Hi All,

Fast question what are the length of K motor corods? Are they all the same is it jsut the crank that was changed to give bigger stroke?

 

As I kow the 3K and K motors have a 10mm shorter stroke than a 4/5K motor but I know the cranks are different. Can anyone tell me the length of a K motor conrod?

 

Cheers

Cameron

I have one new unused one here, if you tell me where you want it measured from.

What cha planning ?

As far as i know the 4k block is taller, so i'd be lead to believe the rods are the same length.

 

I do have a set of 4k rods hiding in the garage some where but they still have the pistons fitted. If you want i can dig 'em up and get some measurements.

Hi,

Well I'm kinda looking at building a nice K motor atm..LOL

 

Man thing I am wanting to know is center to center and Big end width. I am building a 5K and I do belive 4K are same rod. But if there not please tell me.

 

Cheers

Cameron

4K exactly the same as 5k (as said in FAQ). I'm guessing they are all the same and the crank is the only difference.

So measuring the new rod I have here, described as a K rod by the reputable ebay seller in the US.

 

Big end diameter 45mm WITHOUT BEARING SHELL

 

small end 18mm

 

centre to centre 120mm

 

Mind you I am no engineer, but I checked my measurements a couple of times and it is a quality dial indicator.

So measuring the new rod I have here, described as a K rod by the reputable ebay seller in the US.

 

Big end diameter 45mm WITHOUT BEARING SHELL

 

small end 18mm

 

centre to centre 120mm

 

Mind you I am no engineer, but I checked my measurements a couple of times and it is a quality dial indicator.

 

Vernier calipers with a dial readout?

NSK Vernier caliper. The dial is too hard for me to follow! I can only read off the scale on the side.

Kinda confused now. LOL

 

With no bearing shell it is 45mm. That makes it about 42/43mm with them.

 

Now I know early K motors have a smaller big end than later K motors like 4K / 5K so what were they?

 

As a conrod manufacture has asked me what size my conrods are he said he has 43mm or 45mm conrods to suit a K motor so Id take it after Parrot your messurement his is also with out bearing shells making his 43mm rods the older K/2K conrod.

 

Also 120mm centre to centre sounds right as in my head I had about 118mm.

 

Also what was the thickness of the conrod Parrot?

 

 

Cheers

Cameron

In the H beam, it's about 10.3mm

 

The big end is about 24.7mm

 

As above, I'm no engineer.....

 

And I am relying on the seller that it actually is a K rod.

Edited February 1, 201016 yr by parrot

Slightly off topic - But Cam, Spool should have 5k H-beam forged rods available by the end of the month for around $600 a set. :jamie:

^^^ Yes I have emails spool all ready...LOL

 

I jsut have noticed a lot of conrod makers list rods for the 3K/4K motor WTF 3K is smaller so I'm trying to get exact messurements on rods so I can cross reference and see if I can get a matching rod stronger/lighter/high reving etc.

 

But on my way home from work hoping to be getting a spare 4K/5K rod off a mate so well see what I come up with.

 

But I am looking at 150HP+ at the wheels hopefully out of this motor N/A but it might be reving hard so id like a nice bottom end :jamie:

 

Cheers

Cameron

Can post this one up to you if you like, for comparison, just send it back whenever.

there's two types of std rod for 4k too. commercial 4k van and late 4k are fatter than the earlier ones. 1g-eu sohc engine has same rod too apparently. smaller gudgeon than the twincam 1G.

^^ WRONG...there are 3 types. I have a all full sets on my shelf. Was early thin type, medium weight type and heavy one.

 

By looking at them id use the medium ones for a high reving road/track car. Also the medium weight range ones are out of a dished piston 4K I wrecked so they seem to be a better engine so there prob the best rod also and Toyota in Japan new that that would be my guess.

 

Also think Ill go with the spool rods. Anyone used them before?

 

Cheers

Cameron