S13 rb20 to rb25 swap - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

rb20 Sil40sx · 07-06-2010, 12:21 AM

Ok so I have a 91 hatch with a s13 Silvia front end, I have a rb20det (1993) engine started over heating and it blew the freeze plug and now my engine isn't worth fixing so I'm thinking about upgraded to the rb25det and I was wondering about where to buy the new motor from and will it drop straight in or will I need to do some mods? Currently my motor hits the hood so I think it has a skyline crossmember... I wanna use the rb20 tranny that I have now, thanks for the help

91drftr · 07-06-2010, 01:09 AM

yes the motor will jus
t drop in no problem and u can also use ur 20 tranny with the starter....no mods needed the motor sits the same as the 20 pretty much
just take the motor mount brackets and monts from ur 20 and put them on ur 25 and that should be it

if u dont want that motor to hit ur hood replace the intake manifold cus i bulieve thats the only thing that hits ... actually its the intake pipe that runs over the motor but either wayreplace the mani

rb20 Sil40sx · 07-06-2010, 08:17 PM

It's actually the front of the motor that hits the hood but thanks alot! Yea I plan on using my rb20 tranny any idea how long it will hold?

07-06-2010, 12:21 AM	#1
rb20 Sil40sx Join Date: Jun 2010 Location: Northern Cali Age: 33 Posts: 2 Trader Rating: (0) Feedback Score: 0 reviews	S13 rb20 to rb25 swap Ok so I have a 91 hatch with a s13 Silvia front end, I have a rb20det (1993) engine started over heating and it blew the freeze plug and now my engine isn't worth fixing so I'm thinking about upgraded to the rb25det and I was wondering about where to buy the new motor from and will it drop straight in or will I need to do some mods? Currently my motor hits the hood so I think it has a skyline crossmember... I wanna use the rb20 tranny that I have now, thanks for the help

07-06-2010, 01:09 AM	#2
91drftr Zilvia Junkie Join Date: Oct 2006 Location: L.A 323 Age: 40 Posts: 588 Trader Rating: (15) Feedback Score: 15 reviews	yes the motor will jus t drop in no problem and u can also use ur 20 tranny with the starter....no mods needed the motor sits the same as the 20 pretty much just take the motor mount brackets and monts from ur 20 and put them on ur 25 and that should be it if u dont want that motor to hit ur hood replace the intake manifold cus i bulieve thats the only thing that hits ... actually its the intake pipe that runs over the motor but either wayreplace the mani

07-06-2010, 08:17 PM	#3
rb20 Sil40sx Join Date: Jun 2010 Location: Northern Cali Age: 33 Posts: 2 Trader Rating: (0) Feedback Score: 0 reviews	It's actually the front of the motor that hits the hood but thanks alot! Yea I plan on using my rb20 tranny any idea how long it will hold?