How To Lower Compression In a Hilux??

[dans-paj92]

Hey all,
I have an '84 4runner with a turbo'd 2L in it.
I want to lower compression as I am getting blow by and busting seals.
I want to lower the compression to solve this problem.
Have been told to get dished out pistons and a thick head gasket.
Where do I get dished pistons from?
And what else has to be done?
Cheers
Dan

[Matt_85Lux]

is it a factory turbo 2L? If not have been told the 2.8 head fits and lowers the compression. MAy be able to get a decompression plate aswell but not sure if available for that motor

[beinthemud]

De-compressing would take away power as well .
Do you have an oil pressure problem (blowing seals)
What filter is on it most use a WZ9 you can put a smaller on on if you have an Low pressure issue someone may have put a smaller one on.
If its realy bad as most have it when cold fixing the engine (rings and bits is prolly the better way .
2lt pistons and a thicker headgasket is the way .
Which engine do you have a 84 should have an early one thicker head gaskets are a pain as not many do them
Prolly be easier to buy my extra 2lt that i have

[dans-paj92]

Its a non-factory 2L motor.
Its been blowing sump gaskets and recently blew the front crankshaft seal.
So a 2.8 or 2L-T head fits?
and it will lower compression?
Cheers
Dan

[beinthemud]

2.8 head is meant to fit ive never seen it and not sure wether it will on the early one

[tweak'e]

Hey all,
I have an '84 4runner with a turbo'd 2L in it.
I want to lower compression as I am getting blow by and busting seals.
I want to lower the compression to solve this problem.
Have been told to get dished out pistons and a thick head gasket.
Where do I get dished pistons from?
And what else has to be done?
Cheers
Dan

first thing you do is go smack the idiot who told you that shit.

lowering compression will not help you one bit. two things can be happening, the breather line for the motor may be partly blocked causing crankcase to pressurize and blow your seals. undo the rocker cover and clean out the breather grill in it. while your at it you could look at driling the breather connection out a bit.
fit a catch can if you don't have one already, make sure it can flow very well and fit the other end of the breather line to the air intake. the suction from the turbo will help suck out the blowby.

the other thing is that you have tons of blowby due to worn rings and pistons, time to reco the engine.
to limit blowby for the time being simply drop your boost level down a bit. thats a far better way and losses less power/economy than decompressing the motor. plus its cheaper.

2.8 head.....will fit a series 2 2L motor but not a series 1 2L motor.

[Matt_85Lux]

first thing you do is go smack the idiot who told you that shit.

lowering compression will not help you one bit. two things can be happening, the breather line for the motor may be partly blocked causing crankcase to pressurize and blow your seals. undo the rocker cover and clean out the breather grill in it. while your at it you could look at driling the breather connection out a bit.
fit a catch can if you don't have one already, make sure it can flow very well and fit the other end of the breather line to the air intake. the suction from the turbo will help suck out the blowby.

the other thing is that you have tons of blowby due to worn rings and pistons, time to reco the engine.
to limit blowby for the time being simply drop your boost level down a bit. thats a far better way and losses less power/economy than decompressing the motor. plus its cheaper.

2.8 head.....will fit a series 2 2L motor but not a series 1 2L motor.

would adding another breather straight from the sump help? As I think mine has the same problems

[tweak'e]

would adding another breather straight from the sump help? As I think mine has the same problems

i'm fairly sure the breather is same size on atmo and turbo motors. its cable of flowing the required amount, theres not really any point to adding another breather. if the pistons are so worn that the blowby is over pressuring the sump, odds are its going to sh*t itself soon anyway. bite the bullet and fix the pistons.

