So i bought a 4k engine & k50 off a mate the other day out of a standard grandma ke70.

I started pulling the manifolds off this morning and thought those ports look big so could anyone tell me if this is a 3kbp ?

I measured the ports with some plastic veneer calipers and got

Intake port - 31mm

Exhaust port - 21mm

My ported head i got from japan ports are

Intake port - 28mm

Exhaust port - 23mm

 

Pics

 

 

 

 

also the valve spring retainers look different to the ones on my other head

 

I will take the head off today and see what condition it 's in

The welsh plug in the back of the head indicates she's a bigport.

ok i figured it was i just don't know enough to be sure has a bit of corrosion around the water jackets I'm going to see if a mate can have a look at it and tell me if its repairable.If it is i'll swap all the rocker gear,valves,double valve springs etc over and just get this one cleaned up and get the exhaust ports opened up because i think the other one i have has be shaved to far

ok i figured it was i just don't know enough to be sure has a bit of corrosion around the water jackets I'm going to see if a mate can have a look at it and tell me if its repairable.If it is i'll swap all the rocker gear,valves,double valve springs etc over and just get this one cleaned up and get the exhaust ports opened up because i think the other one i have has be shaved to far

 

That looks like a pretty clean head. The welsh plug appears to be welded? or brazed? Look like blow... i mean flow.