4age head on 4ac bottem end

[reg450]

ive got all the shit for it will it work will it make any power

[rthy]

do you have 4age pistons?

[86sp]

No

[mattysshop]

if you have a set of 4age pistons it may be worth while.. but you'd still need to pull the bottom end down to fit the pistons onto the rods..

[RobertoX]

been done sucessfully before

[Course_Out]

Yep, can be done but without the ge pistons you end up with like 6:1 compression, lol

Great way to get around having to get car engineered/blueslipped, but only worthwhile if your going to rebuild the engine anyway. If you've got the bits there I'd say go for it, buy new pistons/rings, get the bottom end rebuilt and go nuts.

[reg450]

yeah i finished the convertion so whats so bad about 4ac pistons
in the convertion

[Course_Out]

Low compression mate, they are designed to work with the 8 valve head, with the 16v head the compression is heaps low. I had heard 6:1 was what it came out at but it may not be that low, I haven't done it myself

[mattysshop]

6:1 won't even run lol... more like 8:1 CR for a 4ac.. your typical bigport 4age would be in the mid to high 9's later ones bit more like 10.. and 20v's up round 11 (as quoted by toyota and static CR)

don't get me wrong.. it will run.. but seem a little breathless compared to a stock 4age.. i haven't done it myself.. but i can't see the 4ac bottom end lasting for ever and ever flying past 7K.. so just keep an eye on oils etc.. and if it lasts great!! but i would definitly be considering this as a 'for the time being, untill i can afford a couple of hundred dollars to by a complete 4AGE' that way you can do a quick re ring and bearings, and slot her in... all the fuel system and electrics will be there..

[rthy]

the general concencus is that for all the trouble its probably easier to just use a 4age