And so the saga continues -.-

S

Sigma

Member +
After posting a thread about a month ago regarding pressurising the coolant system, the fault turned out to be the headgasket.

It was replaced for a new Toyota OE item, with OE bolts and 600miles later, et voila; Missfire on start-up, pressuring and blowing coolant out of the bottle.

My thoughts are, as with the head and block both being checked when I changed the HG and found to be true, that either the stock HG isn't upto it, or I'm experiencing head-lift.

The fault is obviously down to the combination of compression hike & boost and the standard items aren't upto the job.

For those unaware of this engine, it's a 4E-FTE, with 0.6mm skimmed from the head and 0.4mm from the block, creating the equvialant of the standard motor, with a 0.2mm HG, running 1.2BAR on a CT9B.

What BHP does headllift usually begin to occur? or is it a boost pressure?

Which MLS gaskets are upto scratch?

And ARP bolts are the best choice?

Thanks in advance, Tommy :)
 
Iain@CRD

Iain@CRD

Lifer
If my head doesnt lift on standard head bolts at 1.5bar on a TD04 then yours isent at 1.2bar on a CT9b. Nick Jones was experiencing head lift on a TD04 at 1.7bar iirc. Is it a reputable company who have checked your head and block? Cruise, ZEP and Athena are what we use when it comes to head gaskets.
 
S

Sigma

Member +
Fuelling is taken care of by standard injectors and a JAM.

Any reputable spanner thrower knows that fuelling, only in extreme circumstances, can't cause HG failure in this manner.

I recon the standard bolts will be upto it then? And maybe fit a 1.2mm Athena?
 
N

Nick@TD.co.uk

Registered Trader <a href="http://www.TuningD
We run motor's with stock headbolts upto 1.4bar, after that we're not confident that they'll last. As Iain says we experienced head-lift when running over 1.5bar.

1.2bar *should* be a doddle for stock headbolts, i'd run at least a metal gasket for peace of mind, Athena are affordable and do the job well,
Cheers

Mike Jones
Tuning Developments Ltd
 
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whiteglanzav

whiteglanzav

Member +
Nick@TD.co.uk said:
We run motor's with stock headbolts upto 1.4bar, after that we're not confident that they'll last. As Iain says we experienced head-lift when running over 1.5bar.

1.2bar *should* be a doddle for stock headbolts, i'd run at least a metal gasket for peace of mind, Athena are affordable and do the job well,

Cheers

Mike Jones
Tuning Developments Ltd
Click to expand...

Mike - bear in mind that this motor is running "equivilent to a 0.2m headgasket with 1.2 bar of boost on a ct9" and im not sure but i think the headbolts have been re-used (tommy to confirm)

with all the material taken off the head and block it must make a big difference.

and tommy have you had your head pressure tested and are all your vac/water lines on right ?
 
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Iain@CRD

Iain@CRD

Lifer
Says above lads new Toyota headgasket and head bolts less than 600miles ago.

Daft question, but you are torqueing the head bolts correctly?

You def need to get a metal head gasket on there.
 
S

Sigma

Member +
New bolts have been used.

Been torquing at 16Ft/Ib, 32Ft/Ib & 90Degrees.

The CR now must be much higher, thus creating the weak point of the headgasket.

Much experience with Athena's, Mike?
 
Phil

Phil

Super Moderator
id tend to think that your not so much "experiencing head lift" and more so experiencing stupidity.

but as usual tommy, so long as it makes you smile... it makes me smile. :)

Phil

has anyone bothered to work out what sort of cr this is at now?
assuming the stock hg compresses to 1mm, your 1mm total skim, really means your running equivlient to no headgasket.
thats 1mm across the board, with 74.5mm bore and the pie r squared crack, thats 13.7cc lost per cylinder. 54.8cc across four.
would anyone be surprised if someone said they where running 10cc convex pistons @1.2bar and they were having "issues" ?
have you thoughT about the extra mm that your headbolts can or cannot get into the block? are they spaced/washered accordingly below the bolt head?
have you considered that at TDC your piston may be passing your hg? could a stock piston ring eat a hg?
 
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S

Skalabala

Member +
phil is saying some true stuff
and by tuning i mean, you are running high boost on high CR. so det can most probably be happening.
and ive seen a case where the block has been skimmed end cylinders oversized and the pistons were touching the HG
 
A

AdamB

Member +
I would say the standard headgasket isn't upto the job after some skimming and the raised compression isn't doing it any favours :)
 
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