Valve spring and stem seal questions

CORVETTE SPECIFIC - Applicable to all or most models

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68ragtop
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Valve spring and stem seal questions

Postby 68ragtop » Thu Jun 14, 2012 10:12 pm

Hi all,

Well I think my 68 is definitely trying to pin the name Frankie (Frankenvette) on herself, as have found one more not quite original thing on her. I have been looking at replacing the valve stem seals in order to try to stop an issue with the plugs oil fouling and oil smoke showing up at idle when the vacuums greatest sucking it though. Plan was to borrow a few tools, take the springs off, replace the seals, put it all back together and adjust the lash and sit back to a good beer.

So tonight I took off the rocker covers to take a peek to see what's going to be needed by way or replacement seals.

Image

So far everything is good. I find some pressed steel? roller tip rockers and signs of thing being well oiled. Now I get to my first question. I noticed the rocker on the exhaust valve on cylinder 3 (4th rocker in pic) actually has about 1/16" side to side rock/play! This can't be normal right? Would it just need tightening down a bit or should I start to be concerned?

Anyway, now I look at the valve springs to check how I'm going to remove them and make my next 2 discoveries as per the following pic

Image

First the valves have double springs on them. Are there any special tricks I'll need to know to get these off correctly?

Second, it looks like there is some kind of orange seal in there. Do you reckon these are just "umbrella" type seals that may be riding a bit high?

Finally I took a closer look at a few of the other valve springs and noticed a few other things that concerned me a bit more. See the following pic.

Image

Now to me this looks like there is no seal in there like the other ones at all. Makes me wonder where it's ended up? More concerning is that to me it looks like that inner spring is actually broken as the base of it there just don't look right to me? Thoughts anyone?

A few addition pics here at these links:
Image

Image


Was a bit hard to see as am doing things by torchlight and cellphone flash, but will get in there on Saturday to see if I can get a clearer picture in the daylight of whats going on there and what the other head looks like. And yes in case anyone asks, the casting number does make them most likely heads off a 305 which judging by the receipts I got with the car may have come from ebay and had a bit of valve work done to them before they went on the car.

Cheers,
Azza

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Postby Fissan » Thu Jun 14, 2012 11:15 pm

G'day Azza
The springs you have just have a dampener inner spring, no special tools needed. Yep you have a broken dampener on that valve the seal may have been chopped by the spring. IMO I don't like the umbrella seals unless they are secured on the valve guide as they could actualy act like a pump and push oil down the valve stem. Be intrested in seeing a pic of the valve tips to see if the rollers help. A new set of seals and springs (up to you if you do the one or all) and you should be all good
Just had another look at the pics and looks like the dampener on the first valve is broken aswell??

Regards Bruce

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Postby DOC » Thu Jun 14, 2012 11:17 pm

Good day Mate.
Yup they have had a bit of work. No, no different getting them apart. I do have the nice little bar and such to pull them off. the broken spring is rare. But I have seen it before. And why the performance springs and roller tiped rockers? what cam is in this thing? How have you got that Dist. tuned?
Looks like an e-z fix. But you might want to order a set of springs from Summitracing.com. , As I doubt you will be able to get just one. And those pressed steel rollertips look like something from Summit.
Not all Bad. At least you know the heads were worked at least a bit. Gotta wonder about the valve sizes, Your receipts say anything about valves?

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Postby Fissan » Thu Jun 14, 2012 11:24 pm

May pay to check for spring bind on the dampeners if there is more than one broke


Regards Bruce

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Postby 68ragtop » Fri Jun 15, 2012 9:11 am

No actual receipts for anything to do with the heads (other than assembly and fitting) just some random notes on the papers and some printouts. There are notes about 1.6/2.02 valves there two, but these heads came with 1.5/1.72 from factory so that woudl be quite some work done. As for cam, from the notes it may be a Comp Cams XE262H or XE268H in there. Maybe. Yes most things probably came from Summit as I know the Dist definitely did from the receipt.

And yeah it looked like a couple of the inner springs were toast, but the pics were the best ones that showed what I was talking about. I am guessing the umbrella seals got caught on those and ripped apart and have disappeared to who knows where in the engine :shock: ! Some at least I think I can see stuck at the bottom of the spring.

