Head Gasket (1 Viewer)
- Thread starter Cruisin94
- Start date
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Maybe, the FSM shows how to check the timing chain but generally you don’t “need” to however many of us like to fix or replace things “while we are in there,” so depends on what you are doing.
As far as brand, I use OEM.
Fj80oregon
GOLD Star
Are you pulling the engine or just the head off the engine in the truck?
Fj80oregon
GOLD Star
OEM gasket is just fine even for stock/low boosted engines. If you want to use a MLS cometic gasket you need to machine the block and the head for perfect flatness. You would need to use a MLS if you machines to much of the block and want to return to stock compression.
Timming chain dampener and slipper are prone to breaking, more so on 93 and early 94. its 30 year old plastic .
Cometic HG you can get in different thicknesses , might be more of an issue on its third HG , or if doing piston rings to keep compression too high and reduce pining
Cometic HG you can get in different thicknesses , might be more of an issue on its third HG , or if doing piston rings to keep compression too high and reduce pining
- Thread starter
- #7
Just pulling the head off.
The plastic chain guides on my 94 disintegrated when the head came off, so i ended up having the timing components replaced too.
Machine shop said that the head would need 8 thou removed and then took 20 thou. If they'd said 20 i might have gone looking for a better head.
Timing worked out (eventually, turns out 20 thou is like half a tooth) and it runs great and passes emissions by a very wide margin.
The thing about the cometic gaskets is that they appear to be the only ones you can get with an additional thickness to compensate. And they're made to order so you might have to wait a few weeks.
I'm also told that stainless steel head gaskets are supposed to be used with blocks that have also been milled, and milled in a particular way. My block had significant pitting, such that the techs working on it cleaned it up with diamond hone blocks before reassembly.
Machine shop said that the head would need 8 thou removed and then took 20 thou. If they'd said 20 i might have gone looking for a better head.
Timing worked out (eventually, turns out 20 thou is like half a tooth) and it runs great and passes emissions by a very wide margin.
The thing about the cometic gaskets is that they appear to be the only ones you can get with an additional thickness to compensate. And they're made to order so you might have to wait a few weeks.
I'm also told that stainless steel head gaskets are supposed to be used with blocks that have also been milled, and milled in a particular way. My block had significant pitting, such that the techs working on it cleaned it up with diamond hone blocks before reassembly.
Fj80oregon
GOLD Star
Then you can only use OEM gasket. Getting the timing chain and components off requires removing the cover which requires removing the upper oil pan. It can be done in the truck but not much fun doing it.
Yeah. the shop doing my head gasket went ahead and removed the engine.
It got expensive.
- Thread starter
- #11
Is there a good video of someone doing this while engine is in the truck?
OTRAMM and RM Garage have videos outside of the truck and after you watch them you’ll understand why.
Edit: Come to think of it I think RM Garage was just doing the head as well but the timing chain plastic broke and he ended up having to pull it all.
^^^^
Most metal (MLS) head gaskets will require a certain Ra value (Roughness Average) for both the block and head in order to seal properly. Often times 30-40 Ra or less.
There was a crosshatch pattern to it, but i would say my block was closer to 200-300 before they manually honed it. I didn't see it afterward.
I've only had it back for a couple weeks, I'm driving it preferentially because i have been working from home for 6 years now and i don't drive a whole lot. No long trips or much time on the freeway because i also need to replace 11-year-old tires.
But so far, it runs *Great.
If I remember right, there was a small block repair on one of the freeze plugs in RM's project as well.
