Turbo L28 vs 3.1 Stroker L28

[BenZed]

Take the bore out to 89mm (3mm over) then get hold of a LD28 (Diesel engine - came in the Laurel's that are imported here in NZ not sure about OZ, we get them for between $50-150 for a crank only or sometimes the whole car for $100-200 which include a long nose R200)

 

The LD28 crank is 83mm vs the L28/L26 79mm. Using L24/L16 or L20a (pre 79) rods (all these rods are the same if the later L24/L16 units are used which have the 9mm big end bolt vs the earlier 8mm) I believe it best to use a good custom piston not the KA24 pistons as these are heavy and have large rings not ideal for performance IMHO.

 

You can get larger I have build L28 block with 90mm bore and owned one with 90mm with the LD28 crank = 3.2L now if you were to take a LD28 offset grind to change the stroke some more maybe 85mm then a 3.3L could be possible but at the 90mm bore the walls are getting thin

 

Hope this helps.

 

Yes at 90mm the walls are very thin. I had to look at a lot of blocks to find one that could take this bore safely. My L-series has the 83mm LD crank and 90mm bore for 3166cc capacity. At 89mm it would be 3096cc. Kameari actually make an 85mm stroker crank, which gives 3171cc on an 89mm bore, but requires a 2.5mm head gasket. The other drawback is it costs $4000 in Japan (plus duty, shipping GST etc.)

I've owned a turbo L28 too and they produce great midrange torque, but I chose atmo this time around for the sound, the instant throttle response and the ever-climbing power delivery. The 3.1 delivers as much torque as you could ever need and adds the searing top end sound and power. Ultimately you can get much more power from a turbo engine, but the character of an atmo engine just seems right for a classic sports car.

[BenZed]

 

One problem I found very early on is the uprated clutches sold don't last long and are to heavy causing nasty harmonics in the engine. I now use a flexplate type setup with a steel button in the middle with a 71/4 twin plate clutch and what a smooth engine it makes.

 

Ricky

 

OS Giken make a twin-plate for the L-series with clutch plate dampers and a light chrome-moly flywheel called a TS2BD. The plates are 204mm. It is rated for 480hp and I find it quite streetable. I had my engine balanced with this clutch attached for the best result. The Australian retail for the clutch is $2150 with the bearing and shorter carrier included. Anyone interested can PM me. For crazy power a triple-plate is available too.