Ok, I feel like doing my rockers and springs later this week (pending on borrowing my friend's air compressor). I have consulted with several of you and it seems that with 130k miles, the spring are probably weak already and need to be changed reguardless of the rockers. I already have LT4 springs ready to put on.

Here is a picture of my passenger side head... does this look really dirty to anyone else??



I know that we've gone over some of this before, but I want to be sure before I start taking things apart.

I know how to remove the rockers.. just undo the nuts, and take them off, then take off the studs. But how do I get the springs off? I know I need a spring compressor to compress the spring down while I take of the spring cap, but how do I do that? I can't tell just by looking at it in that picture. I take the cap off and the spring should be free then, or what? All I need to do is just swap the springs, or is there anything else I need to do replace with the springs?

Sorry for mentioning this so many times on the forum, but as you can tell, I've never done this, so I want to be sure I do it right and don't end up having to take a head off... :eek: Though if it comes to that.. it's port and polish time. :D :D


[Modified by Glock'94, 3:19 PM 8/19/2001]


[Modified by Glock'94, 4:48 PM 8/19/2001]

 

Though you have an LT4 it looks similar to my L98 in there, so here is my advice.

With 103k miles my valve train just had a slight brownish tinge indicative of slight varnish build up. You have severe sludge build up maybe due to infrequent oil changes or very low temps. Possibly the prior owner didn't use correct oil or didn't change it frequently enough.

When I recently did the ProMagnum 1.6 rollers I yielded to the Forum advice and did the springs too. When doing springs you will need new O-ring seals for the tops of the valve stems, possibly bottom oil seals that fit over the valve guides, and maybe a shim set (Comp Cams has a nice variety pack) to assure consistent and correct installed height.

You can get a spring compressor at Sears that fits under two lower spring coils and compresses the retainer. You will likely have to tap each retainer to loosen the keepers (I put a small socket on an extension over the valve stem onto the retainer and rapped on the extension several times). A magnetic wand (Sears) is quite handy for extracting the keepers. I suggest you get a set of vernier callipers (Sears has em) to measure installed spring height.

A jar of Comp Cams light assembly lube is needed for the tips of the valve stems, the rocker pockets, the pushrod tips (if new pushrods), and the rocker fulcrums and tips (if not rollers).

To avoid a potential PITA situation (valve dropped) I would manually rotate each piston to TDC (use a screwdriver in to spark plug hole as an indicator) before removing the valve springs. And put the parts into labeled zip-locks as you remove and clean them, just in case.

You will need lots of carb cleaner and/or laquer thinner to clean up that sludge.

And don't foreget to check for coil bind with the new rockers.

When you are working with those keepers, place towls around the heads and block the lifter and oil return holes in case any of them take flight (don't ask).

If you like to rev high and are increasing breathing up top you might consider Ti retainers with 10deg keepers and a little more seat pressure (less installed height). Also the 10 deg keepers and retainers have larger inside dia than stock so you can install the upper oil seals before compressing the springs (mine disintegrated as I removed the old springs); otherwise you will need to compress the spring, install the O-ring seal and then the keeper.

This job was a real learning curve for me but glad I did it. Good luck on the project.

 

Actually it is an LT1, I'm upgrading to the LT4 springs because of the rocker change. They are non-adjustable 1.6 roller rockers with just a few hundred miles on them.

I know the previous owner used Castrol GTX synthetic, but i'm not sure about the owner before that. I would hope they used the correct oil. I did do some cleaning around there while I had the valve cover off.

Is it OK to just spray carb cleaner aroud there to clean all that stuff off? All I used was a screw driver and paper towels and I was able to get quite a bit of the sludge out. Doesn't look anything like new though.

What is coil bind?


[Modified by Glock'94, 5:12 PM 8/19/2001]

 

Man that's dirty! :eek: Mine looked realitively new compared to those and I had more miles! I'd eat off of mine compared to that!

