Well nearly,

 

Not sure how but I think the left hand cam block has warped or damaged.

 

Reassembled the block for the third time and when everything is torqued up the cams cease and can barely move.

 

Now I know when times they are under pressure pushing on the lifters and springs but its so tight its ridiculous.

 

The cam brackets are all in the correct order and its properly lubricated and the torque settings i'm getting from the manual.

 

Looks like i'm gonna need two new top cylinder blocks.

 

 

Now the question is -

 

My zed is a series 4 and the top plenum along with the lower plenum are slightly different.

 

Does that go for the blocks too ?

 

 

Anyone got a known workings set they can sell; fully working with cams, lifters and valves ?

Heads are different casting I recall. Go by the 'P' number on the back of the head.

48P yes?

Is it both cams on the left bank? Try fitting your cams without the cam followers in place. That will indicate if its a cam bearing pinching the cam without the load of the valve springs. If your head is warped or not correctly torqued down it will cause the cams to pinch. You sure all your bearing caps are fitted in correct order and facing the right way? Are these the original cams to the head?

I've got 3 tt engines all with blown cylinder heads .

And one fully working n/a if They can be any use to you

The outer one is stiff but I can move it easily enough with a wrench.

 

The inner one takes a fair force to move at all.

 

Removing the lifters I can turn it over but again its stiff and can barely move by hand.

 

Somethings not right and I've stripped and rebuilt it 4 or 5 times now.

 

 

 

Is it both cams on the left bank? Try fitting your cams without the cam followers in place. That will indicate if its a cam bearing pinching the cam without the load of the valve springs. If your head is warped or not correctly torqued down it will cause the cams to pinch. You sure all your bearing caps are fitted in correct order and facing the right way? Are these the original cams to the head?

What year are they ?

 

Newer model the better but i'll take one off you hands.

 

I'll have to split the block at your place as no way to move it down here.

 

PM me a price buddy and i'll see about coming up at the weekend if I can.

 

Cheers Sandy

 

I've got 3 tt engines all with blown cylinder heads .

And one fully working n/a if They can be any use to you

I know you answered this sort of but to clarify, the cam caps are numbered and are designated I or E for exhaust and inlet, these are definitely as they came off? did not mixed up yes / no .

 

Sure you got it right but got to ask, cannot see anything else could cause the issue, twisted head ?? how or why?

 

Jeff

 

- - - Updated - - -

Yes all numbered and in the correct order, they were carefully placed in tubs before and after each disassembly.

 

The right hand bank [passenger side] is freely moving and is fine and the the left side only moves freely without the bolts being torqued down.

 

Soon as it is torqued down then its extremely tight.

 

Done this with and without the lifters installed so nothing below is obstructing theme from moving properly.

 

 

 

I know you answered this sort of but to clarify, the cam caps are numbered and are designated I or E for exhaust and inlet, these are definitely as they came off? did not mixed up yes / no .

 

Sure you got it right but got to ask, cannot see anything else could cause the issue, twisted head ?? how or why?

 

Jeff

 

- - - Updated - - -

Yes all numbered and in the correct order, they were carefully placed in tubs before and after each disassembly.

 

The right hand bank [passenger side] is freely moving and is fine and the the left side only moves freely without the bolts being torqued down.

 

Soon as it is torqued down then its extremely tight.

 

Done this with and without the lifters installed so nothing below is obstructing theme from moving properly.

 

 

For future reference the passenger side is left bank. Do both cams go tight when bolted down or just 1?

Dont try and turn the cam if it doesnt want to. You will mess up the bearings. Maybe the cams are bent? How were they stored? How long etc? I had this issue once on EJ255 Impreza engine. That was due to a warped head.....

Inner is extremely tight, outer I can move with a bit of help from a wrench.

 

For future reference the passenger side is left bank. Do both cams go tight when bolted down or just 1?

Were heads removed from the block?

Yip,

 

Whole thing was stripped down, new baring's, seals, piston rings.

