RED-85-Z51

Even after all of the replacing of parts Ive done, I still get smoke on start up. Ive come to the conclusion that I need new injectors, or at least have these rebuilt. New AFPR, and valve guides replaced.

So, what is involved in replacing valve seals/guides? I know that they themselves are cheap, but its the labor. I want to do it all myself, and Ive got all the tools Id need.

The only limits I have are this,

no more than 5 days downtime
Engine must stay in car.
If I run into a big expensive problem, Im screwed.

I can rent a valve spring compression tool from Auto-zone, thats one of the only tools Idont have yet.

Id like to be able to do Thinner head gaskets and port polish heads, but thats simply not possible now.

mitymek

you need an air compressor and a spark plug adapter to air each cylinder.
then you need a compact in frame spring compressor similar to this one http://www.cranecams.com/?show=newPr...dfa838c57b21a4
(might get one from a tool rental but napa or most any parts store should have one for 20 to 30 bucks)
most vehicles where the plugs are fairly accesible the job takes about 4 hrs.
i dont know about our cars yet,but mines puffin on start once in a while too.
keep track of your time and let us know how long it took eh
good luck

oh-if you dont have a compressor you can also insert a piece of small nylon rope in the plug hole,then turn the engine by hand until the piston pushes the rope against the valves.change the seal,install the spring,back the piston down,pull the rope out and start on the next one....i like air myself,but either way works good.

RED-85-Z51

So It isnt an impossible thing to do?

Thats good, now all I have to do is do it....

65Z01

Your '85 with iron heads has a rotator assy on the top of the exhaust valves, so the lower seals are not the same as for the intake valves. I would pick up a complete set of intake & exhaust lower seals along with upper O-rings from a local Chevy dealer. It would also be a good idea to pick up a set of new keepers for all the valves.

You should pick up a magnetic wand at Sears. It will be very handy for removing, inserting, retrieving the keepers. I prefer the spring compressor that clamps under the valve spring as there wasn't enough room for the lever type with the engine in the car.

To use the rope trick to hold the valves from dropping:
-remove the spark plugs & serprntine, and disconnect the battery
-turn the crank till the exhaust valve is closed and the intake valve is closing
-insert a screw driver blade into a spark plug hole and manually turn the crank CW till the screw driver moves or it stops
-remove the screw driver and feed a section of nylon rope (with end seared) into the spark plug hole.
-manually turn the crank till it stops against the rope (the piston is now at TDC on compression stroke, with the rope pressing against the valves)
-remove the rocker arms (keep track of which is which) and put a small socket over the top of each valve and tap it, firmly but not too hard, to loosen the keepers
-comperss the spring, remove the keepers, valve cap, oil shield, O-ring and lower seal
-lube the new seal & guide base with motor oil and slide the seal over the valve, install the spring, shield, O-ring, retainer and new keepers
-remove the spring compressor and do the other valve
-rotate the engine CCW if needed, and remove the rope

Repeat for each cylinder, set valve lash and button her up.

You may find that it's necessary (or easier) to install three long bolts into the damper in order to manually rotate the crank shaft with a pry bar between the bolts.

BTW, this should be a nice weekend job if you have all the tools and a nice set of FelPro valve cover gaskets ready to go.

Midnight 85

You didn't mention your mileage but if you've got a lot of miles on the engine you may have worn valve guides too. If you do then new seals will not do much good. In order to replace the guides you have to remove the heads and have a machine shop install new guides. If this becomes necesary go with bronze guides.

corvetteronw

What 65Z01 said. Also see my post from yesterday in the C4 Tech section. I already had a set of 8 FelPro lower seals and 8 upper seals but after reading the answers to my question I went to NAPA and bought another set of lower seals and 16 more upper seals. I bought all the supplies below for under $30 (I did not figure in the cost of the wrenchin fuel as it was already in the frig). This is a great time to replace plugs, wires and to repaint the valve covers too!

RED-85-Z51

The car has 124,500 miles on it.

I think the guides are fine, but I guess if they were worn I would have valve noise or something? I dont know...

Anyways, it runs fine, just has a puff on start up.

corvetteronw, why did you go get more seals? Anyone have pictures of where the seals and guides go? Im trying to mentally picture how to go about doing this.

Pete K

Valve guides are a weak link in the small block chevy, Most small block could use a valvejob at 70 or80 K.This is not to say you do. You can use air or rope to dissassemble sprigs and move valve a small amount off seat and give it the wiggle test. This will tell you if you need guides without expensive tools.You can run with minor worn guides for a long time. Fill the oil and check the gas is what my ford and mopar buddies say to bust my chops. They are kind of right. Haven't owned 1 yet that did not puff a little.

Atok

With that many miles I would plan on pulling the heads and sending them off to a machine shop for new guides. You might as well have the seats reground as well if you have the heads off. If the guides are worn there's a good chance your new seals will still leak. You will not hear any noise with worn guides. Most machine shops are pretty resonable for R&R on SBC heads.

corvetteronw

RED-85-Z51 I sent you an IM.

RED-85-Z51

So about how much should it be to just pull heads, and new guides?