Broken valve guide boss

Performance mods and Advanced Stroker discussion.
Post Reply
GASnBRASS
I think I'll order a "tab"
I think I'll order a "tab"
Posts: 40
Joined: June 23rd, 2017, 7:01 pm
Stroker Displacement: 4.1 / 250ci
Vehicle Year: 1998
Vehicle Make: Jeep
Vehicle Model: TJ

Broken valve guide boss

Post by GASnBRASS »

So I just got my 0630 head back from the machine shop for crack check, surfacing, valve grind, springs, seals, and replacing any bad parts. Get the head home and I'm checking it over and find this broken casting around the cylinder 5 exhaust valve guide. Work order says one guide was replaced. Is my cylinder head hosed now? :x

Image
Russ Pottenger
Strong Poster
Strong Poster
Posts: 889
Joined: August 15th, 2009, 1:27 am
Stroker Displacement: 4.7
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: Broken valve guide boss

Post by Russ Pottenger »

You're machine shop must've determined you had one worn out guide.
They bored out your old valve guide and installed a pressfit .500 OD valve guide.
Because it's bored from the top, it's common for the thin portion on the bottom to break apart. What they should've done is spend a little time with a Dremel tool utilizing a carbide cutter then switching over to a sand roll to clean things up a bit.
GASnBRASS
I think I'll order a "tab"
I think I'll order a "tab"
Posts: 40
Joined: June 23rd, 2017, 7:01 pm
Stroker Displacement: 4.1 / 250ci
Vehicle Year: 1998
Vehicle Make: Jeep
Vehicle Model: TJ

Re: Broken valve guide boss

Post by GASnBRASS »

What does this mean for my cylinder head then? Can things be salvaged or is it junk now? I really don't want to have issues down the road because of this.
Russ Pottenger
Strong Poster
Strong Poster
Posts: 889
Joined: August 15th, 2009, 1:27 am
Stroker Displacement: 4.7
Vehicle Year: 2000
Vehicle Make: Jeep
Vehicle Model: Cherokee

Re: Broken valve guide boss

Post by Russ Pottenger »

Head isn't junk.
Bring it back to your machine shop and have them pull the one exhaust valve out and have them give the bottom of that guide some love.
Tell them you just want to make sure that a chip of the cylinder head casting doesn't break off.
If they do that you'll be fine.
Post Reply

Who is online

Users browsing this forum: No registered users and 11 guests