So based on the facts so far I am thinking I'll be having to find the cash for:

1. A new spring kit (as if some have gone already, I'm not likely to trust the rest for long).
2. New stem seals. O-rings would be easiest, but without the splash shield on top of the spring would they still just leak? Umbrella seals would be easy if I just go with single springs as replacements. Or the positive control viton seals which may need some machining to get on there?

Cheers,
Azza

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Postby australi » Fri Jun 15, 2012 9:37 am

Normal to have a slight bit of lateral play on rockers.

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Postby Bazzas77 » Fri Jun 15, 2012 10:23 am

Dont muck around with it ,get that motor out , get those heads off so you can find what else is wrong with it (and what you have in there !)

thats what i,d do anyway :o

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Postby 68ragtop » Fri Jun 15, 2012 2:51 pm

Bazzas77 wrote:Dont muck around with it ,get that motor out , get those heads off so you can find what else is wrong with it (and what you have in there !)


Would love to just replace it with a crate 350, but house repairs come before car mods, at least according to my partner. Gotta defer to her on this seeing as she put up the $$$ for the deposit on our house because I'd spent all mine buying the vette a few months before :) Funny thing is that unlike her she asked this morning if we could take it for a cruise up through the hills and Sanford at the weekend and looked a bit disappointed when I told her it needed repairs first. Maybe I can work on her a bit after all to change the priorities.

With the budget in mind I think I'm going to hide my head in the sand and assume nothing else is bad and just replace the springs based on the cam that is circled in the notes I got with the car. At least that way I might be able to get her along to some of the car shows in the next little while.

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Postby riverracer » Fri Jun 15, 2012 5:21 pm

i changed mine a few months ago, not a hard job, spring compress lever and an air compressor
and a pick up magnet for the collets
go to performance wholesale, their up your way, and pick up a set of springs
i just put the original rubber/viton caps back on mine as my heads aren't machined for those fancy type seals

just out of interest what casting number are they?
Speed has never killed anyone,
Suddenly becoming stationary that's what gets you.

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Postby DOC » Fri Jun 15, 2012 6:16 pm

I'm with River, Just get some replacement seals, and a good set of springs. I would assume that the dampner springs were junk. And like you, If your on a budget, Just replace the springs and seals, and Drive on.
Do you need to borrow any tools? Do you want a hand? I am free Sunday

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Postby 98lux » Fri Jun 15, 2012 6:32 pm

DOC wrote: I am free Sunday


Between 9.30am and 9.55 am :) :) :-o :-o

The way you offer to help people is unreal :D to you. IF i ever meet you i will bye you a beer (if you drink) 8)

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Postby Bazzas77 » Fri Jun 15, 2012 7:04 pm

Hey Doc and riverr, how do you know which strength spring to buy ?, a good quality set yeah but what rating should it be if you cant identify the cam used ?

If he tests a few thats on the motor and gets an average number how do you know its right and he,s not just copying the original potentially wrong size again ?

If he,s got hyd. tappets how can you measure the lift accurately by turning the motor over by hand ?

just curious or am I overthinking the problem ??

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Postby DOC » Fri Jun 15, 2012 7:45 pm

Yes Barry, I think your over thinking it big time. He's not building a7,000 R.P.M. Drag car. Just a street car with a mild cam, Most likely will never rev over 5 grand, Just a good set of performance valve springs will be just fine. Hell, I run stock Chevrolet ones in mine, No problem as I am far from coil bind, And I really don't go over 5,500, And then only rarely.

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Postby shipy59 » Fri Jun 15, 2012 9:19 pm

I agree with DOC , whack on a set of performance GM springs with original or umbrella seals and drive the sucker :C :)

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Postby 68ragtop » Fri Jun 15, 2012 10:18 pm

Receipts show motor was built in 2004. Can see receipts for crank kit, rings, timing gear, balancing, and fitting of heads. Notes written on receipts indicate a comp cams XR270HR cam with max lift .502. Note also about .550 lift rated springs. Spring tension is another unknown but guess can look up whats right for that cam.

As for performance, well i had it up to just over 4000 revs once but she mostly loves to sing in the 2-3k range.

And Doc I would love to borrow the handy 2 tools for the job that you have but it looks like i wont have a borrowed compressor until next weekend. Also will have to find somewhere open on a Saturday to get the parts or go online and wait for shipping.

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Postby 98lux » Fri Jun 15, 2012 11:07 pm


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Postby 68ragtop » Fri Jun 15, 2012 11:14 pm

Yeah 98lux I checked them out earliet but theyre closed weekends.

