issue with piston

1. quickkwak07 Regular Poster Joined: Mar 2008 norwich Posts: 317 1999 vtr

   #1 14th March 2010, 13:51

   a while ago saw some je forged pistons on ebay and took a gamble and put a low bid and won them and ramdomly one piston came with out a con rod, i went to fit a standard 106 gti rod and it is a very tight fit and when it is compared to the rods that came with the piston it is a good 5-8mm wider.can any one shed any light to this or have i been had.
2. raunchz Saxperience Addict Joined: Jul 2005 Solihull / Bournemouth Posts: 14233 2015 Lapiz Blue Golf R

   #2 14th March 2010, 13:58

   Maybe put a couple of pictures up of them and both rods?
3. user_39821 Saxperience Forum Bum Joined: Dec 2009 Uckfield, East Sussex Posts: 3362 Citroen saxo 1.4 furio

   #3 14th March 2010, 14:07

   The forged rods are obviously different to standard ones at the small end, but are they different at the big end? i'd hope not
4. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

   #4 14th March 2010, 14:11

   What were they sold as?
5. quickkwak07 Regular Poster Joined: Mar 2008 norwich Posts: 317 1999 vtr

   #5 14th March 2010, 14:43

   they were sold as saxo vts forged pistons pics on way
6. raunchz Saxperience Addict Joined: Jul 2005 Solihull / Bournemouth Posts: 14233 2015 Lapiz Blue Golf R

   #6 14th March 2010, 14:43

   Pics say a thousand words
7. quickkwak07 Regular Poster Joined: Mar 2008 norwich Posts: 317 1999 vtr

   #7 14th March 2010, 14:44

   here is a picture of the standard rod
8. quickkwak07 Regular Poster Joined: Mar 2008 norwich Posts: 317 1999 vtr

   #8 14th March 2010, 14:45

   and this picture shows the rods that came with the pistons and the standard rod
   
9. quickkwak07 Regular Poster Joined: Mar 2008 norwich Posts: 317 1999 vtr

   #9 14th March 2010, 14:53

   the last picture has the standard rod on the left and you can see the difference in size
10. raunchz Saxperience Addict Joined: Jul 2005 Solihull / Bournemouth Posts: 14233 2015 Lapiz Blue Golf R

    #10 14th March 2010, 15:04

    Could be jp4 rods?
    
    The jp4 rods have an 18mm small end whereas the j4 rods have a 19.5 (19.43) small end. If possible have a measure as could be your problem?
11. quickkwak07 Regular Poster Joined: Mar 2008 norwich Posts: 317 1999 vtr

    #11 14th March 2010, 16:43

    Quote:

    Originally Posted by raunchz Could be jp4 rods? The jp4 rods have an 18mm small end whereas the j4 rods have a 19.5 (19.43) small end. If possible have a measure as could be your problem?

    i will have a measure up but im pretty sure the difference in the sizes is more than that but thanks all the same
12. raunchz Saxperience Addict Joined: Jul 2005 Solihull / Bournemouth Posts: 14233 2015 Lapiz Blue Golf R

    #12 14th March 2010, 16:52

    Quote:

    Originally Posted by quickkwak07 i will have a measure up but im pretty sure the difference in the sizes is more than that but thanks all the same

    A bigger difference than 1.5mm in small end diameters? I'm talking about gudgeon pin diameter - not the width of the small end part of the rod
    
    If so then god knows what rods/pistons you've bought. What is the piston diameter?
    
    Any part numbers on them? Might be worth posting up any part numbers/search for them/ email JE to confirm you have the right pistons
13. quickkwak07 Regular Poster Joined: Mar 2008 norwich Posts: 317 1999 vtr

    #13 14th March 2010, 20:04

    there 79mm they have got some numbers on them so will try and contact them,if not just have to fork out for some new pistons
14. Sandy309 Regular Poster Joined: Jan 2010 Cornwall Posts: 349 106 XSi

    #14 14th March 2010, 20:27

    The JE pistons I've seen for the TU 16v have been like this, a tight fit at the small end. This is bad, because clearance is needed, about 2mm minimum with a crank located rod such as this. A good engineer will be able to narrow the small ends for you, just enough to get enough clearance. If there's any side load on the rod/piston or restriction of movement, there'll be tears.
15. quickkwak07 Regular Poster Joined: Mar 2008 norwich Posts: 317 1999 vtr

    #15 14th March 2010, 20:38

    Quote:

    Originally Posted by Sandy309 The JE pistons I've seen for the TU 16v have been like this, a tight fit at the small end. This is bad, because clearance is needed, about 2mm minimum with a crank located rod such as this. A good engineer will be able to narrow the small ends for you, just enough to get enough clearance. If there's any side load on the rod/piston or restriction of movement, there'll be tears.

    i think might just take the £70 they cost on the chin as don't know enough to be messing around with things like that and i don't want to see it got pop after spending the money on it