machine23

i just got my heads back from the machine shop. they passed a pressure test and were hot tanked. but looking at the valves will show lots and lots of crusty carbon buildup. so how can i pull these things out of the head? i was thinking i could clean them up myself since i know they dont need to be lapped/redone. and will i need to replace the valve stem seals? im trying to do this hg job myself. any help i would greatly appreciate

ovrrdrive

Don't bother to pull them out. Just get the 3M pad tool for your drill and the green scrubbie pads for it. I've seen several people use them and the valves look like new.

TNRabbit

As long as they are seating properly, it's immaterial what they look like, to a point....

machine23

well, like i said, they are crusty on the bottom. as well as all around them. i dont know how much the surface of the valve affects the air+fuel delivery. i figured it would be better if i cleaned them and made them shiny again. but if you guys are saying i really dont need to worry, then i wont.

there is, however, a valve that has some rust on it from the tap water i had to put in the system to make it home with the blown head gasket. is this ignorable too? i wouldnt think so, but im not sure

yoterr

like said above clean them the best you can with a scrubbie pad and attachment for a drill

sb5walker

I'm always in favor of replacing stem seals when heads are worked. I prefer the toyota ones, though they're pricey. Probably cheapest from 1sttoyotaparts.com

However. autohausaz.com sells Ishino seals for $3.70, near half of the cost from 1sttoyotaparts, and Ishino may be the OEM. Not sure, but they're japanese-made and probably excellent.

For cleaning carbon off valves I use a 3" wire wheel drill attachment. Carbon can be a hot spot that causes preignition.

http://www.amazon.com/Weiler-Mounted...dp/B000CEORSU/

Use a good assembly lube.

machine23

i think my hg set from yota came with stem seals. but im not sure if that is what they are. im looking at smaller rubber rings larger than an oring. they dont look like anything else that i have pulled off my engine

abecedarian

Never heard of hot tanking a head with the valves still installed. The cleaning fluid (can be caustic and) can destroy valve stem seals.

machine23

well..they did. so if i had doubts about my valves working properly...how do i pull them out?

ovrrdrive

Hot tanking is just with really hot water and pressure. If you get one acid dipped they have to remove the valves.

sb5walker

Haven't done it myself, but here's the fsm section on it. Maybe some voices of experience will pipe up.

http://personal.utulsa.edu/~nathan-b...68cylinder.pdf

sb5walker

They should look like this:

metalhed

To remove the valves you will need a valve spring compressor, and new valve stem seals.

If you are there you might as well have a valve job done as well. Seems worth it if the head is off and clean.

Matt16

I'd use a brass wire wheel- steal may score up the valve.

Stuwy123

iTrader: (1)

I have a similar situation, sort of.
I just put in a new exhaust manifold gasket and manifold studs (the works) but my exhaust/ heater piping and manifold are filthy.
I managed to clean out that exhaust return line (copper tubing of the manifold) but everything else is crusted with soot.
Is there a way to clean out that power robbing soot out of my engine with dismantling it?

sb5walker

Valves are pretty tough - I've never damaged one with a steel wire wheel. I am careful to keep the brushing action from the center of the valve head outward, and I avoid brushing the valve face - the part that seals against the seat. You could try brass but some carbon is hard to remove even with a steel wheel.

An option is chemical treatment. Some people use phosphoric acid based rust removers. That will remove carbon, all right, but the acid will also carry away some metal while it's at it. I think it's a bad idea. An alternative is a product called Piston Kleen that apparently works well and is not corrosive:
http://www.orisonmarketing.com/clean...on/carbon.html
http://dirtbike.off-road.com/dirtbik....jsp?id=517223

This is a pretty good thread on cleaning valves:
http://www.d-series.org/forums/engin...on-valves.html

d71889b

the steel wire wheel will work fine, it won't damage the valves. it would be a very good idea to do a valve job while the head is off