Hello,

I used the OZDAT engine calculator to test if I could use the ld28 crank in my l24 engine to get 2700cc.

the problem is that this would only work with the shorter L20a connecting rods but I cant seeb to find those anywhere not even aftermarket from maxpeedingrods or another seller does anyone know were I could find them?

Youre help would be greatly appreciated!

Greetings from Germany,

Elias

it depends what pistons you want to use. for example, Kameari offer pistons with 3 or 4 different pin heights to suit different rod length and crank throw combinations. 

L20a rods are gonna be scarce. It is a popular motor for the Datsun 510 crowd. Also the short rod is probably going to give you a bad crank/rod ratio. Longer rods are generally preferred. I think jonbill is right, look for pistons with a shorter pin height

28 minutes ago, Patcon said:

L20a rods are gonna be scarce. It is a popular motor for the Datsun 510 crowd. Also the short rod is probably going to give you a bad crank/rod ratio. Longer rods are generally preferred. I think jonbill is right, look for pistons with a shorter pin height

I think you might be getting the L20A (6-cyl) mixed up with the L20B (4-cyl).

L20A rods are 133mm centre to centre. Same as late L24 and late L16.

9 minutes ago, HS30-H said:

I think you might be getting the L20A (6-cyl) mixed up with the L20B (4-cyl).

L20A rods are 133mm centre to centre. Same as late L24 and late L16.

Well the ozdat calculator says that l20a rods will work and that with l20b rods the piston protrudes beyond the head gasket.

those Kameari pistons look really nice but I dont have the 1000 to 1200 euros for pistons 😅

28 minutes ago, z shredder said:

Well the ozdat calculator says that l20a rods will work and that with l20b rods the piston protrudes beyond the head gasket.

The Ozdat calculator is mistaken on the length of 1969 through 1975-ish standard L20A (6-cyl) rods. They are 133mm centre to centre.

L20B (4-cyl) rods are much longer, at 145.9mm centre to centre.

 

which pistons do you want to use? you'd want to do the sums properly, but standard l28 pistons and rods with a thick gasket might work. 

1 hour ago, HS30-H said:

I think you might be getting the L20A (6-cyl) mixed up with the L20B (4-cyl).

L20A rods are 133mm centre to centre. Same as late L24 and late L16.

You are correct

2 minutes ago, jonbill said:

which pistons do you want to use? you'd want to do the sums properly, but standard l28 pistons and rods with a thick gasket might work. 

right now I have an l24 with all standart internals.

If using the l28 rods and pistons would work that would be great but I really dont want to bore out the engine block.

I reckon l28 rods with your standard pistons will put the pistons about 2mm up - assuming that doesn't put the top compression ring too close to the combustion, Kameari do a 3mm head gasket that would sort it out.

But that's all a lot of effort to get less capacity that just dropping an L28 engine in. 

13 minutes ago, jonbill said:

I reckon l28 rods with your standard pistons will put the pistons about 2mm up - assuming that doesn't put the top compression ring too close to the combustion, Kameari do a 3mm head gasket that would sort it out.

But that's all a lot of effort to get less capacity that just dropping an L28 engine in. 

That is exactly what I mean I want to keep my original engine but i would also love to get some extra capacity by dropping in a crankshaft and some rods or pistons I really do not want to bore it out.

59 minutes ago, z shredder said:

That is exactly what I mean I want to keep my original engine but i would also love to get some extra capacity by dropping in a crankshaft and some rods or pistons I really do not want to bore it out.

Why are you opposed to boring your block?