Valve clearance Issues

[actionbstard]

Kind of in a tight spot here.I have a rb25det S1 that has ferrea standard size(oem size)Valves,converted to solid l;ifters reshimmed for 270 10.25 lift camshafts,my Cylinder head is polished to 3thousandth block is to 2thousandth.
I have wiseco 86.5 pistons bore to .0035
RB26det H beam rods
RB26det crankshaft

Now my cams and crank are aligned to specs
but when I rotate the crank with out the balance to check for valve clearance
It moves up to 10 degrees before the cams start moving as well.so I have like almost a 10 degree play.Now by the time the crank turns to 40 degrees it locks.Hits the exh valves.
Now if I retard the intake cam and advance the exh then I can almost turn half.

I don't know what size is my head gasket since I forgot.But there shouldn't be no issues with it.I think it was a 1.0 or 1.2what they send me at least.I ordered a 1.5 87mm one?
any ideas whats going on here.

[mcfly]

oh that's too bad for you

[J-Ran]

how would the crank move and the cams not move? is your timing belt on properly and tensioned? lol

[actionbstard]

yep
top dead center and cams on there mark.
Thats probably due to the fact that the damper is not installed and the key on the crank has a small play which later turns to 3 or 4 degrees.Now the tensioner is the only one after that,that can be affecting the other degrees.So 10 degrees of the mark will affect the valve clearence?I think it should kiss it not stop it...........But the cams can affect this aswell...................
Im still waiting for suguestions on my suspension set up.Even knowing what is the correct set up since its sitting at jic magic waiting to be installed.lol.Your just getting it wrong man.,lol.Sometime they're called humble and so not stupids.They don't answer because in the end of the day its just the right think to do.which actually means your just a waste of time.Just an example man.lol.I some times ask my self wtf i'm I typing.It just sounds cool to me.lol.

[JD74]

English much ?

[actionbstard]

No comprende me problemo

[Skym]

Sounds like something is wrong with cambelt setting or headgasket thickness. Not sure if tension would fix the problem.

Did you set cam gears to the marks on backingplate when fitting cambelt???

Also do pistons have valve reliefs in piston crown (top of piston)????

[actionbstard]

Thanks guys.yeap everything was to spec.The pistons are the same as oem only forged.put 86.5mm
I think its the tensioner and a incorrect headgasket.The movement on the crank and cangears say its the tensioner.The timing belt its on it marks.The high lift and duretion plus bore job really explains the valve clearence issues.But thats just me.Shims are shimed to cams specs and theres no way I'm redoing the shims for a while.
anyone knows what kind of gaskets does tomei recomend for 10.25 lift cams?I would like to get a cosworth or tomei?My money is on those to.But i have been wrong before you know........??

[JD74]

Did your machine shop also maybe 'deck' the block and head a little too much ?

You should find out what they removed, because if that is part of the problem, you may have to run a larger headgasket than you think....or scrap 1 of the 2 (head or block) and start again.

Here's another quick question: DO your cams turn freely WITHOUT the belt ? are there any LOBE clearance issues with the increased lift ?

Just a thought.
Allan

[Skym]

That could be part of the problem. In some cases the headgasket needs to be thicker to compensate for the removed metal on head, shortblock to get similar compression. Should be able to get at least 4 or so rebuilds out of a engine before thinking about replacing head, block.

As far as I know they don't list gasket thickness for so and so lift cams -

http://www.tomei-p.co.jp/_2003web-catalogue/e072_cam_RB25.html

Measure the squish area's from deck of head to valves and measure squish area's from top of pistons (piston at TDC / Top Dead Centre) to deck of shortblock. Then measure lift of valves at lowest point. Then find a headgasket thickness to run to get near to desired compression (combined squish area's in head, block + gasket thickness) and to get sufficient clearance for valves.

Best to talk to your machine shop who did the machining and get their advice, as they probably have the measured squish area's for head listed somewhere or can measure them again. They normally even all the squish area's on each cylinder in head on high hp engines by measuring each cylinder, then machining the deck of head to match the lowest cylinder (common practice with high hp V8 engines). At factory the squish area's are sometimes not even. If they are even after machining, then it should make it easier to select headgasket thickness.

Tomei list the compression to thickness of metal headgasket to piston diameter on their website -

http://www.tomei-p.co.jp/_2003web-catalogue/e105_RB25_gasket.html

[actionbstard]

Thanks guys.So it should be the Gasket.I'm pretty sure that they send me the wrong one.I talked to John my machine shop guy and he told me 3thds on the cylinder head and 2 thds on the block.they most have sended me a 1.0 head gasket plus the tensioner adds to the problem.I mean i rotated the crank with the timing belt on but with out the damper to check the clearence.I shouldhave checked the MLS thinkness before I installed it.Stupid me

[JD74]

It sounds and looks to me that the assembly is WAY over your head and you should have had an experienced builder do the work for you.

[anthony]

well better you find out now, before the engine is in, hooked up
and you turn the key, ive heard of this happening

[archaeic_bloke]

yo guys... why are all of you giving this guy flack? hes asking your advice... its not an invitation to start telling him "he doesnt know what he`s doing"..."too bad for you" etc...

come on.. get back with the spirit of owning a skyline in North America.. we are few, and proud.. and SHOULD always help each other when possible.


i know if i ever need a rebuild ill be doing it myself aswell.. and i hope when the time comes i get better responses than this.

[Kras]

I think the problem was that the OP was very hard to understand - I've read his post multiple times and still I am having a hard time comprehending it.