LMBC6Z

Just as the title says...some may have seen my other thread regarding a potential purchase of a C6Z. I do want to get a wiggle test done prior to purchase.

Can anyone recommend somewhere near/around central Connecticut that is familiar with C6Z's and complete a wiggle test? The closer the better!

Ideally looking for someone that wont charge $4,000 like one shop wanted to charge in an old thread I found while searching

bjmsam

The closest one on the crowdsourced interactive map of "wiggle testers" is on Long Island. If you find one closer, please add it!

ttx350z

Can't really help...

Geez. For $4,000, that wiggle test better come with a set of reworked heads, cam, labor and dyno tune!

LMBC6Z

That is awesome, thank you for that link!! Didn't come across that while searching...looks like Long Island is closest to me. I don't know if the seller would be willing to drive all the way there to do the test so I may need to keep my ears out for something more local. I'll find out tomorrow. Thank you again!

reasonable suspicion

Don't waste your time, money, and effort on a wiggle test. ......do the heads.

bjmsam

Checking the valve to guide clearances and making informed decisions is IMO a sensible alternative to ignoring potential problems under an assumption that the heads are fine (risking catastrophic engine damage) or reworking the heads under an assumption that one or both are among those with manufacturing defects (especially if the reworked heads result in valvetrain imbalance). Many shops will discount (if not waive) the cost of a wiggle test if the heads need to be reworked, so there is really more to gain than there is to lose.

An early draft of Hib's procedure was followed to check the valve to guide clearances on my '07 last summer at 62k miles and the bill totaled just over $500 (all were checked since none were found to be out of spec). I'm glad I did not blindly spend far more money having them reworked only to end up with a "fix" like this.

I will have the clearances checked again at 100k, and if they are too close for comfort, then I will likely go with AH package #4 with stock valves, probably using my heads rather than cores since they appear to be better than many others.

reasonable suspicion

Ok, you're right.

Bill Dearborn

The wiggle test accuracy is questionable. If the dial indicator isn't held at the correct angle using a bracket that doesn't have any movement you will get false readings. Read Hib's article on the Corvette Action Center site. If somebody is careful and knows what they are doing, uses the proper equipment and is careful setting up the equipment so measurements can be accurate you can get good results when compared to pulling the heads and making the measurements with a guide bore gauge and a micrometer. I spent a fair amount of time talking to dealer mechanics in my area and none of them were comfortable with doing the wiggle test. They all thought it would be best to pull the heads and make the measurements that way. Based on Hib's article, the local mechanics opinions I found a shop that would do all of the work if required. We started out with a price for them to pull the heads, totally document their measurements and to reinstall the heads if they found everything in spec. That costs about double what a wiggle test costs. What I got was everything in spec except two intake guides that were a shade out of spec and several other intake guides that were close to being out of spec. All of the valve stems were within GM's production spec. That is when it gets to be decision time. Buttoning everything back up was an option since they weren't all that bad but I would be looking at going back in a year or so to check everything again.

Bill

2k Cobra

When mine were done. (Wiggle) Some measured ~ 3X tolerance.
(Work was done by people who wrote the book on it) The same measurements were 3X after heads were removed.

Heads were replace under warranty and testing also covered.

With some of the heads I've seen on this site, you don't even need a dial indicator. The valves will move freely in the guides with finger pressure.

All this discussion and wasted time is because GM didn't face up to a major mistake and recall all LS7s and replace the heads with good ones.

Bill Dearborn

That really isn't an indicator of a bad guide. A fair number of my guides measured .0019, .0021, .0024 which are all within GM's production specs. All of those valves could be wiggled by pushing on them. As the guide clearances grew larger you could see more movement but just the fact they moved didn't prove anything.

Bill

Z06Ronald

May I suggest that you first read the following thread about the wiggle test accuracy ...

https://www.corvetteforum.com/forums...uide-news.html

reasonable suspicion

LOL, now how do you feel about your reply to my post....LOLOLOLOL

https://www.corvetteforum.com/forums...uide-news.html

'06 Quicksilver Z06

I thought that it was a given that if movement could be perceived or seen thy the guides were out of spec.

bjmsam

Well, I feel a lot better than the myriad folks who unnecessarily and in some cases detrimentally reworked their heads for $2k+.

Sorry if you were somehow offended by my post.

shane p

The wiggle test is a joke.