1800 or 2000 FI head

[TomS]

I plain on rebuilding my 2L motor, using HC Pistons, porting of the head with larger valves, either head. My question is I have a 1800 head, which head would be better to use? Motor will have dual carbs, header, and larger exhaust. Everything else will be equal.

[baltobernie]

The combustion chambers of the 1800 head are smaller than the 2 litre, so theoretically you would use this head, since "more is better" (up until the point of pre-ignition). But since you're fitting HC pistons anyway, the difference might amount to 10:3 vs. 10.5 to one, for example. You or your machinist is probably going to de-shroud and smooth the chambers anyway, so that's going to lower the static CR. And don't even bring up the subject of dynamic compression ratio

I'd start with the head which has the least damage from detonation. Look particularly in the #4 cylinder; these seem to run leanest. Also have both of them checked for flatness. Lastly, I'd mount my chosen intake to both of them, to see which will need the least amout of porting. In the words of Fiat/Lancia TC expert Guy Croft, "In a street engine, flow is more important than compression", so keeping the transitions along the stream as un-abrupt as possible will yield the best street performance.

[Rmprotune]

The 2.0L FI Head is a superior casting.

[lanciahf]

I like the 2.0 FI head since there are no emission holes to plug.

[mbouse]

i think, and please correct me if i am wrong, but i think that the original question speaks to performance. Which head will give better performance.

in what way is the F.I. head superior to the 1800 head for purposes of this discussion? why have you made this choice? please elaborate for the dummies like me.

how does the emissions ports affect performance after the emissions equipment has been removed, and the ports plugged?

not attempting to poke an argument, just trying to understand.

[lanciahf]

Well the 2.0 head looks cleaner without the ports so that is worth at least 5hp.

Performance wise I have read the 2.0 heads flow "better" but the smaller chamber of a 1.8 head increases the compression on a 2.0 block by 1/2 point. So it might really just be a trade off. I thin there is a detailed post in the past by Alvon on the differences.

[launieg]

The 2.0L FI Head is a superior casting.

Now that is the first time I've heard this. Why is it a superior casting (flow, strength, shape...?) I have no allegiance on this issue, but I do drive a 2.0L FI and have often thought of putting on the 1.8 head from the parts car.

[So Cal Mark]

another urban legend

[Rmprotune]

[quote="So Cal Mark"]another urban legend[/quote
I agree!

[TomS]

Thanks for all the good info, but I still am unclear if there is a difference in performance between heads ?

[pope]

another urban legend

Which one are your talking about, the superior casting of the 2.0 or the 1.8 being better than the 2.0?

[So Cal Mark]

the supposed "better flow" of the 2L head

[launieg]

another urban legend

Thanks Mark.

I've followed these "head change" threads before, but I'm still unclear about two things: (1.) will I notice the improvement? I like to push the car, but not like a racer. Keep in mind that I have little opportunity to take it up to high speeds, so I guess it would be a torque improvement that I might notice; and (2.) will I have to use a higher octane gas? I use 87 at the moment. Thanks.

[So Cal Mark]

the 1800 head gives a nice little boost with the extra compression. If you have stock flat top pistons you should still be able to use the 87 octane. I use the 1800 heads on every 2l I build unless something out of the ordinary is going on.

[Rmprotune]

So I would assume you have a few 2.0L F.I. heads you would be willing to part with?for a cash value ,of course.