Zvh help

[petefrst]

Hello ive picked up a zvh engine,its on a engine stand and im replacing the cam belt,my query is this,with the old belt off and the lifters out i thought id try cranking it over by hand,but although it turns it seems really hard to do it by hand,it go's soft then hard and soft again is this normal?its a newly rebuilt 2.1 engine,any advice would be welcome thanks Pete..

[stevieturbo]

If all valves are closed, then in theory there should be little or no air to compress as the piston approaches TDC. But there will still be some there.

Are are the spark plugs also removed ?

[petefrst]

sorry should have added the spark plugs were removed too,it just seems like a lot of effort to turn it.....

[stevieturbo]

Well, assuming if it was just the main rotating assembly with no valvetrain attached and no plugs in, I would expect it to rotate smoothly throughout the entire 360deg.

The only other thing that is attached that might have some impact, is of course the gearbox. Obviously that is in neutral though so shouldnt be an issue.

So you have just bought this second hand, and never heard or seen it running ?

If so, looks like it would make a lot of sense to pull it apart to inspect.

[petefrst]

Its something im going to have to consider,the engine is new perhaps it is tight because of that?cheers Pete..

[stevieturbo]

petefrst said:

Its something im going to have to consider,the engine is new perhaps it is tight because of that?cheers Pete..

It should not rotate loose/tight/loose/tight if there is no compression taking place and no valve train attached.

It should rotate smoothly throughout and relatively easily with a socket/ratchet on the crank

[petefrst]

Hmmm its definitely hard to crank with a socket,could be some bent valves?

[GavinPearson]

It sounds like there is something really seriously wrong.

You need to strip the engine to try to figure out where all the friction is.

While the parts alone for that are not cheap, there really is no point in putting it in a car if it's as bad as I think you are making it out to be.

[stevieturbo]

petefrst said:

Hmmm its definitely hard to crank with a socket,could be some bent valves?

Valves bent or otherwise would have no impact on the engine turning over in it's present state.

Just how exactly was the engine sold to you ? for parts or repair ?

As Gavin says, doing anything other than stripping it down is a waste of time. It needs to come apart.

[petefrst]

Okay ive been on the net and had a look around and a guy with a newly rebuilt honda engine is showing exactly the same tendencies as mine and it turns out he spun a shell,lol its tough because some of the guys on PF say zvh's are like that but you cant tell me it go's from very easy and smooth to hurting your hand turning it,i did spray some wd40 in the bore's and it was a little easier to turn but then it went back to being hard and i don't think fitting a starter motor from an 1800 diesel is gonna crank it over,cheers for all your help, appreciated,Pete

[stevieturbo]

There's nothing tough about it. It should not be like that.

[petefrst]

Okay update time,the reason it turned soft and hard was because the engine was on a engine stand but i left a flywheel bolt protruding so it showed symptoms of a worn/damaged shell........tw@t but a releaved tw@t....

got to time it up now and i think that's a job for a professional......thanks again........Pete...

[Simon says]

petefrst said:

Okay update time,the reason it turned soft and hard was because the engine was on a engine stand but i left a flywheel bolt protruding so it showed symptoms of a worn/damaged shell........tw@t but a releaved tw@t....

got to time it up now and i think that's a job for a professional......thanks again........Pete...

At least your honest well done good luck with the build