 

With the heads off I can move the crank and pistons move fairly easily so its nothing below that's the issue.

Yes all numbered and in the correct order, they were carefully placed in tubs before and after each disassembly.

 

The right hand bank [passenger side] is freely moving and is fine and the the left side only moves freely without the bolts being torqued down.

 

Soon as it is torqued down then its extremely tight.

 

Done this with and without the lifters installed so nothing below is obstructing theme from moving properly.

 

Well I do not know, you have done it correctly, what was the back story to the engine needing the strip down? as in did it have problems in that areas?

Was the head 100% torqued down correctly? And u say the cams are tight even with followers removed?

Yes torqued to specification noted in the manual I have.

 

followers ?

 

Do you mean the cylinders the cams push down, ie lifters ?

 

Yes, I removed them and fitted the cams back and torqued them down again and they are just as stiff.

 

 

 

Was the head 100% torqued down correctly? And u say the cams are tight even with followers removed?

What torque did you tighten the caps to? Try backing off one cap at a time and see if you find the one causing the cam to go tight.

take off the caps and inspect the cam bearings and the caps and see if you can see any scoring that will give you a clue as to where it's pinching

 

Have you had the heads checked for straightness by a machine shop? If the heads check out as straight, then you could have the cam journals line bored to regain correct fitment

Done exactly this and found i5 to be the culprit.

 

After I tighten i5 the cam locks up. :(

 

There is a score on the cap so its somehow got damaged.

 

Spoke to Jimmer also to diagnose the issue (thanks).

 

Just need to try and fix this cap or somehow get it replaced.

 

take off the caps and inspect the cam bearings and the caps and see if you can see any scoring that will give you a clue as to where it's pinching

 

Have you had the heads checked for straightness by a machine shop? If the heads check out as straight, then you could have the cam journals line bored to regain correct fitment

Take the head to a machine shop with the camshaft. They'll be able to check the bore on the journal and if there's any eccentricity or throw out in the camshaft itself.

 

You sure a valve spring or retainer isnt sat correctly and fouling inside its bucket. Maybe an excessive spring height issue?

 

As long as it's not a bad score, they should be able to hone it out to give you your clearance.

 

- - - Updated - - -

 

Infact, I take back that spring height remark, it should only sit as high as the valve stem when the valve is fully shut

Few more hours on the engine yesterday and its def gubbed :(

 

Removed all the lifters and slowly torqued the caps one at a time in a slightly different order and

I have managed to get them free enough on one side and smooth turning by hand.

 

But disaster struck on the right cylinder after a bolt snapped in the head when trying to remove it.

 

I don't 100% trust these heads now as issues with the caps and now a busted bolt.

 

So after another full set and hopefully SandyZ can assist me with his spares.

take off the caps and inspect the cam bearings and the caps and see if you can see any scoring that will give you a clue as to where it's pinching

 

Have you had the heads checked for straightness by a machine shop? If the heads check out as straight, then you could have the cam journals line bored to regain correct fitment

Not possible without an original Nissan head jig to ensure correct alignment of boring tool. Once cam bearings are damaged, the heads are totally useless and will need to be replaced.

Few more hours on the engine yesterday and its def gubbed :(

 

Removed all the lifters and slowly torqued the caps one at a time in a slightly different order and

I have managed to get them free enough on one side and smooth turning by hand.

 

But disaster struck on the right cylinder after a bolt snapped in the head when trying to remove it.

 

I don't 100% trust these heads now as issues with the caps and now a busted bolt.

 

So after another full set and hopefully SandyZ can assist me with his spares.

No problem got 3 full engines here you to hopefully get going again.

Wasn't this a perfectly good engine before you stripped it?:confused:

Bottom end is perfect, I have an issue with a snapped bolt on the upper right cam head.

 

And for some reason the last two caps when torqued jam up the cam shaft.

 

Unfortunate chain of events and moving of the parts from the work yard to my house a few things got mixed up.

Wasn't this a perfectly good engine before you stripped it?:confused: