Tak510

Thank you! Yes, I read this one before, too. He says, "The block of choice for the 3.1 stroker is the F54. Although some people have used the N42, the F54 block has webbing built in between the cylinders for extra rigidity." The F54 has a better cooling design without sacrificing rigidity by adding the webbing between the cylinders, and I am totally for that, too. But, the N42 has less water passage, means has more metals left between the cylinders than the F54?? My wild guess is, the F54 gained water passages but also had to shave some metals out of the block. Nissan engineers managed to maintain the needed rigidity by using the webbing design. When the F54's cylinders are bored out beyond the certain point and the walls get thinner, the advantage of the webbing design for extra rigidity may be lessened?? I don't know. I'm just curious.

Thank you, jbuenviaje! Wow, you solved my mystery. This forum is great!!

Thank you! Yes, I read this one before, too. He says, "The block of choice for the 3.1 stroker is the F54. Although some people have used the N42, the F54 block has webbing built in between the cylinders for extra rigidity." The F54 has a better cooling design without sacrificing rigidity by adding the webbing between the cylinders, and I am totally for that, too. But, the N42 has less water passage, means has more metals left between the cylinders than the F54?? My wild guess is, the F54 gained water passages but also had to shave some metals out of the block. Nissan engineers managed to maintain the needed rigidity by using the webbing design. When the F54's cylinders are bored out beyond the certain point and the walls get thinner, the advantage of the webbing design for extra rigidity may be lessened?? I don't know. I'm just curious.

It has been a long year mystery for me... For building a 3.1 or 3.2 stroker, is it better using the F54 block or N42? Almost every article I read in English says, the F54 is the best choice when building the stroker." But, what I hear in Japan (yes, my native language.) is totally the opposite. They say, "If you're going to bore 89mm or more, then the N42 is your best bet, especially if you were building it for drag racing. The largest bore you can go safely with the F54 is 88mm." That seems to be the common understanding among the L engine tuners in Japan. More interesting to note, they say that some early production of the N42 up to the certain lot number came with thicker cylinder walls and had more rigidity than the later produced N42s, hence it's even more desirable for building the strokers, but they are a very rare find now... The F54 came out later than N42 and it has improvements like the added water passages between the cylinders for a better cooling. But my question is, is the F54 really not safe if boring 89mm? What do you guys think?

It's kinda old thread, but I just want to share with you that my z has the L28 short-stroke setup: N42 block + 280ZX flat pistons + L24 crank + L24 rods + N42 head. The compression is 9.5:1 with 1mm thick Felpro head gasket. This can be built with all stock parts and it's very easy. I have been running this setup with a lighten flywheel and triple carbs and I love it!! With .6mm thick metal head gasket MSA carries, a 10.0:1 compression can be had without shaving any metal, but it's a little pricey item..

Thanks a lot for the quick info!

I just found a broken thread on one of the head bolt holes on my N42 block, and I'm thinking to fix it with a helicoil. Does anyone have the head bolt size (dia. and thread pitch) info. or maybe the helicoil part number handy? Many thanks in advance.

Have you replaced/upgraded either a master cylinder or a booster lately? If so, your push rod found in the booster could be out of adjustment. You can adjust the length of the push rod and change the pedal height. But, be very careful there! I would strongly recommend to read the Nissan manual first before dealing with that push rod. Adjusting the rod too far out will cause brakes to drag or lock up while driving. Another caution that there is a small rubber seal called "reaction disc" set right behind the push rod. This disc can easily fall inside the booster while working on the push rod. If this accident happens, you will see a new deep problem which I just gone thru... Hope this helps. Tak 72