club.liberty.asn.au

I have a suspect blown head gasket so i am looking to the repair side of things, which is circa 3-5k
my symptoms at the moment are only very minor, after an extended period of hard driving my coolant begins to be pumped out of my reservoir into the overflow (already replaced caps)
levels are normal cruising.
my question is, if the engine has never overheated is it still necessary to deck the block before replacing the head? is it a compulsory thing or is it just insurance?
reason being that i feel i'm capable of removing the engine and changing the head gaskets, putting in some arp2000 and be done with it, but will it last without a deck job?.

The DIY solution is to glue emery/sandpaper of a certain grade to a plate glass surface, eg a table top and have at it till the high spots are removed.
But yeah I'm in for the real answer...

bigBADbenny wrote:The DIY solution is to glue emery/sandpaper of a certain grade to a plate glass surface, eg a table top and have at it till the high spots are removed.
But yeah I'm in for the real answer...

how do the high spots get there in the first place? are they defective from factory like that?
what sort of tolerances are we allowed to play with in regards to "flatness" a few thou?
is it not the role of the head gasket to expand/compress to these imperfections?

These ej25's blow head gaskets so easily that i will guarantee you that if you do what BBB sugested above, that you will have the head gaskets blow again in a short period of time.

What LOOKS flat, isnt always flat.!!

And ive learnt that these engines are so picky on tolerances that i would simply not risk it.

But, pull the motor out and apart and get the bits sent to a machinist and then put it back together yourself if you feel like you can ( and have the correct tools ) to put back together.

From what I have read there are a few things that cause blown head gaskets, but I'm not going to delve into it. My question is, if I lift the motor out remove head then gasket. Replace gasket replace head and re torque to specs with better head bolts, the deck shouldn't have been affected,no? it's not like the blocks have been moved around or sleeved or something else crazy

Im same situation as you dan, if I have someone pull my engine out I would rather spend 10k for a stronger engine than 5k for what I already have.... Maybe i should have a look at those out front cd blocks. I read through the whole 60odd pages the other day on nasioc. The look pretty good

wally09 wrote:From what I have read there are a few things that cause blown head gaskets, but I'm not going to delve into it. My question is, if I lift the motor out remove head then gasket. Replace gasket replace head and re torque to specs with better head bolts, the deck shouldn't have been affected,no? it's not like the blocks have been moved around or sleeved or something else crazy

Im same situation as you dan, if I have someone pull my engine out I would rather spend 10k for a stronger engine than 5k for what I already have.... Maybe i should have a look at those out front cd blocks. I read through the whole 60odd pages the other day on nasioc. The look pretty good

Yeh man i know what your saying about the head/block not being affected , but if you think about it there will be be "some" change in them as there is now a cold spot where it was hot because of the coolant passing thru it. And that difference in temp is what causes the peak/trough in the head/block due to alloy expanding when hot and then suddenly cooled it will shrink.

It really is throwing money away if you dont get it machined. The machining cost may only be $800-1000 but you are guaranteed a perfect surface. And its NOT like these fecking engines dont do HG easily either, just not worth the risk.

There's only 6 bolts holding the head to the block.
And the block itself flexes under the force of having a head bolted down.

Are you commited to DIY it?

I'm not 100% committed to only doing it myself, just trying to avoid having to strip the block to bare having it machined and re installing everything the way it was. on a side note, during the milling process does the block have to be split with pistons and crank removed?
I feel somewhat confident on the end of a spanner, the process when laid out seems pretty straight forward.
for situations like mine which I believe is the cause of stretched head bolts and heads lifting under heavy boosted driving, replacing gasket, head studs, timing belt, water pump, thermostat and oil pump should be a acceptable repair (providing nothing is found to be fubar)

any opinions from people that have done this replacement process before?

What if one was looking to change the head studs before a head gasket failure. I would assume that there would be no need to get machining done?

Im thinking.....Buy tough short motor from deschele. Machine your heads flat and bolt on. On get full motor from then annd drop in......

Have you checked your thermostat?

Are you aiming for more power down the line?

Do the HG job yourself, isn’t rocket science by just slapping a new head gaskets and stronger head bolts isn’t going to solve the problem.

You need to get the head serviced when would mean a complete rebuild and skimming of the head to ensure flatness.

No need to do any further work to the block unless you’re chasing 250kw+

jslayz wrote:Im thinking.....Buy tough short motor from deschele. Machine your heads flat and bolt on. On get full motor from then annd drop in......

Who is deschele? Any idea on various long block prices?

Thanks senator. I'll check it this break, but wouldn't a busted thermostat cause it to run below optimum temp? Or over heat during general operation if blocked? It has never had a temp issue

More power would always be nice

Ok so in your opinion if heads are pulled off a block they must be machined flat, which from what I understand by rebuild you mean valves, springs,retainers and cams are removed during the process?

Preformed a head leak test today, which surprisingly came up as a pass, tested it onto the exhaust to make sure the fluid was fine and bam yellow.

I'm not confident with the results because referring to my original post ,I have no issues idling with coolant lost. So I'm going to do some lo logs in the next few days with long runs and try preform a test straight afterwards

what test did you do? a t-kay test?

https://www.toolmart.com.au/tools/measuring/70586.html

Tested it onto the exhaust and it worked fine.

Have to somehow get my coolant to bubble. Which is difficult with the fact it has to be driven hard and the coolant is hot. Obviously. So it sprays everywhere when I open to do the test haha