Ive been doing a little prep work on my 95 engine and in the process noticed the S1 lower plenum ill be using has holes where the S2 plenum has square cut outs. Not only that but the S1 holes are sketchy as.. look.. should i just gut the lot like the S2 version? even though the S2 version has that ledge where the hole would be, and the S1 is a straight hole.
So your saying if i use a S1 lower plenum on S2 heads ill have a port mismatch ? Grindable without touching heads?
You have to match series 1/2 heads to series 1/2 lower plenum. Why aren't you using the complete 1995 motor?
Many thanks guys. Looks like i'm going to have to find some S2 injectors and a rail, can still use the upper plenum with some grinding tho right?
When i purchased it from Martin it was missing the upper plenum. I had already set myself up for an S1 build before i realized my block was cactus
NO if you are going down that route ........... the fuel rail matches the lower plenum . you use series 1 fuel rail on series 1 lower plenum . options are series 1 injectors or series 2 injectors with adaptors or series 2 injectors with 300 degree fuel rail then you do your attempted port matching with series 1 plenum to series 2 heads (which I don't recommend) gaskets barely seal I've run series 2 fuel rail in series 1 plenum ..doesn't sit properly , have to run both series 1 and 2 insulators and its dangerous . .
Use your series 1 heads/plenum/fuel rail and the block from the 1995, sell the series 2 heads. Or sell the series 1 heads and use the money to buy a series 2 lower plenum and fuel rail.
Well ive got 3 engines the 89 with less than 100 tho on the clock(true) with a rusted bore but everything else on it is mint. I have the 91 out of the slicktop i just purchased which has a valve problem on cylinder 4, hopefully just a lifter. and the 95. I just want to get the slick running for the moment with the least headaches. Taking the cam covers off the 91 to have a look tomorrow.
Just a bit of info: RB25DET lower insulators will seat a S2 rail into S1 heads quite nicely (if you want S2 injectors on a S1 engine). Will sit up slightly higher that stock but not much higher at all vs 300 degree rails... But, as black beast said, you cant (well shouldnt) use the S1 lower plenum on S2 heads as they may not seal. As i understasnd it, you have a S2 lower plenum but no S2 upper plenum. Just port/gasket match the lower S2 and upper S1 plenum then get a S2 fuel rail and injectors.
Sorry confused, you still planning on using the S1 lower plenum on the S2 heads? The S1 lower plenum (if using with S1 heads), clean up the holes and thats about it really. I might have missed something tho, you do have a S2 lower plenum also yeah? *edit* Oh wait, i just saw the text under the photos and was confused by the quote below: Guessing that was "missing the lower plenum"? In short, shouldnt use the S1 lower plenum on the S2 heads at all (even though it has been done but it is a shitty compromise) Buy this if ur using the S2 engine: http://www.ebay.com.au/itm/NISSAN-3...hicles_CarParts_SM&hash=item1c3848fa47&_uhb=1
After the advice from rob, Beast and yourself i am absolutely NOT using a S1 LOWER plenum on S2 heads. I do own a S2 lower plenum, just need to pay for it For now ive started taking apart the 91, and ive found i can push the 2 lifters on the exhaust down with my fingers freely (cylinder 4) Im no mechanic but im guessing i shouldnt be able to do that... Why would both go at once??
The lifters can fail. Generally due to build-ups of gunk. As the engine has been sitting soo long, it is possible those two particular lifters may just be dry/drained of oil. U can either pull all of your lifters out, disassemble them, clean them and reassemble or just start the engine up and hope they pump back up. Running a bit of diesel oil will help with some gentle cleansing. Cleaning guide below: http://www.gtrpwr.com/showpost.php?p=9630&postcount=2
