View unanswered posts | View active topics It is currently June 6th, 2020, 4:55 pm



Reply to topic  [ 429 posts ]  Go to page Previous  1 ... 38, 39, 40, 41, 42, 43  Next
 1955 Traction Avant 11cv 
Author Message
Firing on two.
User avatar

Joined: December 17th, 2012, 10:03 pm
Posts: 966
Location: Luscan, Pyrenees, FRANCE
Post Re: 1955 Traction Avant 11cv
So I have done the compression test working from left to right 1, 2, 3, 4

Published ratio is 6.2/1 and compression circa 7.7bar or 111 psi with flat top pistons (I have domed pistons so this should lift the ratio slightly)

Cylinder 1 - 8.8 bar (127.6psi)
Cylinder 2 - 9.2 bar (133.4psi)
Cylinder 3 - 9.0 bar (130.5psi)
Cylinder 4 - 8.0 bar (116.0psi)

So I am a bit low on number 4 - why could this be.

I am super worried about the seal on the base of the cylinder sleeve, not that I have done it wrong, just because I have never done this before. But then that should not have an effect on the compression. Maybe the piston rings are lined up with the gaps?? Just guessing here so any advice would be appreciated.

Otherwise the figures seem OK to me.


March 24th, 2015, 2:04 pm
Profile WWW
Firing on two.
User avatar

Joined: March 5th, 2009, 6:23 pm
Posts: 1853
Location: Near Monmouth
Post Re: 1955 Traction Avant 11cv
Does the engine need "Running In"?


March 24th, 2015, 2:22 pm
Profile
Firing on two.
User avatar

Joined: December 17th, 2012, 10:03 pm
Posts: 966
Location: Luscan, Pyrenees, FRANCE
Post Re: 1955 Traction Avant 11cv
Yes, it will do - done 100km so far.

I am just paranoid - I have ordered a CO2 detector to check any combustable gases in the coolant and also a leak down tester :(


March 24th, 2015, 2:33 pm
Profile WWW
Firing on two.
User avatar

Joined: June 19th, 2010, 8:40 pm
Posts: 761
Location: Kingswood, S.Glos.
Post Re: 1955 Traction Avant 11cv
Could be a slightly leaking valve on no.4. Did you lap the valves in?

_________________
John Jordan

It is a truth universally acknowledged, that a single man in possession of a good fortune must be in want of a d'olly.


March 24th, 2015, 3:30 pm
Profile
Firing on two.
User avatar

Joined: December 17th, 2012, 10:03 pm
Posts: 966
Location: Luscan, Pyrenees, FRANCE
Post Re: 1955 Traction Avant 11cv
New valves and valve seats done by the machine shop - I would hope they would have done that but no I did not do it as they were fitted when I got the head back.


March 24th, 2015, 3:57 pm
Profile WWW
Firing on two.

Joined: February 21st, 2012, 9:01 pm
Posts: 1136
Location: Avranches, Sud Manche, France
Post Re: 1955 Traction Avant 11cv
Must admit that I always checked the heads I did on racing Mini's and the Dyane by turning the head upside down and filling the valve area with WD40 leaving over night and checking the next day by looking into the exhaust/inlet port for WD40


March 24th, 2015, 9:10 pm
Profile
Firing on two.

Joined: December 6th, 2013, 9:55 pm
Posts: 115
Post Re: 1955 Traction Avant 11cv
You got a point there ChrisW
WD40 is very thin and is a good valve seal checker.


March 24th, 2015, 11:50 pm
Profile
Firing on 1-2 Spark
User avatar

Joined: November 8th, 2009, 5:42 pm
Posts: 2802
Location: NL
Post Re: 1955 Traction Avant 11cv
I wouldn't worry much... It needs to run in and also the numbers you mentioned are higher then original, so nothing to worry about... as long as there is no coolant in the oil of the engine everything is fine.. Let it use some water.... they always did and always will do.. Your talking about a 60/65 years old engine (still) and no 2015 hightec magic piece of shit....

:lol: :lol: :lol: :lol: :lol:

_________________
Russell wrote:
Hi Geo,
you've been one of the sites biggest attractions in recent years.
Russ


March 24th, 2015, 11:59 pm
Profile WWW
Agony Aunt - You have a car problem? Speak to Ken

Joined: March 6th, 2009, 1:40 am
Posts: 3675
Post Re: 1955 Traction Avant 11cv
Vasil,
diesel fuel is cheaper, also seems to be of similar viscosity to WD40... ;)

@ Chris, did you check the valve clearances prior to the compression test?
Whenever I've rebuilt an engine, I usually do the 'initial break-in' runs plus some more mileage, then check and adjust the clearances before a compression test

_________________
Image


March 25th, 2015, 12:41 am
Profile
Firing on two.
User avatar

Joined: December 17th, 2012, 10:03 pm
Posts: 966
Location: Luscan, Pyrenees, FRANCE
Post Re: 1955 Traction Avant 11cv
Just a quick compression test first.

I will take off the rocker cover and re-tighten the head bolts (loosen and torque back up) and I will also re-adjust the valve clearances now it has run a while.

As I mentioned - I am just being paranoid as it is my first full engine rebuild.


March 25th, 2015, 8:55 am
Profile WWW
Display posts from previous:  Sort by  
Reply to topic   [ 429 posts ]  Go to page Previous  1 ... 38, 39, 40, 41, 42, 43  Next

Who is online

Users browsing this forum: No registered users and 30 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group.
Designed by STSoftware for PTF.