pcakes55 Posted November 14, 2009 Share Posted November 14, 2009 Please dont say search, I've been at it for a few hours.. Anyways, I was wondering if there are any pros/cons to using the earlier n42 over the later f54 blocks, or if they're virtually the same just with different heads and internals. I plan on doing a total build regardless of which one i start with; it would just be purely magical if i can buy this $100 long block n42 instead of $500+ on f54. I also plan on running the 280zxt ecu, do i need a p90 head? ok, my head is going to explode with all these uncertainties, goodnight Hybridz Quote Link to comment Share on other sites More sharing options...
stravi757 Posted November 14, 2009 Share Posted November 14, 2009 block specifications Quote Link to comment Share on other sites More sharing options...
woldson Posted November 14, 2009 Share Posted November 14, 2009 1fastZ did some extensive research on cylinder wall thickness using a sonic tester. You might want to look that up. The f54 blocks have extra webbing cast into them for strength. Biggest problem right now is you have not specified what your goals are. You mention p90, what for? Why do you want a "stronger" block? Quote Link to comment Share on other sites More sharing options...
johnc Posted November 14, 2009 Share Posted November 14, 2009 It depends on your build plans. I spent a buttload of money on a Kinetic/Sunbelt built NA 3L L6 and they chose an early (1975) N42 block. Their reasoning, based on a lot of L6 engine builds, was: 1. Highest nickel content of any of the L6 blocks. 2. The cylinder bores will stay rounder at high engine temps compared to the webbed F54 and make more consistent power. 3. At the power levels I was shooting for (300 to 325hp) the extra webbing of the F54 was not needed. Kinetic/Sunbelt was also building a turbo 3L L6 for a customer at the same time and that engine made 628 hp on their engine dyno. They chose a F54 block for that build. Quote Link to comment Share on other sites More sharing options...
pcakes55 Posted November 14, 2009 Author Share Posted November 14, 2009 I forgot to add it will be turbo, not N/A. Probably running 15 and at times 20 PSI. I'm shooting for 350ish give or take whp, will that exceed the capabilities of the earlier block? And as for the p90 head; I wasnt sure if I could run the 280zxt ecu/wiring on with the n42 head. Also, I think the n42 head is a smaller combustion chamber, yeilding higher compression regardless regardless of the piston change? Thanks for any help guys, just trying to get the facts straight before starting to spend all my allowance. Quote Link to comment Share on other sites More sharing options...
johnc Posted November 14, 2009 Share Posted November 14, 2009 I'm shooting for 350ish give or take whp, will that exceed the capabilities of the earlier block? No. The N42 block has been successfully used for 500+ horsepower turbo applications here in the US and in Japan. Quote Link to comment Share on other sites More sharing options...
Xnke Posted November 14, 2009 Share Posted November 14, 2009 It is not that one block is particularly stronger than another, I think, but more that the blocks are designed for different applications, and have different design mechanisms in place. NOTE! This is pure speculation, based off the knowledge gleaned from this site and some personal experience. Has anyone weighed a bare N42 block vs a bare F54 block? I'll bet the F54 would be lighter. The N42 has thick, strong cylinder walls, and is designed around that. The additional bracing is not needed, with those thick walls. Pros would be less cylinder distortion, less prone to cracking, and more even distortion characteristics. Consequences would be slightly longer warmup time, different weight distribution in the block, or heavier block. The F54 has thinner, well-braced, stiff cylinder walls, and is designed around this. The thinner wall allows for faster warmup time, at the expense of more cylinder distortion, and less even cylinder distortion. I would venture a guess that due to the uneven thicknesses, cracking would be more common in this casting. Pros are faster warmup, lighter block possible due to more efficient block design, and more overall cooling capacity. Again, this is all conjecture, and I would use either block for any application short of a massive overbore, where I would grab an N42, just because that would be my personal preference. Quote Link to comment Share on other sites More sharing options...
bmarchuk Posted November 15, 2009 Share Posted November 15, 2009 I think its a common misconception that the f54 is a better block. I did alot of research on this before I decided which block to use. Im definitly using my n42, for the reasons stated above. Quote Link to comment Share on other sites More sharing options...
cockerstar Posted November 15, 2009 Share Posted November 15, 2009 I also plan on running the 280zxt ecu... I forgot to add it will be turbo, not N/A. Probably running 15 and at times 20 PSI. I'm shooting for 350ish give or take whp... I think you've got some more general research to do before you start getting into the specifics between the strengths of an f54 and an n42 block that really only come into play in the high horsepower levels Quote Link to comment Share on other sites More sharing options...
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