Compression/ Bottom End Work..?

1. evans1089 Saxperience Post Whore Joined: Jun 2007 Chesterfield Posts: 8935 Ibiza Cupra 204bhp

   #1 30th May 2009, 19:52

   Hi all, when i had the vtr mapped up about a month ago i was told i had a compression problem on the bottom end, perhaps its the piston rings getting old?
   
   What are the true facts that are my disadvantages of this? As i want as much as, out of vtr as possible after spending £700 on the cams and remap.
   
   What can i do? What can i change or add?
   
   Much appreciated !
2. user_16747 Banned Joined: Jul 2007 Posts: 4328

   #2 30th May 2009, 19:58

   Low compression can be many things
   worn rings
   worn cylinder bore
   worn valve seats
   valves not closeing fully
   
   do a compression test and try and work out where the problem is.
3. evans1089 Saxperience Post Whore Joined: Jun 2007 Chesterfield Posts: 8935 Ibiza Cupra 204bhp

   #3 30th May 2009, 20:03

   Cheers mate, what bottom ends can be put underneath a vtr head? and what are the benefits?
4. user_16747 Banned Joined: Jul 2007 Posts: 4328

   #4 30th May 2009, 20:14

   Havent got a clue
   but you can normaly mix and match bits to alter compression and cylinder capacity
   things like different crank and pistons will alter things alot
   have the crank, rods and pistons dynamicaly balancd
   this will help it rev smoother and sometimes allow a higher rev limit.
   Couple it with a lightend balancd flywheel and crank pulley and you will get a very fast hard revving engine.
   The lighter the items attachd to the crank the better!
5. evans1089 Saxperience Post Whore Joined: Jun 2007 Chesterfield Posts: 8935 Ibiza Cupra 204bhp

   #5 30th May 2009, 20:18

   Quote:

   Originally Posted by swampy Havent got a clue but you can normaly mix and match bits to alter compression and cylinder capacity things like different crank and pistons will alter things alot have the crank, rods and pistons dynamicaly balancd this will help it rev smoother and sometimes allow a higher rev limit. Couple it with a lightend balancd flywheel and crank pulley and you will get a very fast hard revving engine. The lighter the items attachd to the crank the better!

   Great info mate thanks, i'll get onto it now
6. ldavies Saxperience Forum Bum Joined: Mar 2008 Driving my GTI Posts: 2659 Boosted 106 GTI 16V Supercharged

   #6 30th May 2009, 21:07

   different topic but whats the saxo like since you had it re mapped.
7. evans1089 Saxperience Post Whore Joined: Jun 2007 Chesterfield Posts: 8935 Ibiza Cupra 204bhp

   #7 31st May 2009, 11:06

   Quote:

   Originally Posted by ldavies different topic but whats the saxo like since you had it re mapped.

   pulls alot stronger and quicker from 4000+
8. user_15516 Saxperience Post Whore Joined: Apr 2007 Posts: 6640 Integra DC5R & VTS

   #8 31st May 2009, 11:11

   I don't think you have problems with compression - get it compression tested if you're unsure.
   
   You're running a raised rev limit with the PH3 right? You know you need uprated valve springs and caps to do that? Otherwise it will suffer from valve float and lower performance.
9. williamsvts Saxperience Post Whore Joined: Feb 2006 northumberland Posts: 7693 pulsar gtir, mk4 astra sxi

   #9 31st May 2009, 15:42

   a leak-down test would be better imo when trying to fault find.
10. spiderxjz82 Infrequent Poster Joined: May 2008 Northampton Posts: 193 VX220 S/C

    #10 31st May 2009, 16:04

    Quote:

    Originally Posted by LeeumH You're running a raised rev limit with the PH3 right? You know you need uprated valve springs and caps to do that? Otherwise it will suffer from valve float and lower performance.

    He speaks the truth! I had to alter the head quite a bit with my PH3 cams.