MigsD16

After reading on the head gasket package that a specific surface roughness was required, I started to research it and found the following article:
Cylinder Head Resurfacing. This article got me thinking...

During this D16Y7 build, I have done the research and made sure everything has been done right and with all the time and money I've invested into this, I want to make sure I finish it up right.

It's time to install the cylinder head and head gasket. I have the head and block resurfaced and bought a Permatorque MLS Fel-Pro head gasket. My only concern now is the surface roughness of the head and the block. The specs for the gasket state it should be between 30-60Ra. I called the machinist who did the surfaces and asked what the surface roughness is and he was rather arrogant and said it's perfect. I asked again, telling him the head gasket I'm using and told him I just wanted to be sure and he went on to tell me how many hundreds of engines he's rebuilt and that if anything goes wrong it won't be because of the machine work. He told me to make sure and clean and oil the threads of the head studs and torque them according to factory specs and everything will be fine. He is probably right, however, I would really like to know that the surface roughness is what it should be. After doing some research, I found that a $2,000+ Profilometer is required for measuring the precise surface roughness (both amplitude and frequency). I also read that there are rather inexpensive surface comparators that can measure surface roughness. I would rather not drag my block and head back to a shop and would like to have the ability to measure this myself. If someone can recommend an inexpensive tool for measure the surface roughness, I would appreciate it very much. Would one like this work? It's for measuring granite countertop surface and is precise to 0.00005 inches.

Questions:
Once I have the measuring tool, what is the optimal surface roughness for a D16Y7 stock engine with the Fel-Pro Permatorque MLS gasket?

I have read about people gluing together their MLS gaskets using loctite 3020, what are your thoughts on this?

Should I install this gasket dry or use copper spray? I was thinking I should do it dry until the manager at AutoZone insisted that I should use the copper spray.

If I'm obsessing over something that really doesn't matter that much, just let me know.

thank you!

TomCat39

In all honesty, the machine shop finish is more than adequate for the MLS gaskets.

They may have been rather prickish about it being they don't actually have the equipment to give you the actual RA but know it's finished within tolerance.

I personally wouldn't use copper spray, I've read it can interfere with the nitrile rubber coating of the MLS gasket.

Copper spray is more for when you didn't take it to the machine shop to fill in excessive roughness.

I wouldn't worry about dropping money on a surface roughness scanner, the proper ones cost you an arm and a leg.

Have faith in your machine shop, as long as they are familiar with Honda (blocks in particular) then you are golden.

More often than not, the machine shops that aren't versed with Honda screw up things in the block such as regrinding cranks and other Honda no-no's.

Really, I think you are obsessing a bit much.

I didn't have any problems with my blue nitrile coated permatex permatorque head gasket for the 2 years I beat on the motor. And all I did was clean up the graphite gasket of the head and block and assemble dry.

As long as you follow the torque sequence, you will be fine. If the FSM doesn't have it already, do the bolts in 3 stages, so add a stage in between if there is only two steps. i.e FSM says 24 ft-lbs then 49 ft-lbs, I would add a 36 ft-lbs step in between.

Hope that makes sense.

PyroProblem

I'd probably just go with it to be honest. Some things you just gotta trust your machine shop on. I'd venture to say that most aluminum head/block engines with a MLS type head gasket call for about the same RA.
Id skip the copper spray myself as well. Ive seen and worked on some really expensive high HP production engines before and have never seen copper spray suggested in the FSM. I've never used it on an engine either. If combustion chamber pressures are high enough to blow a headgasket, copper spray isnt gonna prevent it.
Many times, those parts stores managers dont have much hands on experience and just kinda repeat what they read on the interwebz. Also, its their job to sell you stuff.

TomCat39

Actually, there is also a lot of old timers in many of the machine shops that swear by copper spray, but they are used to the non coated metal gaskets for the old flat heads and old v8 motors. So you will find the suggestion isn't just parts store folk. That's what makes it so confusing at times.

MigsD16

I once again appreciate the advice very much. I think this is the last major step before putting the engine back in the car and firing it up! I noticed a big crack in my exhaust manifold, but luckily found one on Craigslist in excellent shape for cheap. The guy pulled it from a low mileage Japanese import. He bought some aftermarket exhaust and didn't need the stock parts. So that worked out. The only thing that concerns me now is reconnecting the tranny to the engine and then reinstalling the engine and tranny back into the car. I'm sure I'll have more concerns when I get to that point.

Thank you!

njn63

Less than 60 Ra recommended with less than 30 Ra being ideal. Rz measurements are better than Ra but that requires a skidless profilometer which is 10k+.
No.
Dry.
A decent test for MLS if you want a really quick one is to drag your fingernail over it. If it catches it's probably too rough. Obviously having a reference gauge or profilometer is better but it's a decent "peace of mind" test.

You're probably overthinking it but it's never a bad idea to ask questions. Many head gasket jobs are done without the head even seeing a machine shop.
That and some of the older fiber gaskets needed shellac or other type of liquid to seal.

Modern gaskets are designed to be used without any type of sealer in almost every case and frankly they work better without it.

TomCat39

Thank you for taking the time to provide solid information and advise. Greatly appreciated!

njn63

No problem. I spent a few years designing gaskets so I kind of know the subject.

MigsD16

I'm not sure why it hasn't been letting me post, but I'm going to try again for the third time now...

njn63, I sincerely appreciate your thorough response to my concerns, the confidence it gave me has helped me push on.

tomcat, I appreciate your help more than you know, I've been incredibly overwhelmed with this project and you have been keeping me going. Not to be dramatic, your encouragement has been a serious help.

I got a chance to get back to work on it today and decided to inspect the $175 "rebuilt" head I bought off ebay a little deeper since it needed a camshaft seal anyway. It wasn't as bad as I worried it might be, but I found a broken 1/4" socket holder clip under the camshaft, it had hardly any lube and the lube it did have was thin. It was likely lubed with plain motor oil, so I used my Lucas assembly lube after cleaning it all up. The person who assembled it also went crazy with the RTV on the ends, so I cleaned that up and applied a small amount only to the location indicated in the FSM. I haven't adjust the tappets yet. I thought I would do that after installing the head and timing belt since I'm not having the easiest time holding the head up and rotating the cam gear. I'm hoping to get the head installed on Monday since I will have the day off.

Thank you again!