hey guys, i just pulled down two 4k's that i got given, one from a ke70 van, one from a sedan, the one in the van had flat top pistons and a head with deeper valve areas than that of the sedan motor. are the flat tops standard or are they forgies and some one has put a different head on it. check my pics, first 3 pics are the flat tops head, last three are the other. also the ends of the head are different, one has a cap with 4 bolts. is it possibly a 3k bigport head? thanks

Edited June 1, 200818 yr by corolla_bitten

Take the manifold off the one with the welsh plug in the back and i'll bet you'll find that it has bigger ports than the one with the plate on the back. The one with the welsh plug is most likely a 3K bigport head.

Edited June 1, 200818 yr by Xany

The second one has lugs under 1 & 4 therefor it appears that it is a 5k head that has been put on the 4k, or a rare (in aus anyway) dished piston 4k.

Double check the block the second one came off, as it might just be a 5k. :bash:

Edited June 1, 200818 yr by Taz_Rx

thanks guys, nah the second one is definately off a 4k, and yes, it has got dished pistons, i thought all 4k's had dished pistons?

if that is the case, will the flat top pistons on the first engine be factory or forgies?

thanks guys, nah the second one is definately off a 4k, and yes, it has got dished pistons, i thought all 4k's had dished pistons?

if that is the case, will the flat top pistons on the first engine be factory or forgies?

flat pistons are stock

thanks, 1st head has now been identified as a 3k bigport according to cameron down unders head guide, other engine has only got 75mm bores so its a 4k of some description. thanks guys, will dished pistons give me any advantage over flat tops?

its going to be n/a twin webbers.

Yeah most australian 4k's have flat top pistons, but there's a few dished ones kicking about which you obviously have one of.

 

Would be an advantage if you wanted to turbo or supercharge it by using the dished piston block and flat top head for low compression. Doing it the other way would have too much!

Spose I should post..LOL

 

4K and 5K dished piston heads are the same I got a few of both. Dished piston heads have a better combustion chamber adn my dissed piston 4K jsut went so much harder than a regular 4K so use one of them for a N/A motor build that would be my choice.

 

Also welsh plug head is a big port head. Pending model it came off the big port head could have smaller valves and be shaved more.

 

K-B motors or 3k-B had a higher compression big port head. So will pay to CC the head to find out.

 

Also flat top pistons stock. And dished pistons aren't uber rare but worth it when you get a motor that is dished as more killer wasps to use.

 

Cameron