7A to 3B conversion using 7A head and MC2 block?

Mihnea Cotet mik at info.fundp.ac.be
Fri Jan 9 03:42:03 EST 2004


Jim, Ben, all,

NG would be the way to go, about 8.5:1 CR, but the problem would be that 
the pistons aren't forged as opposed to all stock 20vt pistons. Apart from 
that, the rods should be strong enough for 500+ HP/450+ lb/ft of torque (at 
the crank) as the rods used in the early NGs are a lot beefier than most 
stock 20vt rods out there, except the ones in the 200q20v's. Use upper S4 
rod bearings all around and you'll be fine.

The head gasket might be a problem though, and so would be the wall 
clearance between the cylinders, but it's worth a shot IMHO...

Cheers,

Mihnea

At 20:55 8/01/2004 -0800, Jim Green wrote:

>--- Ben Swann <benswann at comcast.net> wrote:
> > If I were to obtain a 7A engine and 3B ECU, sensors
> > and harness, what would be necessary to convert the
> > 7A to a 3B?  Could I use an MC-2 bottom end and 7A
> > and pretty much have the 3B configuration.
>
>Nope, you'll have way to low compression since the
>volume in the head on the 20v is larger than the 10v.
>The only thing that will get you close is an NG bottom
>end.
>
>
> > I presume I'd need to source an EM, Is the intake
> > different?
>
>Yes, and yes, the intake is totally different.
>
>HTH,
>
>=====
>Jim Green
>'89 80q ... slow
>'89 90tq .................fast
>http://www.mswanson.com/~jgreen/car_home.html
>
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