[beinthemud]

Hey all,
I have an '84 4runner with a turbo'd 2L in it.
I want to lower compression as I am getting blow by and busting seals.
I want to lower the compression to solve this problem.
Have been told to get dished out pistons and a thick head gasket.
Where do I get dished pistons from?
And what else has to be done?
Cheers
Dan

first thing you do is go smack the idiot who told you that shit.

lowering compression will not help you one bit. two things can be happening, the breather line for the motor may be partly blocked causing crankcase to pressurize and blow your seals. undo the rocker cover and clean out the breather grill in it. while your at it you could look at driling the breather connection out a bit.
fit a catch can if you don't have one already, make sure it can flow very well and fit the other end of the breather line to the air intake. the suction from the turbo will help suck out the blowby.

the other thing is that you have tons of blowby due to worn rings and pistons, time to reco the engine.
to limit blowby for the time being simply drop your boost level down a bit. thats a far better way and losses less power/economy than decompressing the motor. plus its cheaper.

2.8 head.....will fit a series 2 2L motor but not a series 1 2L motor.

Good point tweked i should of thought of the blocked breather (as thats what happened to mine )

[dans-paj92]

i compression tested it this arvo and the lowest was 420psi and the highest was 480psi and the other two were above 450psi.
Was told they should be in the 400-500psi range.
So its not the pistons or rings.
Was told to put an oil catch can in-line of the pcv valve hose line to the air intake to the turbo as this will lower blow-by.
cheers
Dan

[beinthemud]

i compression tested it this arvo and the lowest was 420psi and the highest was 480psi and the other two were above 450psi.
Was told they should be in the 400-500psi range.
So its not the pistons or rings.
Was told to put an oil catch can in-line of the pcv valve hose line to the air intake to the turbo as this will lower blow-by.
cheers
Dan

Diesels have blow by
If your blowing seals your pressurising the oil system some how
Running your hose like factory to the front of the turbo wont do anything but pump oil in to the compression side which the turbo will compres and pump into the engine and maybe boom.
Putting a catch can will slow this oil supply but venting the catchcan out will do more (yes i know its technically illegal),dont leave the intake hole open

[MrSparkle]

The Catch can wont fix the problem it will just deal with it - leaving the pipe off that will help the problem. This is pressurising the sump and that puts extra pressure on the seals and the like causing all that oil to get into places it isnt supposed to. As someone said before check your breathers or pcv valve. The longer the engine is pressurising itself the more damage it will do. If the breather isnt blocked and the pcv is operating properly then its time to look at the engine.
Piston rings (perhaps even a hole in the piston if its serious), Broken ring lands, valves that are worn out or not seated properly. Worn out turbo maybe?

Droppping compression will do SFA

[fumduk3]

did you fit up turbo kit? sumthin extra 2 thow out there but wen kit was fitted was the breather hose from rocker 2 inlet when non turboed(if it has 1) get changed to rocker to inlet of turbo? as it will be blowing/forcing air into your rocker cover........

[tweak'e]

i compression tested it this arvo and the lowest was 420psi and the highest was 480psi and the other two were above 450psi.
Was told they should be in the 400-500psi range.
So its not the pistons or rings.
Was told to put an oil catch can in-line of the pcv valve hose line to the air intake to the turbo as this will lower blow-by.
cheers
Dan

sounds like breather is blocked up then. take off rocker cover and give the breather baffles a clean out. sometimes they get filed with sludge.

catch can is just to catch the oil coming out the breather which 2lt's are notorious for. it will not reduce blowby.
having breather line to pre turbo (which is where its meant to be) doesn't reduce blowby, its just the turbo helps suck blowby out of the engine. especially if you have a catch can fitted. also its required by your guys regs.
i noticed with my catch can, its substantially cooler when hooked to turbo air intake.
also make sure catch can flows enough. more than a few guys fit restrictive catch cans and end up with oil blowing out the seals.

[dans-paj92]

tweak'e, what brand of oil catch can do you use?
I was going to fit mine pre turbo, so the pipe from the air cleaner to the turbo.
This pipe was coated in oil when removed.
Cheers
Dan

[tweak'e]

just a supercrap can but modded to fit a breather filter inside of it as filter medium. however you might just get away with an empty can.

[Zookified]

did you fit up turbo kit? sumthin extra 2 thow out there but wen kit was fitted was the breather hose from rocker 2 inlet when non turboed(if it has 1) get changed to rocker to inlet of turbo? as it will be blowing/forcing air into your rocker cover........

I was thinking the same thing. Nearly did I when I turbo'd mine