Hi guys,


My shop after previous experience recommended me to get the heads checked which I agreed to do and found some problems with my valve guides. Upon previous experience they found problems with the stem seals on another VQ35DE, but they only found that after rebuild, with all the extra cost involved and eventually the previous customer went all out with the Cosworth heads replacement.


I'd like to ask you guys with built engines experience (both owners and builders) how common is it to find valve guides and stem seals damaged upon first inspection, while stripping down a std engine? Seems awfully unlucky here in the UK, or is it?


Thanks

 

Mine were fine. Even after 3 builds.

 

How many miles on the motor?

 

47k on mine, the other guy's.. I don't know. Could it be wear and tear? I've got pics of them in my build thread, let me link them

 

So they said all you need is stems and seals or is there a bigger problem?

 

no bigger problem (after all I gave them the car in perfect working order!) they suggested the below options:

1. Recondition existing heads with new exhaust valve guides, retain the standard valves, gas flow the cylinder head to increase performance.
2. Buy new Cosworth heads with big vales and racing springs.
3. The cheapest option is to just recondition the exhaust valve guides.


I wasn't interested in headwork to start with, and there now might be another option of buying one of their previous customers' heads as he went Cosworth ($4.5K ffs!!!) but his problem was the stem seals which they have fixed.

So i could buy his heads cheap and finish the build, then with my own heads get them ported with a new set of valves etc at my leisure!

 

I have a set of heads too with only 30k miles on them. Might be too expensive for you too cuz of shipping but just throwing it out there for anybody that is interested. LOL.

Also, if you think about replacing seals, i have brand new seals for sale.

 

I had 50K on mine and they were upgraded because I went with bigger valves. Otherwise they were fine. Also, still plenty of stock Z's out there. None with reported valve related problems, with well over 50-75K miles.

 

yeah that's what I thought. hadn't heard much about any valve issue anywhere before.

From my pics do you guys see the problem? Apparently one is clear from the pics, the other is a clearance issue:

From email:
"You will be able to see the valve seat damage from the pictures, but not the guide wear because it a clearance issue. "

 

It's standard practice,,,I hope...to change valve stem seals on rebuilds. Valve guides are pretty durable, and barring damage revealed on inspection, they are typically reused on low mileage cores.

 

if you say so I believe you! I "think" this had not been done on the previous customer's build.

So if I get the chance to get heads with new valve seals and good valve guides like the ones they have in the shop I should be good to go, then.