After several months of searching I finally came across a set of 4 (only) L14 rods. Alot of people are unfamiliar with these rods, mainly because they were only available in selected markets around the world. Some of these markets are the UK (United Kingdom), South Africa and New Zealand.

These were found in a small 4 cylinder L-series engine. Like all other L-series engines the number reflects the engine size. That’s right a little 1.4ltr engine, why would anyone want those in a L28 stroker? Well the main reason is their length. They are possibly the longest rods available at a length of approx. 136.5mm centre to centre.

So why is this important? When building a L31 engine you must do two things to change the displacement of the engine. First of all you must stroke the motor by installing a longer stroke crankshaft. In my case the LD28 crank. As a result of this increase in stroke the standard rods are put on a greater angle in relation to the crankshaft which in turn causes more pressure to be put on the cylinder walls of the block. What this means is that less power is put into pushing the piston down.

Installing a longer rod will allow the engine to rev easier because less force is placed on the cylinder walls and more force is placed on turning the crankshaft. The longer rods also allow for shorter pistons, shorter pistons means less weight, which in turn allows for a faster revving engine.

The crank rod ratio can be worked out by the following formula:-

Rod Ratio = Rod Length / Crank Stroke Length
L14 rod length = 136.5mm
Crank stroke length = 83.0mm
Rod ratio = 136.5/83.0 = ~ 1.644

In general I have read that the ideal rod ratio for higher revving engines is ~1.7 and above. Considering that these are factory rods being used with the LD28 this is pretty close to that figure. The longer rods help to reduce friction on the side walls and increase the life of the piston rings.
Currently I have L24 rods (same as L16) from my 240z’s shortblock however these rods are approx 133mm centre to centre. So they are a little shorter, they will work nicely though if you don’t have the patience to hunt for the hen’s tooth L14 rod.

Using the same formula above this will give the following result:-

Rod Ratio = Rod Length / Crank Stroke Length
L14 rod length = 133.0mm
Crank stroke length = 83.0mm
Rod ratio = 133.0/83.0 = ~ 1.602

Bookmark to:

This entry was posted on Thursday, June 29th, 2006 at 12:41 am and is filed under Engine. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

After several months of searching I finally came across a set of 4 (only) L14 rods. Alot of people are unfamiliar with these rods, mainly because they were only available in selected markets around the world. Some of these markets are the UK (United Kingdom), South Africa and New Zealand.

These were found in a small 4 cylinder L-series engine. Like all other L-series engines the number reflects the engine size. That’s right a little 1.4ltr engine, why would anyone want those in a L28 stroker? Well the main reason is their length. They are possibly the longest rods available at a length of approx. 136.5mm centre to centre.

So why is this important? When building a L31 engine you must do two things to change the displacement of the engine. First of all you must stroke the motor by installing a longer stroke crankshaft. In my case the LD28 crank. As a result of this increase in stroke the standard rods are put on a greater angle in relation to the crankshaft which in turn causes more pressure to be put on the cylinder walls of the block. What this means is that less power is put into pushing the piston down.

Installing a longer rod will allow the engine to rev easier because less force is placed on the cylinder walls and more force is placed on turning the crankshaft. The longer rods also allow for shorter pistons, shorter pistons means less weight, which in turn allows for a faster revving engine.

The crank rod ratio can be worked out by the following formula:-

Rod Ratio = Rod Length / Crank Stroke Length
L14 rod length = 136.5mm
Crank stroke length = 83.0mm
Rod ratio = 136.5/83.0 = ~ 1.644

In general I have read that the ideal rod ratio for higher revving engines is ~1.7 and above. Considering that these are factory rods being used with the LD28 this is pretty close to that figure. The longer rods help to reduce friction on the side walls and increase the life of the piston rings.
Currently I have L24 rods (same as L16) from my 240z’s shortblock however these rods are approx 133mm centre to centre. So they are a little shorter, they will work nicely though if you don’t have the patience to hunt for the hen’s tooth L14 rod.

Using the same formula above this will give the following result:-

Rod Ratio = Rod Length / Crank Stroke Length
L14 rod length = 133.0mm
Crank stroke length = 83.0mm
Rod ratio = 133.0/83.0 = ~ 1.602

Bookmark to:

This entry was posted on Thursday, June 29th, 2006 at 12:41 am and is filed under Engine. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.