16V and 20V head gasket differences ?

[t-nol]

After some info on the difference between a 16V head gasket and a 20V head gasket? I still don't understand why run a 16V gasket on a RWD 20V?

I have pictures of the two heads, and the gasket which came off my engine. I don't know what type came off it, and with the gasket on both heads does the same thing, and only blocks 1 hole in the head (as pictured).
Any advice or comments welcome.



This is the hole that will be blocked on the 16V head.



And the same hole on my 20V head.

[Sam-Q]

didn't we have this discussion a short time ago on this forum?

[t-nol]

I searched and couldn't find it.

[Sam-Q]

found it in the technical index however the information in there is specific to rwd conversions so I will let this thread live. The 16B gasket has the water flow out of the front of the head and the back for a 20V. Because of this the 16V alows for more water to flow through the back of the gasket and vice versa for the 20V. Fit a 16V gasket to a 20V and the rear cylinders will run cooler.

Just for the record a 7afe is the same as a 20v in water flow.

[Matt]

So what you are saying sam is the Water flow on Trents setup is the same as a 16v? And based on the way the water flows is why he needs it?

Your post is kinda confusing

[Sam-Q]

You mean Trents with the water outlet out the front of his 20V where the welsh plug used to be? If we are talking about that one then yes he needs a 16V gasket because it's converted to a 16V flow where the water goes into the block at the front and and out at the front as well.

The size of the holes in the head gasket are shaped such that the flow from the block to the head is even. On a 16V where the water wants to go from the block at the front straight up and out at the head. If all the holes would be even in the head gasket then not much of the water would flow through the rear cylinders and hence run hot. So the gasket restricts the flow to the front and allows more at the back. On a 20v because of the front in and rear out it's more likely to be even in water flow hole size.

Hope that makes sense, I never have been great at explaining things.

[Matt]

Yeah that makes sense, thanks... I had the thought for a minute on my 7a that i'd need a 16v HG.

[Sam-Q]

however if you put a 16V head on a 7A bottom end you still need a 4age 16V gasket. The head determines the gasket.

[t-nol]

I got my cometic head gasket today, and it's the same as the one that was on it, so i can only assume it had a 16v gasket on it already. The holes on the cometic are all a fraction larger than previously though.
Any chance of pics of a genuine Silvertop gasket Sam?

[Matt]

I'll put one up tomorrow