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Postby Fissan » Sat Jun 16, 2012 12:26 am

Why not just dump the dampeners and replace the seals if the springs are ok

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Postby DOC » Sat Jun 16, 2012 7:46 am

Not a bad plan, but I would change the set. The main springs in this set were designed to run with them. might be just fine. but, why take the chance. a set of springs shouldn't be that much.

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Postby DOC » Sat Jun 16, 2012 7:52 am

took a look on Summits site. Any where from 60 bucks to a little over 200. I would think should be able to get a good set around here for around 150. I can stop in at Eagle today, They are normally high. But I'll check anyway, Cheers

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Postby australi » Sat Jun 16, 2012 12:36 pm

Seals aren't that dear either; I have a new set for my C4 in my cupboard and don't recall them costing much.

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Postby 68ragtop » Sat Jun 16, 2012 2:29 pm

Well picked up a set of standard springs at Eagle Auto Parts for $40. Even ran into Doc there. Unfortunately they were out of the umbrella type replacement seals and only other option there was a full seal kit for $50 that had some oring seals it. Might try repco or autobarn next.

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Postby DOC » Sat Jun 16, 2012 4:46 pm

Bummer that they were out of Valve seals for a Small block Chev. But someone must have some. To bad I didn't put those tools in my saddlebags this morning. Had no idea I would run into you on the south side. I'll get them up there soon. Cheers!

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Postby 68ragtop » Sat Jun 16, 2012 8:02 pm

Yeah Doc what were the odds of us both turning up there. Real helpful guys behind the counter, just not the seals i needed. Will be trying the standard auto parts places tomorrow. Not too urgent as still havent heard back about borrowing an air compressor to use Docs tool anyway.

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Postby 68ragtop » Thu Jun 21, 2012 3:36 pm

Wouldn't have thought it was this hard to get seals. Local Repco have ordered some in for me, now just playing the waiting game to see if they arrive before the weekend. And also still waiting to hear back from my partners brother about borrowing his air compressor while he's up at the mines, but the useless bugger ain't got back to me yet either.

Guess it gives me time to read up on removal/reinstall process and resetting the lash once done. :)

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Postby australi » Fri Jun 22, 2012 10:48 am

$40 for a set of springs???????? JESUS that's cheap!!! :shock: :o

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Postby 68ragtop » Fri Jun 22, 2012 1:39 pm

australi wrote:$40 for a set of springs???????? JESUS that's cheap!!! :shock: :o


Seems comparable to the US price for a set of standard springs. Hopefully they'll be strong enough for whatever cam is in the engine.

And just got back from picking up the seals Repco ordered in for me, and despite their assurances they were ordering the umbrella type I was after they turned out to be just the basic o-rings. :evil: Guess it's a start, and once I get the springs off I can measure the guides to see if/what size viton pc seals will fit.

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Postby bfit » Fri Jun 22, 2012 6:19 pm

Changing the valve springs on the engine is easy.
Make a lever that uses the rocker stud as a pivot
Wing the engine up to TDC ON THE CYLINDER YOU ARE WORKING ON and give it a go .
I have seen it done with air pressure applied to the cylinder but then you have nothing to help get the retainers loose.
The problem is you may have dome pistons in there and you could bend the valve stems .
It would be better to pull the heads service them and at the same time you can inspect the pistons to see if your fouling problem is the piston rings.
Bfit

Ps Fissan is rite about those umbrella seals they can cause problems

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Postby bfit » Fri Jun 22, 2012 6:37 pm

Mate I worked in an engine shop years back and we used the same seal on chev 327 350 and Holden red engines 186 etc .
Any engine reco shop should have seals to do the job.
And most likely a lot of info to help you
Bfit

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Postby DOC » Fri Jun 22, 2012 11:24 pm

Doing the Valve springs/seals with the head on is a walk in the park. I've done it several times, And a few times on Corvettes. Breaking the valve stem keys loose is not a problem. And I think you would have to try to hit a valve-head on a piston crown. Azza's car smokes most on start up, And if he lets it idle awhile if I remember correctly. Sounds like Valve seals may be a large part of it. The engine was re-done not all that many K's ago. I think Azza is right by just fixing whats broke for now. Don't think his partner wants to see him spend anymore than necessary. even if She does want to go for a spin.


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