RusMan

Does anyone know how thick the stock head gasket is on a 1.8l?

RusMan

You guys suck

Anyway I found out it's 1mm. One more question though, how much will my compression change if I go with a 2mm head gasket? I have 9:1 pistons

cjernigan

iTrader: (13)

Why do you want a 2mm gasket?
9:1 will be low enough compression for the power you want, if you lower the compression anymore you're just robbing yourself of power.

RusMan

I don't really want to but I need a head gasket that will work with my 84.5mm bore (stock is 83) and the bigger bore gasket I found is 2mm thick. Do you think the stock gasket will work with that bore?

cjernigan

iTrader: (13)

I don't know if it will work or not but I do know that the 2mm that you're looking at isn't going to be that big a deal. For someone to tell you what your compression ratio is going to be they need to know all kind of specs for your pistons and if you have the block and head resurfaced all that changes your compression a miniscule amount as well. Either way, the slightly thicker gasket isn't going to hurt or benefit you enough to matter, atleast I don't think it will.

hustler

iTrader: (6)

you'll rob yourself of power off boost. In boost nothing changes in boost becuase you're still compressing the same amount of air.

RusMan

Alright, I didn't really want the 2mm gasket. I just went to the shop and measured the stock gasket and it's just fine with my pistons so I'll be just using that.

Loki047

iTrader: (6)

Just over tighten the head bolts... voila 1 mm head gasket.

This isnt that hard, anyone know the clearance volume on the stock motor?

RusMan im dead tired, but we can figure this out later if you really want to know...

RusMan

Well from what I calculated with 1mm thicker head gasket the compression should drop to aproximately 8.3:1, but my calculations are as inaccurate as they can get, haha

lazzer408

iTrader: (1)

1mm is 1/85th of the stroke. Would that make a 5.29cc difference? (450cc/85=5.29cc) and (450cc/9.1=49.5cc) and (1/49.5*5.29=0.1) 49.5cc=1 and 5.29cc=0.1 Would it be 9.0:1?

I'm guessing here. =)

RusMan

To tell you the truth I have no idea what you just did but it doesn't look right to me for some reason, and FIY I have 9:1 pistons so that's the starting point

lazzer408

iTrader: (1)

I was trying to figure out what 1mm was in relation to the stroke of the engine and if the 9:1 ratio is the relation between stroke length and combustion chamber volume then adding 1mm is adding like 5cc or something like that. It looked right when I did it. lol