well, people always say you can put 1ggte pistons and rods into a 4k going off the measurements etc, so i thought to prove it true or false, having the majority of the ingredients. not a perfect experiement, but close enough.

 

you will need 1ggte or gze or ge rods, so long as they are not gen 3 1ggte rods you will be fine, as these have a bigger big end.

the ones i had had .25 oversize bearings, so they were a little tight on the crank, but for my purpose all was well.

i also had no bearings on the crank, don't know what id done with them, bin I'm guessing. but it was bolted in, so again, close enough :lolcry:

i took the rings off the piston for ease of use.

 

anddd, it works

 

 

thats the piston near bdc

 

and at TDC, it was about 3mm below the deck, which may work well for a turbo setup, or now you know it works, rig it up and work out exactly how much you want to deck the block by, but 3mm is a good rough guide. it was measured with verniers :P

 

 

 

you have to swap rod and piston, as the piston (edit: gudgeon, duh) pins are different, 1g is 20mm and 4k is 18 mm.

 

I'm pretty tired so its fairly breif, and no point boring you with shit, any questions, please ask, I'm willing to help :bash:

 

cheers, andrew

you can also modify (turn down the front to fit 2T pully's) an easily obtainable 2Y crank to work in a 2T, instead of trying to find a 3T crank.

 

good work on the 1G stuff :lolcry:

 

Cheers

Jordan

WELL DONE :lolcry:

 

All ways wondered if this was true. But now I know will help lots in my 5K I am planning to build as they run a 4K crank.

 

Also the width of the conrod at the big end was it the same as a 4K one? I know you can run 4agze internals in a 5K to run wicked boost but the conrods are thinner so need some loving to take up the space. So was there any "space" or gap between the con rods and crank shaft on the big end?

 

Cheers

Cameron

Edited October 19, 200719 yr by camerondownunder88

theyre both 24.95 ish mm using digital verniers, they fill the gap.

 

are you planning on using custom pistons in your 5k? the 1g pistons will be too small to fit the 5k bore....

Opps I forgot about the bore..LOL

 

But does anyone know the diameter of the gudgeon pin in a 4agze piston? I know these fit a 5K so if they have the same pin diameter as a 1g con rod you could use a 1g conrod and save the hassle of welding and machining 4agze rods.

 

Also how long are 1gg rods and then how long are 4agze rods also?

 

Cheers

Cameron

Hi Cameron

the 4agze or 100kw 4age takes the 20mm pin. the piston is about 5mm down the bore with the 4age rod.

 

the bottoms of my 4age rods havn't been touched. been in there for about a year & no problems. theres a guy in finland who ran them in a rally car for over 2 years without any problems aswell.

Hi TRD,

Long time since I last talked to you ont eh phone.

 

I have always been thinking about this as the 4agze rod is thinner with out the nice "fit" at high RPM they could slap about. But after being in your car I am sure if after a year there still good well I wont bother welding them up on the sides to take up the space.

 

But after your piece of info a 4agze gudgeon pin is 20mm diameter. A 1G rod also runs 20mm. Not a 4K crank is in a 5K factory so a 4K crank 5K block 1g rod and 4agze piston and it should work for a mean forged piston high boost K motor.

 

Can we possibly get specs on con rod lengths at all? As if one rod drops the piston lower or lifts it more you can play with length to get the compression ratio correct.

 

Cheers

Cameron

Hi Cameron

the 4agze or 100kw 4age takes the 20mm pin. the piston is about 5mm down the bore with the 4age rod.

 

the bottoms of my 4age rods havn't been touched. been in there for about a year & no problems. theres a guy in finland who ran them in a rally car for over 2 years without any problems aswell.

 

The 1st gen bigport has a 18mm pin with a 40mm bigend, The 2nd gen bigport along with all smallports and gze's have the 20mm with 42mm bigend.

would i be right in assuming at 1ggue pistons/rods would also fit for higher compression..?

^^^ on that note. If the 1G rods are lower in the bore from the photos at the start of the thread. So it will drop the CR but if you want it high again for a tough NA motor shave the head or the block I guess that would work

 

Cam

I'm trying to remember what is different, i think its the heads that are different and piston/rod are the same. ill do some digging..

preliminary digging says pistons are different.

so it may work yes.

but you could just as easy deck the block...

Yeah that's what I'm thinking, 90% sure that the heads are the same ge/gte pistons are definitely different, rods maybe..