Head Gasket leak, oil

[N-gin]

I moved to Georgia 2 years ago, and between schooling for a new career and building I have forgot what I did to install the comedic gaskets. I don't see copper spray on the exposed gasket area. The bore for gasket is 4.2 and thickness is .03 .
Is there an O-ring suppose to be there? The engine is fresh top to bottom with only 1400 miles. Pistons and cylinders from FM. Heads from HDSP. Bottom end from DH. DT oil pump. S&S T2 block.
A bit after the build it would filling up the oil catch can pretty fast over 3000 RPM, about the same time I noticed a oil spot on the ground. Could a popped head gasket make the oil catch fill up? My compression is down to 170 when, fresh it was 235psi cold.

[Ohio HD]

You should try a leak down test. Chances are the cylinder pressure is going by the rings, causing high crank case pressure, and causing the head breathers to evacuate more oil. It's a place to start.

I've never used an o-ring with an MLS head gasket.

[les]

You should try a leak down test. Chances are the cylinder pressure is going by the rings, causing high crank case pressure, and causing the head breathers to evacuate more oil. It's a place to start.

I've never used an o-ring with an MLS head gasket.

I did.  I used an o-ring on my first top end build with an MLS gasket.  When I got tired of the oil leaking all over the engine, I changed my mind and decided to not use o-rings with MLS gaskets.  lol

[N-gin]

Hi guys so it's been a while.
I gone through withdraw with the bike not running well. Good thing my sister had a Street 500 I could get in the wind on.

Did a cylinder leaked down test finally and it reads 80 regulated and 79 cylinder. It was pretty hard to stop the tire from spinning even with the brake and in gear.
So I tore into it.

[N-gin]

This is the rear head.
Any helpful suggestions on sealing big bores?
Running 220 PSI in the cylinders.

I may have them opened up a bit to lower it 210. Besides I don't like the sharp edges around the CR.
There can s a good amount of oil in the exhaust runner as well..
But from what I gather I'm guessing the gasket was leaking into the oil passage due to the witness marks on the gasket.
I think the next go around will be some sealer on the does for the oil passages.

[Pirsch Fire Wagon]

You shouldn't have to seal anything.

Did you use the Torque Specks that come with the Cometic Gaskets? They're quite a bit higher than stock ones. Check the Deck as well for being true. I know you said they were done but perhaps something was overlooked.

At 220 psig I would consider venting the Crankcase as well. Perhaps the Fueling.

[kd]

   and would add that the Cometic MLS gaskets have a micro rubber coating, The gasket surface should be surgically clean with no finger prints or the like to jeopardize the rubber contact to the head and barrel surfaces.  An easy mistake to make when assembling.

[N-gin]

Yes I have a catch can. It is hooked up to the HP breathers.
The catch can would fill up fast at 3000 rpm or higher. But below that I could go some distance before emptying the can.
I'm thinking the cylinder pressure would overcome the oil system and force it's way in creating excessive crank case psi and that's why it puked out oil. This is speculation though.
And oil in the port was clause at idle the oil pressure will infiltrate the cylinder. Again speculation. Anyone have some insight?

[838]

I had a cylinder go out of round. Caused exact same symptoms. Other things I checked were opening up breather bolts, checking umbrella valves for proper direction. Ended up boring cylinders .020” over with some KB pistons... problem solved.

[HD Street Performance]

Bingo 838. Your rings are not sealing. Blowby is crankcase pressure, leakage by the rings. Now the cylinders need to be bored next oversize and proper honing done to enable a break in that happens relatively quickly. I would bet your cylinders are all over the place as far as straight and true.

[Ohio HD]

Yes I have a catch can. It is hooked up to the HP breathers.
The catch can would fill up fast at 3000 rpm or higher. But below that I could go some distance before emptying the can.
I'm thinking the cylinder pressure would overcome the oil system and force it's way in creating excessive crank case psi and that's why it puked out oil. This is speculation though.
And oil in the port was clause at idle the oil pressure will infiltrate the cylinder. Again speculation. Anyone have some insight?

I get zero oil in the catch can, TC 124". I get a little dirty slimey  moister when the weather is really humid. Or a really cold motor (40° or less) and warmed up it makes some condensation. I have great ring seal. Only use the OEM head breathers. Solve the seal problem, not add more venting.

