c-rad wrote:
You do realize its the same motor save for a few slight mechanical differences, right? And the only internal difference is lower compression pistons, oil squirters, and a main cap girdle.
Yes, i do understand its the "same" engine but at the same time its not. I couldnt imagine Nissan using some of the same materials for internals on the USDM NA engine. What would be the point? Definately not cost-worthy for them. Its not turbocharged so some things dont have to be made out of the same metals/materials. Yes theyre both 1809cc, 83.0 x 83.6mm, DOHC, 2 compression rings 1 oil, 5 main bearings, and also the turbo model has 8.5 comp. ratio and 10.0 for NA version. Agreed. But the fact that one is turbocharged and the other isnt, i would imagine it would have to have stronger if not different size/material bearings for the Crankshaft and Connecting Rods, because of the extra pressures or different oil clearances. Also theres the tolerance differences the manufacturing porcess but i dont think thats really a big issue. Correct me if im wrong.
I wanted to see if this is actually true so i decided to look for the information from Nissan. You mentioned the only major differences being the low comp. pistons, oil squirters, and main cap girdle. I went digging through the S13 CA18DET FSM and i have access to FSM information from a 1989 Nissan Pulsar and found that a lot of the measurements are identical with a little difference here and there. Looks like the end gaps on the piston rings are different. Also some slight differences in the pistons themselves and the side clearances. All in all this is what i found, Crankshft and Connecting Rod Bearing clearances are the same. Crankshafts are the same as in measurements. Connecting rods are the same. Piston rings are slightly different. Piston pins are the same. Camshafts are different (they have to be)! Valves are the same. Valve springs are the same. Hydraulic valve lifters are the same. Valve seat inner and outer dieameters and heights are different. Other valve seat measurements are the same. Theres slight differences in the Cylinder head hole diameter and Interference fit in the Valve Guides. Cylinder heads are the same measurements. Blocks are the same measurements except maybe one thing i found, Feeler gauge extracting force? Thats it. Not to different at all except for somethings like the main bearing beam, pistons, and oil squirters. Well i just answered my own questions...
What about the metals these peices are made of?