Head Job

[TimD]

No thanks fellas im fine......
Seriously tho, finally got around to doing the head ont he TE. The ppl i got it off didnt have a clue what was wrong with it, had no power, over heating etc.....they invested in new radiator, inlet mani' etc.....everything but fixing where the problem was......blown head gasket. Between the 2nd and 3rd cylinder blown out completely. Besides that everything looked mint, oil clean, not too much oil/water mix. Decided to strip the whole shit show down and degrease while it was off. Stripped down the rocker assembly thought id replace stem seals while i was there. The 2nd and 3rd exhuast valves were totally fucked. No wonder it had no power. Replaced these. Do you think after damage like this i would HAVE to get the head shaved? I tested it with a rule, and over those suspect 2nd n 3rd cylinders it is only slightly warped. I seems so easy to just bolt the prick back on, after considering what ive explained, should i get it shaved? In the gregorys manual it specifies a minimum of .20mm warp before getting shaved. .2mm is fuck all, could i get away with more than .2?
I just dont want to bolt it back on and blow another gasket when i could have got it shaved for 50 bucks.
Cheers.....Tim

[TXcoupe]

when you blow a head gasket and it "pings" yes you would and in this case i would definitely shave the head.

[Ben Wight]

Get a couple of mm shaved off it you tight ass.

[TimD]

At 17 with a TE im looking to get redg asap and needs a lot of work, fuck oath im a tight ass so save yourself

[Ben Wight]

If your gasket blew the first time, then what makes you think it wont happen again? I would personally get it shaved to be sure, and why you are there, ask for an extra 2mm to be taken oof to give your engine some more compression and hence more grunt.

$50 is very cheap for the extra power more compression will make, especially such a rise from 8.3:1 to around 9:1.

Ben Wight

[TimD]

Thanks for the genuine reply Ben.....
By taking 2mm extra off, will i then have to watch how much room ill have left before the valve hits the pistons. Or is it a straight cut procedure, get it shaved, bolt it on type thing,
cheers.....Tim

[TXcoupe]

well i wouldnt take that much off if you 17 and on your P's
i would just take 20 thou off and clean it up to get rwc.

then save up and get a reground cam even more grunt but take it easy no one likes to see P platers wrapped around trees.

[TimD]

Therell be no crashes involved mate
Can you outline the the benefits of getting an extra say 1 or 2mm shaved off? If 2 is too much, how would 1mm go
cheers

[TXcoupe]

well basically 1mm still increase compression ratio but allows you more room incase you blow another head gasket (if the head hasnt already been shaved) buit as ben has stated its all about comp ratio

[Ben Wight]

I've usually found a fairly original head can have about 3-4mm of machining done, before they are down to the valve seats. Most heads buy now will probably be shaved 1mm, with the average skim to straighten them up being about 10-20thou, which is 0.25-0.5mm, but it depends how bowed they are, or how corroded. I have had more heads shaved because of the need to weld up the water jackets than because the head was warped.

It would be a fairly safe bet that around 2mm with a standard cam wont make the valves kiss the pistons, if you want, go 1.5mm. The extra compression might give a 10% power increase, and shouldn't need to be countered by retarded ignition timing becasue gems run so little compression to start with relative to what is capable with the octane rating of todays premium unleaded fuels.

Ben Wight

[TimD]

Cheers for the informative reply Ben, you outlined basically everything i wanted to know
cheers!......Tim