Found under valve cover
 

1990 5.7 TPI
Heads were swapped with ZZ3 heads 25 years ago.They were modified by Ray Bohacz and installed by him when he had the shop in NJ.

Found these when I pulled the valve covers during intake removal to change gaskets.these were on the pass. side but nothing on the driver side.
https://cimg7.ibsrv.net/gimg/www.thi...e5524628d3.jpg
https://cimg8.ibsrv.net/gimg/www.thi...acc4442f39.jpg

Look like valve seal parts to me.

Still haven't pulled the intake base to see if there are any more pieces in the lifter valley.

Re: Found under valve cover
 

I'd agree. They look like the clamp bands from valve seals. Fortunately, they are probably too big to make it through the oil pickup screen - Probably.

Re: Found under valve cover
 

Agreed.

I'd suggest popping the springs off and finding the source. Maybe refreshing the seals & springs while you're there. And of course, verifying that the retainers aren't smashing into the seals and destroying them, due to too much lift for the height of the guides. Then if that's an issue, maybe put some LSx springs on there such as PAC1218 with Comp 787 retainers. Although those heads look like they're already cut out for 1.45" springs, in which case you'd need locators as well, and maybe offset keepers.

Re: Found under valve cover
 

https://cimg9.ibsrv.net/gimg/www.thi...e78a564caf.jpg
Had some time and finished pulling the intake.
Defiantly was leaking on the passenger side front coolant passage.
Also found that the gasket was distorted between the ports.

This project has really bloomed into a big job.

Going to replace the valve stem seals.
I haven't done this before.
Need to purchase new seals and a valve spring removal tool.
Suggestions?

Re: Found under valve cover
 

The stud-mounted cam/lever spring compressors seem to work well if you're not planning to pull heads - Provided you have clearance for the tool. Braided nylon rope stuffed through the spark plug hole is a reasonably safe way to retain valves without fear of losing air pressure in a compressor type retention scheme.

Re: Found under valve cover
 

Yikes! :eek:

I'm going to be following this, to learn a little bit more about SBC diagnostics.

Anxious to see what you find as a cause of the stem seal failures.

Any idea about the intake gasket failures between the ports (happened at install?) and coolant passage?

Re: Found under valve cover
 

The gasket failure looks installation-related to me. Maybe not "installer" related, that is to say it wasn't necessarily that somebody screwed up, but definitely related to the installation.

Looks like the top surface of the intake pulled the top of the gasket downwards as the bolts were tightened, which caused the part over the septum between the ports to bulge out. THe most common failure of that sort that I've seen is when that happens across the bottom, and the ports are then exposed to the crankcase.

That (FelPro 120x) is prone to that sort of thing and therefore not my personal favorite type of gasket to use. For a stock-ish sort of application like the photo, I prefer the MS90314. They're just all-around more robust.

Re: Found under valve cover
 

Thinking about getting the first pic.
Any known issue with getting to all the springs on the pass.side with AC.?

Whats a good valve stem seal to ?

https://images-na.ssl-images-amazon....1CZRV7BPJL.jpg

https://images-na.ssl-images-amazon...._AC_UL115_.jpg

Re: Found under valve cover
 

Looks like the gasket failed because it never sealed - but why ? Was the gasket to thin in that spot ( Bad Quality out of the box )? Maybe a low spot in the head,... or low spot on the intake ?? I'd be sure to check the Head and Intake before re-mounting the intake again.

The smaller spring removal tool is the one I always use,..... Made by Craftsman, Buy it once.

Craftsman Overhead Valve Spring Compressor, NOS, made in USA - Part # 47704
https://www.ebay.com/itm/Craftsman-O...DEXI:rk:4:pf:0

http://c.shld.net/rpx/i/s/i/spin/ima...&wid=64&qlt=50



:driving:

Re: Found under valve cover
 

The simple claw-&-screw type spring compressor won't work on double springs, if that's what you've got. I have one of those also but haven't used it in years.

Worse yet, it tends to scratch the springs, which can lead to failure.

I'd suggest getting the first one.

AC is no big deal. If it's in the way, take it off. But I doubt it will be. A bigger problem will be, interference with the handle, esp near the rear of the motor; not enough room to move it in all the directions it needs to go.

