jp or jp4

1. leighk18 Frequent Poster Joined: Nov 2009 stafford (hixon) Posts: 743 red mk1 vts

   #1 8th August 2011, 16:01

   hiya guys and as of the next few days i will be back in a saxo.
   
   im buying the girlfriends (Nixinoo) vtr off her. as my plan of a high power fiesta is costing me far to much money.
   
   the engine in the vtr is on 120k ish now so my plan is to do a 16v conversion on it.
   
   but as i have been away from saxos for a while which would be the best one to get the normal 16v engine or a jp4? either way i plan a full re-build of the engine.
   
   what would be a good spec engine with out going to mad?
   
   The car will still be daily used but plan to track it and enjoy it and spend money on suspension and tiers to get the most out of the saxos great handing and just learn how to really drive the wheels of the car.
   
   cheers guys leigh
2. wolf_gsxr Frequent Poster Joined: Jun 2010 wigan Posts: 778

   #2 8th August 2011, 17:44

   I'd use a j4 as I a jp4 is a pain with cam clearences if your gonna cam it at some point. Or have a jp4 but with j4 head internals (springs and cams) as theyr wilder than jp4 cams without tw@ting the pistons
3. leighk18 Frequent Poster Joined: Nov 2009 stafford (hixon) Posts: 743 red mk1 vts

   #3 8th August 2011, 17:53

   Hmmm I plan on camming it why its been rebuilt
4. wicked-vtr Saxperience Forum Bum Joined: Jan 2009 Surrey Posts: 2608 200sx s14a mark 1 vts

   #4 8th August 2011, 18:16

   As said, Cant run decent cams with a jp4 head without pocketed/forged pistons or some other method of getting some more room as i understand it, they dont leave much clearance at TDC with the j4 bottom end.
   
   Give us a rough budget and we'll be able to help much more
5. leighk18 Frequent Poster Joined: Nov 2009 stafford (hixon) Posts: 743 red mk1 vts

   #5 8th August 2011, 18:23

   Hmm that's a bit annoying I have just been looking at bodies.
   
   Budget wise I could have up two around 2k if I wanted to spend that much just waiting for all my fiests stuff to sell. But dnt want to go to mad with the power just a good strong fun engine.
6. wolf_gsxr Frequent Poster Joined: Jun 2010 wigan Posts: 778

   #6 8th August 2011, 20:27

   I'd deffo go j4 thinking about it. The only advantage with the jp is bigger valves but unless it's turbo'd or a fully forged monster I'd go with the stronger mOre tuneable j4
7. crabzy Established Member Joined: Jan 2010 Leyland Posts: 1998 have to find out ;)

   #7 8th August 2011, 21:31

   i been told wilder the cams you can have for jp4 is Newman ph3 irc ?
8. wolf_gsxr Frequent Poster Joined: Jun 2010 wigan Posts: 778

   #8 8th August 2011, 21:48

   You can just get them in but you need a thicker head gasket which lowers the compression which in theory will lower the power slightly. J4 is the way to go unless your getting forged pistons
9. Matt.S2 Frequent Poster Joined: Feb 2010 Redditch Posts: 672 iTB 106 Rallye

   #9 8th August 2011, 22:26

   Im currently deciding on cams as I've got bodies to go with them, and I think I've decided on the JP4 specific PH3's. These will run without any piston modification but you will need stronger valve springs. (J4 or uprated springs) Hope this helps...
10. wolf_gsxr Frequent Poster Joined: Jun 2010 wigan Posts: 778

    #10 8th August 2011, 23:09

    I'd be careful with cams as 708 cams for a jp4 are turbo spec I believe. I'd seriously go with the j4 mate. A nice thin gasket will I've good compression, bodies and ph3/708. With a good induction and system you could c 165-170 bhp. And you can use standard springs as vts/gti springs are stronger.
11. laurence Frequent Poster Joined: May 2009 south west Posts: 798 03 black vtr :) RB FF 182

    #11 8th August 2011, 23:50

    im putting my jp4 in at the weekend i think there a good idea as you can pic one up low miles and if you get one out of a 307 you not its not been ragged all its life,
    
    im putting my j4 springs and cams in my jp4 with the standard head gasket