Opinions Wanted 91 CRX - How Bad Is This? Head Gasket and Block

[UfoTofU]

Someone from Honda-tech pointed me to this :

http://hondaworkshop.com/misc/97-047TSB.jpg

The gasket was more expensive and had to buy all new head bolts as well but once I saw that it was a bulletin straight from Honda I figured I should buy the right parts.

The baked on fiber gasket makes me mad too. It's a big pain.

[Danronian]

I've always used multilayer gaskets on the Hondas I've replaced HGs on.

If you think you'll ever take the motor apart again you might want to invest in some ARP head studs since they are safely reusable. I think you could probably be fine with the original head studs though (which I've done before with success when I was on a tight budget), but then again, it would suck to get it together and have them be stretched and not seal 100%.

Good luck getting it back together!

[mrmad]

Originally Posted by Danronian

I've always used multilayer gaskets on the Hondas I've replaced HGs on.

If you think you'll ever take the motor apart again you might want to invest in some ARP head studs since they are safely reusable. I think you could probably be fine with the original head studs though (which I've done before with success when I was on a tight budget), but then again, it would suck to get it together and have them be stretched and not seal 100%.

Good luck getting it back together!

Honda headbolts are not stretch bolts but are reusable. They have a normal torque value not the directions torque to yield or stretch bolts have. Check the manual, it does not mention replacing them.

[UfoTofU]

Do you guys know if it is safe to get both the head and block machined or does that screw the tolerances up?

Will I be banging valves on pistons, or will the head bolts be bottoming out in the holes?

I want to be able to use the new head gasket and bolts that I just got in the mail.

[GasSavers_DaX]

UFOtofu -

Get both the head and block machined. Tell the shop to clean them and take off the minimum required. When you get it back, ask how much they took off. If it's only a few thousandths per side, you'll be fine. If you look at the head and block surfaces, there are actually indicators to tell you how much "meat" you have left to machine off. Look at the attached picture at the areas circled in red - if the small "button" in the middle has any metal machined off, the block or head is at the end of it's life. If the button is still a casting and hasn't been machined, you're fine. A shop should only charge you around $100 to machine both the block and head, and clean both.

If you do take the block, you'll have to drop the crank and pistons out and take them just the block. I know it's a lot of work, but take it from someone who has only had the head milled and didn't take out the block, it might still blow head gaskets! Ask me how I know.

[UfoTofU]

Dax,

Thanks for the input, I appreciate it.

I was looking at my pictures but I don't see any wear indicators on my block.

[Gary Palmer]

It all sort of depends on what your financial budget will allow. I would ditto the multi layer, metal head gasket. I bought a head gasket for a later head, for that exact reason. Although the chambers look a little ugly, they are not as bad as they could be.

A lot of what you might want to do depends on how much oil it was using and how well it was running. If it was running Ok and it wasn't using much oil, then you could either do a inexpensive, diy, econo rebuild. Going from less $ to more, I would have the head rebuilt at a minimum. I can tell you how to rebuild it yourself and how to build tools to do it, but for $200 or probably less, since your not in California, it really is a time consuming task.

As far as the block is concerned, the first thing you should do is get a steel straight edge, like the edge of a large square. You can lay the edge against the top of the head to see if it's flat or if it has warps. It is fairly likely it is Ok, because Honda head gaskets seem to go bad before it has a chance to get hot enough to warp. If it's flat, then you can go with just cleaning it up or you could pull the pistons and replace the rings and bearings.

I have 2 Honda engines I have done this with and they both had about 200,000 miles on them. When I got done they don't use oil, the bearings are in tolerance, the oil pressure is good and the car runs great.

The other option would be to just get a used engine from an importer. If the inside of the valve color is just a light semi-transparent copper color, you would probably be fine and spend less time, hassle and maybe even money.

On your cooling system, I have been using distilled water mixed in with the antifreeze coolant and it doesn't leave any deposits in those water passages, like using tap water does. If you just do the head gasket, if you replace the coolant using the distilled water/antifreeze, I would give it a month and then drain and refill the cooling system, just so that you can give it a chance to get some of that crud out of the water passageways.

[mrmad]

Originally Posted by UfoTofU

Someone from Honda-tech pointed me to this :

http://hondaworkshop.com/misc/97-047TSB.jpg

The gasket was more expensive and had to buy all new head bolts as well but once I saw that it was a bulletin straight from Honda I figured I should buy the right parts.

The baked on fiber gasket makes me mad too. It's a big pain.

Forgive me for jacking this thread, but are all D series HGs the same size? Meaning will the MLM gasket shown in the Honda bulletin fit my HF's D15B6? Looks like I'm ripping my car apart as my new fiber has failed after 3 months.

[Gary Palmer]

If your taking it back apart, their are two multi layered head gaskets which are the exact same layout, but they are both from D16's. The D16Z6 is for a 92-95 Civic Hatchback. The D16Y8 is for a 96-00 Civic coupe.

The catch is that the head gasket is the same, but the intake and exhaust gaskets are not, so I ended up purchasing the head gasket as a single item and the other gaskets as single items. By the time I was done I probably could have just purchased a head gasket set and the separate head gasket.

I like the potential of the multi plated head gasket. Instead of the fibre gasket with just the thin tin lips, it looked to me like it was 4 or 5 layers of thin sheet metal.

I also just reused the head bolts.

I would use Fel Pro Aviation gasket sealer or something similar.

I don't know if the MLM gasket will fit, but I believe that all of the D15's are the same layout. When you have the head off, from the block perspective, the head layout looks to me like they just used the same head, but they only put in 2 valves, instead of 4, along with a different cam profile.

I pulled the oil restriction temporarily out of the block and then used a block of wood about 4" * 12" with a piece of 120 grit wet, dry sandpaper to square up the block. It is doable, but tricky because of the alignment posts on the block. I put a layer of grease in the top of the pistons, which I then wiped out, after I got the head squared up. I think it worked Ok, but I've only been driving the car for a couple of weeks, so this is just a FWIW.

I also squared up the head, by using the top of my table saw and some 120 grit wet/dry. I worked the head in a figure 8 shape on the steel saw table, until I got it squared up.

Both of these are somewhat hoakey, cheapy ways to keep from spending cash and keep from having to pull the whole engine. They seem to have worked out Ok, but they involve some tradeoffs in the interests of conserving cash expenditures.

[Danronian]

Originally Posted by mrmad

Honda headbolts are not stretch bolts but are reusable. They have a normal torque value not the directions torque to yield or stretch bolts have. Check the manual, it does not mention replacing them.

I never realized that! I just read the Honda manual and you're right, it says nothing about replacing them.