free hit
counters
Leak down test - Engine/Ancilliaries - The Lotus Forums Jump to content
Sign in to follow this  
robertcosta

Leak down test

Recommended Posts

I've had the engine out of the car and noticed a fair amount of oil in the air box.

So I figure I'll do a leak down test. Number 1 cylinder about 15% leak.

Numbers 2,3,4 all at 90% leak. N2-exhaust leak N3-inlet N4-Exhaust leak.It didn't seem to leak too much air out of the crank case testing any of the cylinder.

I did have the engine at TDC on the compression stroke.

The 3 and 4th spark plugs seemed to be burnt somewhat, running lean?? This might be my tuning ability :lol:

Weird, thing is that the engine seemed to be running fine when I pulled it...

I assume this is a head off to see whats what??

Rob

Edited by rlc

Robert Costa
1984 Turbo Esprit
Very Black!
2004 Lotus Elise
Quite Green! gone :-(

1977 S1 Esprit, in bits

1998 Lotus Elise S1, Azure Blue
Sydney, Australia

“The parts falling from this car are examples of the finest British craftsmanship”

Recommended procedure before taking on a repair of Lucas equipment: Check the position of the stars,kill a chicken and walk three times clockwise around your car chanting:" Oh mighty Prince of Darkness protect your unworthy servant.."

Share this post


Link to post
Share on other sites

Upgrade today to remove Google ads and support TLF.

With the engine at TDC only the valves on no1 cylinder will be fully closed! You need to crank (by hand/socket + bar) to the firing stroke of each cylinder to make sure you're testing with the valves firmly shut for each one.

Up to around 20% is considered acceptable. Your 15% on no1 is good.

Share this post


Link to post
Share on other sites

DOH!...I new I was doing something wrong! Thanks..how do you find the firing stroke of the other cylinders? Should I take the cam cover off and sight the cams?

Rob


Robert Costa
1984 Turbo Esprit
Very Black!
2004 Lotus Elise
Quite Green! gone :-(

1977 S1 Esprit, in bits

1998 Lotus Elise S1, Azure Blue
Sydney, Australia

“The parts falling from this car are examples of the finest British craftsmanship”

Recommended procedure before taking on a repair of Lucas equipment: Check the position of the stars,kill a chicken and walk three times clockwise around your car chanting:" Oh mighty Prince of Darkness protect your unworthy servant.."

Share this post


Link to post
Share on other sites

Also with each cylinder at tdc engage 1st or reverse so the motor doesn't "rock over" due to the air pressure.


DanR

Share this post


Link to post
Share on other sites

The easiest answer to your conundrum is the firing order: 1342.

When the engine is at TDC test cyl no1. Rotate the crank 90 degrees and test no 3, a further 90 degrees and test no 4, etc. If you're having issues turning the engine accurately 90 degrees then, yes popping the cam covers off to make 100% sure both inlet and exhaust valves are shut would be a good idea.

As Danny suggests it would be handy to have a glamorous assistant on stand by to chock the flywheel with a screwdriver or similar.

Share this post


Link to post
Share on other sites

The easiest answer to your conundrum is the firing order: 1342.

When the engine is at TDC test cyl no1. Rotate the crank 90 degrees and test no 3, a further 90 degrees and test no 4, etc. If you're having issues turning the engine accurately 90 degrees then, yes popping the cam covers off to make 100% sure both inlet and exhaust valves are shut would be a good idea.

As Danny suggests it would be handy to have a glamorous assistant on stand by to chock the flywheel with a screwdriver or similar.

LOL...I don't think my wife would appreciate the "glamorous assistant"! ... Thanks for the advice :(


Robert Costa
1984 Turbo Esprit
Very Black!
2004 Lotus Elise
Quite Green! gone :-(

1977 S1 Esprit, in bits

1998 Lotus Elise S1, Azure Blue
Sydney, Australia

“The parts falling from this car are examples of the finest British craftsmanship”

Recommended procedure before taking on a repair of Lucas equipment: Check the position of the stars,kill a chicken and walk three times clockwise around your car chanting:" Oh mighty Prince of Darkness protect your unworthy servant.."

Share this post


Link to post
Share on other sites

That should be 180 not 90 degrees.


DanR

Share this post


Link to post
Share on other sites

Sorry, Graham. You lose a gold star for that one. Almost as bad as using cable ties to hang an exhaust. :(


British Ambassador to Florida, New York, Denmark and Newfoundland.  And Sweden.

Share this post


Link to post
Share on other sites

yes...720 degrees /4 = 180....now that I looked it up :(


Robert Costa
1984 Turbo Esprit
Very Black!
2004 Lotus Elise
Quite Green! gone :-(

1977 S1 Esprit, in bits

1998 Lotus Elise S1, Azure Blue
Sydney, Australia

“The parts falling from this car are examples of the finest British craftsmanship”

Recommended procedure before taking on a repair of Lucas equipment: Check the position of the stars,kill a chicken and walk three times clockwise around your car chanting:" Oh mighty Prince of Darkness protect your unworthy servant.."

Share this post


Link to post
Share on other sites

Hey Graham

Standing in the cold, with oil and grease on your hands, while your hubby runs around tinkering and swearing is not any woman's idea of being a glamorous assistant!!!!!! thumbdown.gif

And I should know I have done it enough times (and not just on my car).

The EXTREMELY GLAMOROUS!!!!!!!!!

Sue kiss.gifkiss.gifkiss.gif

Share this post


Link to post
Share on other sites

It was an intelligence test. I'm pleased to say you've all passed. thumbsup.gif

Now, hand back your intelligence before you hurt yourself with it.

getmecoat.gif

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...