Possible Engine Build for my 93 Truck

[Will L.]

Don’t try reaming the tops of the cylinders unless pulling the pistons replacing rings. Remember the ridges at the top are not something built up on it- it is the amount of the cylinder wall that has worn away.

I think he needs input from others who ran small precups with turbos and had good or bad experience with it.
It’s added cost to change them but is it worth it for his situation?
I tend to overdo everything. I don’t wanna drive him towards it if it’s a mistake for his situation.

 

[dbrannon79]

It I can get away with the small precups and save some $$ that would be better. don't have much I can spend on this build. I would rather put $$ on the immediate things to make it last and maybe on things I can do rather than having to send to a machine shop if at all possible.

Heck if I can be that experiment on the small precups to see what happens LOL if it's a fail, a couple of new head gaskets and bolt set would allow the heads to come back off later on!

 

[MrMarty51]

if you decide to remove the precups you first remove the injector and then use a wooden dowel to reach in and drive it out

How is the replacements held in without coming out once the engine is started, running and brought to operating temps ?

 

[ak diesel driver]

They are squished between the head and block.

 

[dbrannon79]

So with lapping the valves, is there a specific compound I need? Or is it one compound does it all kind of thing. I was going to order some and the tool to start working on getting them all lapped in.

also what about the stem seals? I didn't find any on this head. do I need them? there wasn't any valve seal that I could see. I am used to seeing a cup style that slips over the top of the guide on the head, all I found was an o-ring that was at the top of the valve just under the keeper. I don't see how that would be a valve seal.

 

[ak diesel driver]

That oring is what gm used on a lot of engines. Not sure on their reasoning. I believe to use the other style the guides have to be machined to be able to have them snap on and stay .

 

[dbrannon79]

I was looking at this compound. and the suction cup tool

Should I just go back with the o-ring that was on there? I believe they come included with the head gasket set. the other cup style are available but are sold separately.

 

[ak diesel driver]

I would try not to use the oring. Maybe talk to your machine shop and see if there's a version that you don't have to machine.

 

[dbrannon79]

@ak diesel driver when I lookup on RA for an 82 chevy burb with a 6.2 these valve seals show up along with the o-rings.

this is the type of seal I'm used to...




looking at the tops of the guide I believe they will work fine without any machine work. what do you think?

Here is the pic I took of the top of the valve guide under the spring.

 

[dbrannon79]

iirc they just push onto the round part and should stay in place. I've done 305/350 gasser heads before, but I don't recall if there was a sort of barb or something other than a round smooth surface that held those type of seal to the head.

 

[ak diesel driver]

They probably will but I'm used to alot of the newer engines having a positive snap on the guide. Again check with your machine shop

 

[ak diesel driver]

Worst case scenario is they become more of an umbrella seal and move up and down with the valve