valves wont stay adjusted, cracked head, bad spring,??? Options

[BigFour1973]

Hello all,

Its been awhile since i've posted, but with my last final at school today ill have more time for teener activities.

So to give a little bit of back story, the 914 was built by fat performance back in 94 or 96 and it was punched to a 2.3 converted to duel webber IDF 44s, some head work done, I believe just opened up the ex and in a little bit.

motor only has about 15,000 miles on it since the build. it sat for about 10 years from the course of 2004-2014, didn't start it, nothing. didn't even loosen the valves to take pressure off the springs.

car got a valve adjustment from glen in Compton, valves sounded good after that and about 1000-1500 miles later they started ticking again. (I learned of his reputation on this board so I assumed he didn't do it properly) then I took the car to Gus at Euro motor works and had him do the valves as well as a couple other things.

fast forward another 1000-1500 miles later and its ticking again, it sounds like its coming from cylinder number 3 or 4.

my theory is that cylinder 3 or 4 was stuck on the intake or exhaust stroke with the spring compressed for 10 years causing some excess slack for the valve.

has anyone dealt with this problem before? or anyone have any theories as to what it could be?

TIA

[r_towle]

Well,

Gus could figure this out or you can take off the rocker assembly and measure things up. You can test the springs and measure the tops of the valves to see if one or more of the seats have settled.
Also, with dual springs, which you may have (it was a thing back then) you may have a spring seat issue.

You did not mention the pushrods or the lifters and camshaft but all of that comes into question.

['73-914kid]

I've seen chromoly pushrods mushroom out where the tip is pressed in. This is usually on the cheaper sets, but causes what you're describing.. valves are good for about 1,000 miles until the tip continues to wear into the pushrod itself.. easily checked by removing the rocker assembly.

[BigFour1973]

Well,

Gus could figure this out or you can take off the rocker assembly and measure things up. You can test the springs and measure the tops of the valves to see if one or more of the seats have settled.
Also, with dual springs, which you may have (it was a thing back then) you may have a spring seat issue.

You did not mention the pushrods or the lifters and camshaft but all of that comes into question.

I have no doubts that Gus would figure this out. I trust the guy to work on my car and have referred a couple people his way as he does a great job.

The reason I came here to ask for some guidance rather then drive out to Gus is, well frankly, why most people ask mechanical related questions on a car forum. To save some money and become more familiar with their car.

But, thank you for the tips. I'll have to start tearing into her this weekend. Anybody else have any suggestions as to what it might be?

Thank you,
Corey

[TheCabinetmaker]

Does the clatter change as the engine warms up?

[r_towle]

Pull valve covers
Pull rocker assembly, keep track of orientation for forensics.

Put a straight edge across the tops of the valves.
Examine each spring, or set of for broken springs etc.
Examine each push Rod.

I would also check all the valve adjustments before digging into the issue to see if you can isolate a bad noisy one...

[BigFour1973]

Does the clatter change as the engine warms up?

It does not, it stays consistent from cold all the way to hot. I warm it up in an ally by my house and can hear the ticking coming from the pass. Side.

[BigFour1973]

Pull valve covers
Pull rocker assembly, keep track of orientation for forensics.

Put a straight edge across the tops of the valves.
Examine each spring, or set of for broken springs etc.
Examine each push Rod.

I would also check all the valve adjustments before digging into the issue to see if you can isolate a bad noisy one...

Thank you very much. I will start with these points.
Cheers (IMG:style_emoticons/default/beerchug.gif)

[BigFour1973]

Attached are photos of cylinder number 4 rocker arm, note that number 4 exhaust is beginning to flatten and mushroom. I'm assuming it's ether beaten it's self to death from being out of adjustment, or it's getting a hell of a lot of resistance from the spring or the guide isn't letting it go down smoothly.

After thinking for a while more I've come to consider a partially dropped seat? Or maybe a partially stuck valve from sitting so long?

Any suggestions on what to do next?

[porschetub]

Those adjusters are shot,could be cheap replacement ones or just plan worn out,I have seen this happen if the valves have been set loose for sometime also.
Replace them after checking everything previously mentioned,could it be that the valve springs are to heavy or are they becoming coil bound on full opening (IMG:style_emoticons/default/confused24.gif) ,this eventually causes the inner spring to break.

[catsltd]

Those adjusters are shot,could be cheap replacement ones or just plan worn out,I have seen this happen if the valves have been set loose for sometime also.
Replace them after checking everything previously mentioned,could it be that the valve springs are to heavy or are they becoming coil bound on full opening (IMG:style_emoticons/default/confused24.gif) ,this eventually causes the inner spring to break.

