Cylinder head rebuilding guides and pointers

[Pirvu Eugen]

Wrong mounted inner spring? I think!

[spink]

Was there anything 'different' about the head that may have caused that, cams etc?

Not that im currently aware of,034 sell titanium versions of these so it must be known for these to fail.

Mark have you always reused them in the past?

[spink]

Wrong mounted inner spring? I think!

Do you mean wrong type?as they are all the same.

[Mark Halligan]

Mark have you always reused them in the past?

Yes I have

Good point made about the inner spring, is it the same length as all the others in the head?

[Pirvu Eugen]

yes! they are!

[Mark Halligan]

yes! they are!

LOL I meant was it an odd spring, different from all of the others which may have caused it to bind and put pressure on the disc.

Probably didn't explain what I meant too well..

[Pirvu Eugen]

They remove the washer at 7a Exhaust probable because higher lift and more stress to the spring.

[Pirvu Eugen]

Sory! I didint understand!

[Mark Halligan]

Good point!

I wondered why my 7A head had no washers on the exhaust side.

[spink]

ok so ive just checked them all and they are identical springs

By the way ive stripped down an obscene amount of I5 20v heads(7a+3b) recently and im still yet to find one that has missing discs under any springs.

[Flat on my back]

Mine did First head i've ever stripped...do i win something?

Q. When turning a 7A head into a turbo fitment, would you fit the washers when using the 7A ex. cam?

I'm of the opinion 'yes' as it will only increase the spring preload a small fraction, in effect keeping the valve closed 'tighter'.

Could be due the the turbo and wastegate and DV all creating some strange pressure changes in the ex.

Only thoughts from a simpleton.

[Mark Halligan]

Q. When turning a 7A head into a turbo fitment, would you fit the washers when using the 7A ex. cam?

Good question

LOL @ the mystery washers, I remember an old conversation here

[Pirvu Eugen]

One teacher off me told me once that "my entire life i have to be afraid off springs and whelds" they can brake at the most inoportune time. 1 mm plus tension could mean spring or cam damage!

[s2_bo]

Just starting to put the head back together.

Didn't get very far -

Look:
IMG_4092.jpg



It would appear that the new VG's have a lip, unlike the others. So now the spring disks dont fit!!

Any one got any ideas short of pulling all the VG's back out and getting different ones pressed in.

Or is there a different disk that has a larger center hole? Maybe Titanium ones?
Any help would as always be much appreciated.

[s2_bo]

Another shot.

Edit: Word of warning Stu, we both bought the same VG's from GSF so dont have yours fitted in yet as they will just mess things up.

IMG_4093.jpg