3.9l head on 4.0 - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

Turbo_EA · 10-06-2004, 02:34

Hey guys, I went down to my mechanic's today to see how he is going with the rebuild on my ef. He said that the head had gotten too hot and needed to be replaced, so he got me a 3.9 head. Said it had better compression thus, better performance. I was surprised to hear that it even fit.

Have any of you guys heard of this/done this before? Any ideas on the outcomes?

Cheers, Waity.

INJECTED250 · 10-06-2004, 02:58

he is ripping you off..... youre ef rocker cover wont fit without the head being modiefed.... 3.9 heads are crap and by this stage in life are full of welds .... There is no reason 2 do this. They have a crapy chamber design.

(how do u fit au valve springs to a 3.9 head i just couldnt see the reason

SPHELL · 10-06-2004, 04:57

yeah mate ur gettin stooged. He probably got you a 3.9 head cause it was cheap as chips from the wrecker. You'll drop a bit of compression by fitting it and probably a bit of power too. Injected250 is right, your rocker cover won't fit properly he'll need to use half a fkn tube of blue silicon to stop all the leaks. Tell him to get an EF or EL head or else. Geez, the sh*t they try and spin........

needturbo6 · 10-06-2004, 05:18

yep i agree, he aint doin the right thing. ea heads are shit, most of em have either been replaced or reused and the alloy is gettin softer and softer aswell, probably why they blow time after time.

i didnt know about the rocker cover issue but now do, very good 2 know tho.

.......and what a load of shit i cant believe he would try and sell u that.

ebxr8240 · 10-06-2004, 06:11

Infact I'd be sus if the head is r/s...He may have had it there and wants to get rid of it ??? Too high a comp doesn't work on efi engines unless spark advance can be changed..It will ping ...Or run like sh!t...

Thanatos · 10-06-2004, 15:26

The compression will be quite a large amount higher with the EA head, but the ports are smaller, chambers have some weird little "wing" thing in them (which is why the comp will be higher)... overall they are just a worse head. These engines don't seem to benefit much from sky-high compression, either.

I agree with everyone else, he's trying to stooge you. Don't let him fit the EA head to your car...

Cheers,
Dave

Turbo_EA · 10-10-2004, 17:17

Problem sorted, I went in to pick the car up on Friday arvo and he said, we just noticed a slight crack in the head, we'll replace it. I said shit, maybe I'll have to put a 4.0 head on it. He laughed and said if you can find one. So, I did. I found a 4.0 head with only 20,000 k's on it for $350! It is going on this morning, with any luck I will have the car done tomorrow morning. Hoorah! I can finally park that shitty ea.