Re: Found under valve cover
 

Thoughts on these seals
https://smile.amazon.com/Cams-518-16-Valve-Viton-Metal/dp/B002EE2CTC/ref=sr_1_11?ie=UTF8&qid=1549225162&sr=8-11&keywords=1990+corvette+valve+stem+seals#customerReviews

Re: Found under valve cover
 

They're fine, assuming that's the size of your guides. Personally I prefer the 503 or 510 (Teflon) but those are OK too. Price is about the same. Measure before buy.

Re: Found under valve cover
 

Heads were brand new that are ported and springs changed.Valves are the ones that came with them.
Guides should be the original ZZ3 ones.
Time is hard to come by for me,I would buy multiple sizes to not have to wait to measure.

Re: Found under valve cover
 

Stock GM heads won't have .530", or .500", guides.

That might even be the problem you have there... if those are "triple" springs (double w/ damper) then the inner might have rubbed against the clippy part of the seal, if they're the stock .575" or whatever it is.

Measure before buy.

You can take one apart easily enough with almost no tools at all. Bring a piston to TDC; stuff the cyl as full as you can with about 3/8" nylon rope; whap the retainer with about a 5/8" socket and a nice BFH; and watch carefully where the keepers sproing off to. They can launch quite a ways. Once you get some springs off, measure. Chances are, you'll want to replace the keepers anyway, but it never hurts to keep all your parts accounted for during tear-down.

Re: Found under valve cover
 

Best thing I've ever found to stuff the cylinder with is an old spark plug wire.......

:driving:

Re: Found under valve cover
 

That discussion jest recently happened: https://www.thirdgen.org/forums/tech...al-theory.html

It seems that opinions vary, but I would avoid that type for my own use.

Re: Found under valve cover
 

There's an interesting thought. I may have to try that in the future, and possibly save a couple old wires for the purpose.

Re: Found under valve cover
 

Ordered the proform compressor.
Might be a couple of weeks before I get time to pull one of the springs off.

What should I be looking for and measuring?
I'll be sure to take a bunch of pictures.

Re: Found under valve cover
 

Re: Found under valve cover
 

https://cimg1.ibsrv.net/gimg/www.thi...ac9aab078f.jpg
Found some time and pulled a couple of springs.
Looks like they squeezed them with pliers and cracked the retaining spring.
Not finding anything when I google the numbers on the seal..
Plenty of room between seal and spring.

Re: Found under valve cover
 

Valve-.344
Guide- .550

Re: Found under valve cover
 

Not sure what seals those are, at .550". Obviously if the guides are.550", a .530" seal won't work.

Might be time to look at a guide cutter tool. Comp 4732 arbor and 4726 or 4715 cutter for .530" or .500" guide respectively.

Re: Found under valve cover
 

Someone recommended these.


11/32" X .520"-.565", Valve Seals Viton Flex Body Type Universal

https://cdn1.bigcommerce.com/server5...60.260.JPG?c=2

Re: Found under valve cover
 

Those are likely the same as what you have now.

Personally I have a deep distrust for anything that comes from Alex's. I have a hard time feeling warm or fuzzy about somebody whose claim to fame is popularizing a hack job. Yes I know, plenty of people have used his stuff and got good results; somehow that doesn't inspire trust in me though. But hey, if they fit, and you can put em on without damaging em, and you feel comfortable with em, it's your choice.

Frankly, I'd still recommend pulling the heads, popping the valves out, and using the cutter listed above, so you can put on the better parts. Might not be a bad idea to check out what springs are on there as well; if they're K-Motion or the like, or show signs of any wear or deterioration, might want to replace those at the same time. There are few things that can cause hard-to-diagnose problems and just general mystery performance issues, than ineffective valve springs.

What is the OD of those springs? What is their installed height? What hardware did the shop use to accomplish it?

Re: Found under valve cover
 

you already bought one, but autozone will rent this tool for free. just pay a deposit and get it back when you return the tool.

Re: Found under valve cover
 

The pro tool compressor is very impressive.
Only took off two springs so far and it works very well.
At the price, I can't imagine the screw type,with the possibility of damaging the springs,being even considered.

Re: Found under valve cover
 

Agreed - Good move. With a little adjustment of position, there aren't many places it can't be used except transverse engines, or in a van.

Re: Found under valve cover
 

Valve stem seal replacement complete.
The Alex's seals worked.
Had called Felpro and spoke to there tech. and ordered the ones he recommended.They were to small.

All of the springs that hadn't broken had a nick were the ones that broke.
Looked at the receipt for the work on the heads and new seals were not listed.Can only assume the installer did something to them that caused the nick.

All broken pieces were found and accounted for.