32 replies to this topic

[Jellevandok]

I bought a new engine a while ago but I'm having a lot of problems. Now on the rolling road it turns out it's running as much on oil as it does on fuel so I'll have to take the engine apart. I already had the cylinder head redone, so that is not the problem. It seems that the problem is originated by the pistons and the hones. It's almost as if there are no oil rings in it. Can you turn these up side down? The piston is a Powermax 20659 std BLD. Does anyone know what the BLD stands for?

I'm having the hones measured to find out what went wrong here. In stead of buying a new ready to use engine, I'm taking apart the hole thing to the pistons and what not. Not a great start of a almost finished project.

I attached some photo's from when I took the cylinder head of two weeks ago. Maybe someone with experience can tell something about them.

Jelle (NL)

Attached Files

•  CIMG2952.JPG   52.75K   25 downloads
•  CIMG2946.JPG   58.36K   39 downloads
•  CIMG2941.JPG   49.92K   22 downloads
•  CIMG2942.JPG   48.2K   25 downloads

Edited by Jellevandok, 06 July 2012 - 04:02 PM.

[Jellevandok]

Difficult with shadows but can you tell anything about the clearance between the piston and the wall? (Don't look at the gasket, was the wrong one)

Attached Files

•  CIMG2947.JPG   52.55K   19 downloads

[Artful Dodger]

all i can say is get the pistons out and have a look at the rings, they should be in the right order, (oil scraper at the bottom, then the two compression rings) and the gaps should be at 30 degrees to each other when installing. ( so when looking at the piston from a birds eye view the gaps in the piston rings look like an aircraft propeller)

if thay are all in order id look at the bore walls to see if they were honed properly and have not glazed over. get them pistons out and get some pictures up :)

[Jellevandok]

Is it possible to have the oil scraper up side down?

I know, the only way to tell is by taking it apart. Hopefully I'll have it done by Sunday.

[Artful Dodger]

Not too sure if there is A top and bottom to it.

But when removing the pistons, pay attention to where the gaps in the piston rings are, that could be the problem:)

[Jellevandok]

Not too sure if there is A top and bottom to it.

But when removing the pistons, pay attention to where the gaps in the piston rings are, that could be the problem:)

Tnx. Will do

[ANON]

what makes you say it's burning loads of oil?

[Guess-Works.com]

They are std 73.5mm pistons ( 1380 )

Did you run a compression test before pulling the engine apart ? did you also check to see if the compression changed with a little oil down the bores..

[Sheikh Pip]

Before you go too far!

Are you 100% sure the valves, guides and seals are OK, it's worth having another look just to check, I'd also have a careful look at the head gasket, especially around the oil gallery passages.

Also if the heads had porting work done to it, it's worth checking they've not gone too close to the pushrod holes with the inlet ports, this can then suck oil into the engine.....

[Jellevandok]

When I got the engine (new) it started with an leaking head gasket as the cylinder head studs were not set with torque correctly. I should have checked it before starting but in the end the manufacturer didn't deliver a ready to use product. Better to be safe than sorry I've taken the cylinder head to a well know tuner here in Holland. He discovered some flaws that he repaired. So the cylinder head is as good as 100% good. All the parts on the cylinder head are new...

I've taken apart the engine as far as the cylinder head and I've filmed how much I can move the pistons in the cylinder.

Any opinions on this? I think they move way to much but I'll have to get it measured and checked by a specialist.

[Jellevandok]

Anyone who has a opinion on the youtube movie?

[Andrew O]

I am no means an expert on engines in any sort of way so take this with a pinch of salt.

But when I had the head of my 998 (57000 miles) the pistons had no where near that much play in them.
So I'm guessing that's not good.

Andrew.

[Artful Dodger]

im sure i posted on this about the gap...

anyways, i wouldnt be too concerned about that gap, maybe it is slightly big. you said its a new engine, if it was rebored and honed any reputable engine machinist would have made sure its within tolerances. as long as there is resistance when moving piston side to side in the bore ( from the rings) the gap is sealed and there shouldnt be any problem. must be within the rings themselves or the head.

[Jellevandok]

The rings, the head or the bore... Anyhow I'm fckd. This not a great start when you've bought a new engine... I should be on a track the 21st. Now I hope to solve this matter asap. Let's hope that the one who's sold it to me will help me out in the right way if it turns out there is something wrong with one of the three.

[ACDodd]

Nothing wrong with that movement. The most likely cause of oil consumption on a new engine is usually bore wash, running too rich a fuel mix while running in. The cure is to re-ring the engine, after having the bores measured (to see if this is actually possible) and then re-honed. This is actually very common in the UK. Owners do not verify the fuel settings before running in and ruin a new engine. I would say that 40% or so of the engines I see at MLMotorsport when they are brought in for a diagnostic have a related fueling problem.

AC