1G Headgasket Prep

[1992 laser]

So I'm in the process of getting ready to put a new head gasket onto my car. I can see that this is a very opinionated subject to say the least. I'm planning on using the OEM composite gasket with new ARP studs. To prep the head I used a ton of razor blades and some lacquer thinner. Also this is this cars first head gasket job so I don't want to screw up the original surface if I don't have to. Here are some pictures of what Ive done so far.

 

[ThunderChild]

so you will want to get a straight edge (preferably a machinist spec) and measure the head and block decks to check for variances with a lash gauge.

other than that, you could always take them in for milling but thats more money and time.

if youre ballsy you could just clean it as good as possible with solvents and toss the gasket on with some copper coat and cross your fingers. but thats a bad way to go about it.

measure, and if you have any variances more than .001" in 3 inches, get them milled/decked.

 

[1992 laser]

Yeah I definitely do need a straightedge and to check it. I'm expecting it to be fine though. The head gasket wasn't blown btw I just decided to overhaul everything now rather than later. You don't think the surface I have is ready for a gasket now?

 

[Dsmkauai]

Also chase and blow out the head bolt holes! IF it was running fine you will be fine with the oem composite and the way things are. Did you check conpression before it was disassembled?

 

[1992 laser]

I vacuumed out the All the passages in the block and head a couple times. we did it on the stand(I've never seen this engine running) and on the stand we manged to get + or - 90, I know that half what its suppose to be but we we're doing it by hand haha.

 

[BogusSVO]

One pic of the head, makes me think the head was off before, the machining marks look a tad course to be factory, But I will also say it could be a trick of the lighting in the pic.

Also I could not see "6T" in any of the valves.

I will suggest that you pull all the oil galley plugs, you need a 5mm hex bit socket, and flush them out with some break cleaner.

Also do oil port mod one.

 

[tmoney20g]

Here's what the guys up further were suggesting:

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Since the motor's out of the car, you might want to go back to his 101 video and watch the whole series if you haven't done so already.

 

[1990TSIAWDTALON]

Looks like a couple cylinders were oiling in the picture, I would want to find out what was causing the oily substance in those cylinders too just to add what I could see in the pictures.

 

[ThunderChild]

I agree with bogus

And 90 psi doesn't seem bad for hand cranking but a dynamic test would be better. Granted ull have to wait till the motors back together anyway now.

Good place to start tho, keep going and ask any questions you need help with

 

[GST with PSI]

The block looks clean enough to me to install a composite gasket. Make sure the small area between each cylinder is especially clean and free of marks and debris. At a minimum, I'd do what the others have suggested and check the block surface for warpage. You can also take a small brass wire wheel and remove the carbon on the valves and pistons. It will help prevent hot spots from developing in the cylinders.

IDK about that head though. I completely agree with Bogus when he says it looks like it's had a rough cut at some point in it's life, especially in this picture:

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[BogusSVO]

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I almost hate to bring this up at this point, But I would suggest the block come apart and be milled. Due to the fire ring pitting. Red outline

It should be ok with a composite HG staying around stock power levels.

It will not be ok for ANY MLS HG with or with out copper spray

The pitting will compromise the clamp load at the fire ring.

But with it out on the stand, now would be the time to do it.

 

[1992 laser]

Damn, the responses I'm getting here are excellent, you guys all rock! So after considering everything you have all said here's the plan.

I'll pull the oil galley plugs like you said Bogus, not going to bother with the oil port mod however, not right now at least. Also isn't that more to compensate for a head that's been milled multiple times? where it starts getting shallow?

I'm going to get a nice straight edge and feeler gauges so i can check everything out, planning on getting new oil pump gears too so I'll need it there anyways.

The oily cylinder is from me spinning the engine around and oil getting absolutely everywhere I'm pretty sure.

I'll use a brass brush on the piston and valves and get them all nice and clean.

Lastly, ill get between the cylinder extra good! I think that's everything, thanks again!!

 

[GST with PSI]

Also, don't forget to reinstall the dowels in the block used to locate the head.

 

[1992 laser]

Oh I won't! those were way harder than I expected to get out actually.

 

[BogusSVO]

Yes that was the original thought for the oil port mod one.

I now just do it on all 4g heads, and clone heads.

It will also help with the ARP studs, the stud diameter is greater than the factory bolt diameter.

 

[bastarddsm]

OP what are your intentions for this this motor?

The shortblock that's in my car right now got block sanded with some 80grit. The head was at the service limit for warp. I bought a large floor tile at lowes. I litterally walked around lowes with a straight edge untill I found a nice and flat one. then I glued some 120grit paper to it, and sanded the head on it. I got it down to about .0005" but it definatly wasn't as nice as a real surface is. It's put together with ARP head studs and a felpro composite gasket. Car has made quite a few 10s passes on this, and it weighs 3200 so it's definatly making some jam. Gasket seems to be holding up well.

From my experience, what you got there is fine.

 

[Anmasher]

Check both surfaces with a straight edge and make sure they are absolutely flat. A composite gasket will seat and seal well for near stock power up to probably 300+ on ARPs. Torque it down in small steps with the ARP Ultra Torque lube (say 15ft. lbs, 30, 50); then back it off 90* per nut until loose and do it again all the way to the final 81 ft lbs. Three passes is enough each time (say 25, 50, 81 for the second one). The two sequences is to establish a clamp load and crush the gasket with the first one, then torque it down with the second sequence. Do not remove the head or handle the gasket in any way after the first torque or you will ruin it

 

[BogusSVO]

@Anmasher .... 300+... a bit short, been more than a few that have gone 500+ on a composite.

 

[fastmojo]

I use a copper coat spray to help seal my gasket seal, I run 25 pounds boost.

 

[Anmasher]

@Anmasher .... 300+... a bit short, been more than a few that have gone 500+ on a composite.

I wouldn't doubt that, but his deck surfaces look a little on the rough side. Plus we don't know how flat they actually are either. I'd hazard a guess that ARPs with a freshly milled head and block and a Mitsubishi composite would hold up to just about anything you throw at it. MLS gaskets certainly are not the end all be all of head gaskets.