s14 Variable Valve Timing

Raymond James Boyd · Jan 2nd, 2006, 04:31 AM

Hello to everybody;
Im a proud owner of a 91 240sx Hicas, and am working on switching to a s14 sr20. I've viewed a few pictures of the s14, and have noticed a few things that seemed to be different which I would like to get some insight on. I believe the hump on the front of the valve cover to be part of the variable valve timing feature (which I no nothing about), however some other pict show the engine with a straight edge on the front. Im curious, are these two different types of the s14? The back of the valve cover does have the downward slant in both pictures, which I no is a good noticable difference in the s13 and s14,(blacktop of course) Can anybody help explain the difference in the two models?

Thanks
New Learner

Joel · Jan 2nd, 2006, 10:12 PM

I dont know what the straight front slope back enginer could possibly be - ive never seen anything like that before. As far as I know all SR's in the s14 and s15 DE's and DET's had the cam lump and the rear slope. I know all S13's had the straight front and non slope rear. Got any pics?

Raymond James Boyd · Jan 5th, 2006, 07:12 PM

Thanks for the help with the vvt. The info explains alot and im unable to send the picts, well im not sure how, however there was something else. Ive been told the s`14 came as a newer model and older. The older was equiped with the T25 turbo and the newer with the t28, if so im interested in the T28, and would like to know if theres a vin number or anything to be specific with when ordering my engine. If there are two different sr's I dont want to end up with the smaller turbo. Can anybody help.

Thankyou,

Joel · Jan 5th, 2006, 07:43 PM

nope, both series of s14 got the t28 although there is some speculation as to if a certain revision of the s14 got the standard journal bearing t28 as opposed to the ball bearing version. I know for sure that the australian s14 got the journal bearing version only. Ive also heard that the japanese s14 also only got the journal bearing version but im not sure.

S13 T25G turbo was not used on the s14 or s15 motors. The onyl way youd find one on there is if they blew the t28 and put the cheaper smaller t25 on instead.

S15 had the ball bearing version of the t28 with the later versions having a wastegate seperator in the exhaust housing

what is confusing is that the 180sx from 94 onwards continued to be released with the s13 version of the SR20DET with the T25G garrett turbo even though the newer s14 SR was available. It was probably due to the poularity in sales of the 180 but Nissan didnt want to re-engineer the engine bay of the 180 to house the newer SR