Will 4.6 heads bolt onto a 3.9 block?

[Siska]

As the title really.

Will 4.6 heads (P38) bolt onto a 3.9 (96 Disco) block?

[justinc]

Yes.


:)



JC

[Siska]

Thanks for the quick reply,

I thought they would, but just read something that put a bit of doubt in my mind. :D

[PhilipA]

But best with composite gaskets.
Regard sPhilip A

[p38arover]

They may not have the holes for the 4 outer bolts. Mine don't but my 4.6 block has holes for the bolts (which it shouldn't have).

[justinc]

They may not have the holes for the 4 outer bolts. Mine don't but my 4.6 block has holes for the bolts (which it shouldn't have).

96 D1 hasn't got the outer bolt holes in the heads either. Most Early non Serpentine belt 3.9's (pre 'MA' VIN) in early D1 and RRC did have the extra row of bolts.

JC

[twitchy]

As the title really.

Will 4.6 heads (P38) bolt onto a 3.9 (96 Disco) block?

what gains are going to come from the swap??????? Valve size larger???? better flowing heads???

[LOVEMYRANGIE]

Doesn't the 4.6 have a bigger chamber capacity than pre serpentine 3.9's????
This is going to drop the compression from the already low 8.13:1 on the 38D engines.

Cheers

Andrew

[PLR]

Doesn't the 4.6 have a bigger chamber capacity than pre serpentine 3.9's????

No .

[PLR]

As the title really.

Will 4.6 heads (P38) bolt onto a 3.9 (96 Disco) block?


G`day , as said they will fit without problem .

What`s not said is , if you look at the casting numbers in this case you will find the reason they will fit is that they are the same thing .

Cheers

[PhilipA]

Doesn't the 4.6 have a bigger chamber capacity than pre serpentine 3.9's????


The 4.6 heads have a 28CC combustion chamber vs 34CC for the 3.9 head.
This is to compensate for the 30thou thicker composite gasket vs the tin gaskets.
AFAIK the heads are physically the same except the 4.6 head has 30 thou milled off. I have milled 3.9 heads with no problems to fit composite gaskets to tin gasket heads and my chambers turned out at 28CC.
Regard sPhilip A