I was/am new to 914 and did not want to adjust valves yet.
So took to Porche shop and have timing and valves set.
Valves were quiet but not for very long,motor seemed to run hot also.(always did).

Finally decided to check timing myself,was not correct,also adjusted valves per Captain guidelines.

Now I know what my car supposed to run like.
Quiet lifters,lots of power,runs so much cooler,and can accellerate great.
After you get new hardware do the timing and valves yourself.

[aircooledtechguy]

I would highly recommend that you pull all your rockers off and replace ALL the adjusters in favor for real 911 adjusters. They are a lot kinder to SS valves (which are fairly soft) and hold their adjustment very well since they have such a wide face like the valve stem. You will need to remove about .060" from the under side of the rockers to make room for the taller adjusters and will need to re-check/set rocker geometry (and all that, that entails), but you'll be done with it and never look back.

My .02 FWIW. . .

[BigFour1973]

Thank you all for the guidance! it is much appreciated. the next step will be to drop the drivetrain so I can remove the passenger side head and examine what the internals reveal.

Stay tuned as this will be my first time removing the engine give me at least a week for updates.

Thank you all again

[BigFour1973]

What is worrying to me is the fact that right when I pulled the valve cover off I noticed immediately that number 4 cylinders adjuster was 3-5 threads further in (making up for slop somewhere) and the last person to adjust the valves didn't find it concerning. But oh well, I'll turn it into a learning experience.

[Dave_Darling]

I would highly recommend that you pull all your rockers off and replace ALL the adjusters in favor for real 911 adjusters.

That won't really work unless you've got the early rocker arms. I'm not completely sure, but those look like the later (fatter) ones to me.

--DD

[aircooledtechguy]

I would highly recommend that you pull all your rockers off and replace ALL the adjusters in favor for real 911 adjusters.

That won't really work unless you've got the early rocker arms. I'm not completely sure, but those look like the later (fatter) ones to me.

--DD

Good call Dave. (IMG:style_emoticons/default/beerchug.gif) You may need to upgrade to 1.7L adjusters w/ the 8mm adjusters if those are the larger 9mm type. Basically if it takes a 14mm wrench to loosen the jam nut, you have the late style larger rockers. If the jam nuts have a 13mm hex, then you're in there like swim wear and you just need to upgrade the adjusters and modify the rockers. If you need/want a set of 1.7L rockers, I have a few sets that I can modify for the 911 adjusters. Just PM me if you need a set.

[BigFour1973]

I would highly recommend that you pull all your rockers off and replace ALL the adjusters in favor for real 911 adjusters.

That won't really work unless you've got the early rocker arms. I'm not completely sure, but those look like the later (fatter) ones to me.

--DD

Good call Dave. (IMG:style_emoticons/default/beerchug.gif) You may need to upgrade to 1.7L adjusters w/ the 8mm adjusters if those are the larger 9mm type. Basically if it takes a 14mm wrench to loosen the jam nut, you have the late style larger rockers. If the jam nuts have a 13mm hex, then you're in there like swim wear and you just need to upgrade the adjusters and modify the rockers. If you need/want a set of 1.7L rockers, I have a few sets that I can modify for the 911 adjusters. Just PM me if you need a set.

I will take a look when I get home today, thank you very much for the offer. I may just take you up on that!

so basically If I have the 13mm jam nut I have no need to look further as my problem is sitting right on the head. or on my parts table ( kitchen table since I'm single (IMG:style_emoticons/default/biggrin.gif) )
but if I have the 14 mm I need to keep tearing into her?

[r_towle]

Before you pull the head, have you tried the put a straight edge along the top of the valves?

[BigFour1973]

Before you pull the head, have you tried the put a straight edge along the top of the valves?

I just ran a straight edge across. It hits cylinder 3 in. And ex. And it hovers a cunt hair over the ex on 4 and hits the in. on number 4

What would be the next step?

Thank you again for helping me out.

[BigFour1973]

I would highly recommend that you pull all your rockers off and replace ALL the adjusters in favor for real 911 adjusters.

That won't really work unless you've got the early rocker arms. I'm not completely sure, but those look like the later (fatter) ones to me.

--DD

Good call Dave. (IMG:style_emoticons/default/beerchug.gif) You may need to upgrade to 1.7L adjusters w/ the 8mm adjusters if those are the larger 9mm type. Basically if it takes a 14mm wrench to loosen the jam nut, you have the late style larger rockers. If the jam nuts have a 13mm hex, then you're in there like swim wear and you just need to upgrade the adjusters and modify the rockers. If you need/want a set of 1.7L rockers, I have a few sets that I can modify for the 911 adjusters. Just PM me if you need a set.

I've got the 14 mm adjusters, so from what I understand this is what I want?