It might be in your interest to contact Zippers and ask them about their cylinder liner stress relieving process. They'll then bore and hone, and deck the head gasket surface after the liner is relived of stress.

Some cylinders although are round when in torque plates and honed. When they're later torqued again, they're not round. It also could be the cylinders weren't prepped right from the get go.

 

[838]

My build was dynod so I broke in the new pistons hard on the road. All I get in the catch can now is water and a little foam every so often.

[FXDBI]

Jamie is pretty anal about his cylinder/piston fit and finish. Try this on a set of cylinders you THINK are clean before assembly. I wont build one with out using this, heard about it here in HTT and bought some it was a eye opener.   Bob

https://www.totalseal.com/product/quick-seat

[838]

Jamie is pretty anal about his cylinder/piston fit and finish. Try this on a set of cylinders you THINK are clean before assembly. I wont build one with out using this, heard about it here in HTT and bought some it was a eye opener.   Bob

https://www.totalseal.com/product/quick-seat

Yup. Great product!

[N-gin]

When I do the leak down test I have very little cylinder leak. I'm only showing 1 psi difference.
I'll have the rest pulled down in a day or so.
Other info; I drilled out the breathers, the break in was on a dyno, the shirts of the pistons were coated.
I think I just got it too hot and popped the gaskets, I hope 🤔
I'll investigate further.

[Ohio HD]

What was the % of leak down?

You should do a leak down test with the piston at TDC, BTD and again at mid stroke.

Lock the motor with this.

https://www.jimsusa.com/wp-content/uploads/2019/09/753-IS.pdf

[838]

When I do the leak down test I have very little cylinder leak. I'm only showing 1 psi difference.
I'll have the rest pulled down in a day or so.
Other info; I drilled out the breathers, the break in was on a dyno, the shirts of the pistons were coated.
I think I just got it too hot and popped the gaskets, I hope 🤔
I'll investigate further.

My build still had 210ccp in both cylinders and very little leak down. They were FM pistons and cylinders too, tiny oil rings.

[N-gin]

What was the % of leak down?

You should do a leak down test with the piston at TDC, BTD and again at mid stroke.

Lock the motor with this.

https://www.jimsusa.com/wp-content/uploads/2019/09/753-IS.pdf

Well I set the gauge at 80psi and the cylinder was around 79psi

[HD Street Performance]

You have it pulled down. The pistons show signs of oil in the combustion,  lots of it. The rest is minutiae. The goal is to get it fixed. If you send me the cylinders I will give you a cylinder map and we can decide what is the best fix for the long haul. I have .005 over CP full skirt pistons with a CVO dome that can be trimmed to suit the application and they have a 2.5mm oil ring.

[N-gin]

I have less than 2000k miles on this. I really don't want to trough out a set of pistons I spent 500$ on to only get that many miles.
Do you guys think I can just hone and re-ring?
I'm going to call Jamie and see what he says. But since it's been so long I fought he will do anything.

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[838]

Line-2-line might have a coating option that will allow you to reuse the pistons. Call them 👍.

Mine also had less than 2k on it. I ordered oversized KB pistons and had cylinders bored and honed. Sold the old pistons (without rings) on eBay for 250 or so to retain some $.

[N-gin]

Here is another picture

[N-gin]

Line-2-line might have a coating option that will allow you to reuse the pistons. Call them 👍.

Mine also had less than 2k on it. I ordered oversized KB pistons and had cylinders bored and honed. Sold the old pistons (without rings) on eBay for 250 or so to retain some $.

I already have the line to line coating on them.

[FLDavetrain]

Line-2-line might have a coating option that will allow you to reuse the pistons. Call them 👍.

Mine also had less than 2k on it. I ordered oversized KB pistons and had cylinders bored and honed. Sold the old pistons (without rings) on eBay for 250 or so to retain some $.

So on a piston/cylinder combo out of round you sold the pistons wout rings for $250...wow guess there really is someone out there for everyone

[838]

Line-2-line might have a coating option that will allow you to reuse the pistons. Call them 👍.

Mine also had less than 2k on it. I ordered oversized KB pistons and had cylinders bored and honed. Sold the old pistons (without rings) on eBay for 250 or so to retain some $.

So on a piston/cylinder combo out of round you sold the pistons wout rings for $250...wow guess there really is someone out there for everyone

🤷‍♂️. I buy and sell on ebay a lot to fund my own horsepower habit. Everything sells eventually. They were good pistons for the right project I guess!