the crank bolt!!! However, that too is nice to hear that it is fixed and better than new.
 

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