Head Gasket Repair - Part 1

[Honcho]

Sorry guys, just saw this.

Jazzman (Will) is the new owner of the car and she is running strong. Michael Meira at Acura cleaned up the heads, so I'm not sure what he did, but I saw a bunch of dirty red scotchbrite pads on the bench when I stopped by to check on progress. Wire wheel also would work great. It is critical you put a straight edge on the heads and measure at all of the points in the service manual. Larry is speaking off of experience- overheats due to coolant loss cause hot spots in the head and can twist it. In my case, I lifted the entire head, so there was no measurable warpage.

As for the HG, per Kaz the factory graphite is fine for a stock engine. He recommends cometic/MLS only for high-compression NA or FI purposes. One benefit of using the graphite gasket is that you don't have to approach the high bolt torque envelope necessary for the MLS gaskets. As Dave noted, the bolts have pulled out of the block in some cases. Also, Kaz noted the graphite gasket has some "squish" in it that will make up for any surface imperfections in the metal mating surfaces. MLS typically requires a machined surface (heads and block) for proper sealing. All things to consider.

 

[jazzmann]

Mike B - Honcho sold his car awhile ago and bought a GTR. AFAIK, the rebuilt engine is still going great for the new owner.

AFFIRMATIVE! ("Newt" from "Aliens"). The engine, actually the whole car, is doing great. Pulls really strong throughout the rev range, every gear. You'd never know there'd ever been an issue.

 

[Dr. JL]

Just got off the phone with SOS. Their MLS gaskets use the same SM torque as the OEM graphite gaskets. The "spuish" is achieved in the multi-layers.

 

[michaelbrat]

Thanks for all the talk guys. Lots of good information. I have a 3.0.

I just checked the heads, and they are indeed warped. About .07mm range. So I'll be having them resurfaced, and would like to remove the valves to refresh them as well.
Does anyone know a good machine shop experienced in head surfacing (in the los angeles area)?

Also, I'm not quite sure which route I'll go with the head gaskets. Still considering all the options (ARP studs, Cometic, OEM) I'm more leaning towards OE 3.0 gaskets + new OE bolts. My bolts have corrosion on them as well, and I feel it's "cheap" insurance to just replace them. I like sticking with OE parts as much as possible, so I'll likely just go with the old tech gasket and bolts. I'll never go beyond bolt on mods for this car. No forced induction.

It's good to hear Jazzman's car is still running strong!

Mike B

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Mike B - Honcho sold his car awhile ago and bought a GTR. AFAIK, the rebuilt engine is still going great for the new owner.

Sorry to hear about your engine.

What HG are you putting in your rebuilt engine? Do you have a C30 with the OEM paper HGs, or do you have the C32 with the OEM MLS HGs? If you have a C30, are you keeping the paper HG like Honcho did, or are you planning on running the Honda MLS or an aftermarket MLS? If you go to MLS, you will need a smoother HG mating surface on the block and heads according to the HG manufacturer specs. Therefore, you can gently scrape with a plastic scraper and then use a mild scotchbrite pad (I forget if red or green is the least mild) to clean it up.

Also, you may not be aware, but there have been quite a few instances of the head stud threads pulling out of the block. It depends how much you were planning on doing to your engine, but it seems to be more common these days to go ahead and Timesert the threads in the block.

See this thread:
http://www.nsxprime.com/forum/showthread.php/161326-Help-leaking-coolant?

I have a Timesert kit if it is something you are interested in doing. If so, please PM me.

Dave

Hi Dave.

Thanks for the link. It was a great read.

The Timesert seems like a great idea, but I'm already starting to exceed my budget greatly. What's your opinion for a stock 3.0 motor? I won't be doing more than bolt on power mods.

I'm all for doing insurance mods (already going with a Toda timing belt and new water pump) but I also don't want to go crazy with it. I recently install a lift in my shop and have disassembled the motor down to the heads myself. So for things that aren't catastrophic, I will just take my chances and pull the motor again if needed.

Thanks for your feedback Dave.

Mike B

 

[Mac Attack]

In that case then, I would stick with OEM parts and buy the new head bolts like you were thinking. Another shameless plug - I have new OEM HGs that came with my Honda rebuild kit for sale in the classifieds here if you don't already have new ones.

One other recommendation is to remove/replace all of the head plugs. Some have leaked over time, and they are cheap to replace. Not only that, but with them removed you can clean out the passageways real well (clean the EGR well too).

Finally, with the heads off, it was recommended to me to buy indexing washers and index a bunch of plugs now while I could see them easily. I guess if you're bored....

Personally, I would still Timesert the block threads. Here's another thread:
http://www.nsxprime.com/forum/showthread.php/156458-Timeserts-for-Headstuds?highlight=Timesert

If you do the labor yourself (it's not hard, just nerve-racking), it would just be the cost of the Timeserts and tool usage. Even if you don't use my kit, someone in California must one you could use. I think the NSX kit is the same as the B16 kit.

Dave

 

[nikey22]

why would you timesert if you don't have a suspicion that the block threads are bad? Or Do you have a suspicion that they are bad, ie - did it overheat and strip the bolts out? thanks.

 

[Mac Attack]

If the heads are already off it is good preventative maintenance. Doing HGs in these cars is no fun.

Did you have a chance to read through the two threads I linked? DA does this in all of their builds.

 

[Honcho]

I just checked the heads, and they are indeed warped. About .07mm range. So I'll be having them resurfaced, and would like to remove the valves to refresh them as well.

I'm more leaning towards OE 3.0 gaskets + new OE bolts. My bolts have corrosion on them as well, and I feel it's "cheap" insurance to just replace them. I like sticking with OE parts as much as possible, so I'll likely just go with the old tech gasket and bolts. I'll never go beyond bolt on mods for this car. No forced induction.

It's good to hear Jazzman's car is still running strong!

Mike B

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Mike B

Mike-

The OEM 3.0 gaskets have a thickness limit. Depending on how much you have to shave off to get them flat again, it might be outside the acceptable range for the gasket. In that instance, you should contact SOS or Driving Ambition to get a custom gasket made in the correct thickness to get you back to factory compression and quench. I believe both vendors use Cometic MLS products.

Also smart to replace the bolts- I did. According to Kaz, in Japan replacing the bolts is not a "must do" rule for Honda techs, but the practice is to replace them whenever there has been an overheat event. For a routine engine rebuild, they re-use them. Since I had an overheat, I replaced them with new bolts.

One other recommendation is to remove/replace all of the head plugs. Some have leaked over time, and they are cheap to replace. Not only that, but with them removed you can clean out the passageways real well (clean the EGR well too).

Dave

Agree 100%. We did mine during this job, including the rocker shaft plugs. Any time you have the engine taken down to this level, it makes sense to replace those small parts. I mean, why would you not replace a 3 cent o-ring? That was my thinking anyway, and Will's engine has all brand new little bits like that in it.