JP4 Head

1. Furio-Gaz-Saxo Frequent Poster Joined: Jun 2009 Birstall, Batley Posts: 890 First Car - Saxo 1.1 Green 1997 97K Second Car -S

   #1 6th October 2012, 17:29

   What difference would I get if I change my j4 head with cams to a JP4 head with same cams.
   
   Cat cams 708's I belive I have
   
   I know they have updated springs, but just want to know about the gains people getting and if its better?
   
   Cheers
2. Ryanp Super Moderator Joined: Feb 2004 Tonbridge United Kingdom (England) Posts: 38236 Vtr, 172, throttle bodied track slut

   #2 6th October 2012, 17:37

   JP4 doesnt have uprated springs, which is why everyone uses J4 internals.
3. Furio-Gaz-Saxo Frequent Poster Joined: Jun 2009 Birstall, Batley Posts: 890 First Car - Saxo 1.1 Green 1997 97K Second Car -S

   #3 6th October 2012, 17:49

   So is there no point in changing the heads?
4. dannygti Saxperience Post Whore Joined: Feb 2006 dudley United Kingdom (England) Posts: 6790 106 gti/ SEAT LCR

   #4 6th October 2012, 17:53

   The c2 has bigger inlet valves as standard
5. Furio-Gaz-Saxo Frequent Poster Joined: Jun 2009 Birstall, Batley Posts: 890 First Car - Saxo 1.1 Green 1997 97K Second Car -S

   #5 6th October 2012, 21:47

   So is it better to use a j4 or jp4 head?
6. user_39461 Super Moderator Joined: Nov 2009 Cambridge(ish), UK. Posts: 10581 BMW 5x M50d.

   #6 6th October 2012, 23:05

   Quote:

   Originally Posted by Furio-Gaz-Saxo So is it better to use a j4 or jp4 head?

   Better for what? It's a lot of effort for fuck all gain if keeping everything else standard. Even if cammed or itb'd I'd personally doubt you'd see anything in it at all.
7. blackie_2k5 Saxperience Hardcore! Joined: Oct 2008 Birtley Posts: 22253 VTR Turbo, 106 xsi track slag, Transit recovery, B

   #7 6th October 2012, 23:10

   only really worth the fuck on if your dumping some money in tbh
8. Furio-Gaz-Saxo Frequent Poster Joined: Jun 2009 Birstall, Batley Posts: 890 First Car - Saxo 1.1 Green 1997 97K Second Car -S

   #8 6th October 2012, 23:14

   Well my car will be getting cammed and re-mapped..
   My friend just recommend to use the jp4 head and I just wanted to know if there was any reason why?
9. user_39461 Super Moderator Joined: Nov 2009 Cambridge(ish), UK. Posts: 10581 BMW 5x M50d.

   #9 6th October 2012, 23:20

   Quote:

   Originally Posted by Furio-Gaz-Saxo Well my car will be getting cammed and re-mapped.. My friend just recommend to use the jp4 head and I just wanted to know if there was any reason why?

   Probably heard "it's better"
   
   Unless you're looking for balls out, top end power, the standard j4 head is fine
   
   Jp4 may actually cost you some mid range torque.
   
   And that's before you get down the road of valve/piston clearance issues, which cams to use, head gasket etc.
10. user_32315 Saxperience Post Whore Joined: Mar 2009 Uppingham, Rutland Posts: 9569 mk1 JP4'd VTR, '16 Fabia Monte Carlo

    #10 7th October 2012, 17:26

    firstly you'd want to use 705 cams, they are 708 spec but are made for the jp4 head, as saxo cams such as 708's dont hit the follower quite right, they will fit and work but im not sure for how long though guessing you will get uneven wear on the cam lobes/followers