Marine Head Gasket?

[PToombs]

From what I have read, you want a smoother head sealing surface on a diesel. You have way more compression than a gasser, and little grooves aren't good. Better to be very fine grooves.

[Begle1]

i already told you what the perf adv is - you can switch heads or resurface your head w/o messin with the wire

By "performance advantage" I ask whether a ring cut into the block will hold any more boost than a ring cut into the head?

I don't know why I was thinking shaving the head down would reduce compression ratio... I was thinking backwards there. But what I meant to get at was the heads that have a skirt around the top of the compression ratio; you could shave the skirt down and increase compression ratio. Which isn't good for the Diesel.

[DTanklage]

what I meant to get at was the heads that have a skirt around the top of the compression ratio; you could shave the skirt down and increase compression ratio. Which isn't good for the Diesel.

lol - where do you come up with this stuff???

anyways, that shop you asked about (contemporary auto machine) is at

16131 gothard
unit D
huntington beach
92647

[Begle1]

Crap. That didn't come out right, either...

What I am attempting to refer to is heads that have the top of the combustion chamber sunk into the casting, and the headgasket seals against a skirt that goes around the top of the compression chamber.

I know they make flathead heads like that, at any rate...

Thanks for that address.

[DTanklage]

I know they make flathead heads like that, at any rate...

Thanks for that address.

i dont think so...but i also dont think it makes any diff

the heads are what they are - there is only one design for the 6b - and it is a flat head

what you are wanting - is less compression and more boost

that has always been the way to go fast...

your welcome

[Begle1]

So what are the advantages and disadvantages of running a marine head gasket, again?

Anybody?

[KTA]

URBAN LEGENDS DEBUNKED

THERE IS NO SUCH THING AS A MARINE GASKET. The 370 marine 5.9 uses the same head gasket as every other 12v 5.9. The Marine gasket as it is commonly incorrectly reffered to is in relation to the .020" over thick gasket. The overthick gasket can be used to lower compression on an engine with stock dimensions, or to keep it about the same on one that has been decked on the head or block.

[Begle1]

Alright, thanks. How much does a .020 overthick headgasket lower compression?

What about Cometic head gaskets? Do they work as advertised? Any experience with those?

[KTA]

I don't think cometic makes a 12V gasket. Yes they work as advertised when the machine work is done correctly, which VERY few do and thats why they have troubles. I didn't do the math on it but I think the over thick gasket drops the compression about 0.2 Its not alot but it helps.

[Begle1]

What kind of machine work needs to be done for a Cometic?

Here's their spec sheet on it. They say that it's "new".
http://www.cometic.com/da_viewimage.aspx?da=722

[DTanklage]

two points of compression can hardly be noticed

its not like a turbo gas deal where you are talking about 7.5:1 or 7.75:1

these things have something like 17:1 stock so i dont think 2 points is gonna make much diff

if you are going to reduce it do it by a whole number

jmo

[Begle1]

It's a step in the right direction for free... It doesn't matter how much you win by, donchaknow.

What is the deal with running the 15.3 compression pistons on the street? They have a constant blue smoke, right?

[bgilbert]

You could always move up here in the Midwest, then you'd be right in the middle of big horsepower, have all the machine shops and diesel performance right at your finger tips .

When I do my next one it will get both the head and block fire ringed. On my 89 it only has the block. This is because Scheid wouldn't do both .

[DTanklage]

cometic most likely makes those rings

they have been making them for 15 years for all sorts of supercharged apps

cept they call them "power rings"

i have used them in a few motors but have never heard of anyone stacking them on top of ea other and to be honest bill, i think all it is gonna do is create one more slot (two more surface area's) where the thing can leak

maybe that is why scheid didnt want to do it for you?

[KTA]

Scheid didn't want to do it because they aren't a machine shop.

The MLS gasket requires the head and block be flat within .001" total, and a surface finish of 20RA or less is ideal. I know they call for 50RA or less but in practice with engines with high oil pressure they need to be 20RA or less or they sweat over time. This means both the head and block need to be machined for the MLS gasket to work properly. You MIGHT get lucky and get by with a good clean up but most likely not.