 

Coil bind occurs when two adjacent coils make contact with each other. It usually quickly overheats the spring, reducing it's life and can lead to catastrofic engine failure if the valve strikes the piston.

With the pushrod at full extension and the valve fully open the valve spring will be compressed to the max for your setup. Then measure the gap between spring coils. It should be at least 0.10" to assure clearance when hot and in motion.

The springs come with a spec on coil bind and installed height, you will measure installed height and can calculate valve lift with the new rockers from the cam lift or from the stock valve lift with 1.5 rockers. From there you can calculate how much clearance to expect between coils at full lift. It's still a good idea to do the measurement to be sure.

You could use nearly any solvent that will remove the sludge and varnish since you will replace the oil seals and rockers. I would avoid (or minimize) getting it into the engine though. A little shouldn't hurt since you will change oil and filter after the 1/2 hr break-in period. It'll be a lot easier to clean up with the rockers and valve springs removed too.

 

Is there something I should add to the oil to help clean this up? Cuz if the heads look like this, I'd hate to see what the crank casing looks like... :eek:

 

well in my opinion the last thing you want to do.....without pulling the intake is to loosen all that sludge and carbon and let it get into the lifter galley.....if the heads are crapped up like that, so is the lifter galley. you might consider pulling the intake off and plug the oil drain holes that drain into the oil pan, and clean the whole thing up. with 130,000 miles, it's understandable with several owners how this could happen.i doubt with a stock camshaft that you will have a problem with coil bind...however it's very easy to check.....and if it does bind...you'll likely bend
pushrods and possibly even break lifters....so it's better to be safe than sorry..
definitely change all the valve stem seals with that kind of mileage.
i will try to send you an e-mail with some pic's of what the keepers look like with the valvespring depressed.
i'm not sure if you're existing retainers will work with the LT-4 springs..you might want to check into that.
in my opinion this is not a job for someone with no mechanical experience...i sure hope you have someone you can rely on to give you a little guidance...and help in the valve adjustments ( the easier part )...
oh well...i've got some pic's to take and send... :smash:

 

Yes that is very dirty, either the oil wasnt getting hot enough, or someone did not use synthetic.
Also, with the Rockers you are talking of, MAKE sure you get a LT4 Knock Module. The LT-4 Roller Rockers (the ones you have are OEM LT-4 Non adjustables like mine, not the Crane Gold/LT-4 Hot Cam Rockers) caused false knock (8 degrees) in my 93. I had to have it programmedout, but the LT-4 Knock Module will fix that. Steve

 

If it were mine and it looked like that I pull the heads and clean it right. As soon as you start touching that stuff you'll never it it all out and some will get into the pan. Then you got bigger problems. Do yourself a favor take the heads off clean it right and maybe even remove the pan and clean it also. :(

 

yes, I have an LT4 knock module on the way.

 

Yeah... I was thinking about pulling them now that I see what kind of condition they are actually in. For the money and the time it would take to do that and upgrade the springs and rockers, I'm going to just hold on to the rockers and springs and wait until rebuild for sure. It would be much more cost effective and time effective to just do everything at once in a rebuild. When that time comes around, i'm going to be doing other upgrades. I'll get the heads ported and polished then too. I wonder how much time those heads are going to have to be soaked to get clean... :eek:

I think this sludge explains the low oil pressure and the little bit of blue smoke that used to come out of the exhaust when i started it up after sitting a few days (hasn't done it in a while). Clogged oil drain holes around the lifter area probably explains the noise that I hear sometimes which sounds like the lifters slapping around a little bit of oil.

I'm still wondering if there is an oil additive that would help eat away at this stuff. I would think there would be something that would run in the engine for a few hundred miles and then you change the oil to clean all the gunk up and then change it again after it rinses out all that cleaner. Any ideas on this??

And I guess what I'm basically asking is what you guys think I myself should do to get some of that cleaned up without having to pull the heads and everything... just to hold me over until rebuild. I would prefer to not have to pull the intake off, but if it comes to that, I certainly have the ability, though it will take some time.


