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[Zamani]

The QV cams are roughly US$650-750 EACH. I paid US$700 for my CB cams 3 years ago when the UK was about the same level as it is now. GTA cams are about that price for a pair. For the price of QV cams, you can get a complete 164QV engine.

BTW the cutoff CSC is perfect for me . No seriously, if you friend's mechanic says no, email me if you're up to shipping it. I'm interested. Just let me know your price.

OK gone off topic now. I have nothing to add to the heads discussion.

[mjr]

jim K,, thanks for the update on the book. It's much appreciated

[grant]

How much can I bump the compression to on a 2.5 without milling too much off that it cannot be milled again if the head gets warped? So, if the heads get milled to bring compression up to, say 9.5:1 or so, will I still NEED to be elongating the pulley holes/will I be worried if I need to mill the head again?

[bcal]

Hmm... so all things being equal, if the engine is relatively stock, eg stock cams valves etc, it's best to just clean a few of the bats out of the caves. The factory finish is a bit rough 'n' ready.

But what about boosting the CR a bit? Say to 9.5 or 10 to 1.

After careful inspection I've decided to junk the old pistons and liners (pit marks and horizontal grooves from sitting with moisture in the bores I suspect) so maybe I should invest in some higher comp pistons.

[Bruce]

Not done any head work on a 2.5 but I took 1mm off a 3 litre heads, ran it 95 RON (UK) with no sign of pinking / pinging.

[Jim K]

I fully agree. Take 1mm off and you'll end up with ~10-10.5:1 CR. You still have plenty left to mill again and again!
Zamani, did I get this right? A pair of QV cams (for one car that is) sells for ~$1500
Jim K.

[Zamani]

Yes, 1 pair of QV cams you can get a used 75 2.5 here in decent shape. $1200-$1500 a pair, for QV cams (for one car).


Bcal,

Paul Spruel sells 10:1 JE pistons, but since the Aus is close to 1.6 to US$1, maybe shaving the heads or getting something locally is more cost effective.

[bcal]

Thanks guys. yep the drop of the oz dollars has sure made importing things rather expensive...again. I should have bought more stuff when it was near parity.

Silly question No.3

So if I shave the head how do I reindex the cams?

[slyalfa]

So how do you tell how much is milled to start with?
Is there a spec for how many CC's the OEM head is?
I can not think of a good way to compare other then the chamber CC
I guess you could check the height of the whole head but if the valve cover side was milled? Or check from the center of the cam?

[bcal]

Good point.
I guess there must be a datum point from which to measure.

Re, reindexing the cams. Machinist at work says he can index (slot) the holes on the key plate slightly and then redrill and fit the locating pin in a new location.

[MR2 Zig]

I've read either here or on the BB that to index the cams you get rid of the key in the end of the cam, set crank and cam as normal (to marks), then tighten up cam pully. The pulley will stay put because of the tapered fit of the cam nose and the cam pulley (think morse taper sleeve).

Note the above is what I've read on the internet

hth
scott

[Mats]

Newer cars never have keys, only taper. Some volvos doesn't even have a taper...

[bcal]

Why did alfa go for belts and braces?
I'll stick with their wisdom. The thought of valves crashing into pistons gives me nightmares.

[Mats]

Then you need an offset key.

[ar4me]

Why did alfa go for belts and braces?
I'll stick with their wisdom. The thought of valves crashing into pistons gives me nightmares.

No key on my 3.7 Alfa 24v, but only tapered.
Jes