G13ba head on G13bb block

[motoking]

Hey guys hows it going, ive got a bit of a problem that i thought some of you guys might be able to help me with.

So hear goes, i bought a 1.3L swb 93 Zook for $500 but the motor that was supposed to be in the engine bay was instead dismantelled in the back seat. I had a quick look at the block and noticed a huge crack down the side of the water jacket which i assume caused the leaking water that the owner told of. getting to the point i bought it anyway and am now trying to get a motor together so i can start driving it. rather than welding the crack i decided to just find an entire new motor for it. i rang arround at reckors and finaly found a g13bb block at gold coast 4X4 wreckers. in my enthusiasm to get the thing running i got a mate who was working near there to get the block for us and bring it home. i got it in the shed and noticed that the top of the piston thad 4 cuts outs for the valves where as the old piston i compared it to had only two.

now the question is will i still be able to use this block with the head that i already have, do i have to modify it so the valves will clear on tpdc.
the same mate that picked up the block for us said that it doesnt matter as the valves are always closed at tdc anyway but i would hate for something to happen like a snaped timing belt or the likes as a valve and piston collsion looks like big $$

Thanks for your help, Allan

[suzimad]

allan , you could probably use that bottom end no worries , what you may find is a decrease in compression.. if it were me id bolt the head on lightly and use plastecine on the top of one of the pistons to determine if any interference will happen.

[motoking]

Thanks for that, do you reckon that the lost compression would be worth worrying about, or just drive with the foot a little closer to the floor?

[cookie monster]

Try comparing the sizes of the piston cutouts. A 4 valve head would have smaller dia valves than a two valve head, so the piston cut outs may be smaller.
If they are smaller then the check with plastecine will let you know of any problems.

cookie monster

[Guy]

You can use your 2 valve head on the 4 valve block, but it will now be an interference motor ( IE your cam timing is out due to be broken or slipped tooth on the cam belt .. the motor dies) whereas the 2v motor with 2v pistons is a non interference design.

Also make sure you head gasket is the correct one, from memory there were a few minor issues with one blocking some oil gallery between the 2v and 4v motors .. but I could be wrong ..