[Mk2] [Turbo] where is the coolant entering the combustion chamber?

[gazrev1tubby]

The missing on wot could be a faulty coil, have you removed it to see if there are any cracks in the casing ? Aslo, when was the dizzy cap and rotor arm last replaced ?

[mr2tinker]

I bought my cometic headgasket\s from real street performance in the usa, and they only list one for all revisions. Afaik, they are all the same

That looks like a score on the cylinder wall to me, did you have a problem when fitting the rings ? Did you use a ring grinder and set the gaps correctly ?
Either that, or a bit of swarf may have been stuck somewhere.

A compression test would give good results, even with a scored cylinder wall. As you crank the engine, oil gets squirted up which would seal it. Even a leakdown test may not pick it up as it's done at tdc, so if that score is below tdc - it won't affect compression

Regarding the loss of coolant, where does your header tank overflow route to ? Could it have been overflowing under pressure where the stat was stuck closed ?

If the head gasket pictured has only been used once, then i'm shocked at the condition of it. It looks battered !

yes i had a problem fitting the rings, i had to gap the top one 0.3 and the bottom 0.4 (nitrous spec) iirc. i believe my mechanic must have been over generous with the hone.
i used a bit of wet and dry wrapped round a piece of wood and trapped in a vice to do the gaps.

i took my time and just did the best i could. do you think this could have caused this score and do you think this score will cause problems in the future?

the header tank overflow is tucked behind the fuse/relay box as stock (i was not aware ppl modded this), the stat is fine i tested it. my exhaust had evidence of antifreeze on it i think the coolant system was being pressurised by gasket failure and blowing out fluid under boost.

the hg has only been used once and for 1500 miles! i was shocked at how bad it looked too, the circumferences around the bores are so out of shape.

[mr2tinker]

oh ignition system is all new

when i pressure tested the coolant system you could see water in the pot. when started after pressure test it would miss badly until it kicked it all out then it would only miss under acceleration

[gazrev1tubby]

If that is a score in the block, then you need to get another one

It's still seems to be a bit of a mystery where the coolant was going ?

[mr2tinker]

why, the compression is perfect?

[gazrev1tubby]

Because it will burn oil, mine done it.

[planted1]

Not all the revision headgaskets are the same,
i had a rev 1 and a cometic rev 3 side by side and they were different.
Skywalker has me worried now,because my triple layer cometic was split apart, remachined and re-rivetted,so that it matched the head with the block.

i had an old NA that would lose coolant when on the move
and stop when i stopped.

[mr2tinker]

well luke, andy at momentum, and many others say the rev3 metal one is good for all revisions. i totally trust them and will get a Toyota rev3 one this time. will also have head skimmed and get my little camera inside to inspect for cracks as pressure testing is expensive round here. maybe arps are a good idea too. i think i will have to live with the score in block, she is old enough to not worry about emissions on mot and if she uses oil there are products (forte) and oils (titan i think) to remedy this. a new block, bored out for those forged pistons, flushed and decked will be out of question financially.

[Slarty]

If that is a crack in the cylinder wall then it won't affect the compression. The crack will open up once the block gets up to temperature.

[planted1]

Yep agreed,they will work for all revisions,but......they are not exactly the same.
Not being picky just trying to add something

[mr2tinker]

If that is a crack in the cylinder wall then it won't affect the compression. The crack will open up once the block gets up to temperature.

i did the comp test on a hot engine.

[mr2tinker]

Yep agreed,they will work for all revisions,but......they are not exactly the same.
Not being picky just trying to add something

Your not being picky your helping. any input is greatly appreciated and thank you.

having had a chat with gtschris he has confirmed that the rev3 gasket needs modifying so i am confused.com again.

that is not a crack, i have seen many a cracked block in my time and it is definitely a score from a foreign object. when you look at it in person it really is not so bad and i think i will just let it be. i believe as the barrel walls wear overtime it will not be an issue. lets face it she is going to use oil with my nitrous circut end gap set up (0.3 & 0.4). i pay 10 pounds cost for my oil anyway so a wee top up each month is no biggy.

these are just my opinions please feel free to let me know yours

[Charged]

mr2tinker = swaggansway = banned user.

http://www.imoc.co.uk/forums/viewtopic. ... 65#1336765

[mark239]

I had good compression with pistons like this:



Ran ok like that lol

[mark239]

every single one was like that and i got 135psi in every cylinder (Get 180 now on my rebuild)

the sleeves werent damaged at all, and amazingly neither was the turbo.

[Moo]

mr2tinker = swaggansway = banned user.

http://www.imoc.co.uk/forums/viewtopic. ... 65#1336765

You'd think he would have given up by now

[dazzz]

mr2tinker = swaggansway = banned user.

http://www.imoc.co.uk/forums/viewtopic. ... 65#1336765

You'd think he would have given up by now

He must really need some help. Shame he's burnt his bridges.

[Moo]

He must really need some help. Shame he's burnt his bridges.

Indeed. Act in haste and repent at leisure and all that. There's no getting past the IMOC forum police!