Jump to content


Photo
- - - - -

Compression Test 850Cc Engine


  • Please log in to reply
5 replies to this topic

#1 gazza82

gazza82

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 2,917 posts
  • Location: Bucks
  • Local Club: TMF+

Posted 06 November 2019 - 12:45 PM

What would be a good reading or it is more they should all be roughly equal?

 

TIA



#2 slidehammer

slidehammer

    One Carb Or Two?

  • Members
  • PipPipPipPipPipPipPip
  • 1,081 posts
  • Location: Surrey
  • Local Club: LSMOC

Posted 06 November 2019 - 01:21 PM

My compression tester shows 100 - 140psi as green. I think if you are around 90psi that would be ok. They need to be roughly equal.



#3 unburntfuelinthemorning

unburntfuelinthemorning

    Camshaft & Stage Two Head

  • TMF+ Member
  • PipPipPipPipPipPipPipPip
  • 1,915 posts
  • Location: Bedfordshire

Posted 06 November 2019 - 01:48 PM

Yes roughly equal.  I'd like to see more like 150 psi.  Test with throttle wide open and with engine warm if possible.


Edited by unburntfuelinthemorning, 06 November 2019 - 01:49 PM.


#4 gazza82

gazza82

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 2,917 posts
  • Location: Bucks
  • Local Club: TMF+

Posted 06 November 2019 - 02:05 PM

115 and fairly close across all cylinders (not my engine).

It's a low compression unit from a late A35 van!

#5 nicklouse

nicklouse

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 17,944 posts
  • Location: Not Yorkshire
  • Local Club: Anonyme Miniholiker

Posted 06 November 2019 - 02:11 PM

again it depends on many this the first is how you do the test. plugs out. throttle open. check and write down reading front to back and then back to front. and average. this is to compensate for battery drain.



#6 gazza82

gazza82

    Up Into Fourth

  • Members
  • PipPipPipPipPipPipPipPipPip
  • 2,917 posts
  • Location: Bucks
  • Local Club: TMF+

Posted 06 November 2019 - 02:15 PM

Thanks gents .. your pearls of wisdom will be passed onto the owner ... I know he didn't do the first attempt with the throttle open wide .. but it was with no plugs. I've seen all four as he was looking for comments on those too! 

 

His engine is using oil but from the comments he's left .. sounds like most is keeping the underside rust free! :D






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users