Does anyone know what the factory head gasket thickness is on a 2014 flhxs? I have my rocker boxes off for powder coating and would pull the heads to put in .030 gaskets if it would make a difference. Thanks

 

Don't know specifically for that model/year, but HD used .045" thick headgaskets on the twin cams for many years.

Going to .030" gaskets will make some difference, but you need to know the resulting compression and make sure that it is right for the cams that you are using. Also, you will need to check valve to piston clearance unless one of the builders here on the forum has used exactly the combination of cams/pistons/heads/head gasket that you will be using and assures you that there will be no valve-to-piston clearance issues.

 

Good point on the clearance issues. I will be running a Woods 555 cam, lifters and pushrods. All else is stock.
I've heard that the 555 performs best at 10.25/1 comp and stock is 9.7/1 so trying to get a little closer without pulling jugs.

 

Assuming the existing HD headgasket is .045" thick on your bike, I would guess that a .030" headgasket should get you in the ballpark for bumping your CR to above 10:1.

You need to measure the "in-the-hole" distance of your pistons at TDC with a straightedge and a feeler gauge to see what your quench will be. Maybe someone here already knows for that model? Shoot for around .035" total (piston ITH distance around .005" + .030" thick headgasket). Headgasket may compress beyond .030" (maybe .002" to .003" less) when fully torqued down.

Again, you should clay your pistons and do a mock assembly to check for valve-to-piston clearance. Better safe than sorry. See attached pics.

 

No worries on valve to piston clearance with a .030" head gasket. An MLS gasket will not compress; it is multi layered steel. Going from an OEM head gasket to a .030" head gasket will net an increase in CR of almost .3. So if actual is 9.7, then you can expect 10. It will make a difference but IMHO, not worth the effort but that's entirely your call.

 

I will yield to your knowledge and experience on this djl, but my old.045" MLS gaskets compressed easily by .002" to .003" by just applying a moderate amount of pressure with a caliper. Confirmed by Steve at GMR. The middle layer is steel but the two outer layers are normal gasket material and seem to compress, perhaps less than a non-MLS gasket in total, but still a little.

 

Dyna, djl is right on this: MLS gaskets are 3 (2 in the case of the .027" gasket), the top and bottom layers are coated with viton. What you get when you measure with a micrometer is what you get when the heads are torqued. Check a set when you disassemble a motor with them already installed, you'll see. They often measure .001 or .002 less than nominal; I believe this is due to manufacturing tolerances.

 

Got it. Thanks. Continuing to learn from you guys and truly appreciate the lessons.

 

I strongly considered doing the same. But ultimately decided against it. My bike only has 10k miles on it. I was thinking the increase in compression was only about .2. If it's really .3, I will reconsider pulling the heads. That should bring me very close to 10:1. Almost ideal for Woods 555. Then again the Woods 222 look awesome. Without breaking down the top. Decisions decisions.

 

Wouldn't milling the heads about .010" (<$100) along with the .030" head gasket get him right around his 10.25:1 target?