[Modified by Glock'94, 6:56 PM 8/19/2001]

 

Do the heads, I wouldn't want to spin a bearing. :(

 

Pulling them and cleaning them up is a good idea. Don't be too surprised if the engine galley looks the same.

I just installed the LT4 valve train in my new L98. You're need (should use) the following pieces with those springs.

10212809 Spring Shim
12495492 Spring Cap
12495503 Spring Keys

These are all light weight components that go with the LT4 springs.

 

Why would that possily spin a bearing?? :confused:

 

Ok, thanks for the parts list.. that is what I was wondering about initially :cool:

 

The additional cost of installing the LT4 springs and rockers would not be much if you're already having the heads done. I'd advise that you pull both heads and take them and the new rockers/springs to your favorite machine shop and have them "do the heads" without a port job ($$). While you have them off, you can clean the lifter valley, drop the pan etc. See how much of a ridge you have on the tops of your cylinders to get an idea of when the short block will need to be done and plan accordingly. Valve jobs on Chevy SB heads are routine and don't cost much so call around---it's not rocket science--for the best price. Your engine will run TONS better after this and you may not need to do the bottom end for several more years. THEN you'll have enough $$ to do a 383 :D and get those heads ported. Doing the routine head work now will not be a waste of time.

 

Thats why I said to pull the pan. No matter how careful you are some of that slug is going to fall into the oil pan. This then can be sucked up into the oil pump and eather clog it up and starve the motor of oil , or the dirt itself can get into a oil gallery and score a bearing.
this is not good :(

 

Ahh.. ok. Gotcha. So how many hours does it take you guys to pull heads? What price should I expect to do a good head cleaning job? I helped Brian Harrison out with pulling his intake and replacing a busted lifter, and it wasn't that hard. Just a lot of bolts to keep track of. The thing i worry about with pull the heads is everything else that is attached to them.. like the headers, pulling off the waterpump again... and just general unforseen issues with working on an engine in the car.

How much should a good port and polish job cost, like $200-400?? If it's around that, i wouldn't mind doing it at the same time as taking off the heads, but I really don't look forward to doing that... at least right now.. I'd wait until it gets cooler to do any of this. It's been working fine for the past 4 months, so I see no need to do this ASAP.


[Modified by Glock'94, 7:45 PM 8/19/2001]

 

I think this sludge explains the low oil pressure and the little bit of blue smoke that used to come out of the exhaust when i started it up after sitting a few days (hasn't done it in a while). Clogged oil drain holes around the lifter area probably explains the noise that I hear sometimes which sounds like the lifters slapping around a little bit of oil........
well if there's that much sludge...it could be around the oil pick up screen, thus causing lower oil pressure, it could also be that the main bearings are a little loose...130,000 miles and it looks like the engine wasn't really taken care of...the clogged oil drain holes in the heads will cause the oil to leak into the combustion chamber because it will lay over the valve guides....and i'm sure you seals are shot...this would account for the puff of blue smoke when you start it up.

I'm still wondering if there is an oil additive that would help eat away at this stuff. I would think there would be something that would run in the engine for a few hundred miles and then you change the oil to clean all the gunk up and then change it again after it rinses out all that cleaner. Any ideas on this??

my idea would be to leave it alone if your not going to take it apart and clean it right, the crap will get into the oil pan and definitely into the oil pick up screen and worsen the already low oil pressure

and as far as pulling the heads....i'd think twice with that mileage....the last thing you want to do is get the compression ratio up with the old rings in there....remember it looks very much like that engine wasn't taken care of and has seen better days, doing a valve job and milling the heads streight will boost the compression if even slightly it could cause a problem. if you were gonna go that far....you may as well do a rebuild......
just my opinion.....and we all know what that means....by the way curtis...you've got mail

:D

 

hmmmmmmmmm.........sounds fimiliar. Been there, done that, sold THAT car! Learned the hard way!