albertz
|
| posted on 29/11/05 at 12:41 PM |
|
|
Cylinder head skimming
I have a Toyota 4AGE engine with the cylinder head removed and the head is currently completely dismantled.
I have been advised that it is best to have the head skimmed before re-assembly to take out any slight warpage caused to the aluminium head during
dis-assembly. Is that right?
I think i can get it done locally for about £20-25, so its far from the end of the world. I was just wondering what others have done and if it is a
necessity, also what implications are there of skimming/not skimming the head. Naturally i intend to re-grind in the valves and will be fitting all
new gaskets and seals.
One other thing, with the engine in this state, is it worth stripping it completely and putting new rings and bearings in? The main problem is that i
have never heard the engine running. The bores look fine to me and i cant feel any lips or anything.
Any thoughts on the subject or advice appreciated.
|
|
|
|
|
Mark Allanson
|
| posted on 29/11/05 at 12:43 PM |
|
|
Have it skimmed now, it will cost you a small fortune and a load of grief later
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
|
|
|
David Jenkins
|
| posted on 29/11/05 at 01:05 PM |
|
|
At least take it to the machine shop and ask them if it needs skimming - they'll know how to check it, and will have the right kit.
But they may just turn around and say 'skim it' anyway!
David
|
|
|
Prez
|
| posted on 29/11/05 at 01:17 PM |
|
|
The mating surfaces of the head and block have to be flat within a prescribed tolerance. This can be checked with a known straight edge and feeler
blades. I have just had my 4AGE head skimmed for 25 quid. The guy just took off 6 thou, which is bugger all and now it looks grand! If in doubt get it
skimmed. In terms of a full engine strip down, that is also what I am on with at the moment. Guidelines would be dependent on the level of tune you
foresee for your engine. If you are not going to tune it heavily I suggest checking the condition of the bearings, running clearances etc, replacing
any defective components. For high performance applications I would reccomend replacing all the bearings with uprated units as a matter of course. As
for the bores and piston, check the piston to bore clearance at several points up the bore and compare with that specified, replace the piston rings.
If the clearance is way out then really the best course of action is a 0.5mm overbore and oversize replacement pistons. All the clearances etc can be
found in the toyota corolla haynes manual or check www.billzilla.org/carindex.htm for more info and links.
Hope this helps
Adam
|
|
|
albertz
|
| posted on 29/11/05 at 01:48 PM |
|
|
Thanks very much for the advice. Thats what i was looking for really, confirmation that is is required. Like i said £20-25 is not the end of the world
(just means less money on the wife's xmas present ). For the peace of mind i will do it.
Not yet sure about the bottom end, i am in the process of fitting GSXR throttle bodies and megasquirt ECU, other than that the performance will be
largely standard, other than the exhaust (obviously) and the air filter.
Maybe in the future the cams might be upgraded, but cant see it really.
Prez, have you got a decent supplier for replacement 4AGE bits? can you give me a link or phone number?
Thanks all for the help so far. I never fail to be impressed with the help offered on this site!
|
|
|
Prez
|
| posted on 29/11/05 at 02:52 PM |
|
|
Albertz,
I am in the process of trying to fathom out who are the best suppliers at the moment. bpj services are reasonably good, www.bpjservices.co.uk but I
have found a place in the US which has fantastically cheap prices. do a google search for import performance parts. They have all the 4age components
under the sun. Of course there is also your local motor factors etc who should be able to source all the standard parts, and give ebay a try.
For the level of tune you describe you should be fine with the standard internals, and I would guess you'd be looking at making somewhere in the
region of 130 - 135bhp with the mods you describe, depending on which 4AGE engine you have to start with. I gather there are a few other people on
this forum with these engines and more experience with them than myself.
Cheers
|
|
|
Prez
|
| posted on 29/11/05 at 03:03 PM |
|
|
Also try fensport; www.fensport.co.uk
|
|
|
rick q
|
| posted on 29/11/05 at 11:19 PM |
|
|
Wonderful little engines - and do have a close look at http://www.billzilla.org/carindex.htm - there's a heap of info on step by step upgrades
there. 175 - 195 bhp is relatively straight forward with throttle bodies, compression, cams and ECU. They also seem to take endless abuse with good
synthetic oil.
|
|
|
