Was having a clean up in my garage the other day and came across a 3K head I'd forgotten I had.

 

Question ! How do you tell the difference between a 3k big port & a 3k std head ?

 

Did a quick search but can't find the answer.

 

I guess it's only the dimenisions of the manifold port openings; but what are those dimensions.

 

Thanks ! :)

If its got a welsh plug @ the back, or just a 4 sided plate on the back

 

:)

My 3k big port had port dimensions of.... Intake 30mmx32mm and Exhaust 20mmx26mm.

and mine has only three numbers on the side of it inbetween spark plugs 2 and 3.

 

115 i think is the number........not sure if this means much though

really? thats wierd, all bigports i've seen have a big long casting number, like 8 digits with a dash in the middle. but yeah, like teddy said, welsch plug at the back

i'll check before i go to work........i'm pretty sure thats the number, i thought it was a little weird at first, i was hearing all these stories of long part numbers, and all mines got is 3.

Thanks guys ! Alas ! Alas ! It was just a standard 3K head, with the four sided flat plate at the rear of the head. Thanks Teddy. Wish it had had a welsh plug. I'll keep my eyes open now I know what to look for. I guess they're as scarce as hen's teeth. I love going through wreckers out in country towns. It's amazing what you find there.

 

I think I read that you can pop a 3K big port head straight onto a 4KC and it will up the compression ration to about 10:1 or thereabouts.

 

My little old 4KC is just starting to use a bit of oil. Would like to drop a 5K into it if I can get hold of one. Anyone know of a good one for sale ?

 

Other than that I've got a 4K-U sitting here in the garage, condition unknown, that I might do up & then swap over. Would love a 5K. As someone has said on these pages before. "There's no substitue for CCs" :)

That was probably Peter and his V8.... :)

Hehe, KE25 with quad cam V8, sure would be a hell load of fun! :)

3k bigports are overrated. they're mostly old worn out pieces of shit so you need to spend a f@$kton of cash renewing valves and guides and having the bits of water jacket rust welded up

 

why don't you take that money, spend it on an already good working non-f@$ked 4k-c head and have something that flows better for less cash. i'm so over 3kb heads, if i did my motor again, i'd send a 4k-c head away for a bigvalve raceport job