Sounds like a plan!

I always assumed the following was the reason these engines seem to be so hard on mounts. I realize I don't truly understand 100% the balance of an engine, but I think I could if I researched it and it was important to me to understand.

BALANCE SHAFTS
Any 90° V6 creates some strong, primary imbalance forces, especially in the vertical mode. The 262 is no exception. Chevy originally underbalanced these engines by putting about 46% on the bobweights instead of the usual 50%. This reduced the vertical imbalance that was trying to lift the engine up off the mounts, but created a strong horizontal imbalance that shook the engine from side-to-side instead. So, in order to eliminate a lot of the "noise, vibration and harshness" in the engine and make it into a world-class motor, Chevy added a balance shaft to the premium engines in ’92 and included it in all of them by ’95.

 

Victory! Good advice from all.

 

Very interesting Les, Okay so two nights ago I popped the head off and immediately found something I didn't like, hence why I have been holding off on making this post until I could figure out a little bit more. So I'm really kicking myself that I didn't do a compression test on cylinder 3 because when I got the exhaust valve spring out for that cylinder and started moving the valve in and out I noticed it wasn't seating correctly, I put a light on the valve from the outside and could see light shining through in the exhaust port when I had it closed. I took the valve out and it's not bent, it's just not seating well. Now I followed this up with shining a light at cylinders 1 and 5 and they both let some light pass through as well, not as much as cylinder 3 but I can still see it when I look in the exhaust port. What do you guys think here? Do new exhaust valves all around or just use lapping compound on these ones I have now? Yesterday while I was figuring this out I popped the oil pan off too, the crack in the pan is so small from the inside I almost missed it at first! Everything is looking good inside to my eye but I still need to rotate the engine so I can get a good look at the #6 rod. Is there anything else I should check while I'm in here?

 

Second video above is "Private" and cannot be viewed.

I think that you need the valve springs on to hold the valves closed, in order to do anything with light like you did. Remember that #1 and #5 had decent compression.

Nevertheless, since you have it torn down and are already suspicious why not get 6 new exhaust valves and lap them in - valves are cheap from Rock Auto. Machinist's blue will check the seal to the seat. If the seal isn't acceptable on all, you will have to take the heads to the machine shop and spend some serious $$$ on them. Since you be will doing multiples, might as well get one of the cheapo suction cup lapping tools. I personally like to put a weak spring under valve head to hold it off the seat intermittently during the lapping process, to add just a bit more lapping compound and/or rotate the valve to a different position. If you use a spring, it should hold the valve off the seat but allow you to push it closed easily with the suction cup tool.

Don't forget to check valve springs. You can cut a 18" piece of 2x4 and use this to compress the spring against the floor or bench (one hand on each side of the 2x4 - spring in the center - knee on top of 2x4). They should be about 70# at installed height (200# at valve full open), so you should easily be able to compress them some with your body weight. Just make sure there are none that feel weaker than the others or ones that sit crooked or are different height. That will be good enough for this job.

Here you can see part of the process. Once the valve is lapped, you spread a thin coat of machinists blue on the seat, hold the valve against the seat, and turn. The blue gets wiped off the seat where the seal is. You want the seal to be all the way around on the seat, and ideally also in the center of the valve face (and not full width of the valve face). Ignore any thing you see involving a drill! Easy does it! Take the heads to the spray car wash after lapping to get all the grit washed out Dry heads well and oil all surfaces afterwards with WD40.

I already said that I believe it will be a mistake to try and check bearings.

 

You may or may not have the 60 degree cut on the seats. Depends on if it had a 2 angle or a 3 angle valve job from the factory.

 

I have not done a valve job in decades. How good are the valve angles and faces out of the box? Does a machine shop face new ones before installation or only those being reused? Is it like modern pregapped spark plugs or old school where you had to set them all first?


George

 

Should be pretty close to 45 degrees on the valve face. Then it can get lapped in if there are any differences. Loose guides can be much more of a problem. At least new valves have unworn stems.

 

Oops I made that video public now, I checked all the other valves a bit more and cylinder three definitely lets in more light than all the others. I think you are right I should have the spring in when I'm testing to be accurate, however, I will just get all six new exhaust valves and lap them in and call it a day. I'll get the machinists blue as said to check them before I put it all back together, thanks for all that information and the video Les I will follow it when I do mine. Okay so I think I'm ready to order all these parts please let me know if I'm missing anything here, Fel-Pro ES74034, ES72224, 2601738, Melling MPR615, V1807, Dorman 264109, Energy Suspension 3.1144R. Other than this I will check the valve springs in a bit here and replace them as needed too.

 

What about the oil cooler hoses? And somewhere you will need to source a protective sleeve for installing the valve stem seals on the valve stems (it might come with your gasket set, but then again it might not). This prevents the keeper grooves in the valves from cutting the seal as it slides over. Remember that valve goes into place, then seal protector, then seal over valve stem, then spring and retainer (don't install seals in head and then push valves through them).

Other than that I can't think of any major things. I'm sure something has been forgotten. It always happens.

 

Yes, I will need to add those oil cooler hoses definitely! Thanks for pointing out that protector sleeve, looking at the gasket set I mentioned up there it looks like it comes with them. Is that your picture Les?! Damn that head is clean lol. Something is just not adding up here guys, I noticed this when I had all the valve springs together and I was testing them that all the springs on the passenger side look brand new. Then the rockers and pushrods tell the same story, the passenger side all look brand new, the driver side older. I haven't cleaned any of these parts, they are just how they were when I pulled them all out. Here are some pictures, it seems like someone must have been in here at some point on the passenger side. Does anyone have any thoughts about this? Keeping in mind that it failed on the passenger side?