LiquidBlue

Short story - injector went bad, need to replace. while in there, why not put new valve seals. well, i've gone this far, why not pop heads. gives me a chance to access heads and loosen exhaust manifold bolts for future header install, or maybe even go for it now. engine has 60K on it.

Any good reasons not to move forward? my thinking is that it will take me less time to pop heads and re-install -vs- fiddle around changing valve seals while heads on car. any thoughts, suggestion appreciated. thx guys!

p.s. I'm thinking I can pop head and exhaust manifold as a unit. Is this possible?

Have also read of a guy who mentioned leaving rocker arms tight, so when head bolts loosen rockers/springs force head off block, but this seems like it could bend push-rods??

8t2 z-chev

With only 60k on the engine,i would just replace the valve seals and leave the heads on-very easy to pull the heads for that job too,heads will just pop right off with a big screwdriver stuck in an intake port.

LiquidBlue

8t2 z-chev

just a little "originality" and you will have to buy head gaskets on the positive you can get a good look at cylinder wall condition and the valves.

sofakingdom

iTrader: (1)

Biggest advantage of pulling the heads is, you get the chance to port them. Which if you do that, DO NOT succumb to the temptation to "hog em out"; rather, concentrate on (1) cleaning up the weird angles and steps and whatnot where the factory jammed the cutter into the port; (2) eliminate any casting flash or other irregularities in the ports; and (c) smooth out the guides a bit, to make them sort of an airfoil or teardrop shape. DO NOT lower the floor of the ports; DO NOT mess around with "gasket matching"; DO NOT remove any more metal than is absolutely necessary. A good home port job is all about SMOOTHING the flow, NOT increasing the size of the port.

Some other little details you can work on that will help out include: get the decks levelled; clean up any sharp edges in the chamber, especially around the edge where the chamber meets the deck; radius the "margin" of the valves (the angle where the face meets the seat). The 1st requires a machine shop, the others you can do yourself.

I STRONGLY recommend replacing the valves and springs at the same time. Doesn't take too much $$$ to do those. I'd suggest Manley street valves and Comp 981 springs with the matching retainers & keepers, set up at the correct height of 1.70 - 1.75". Do away with the exhaust rotators, add about .090" of shim to take up that space; use the Vortec (96-2000) head seals, which are the "positive" type and usually fit older heads too.

Don't get all fancy with the gaskets. Just pick up yerbasic FelPro HS7733-PTx set.

The flip side is, it's ALOT more work to pull the heads, and at your low mileage, they're probably not worn out or otherwise in desperate need of "maintenance". At some point you have to decide for yourself what your goals for this project are. If all it is, is to get rid of the puff of smoke at startup, and you're completely happy with everything else like it is, then you can just change out the seals. If on the other hand you want to renew and improve it, pulling them is the only way. Only you can make that call.

And no you can't leave the exh manifolds on the heads. There's a row of bolts underneath them that you won't be able to get to. They gotta come off the heads first.

AlkyIROC

LOL. I saw a picture in a car mag a few decades ago showing someone who pulled the head without removing the bolts below the exhaust manifold. All the bolts and part of the manifold stayed on the block as they pried the head off.

Kingtal0n

I don't like the idea of snowballing from a simple job to some kind of crazed metal shaving mess etc...
so I am going to go ahead and say that if the job you started out doing can be done with the heads on the engine safely

to just do it and move on and forget you ever got any crazy ideas from the internet,
of 'that time you decided to port the heads of your perfectly good low mileage engine and XYZ happened'

just caution talking

427seven

Don't look for easy ways of doing things like letting the valve spring pressure pop your heads off. Get used to the proper sequence, you will make many fewer mistakes over time. Perfect example leaving a bolt untouched somewhere and breaking the parts, costs much more in the long run. As far as doing it in the car, it's no problem it can be done, you just have to weigh your total job, how much you save in terms of time, you have to know how much more accessible everything is with the engine out. If you don't have air, it's not that bad pulling the motor....

Orr89RocZ

iTrader: (20)

dmccain

iTrader: (2)

That mileage i would go no further than valve stem seals. You don't want to open a can of worms.

LiquidBlue

Thanks for your responses guys, didn't realize there was a row of head bolts under the exhaust manifolds. That definitely puts the brakes on a bit. My 2 biggest reasons for wanting to do this was to loosen up the exhaust manifolds with heads OUT of car. (lot less chance of breaking off bolts if you can get it to the bench)

The other big reason was to refresh the heads and port them. Not sure if 081 heads are worth porting other than the basics that Sofakingdom went over???

AlkyIROC

For the cost to freshen up heads with port work, valve grind, springs etc, it can be a lot cheaper to just buy a set of replacement heads.

Tootie Pang

iTrader: (2)

Huh? Am I missing something? A fuel injector change is about 1-2 hours tops. You don't remove the valve covers or the manifold. Are your stem seals gone? Are your head gaskets gone? 60,000 miles is nothing.

LiquidBlue

Perfectionist at play, cant help myself. And ya, so far I pulled out cyl #1, exhaust. bottom seal no where to be found, top seal 3/4 of it was still intact. I don't think the factory seals from 1990 were very stout. I wasn't burning oil, but was a small bit of smoke on startup. i think the fact that the car was not run regularly for 23 years has a lot to do with it too. they just get old when they sit there.

just ordered a endoscope. gonna have a peek in there and see how things look. that is, if a $35 endoscope is worth a damn. always wanted one anyway.

Tibo

iTrader: (15)

I own the Harbor freight bore scope and the Milwaukee bore scope and I prefer the Harbor Freight. The Harbor Freight allows you to invert the screen whereas the Milwaukee just has you rotate the screen itself kinda like on a digital camera.

AlkyIROC

Exhaust seals are not as critical since the exhaust gases are under pressure and oil won't get sucked into the exhaust. An intake seal is a little different since the vacuum created by the piston moving down into the cylinder can also pull oil past the intake valve stem.

My race engine isn't a high mileage engine. I don't use valve seals.
I had a 91 454SS for many years. RH plugs would always foul up. Eventually I replaced all the valve seals and the plug fouling went away.

LiquidBlue

Kingtal0n

thanks for the progress picture

more pictures pls

LiquidBlue

Kingtal0n

Wow haha. In my experience the closer you look at something the more you will find wrong with it.

Don't get carried away rofl just remember nothing is perfect