4age Pistons Into 4k

[thimio38]

hey guys does anyone no if i can put 4age pistons into a 4k... thx

[Taz_Rx]

Yes, you can.

 

Suggest you actually use the search tab in the top right corner as there is several threads here discussing this. :D

Edited May 13, 2009 by Taz_Rx

[tas_ae71]

i hear 1G pistons are a closer fit?

[Felix]

Aren't 4age's 81mm bore?

 

4k is 75mm bore std

[Hiro Protagonist]

Aren't 4age's 81mm bore?

 

4k is 75mm bore std

 

4AGE bore is 81mm

1G bore is 75mm

5k is 80.5mm

 

Considering a 5K is a bored 4K, it would most likely be possible to bore a 4K block out to 81mm for 4AGE pistons (or just use a 5K block), but 1G pistons would a close fit for a non-bored block.

[OniBerserker]

didnt a guy called noodles have 4age pistons in his 4k? i can't remember which forum i was reading it on

[Felix]

The early 4age bigport pistons may have 18mm piston pins like k series, but the comp height is all wrong. The pistons would sit over 5mm down the bore at TDC.

 

The 1G pistons comp height would likewise put the pistons approx 3.5 mm down the bore. The 1ggze pistons have 20mm piston pins.

 

Unless you were to run longer rods the end result would be far from ideal. Having the pistons sitting so far down the block may be good to lower compression in a forced induction motor. You would end up with no squish though. Maximising squish reduces the likelihood of detonation.

 

I wouldn't bore a 4k block out 6mm. It would most likely crack. The 5k blocks have an extra strengthening rib running below the welschplugs.

Edited May 13, 2009 by Felix

[love ke70]

felix have you seen my pics of 1g pistons and rods in the 4k?

came very close to being right, and was only a rough up, i think it would give compression very close to stock

[Felix]

No I haven't love ke70.

 

If the 1g rods work then go for it.

[love ke70]

http://www.rollaclub.com/board/?showtopic=15799

 

and these rods and pistons are 9 second and 10,000rpm proven :D

[Felix]

Cool. I see the piston sits 3mm down the bore.

 

There is no squish though. Guess you could skim the block. Wonder how that would affect block deck stiffness?

Edited May 13, 2009 by Felix

[Medicine_Man]

My 5K is getting 4AGE pistons put in it..

[love ke70]

that would come up a little once you get bearings around the crank, as it was moving around a little without them.

3mm off the deck height wouldnt hurt.

plenty of people when they fit oversize pistons to 308s and stuff then deck the block to get them flush again.

if you wanted to get really tricky you can get offset gudgeon pin bushes to move it up a bit more...or so ive been told something along those lines...