sirius dash

[Glen GSR III]

Can anyone tell me the difference between the sirius dash version, and the normal 4G63. Im a bit confused thanks :?

[MrBishi]

Put simply the dash version has 12 valves - 2 intake and 1 exh per cylinder. Only one intake valve operates at idle to 2000rpm (not exact) then the other valve kicks in via an electronic solenoid. Exhaust manifold is the same as regular SOHC, but intake is different. The most important fact is they make more power stock, but can be a bugger to play with when you want to use MPI and an aftermarket computer.

[WANTSOM]

Mr Bishi wrote:
[quote]but can be a bugger to play with when you want to use MPI and an aftermarket computer.[quote]

Understatement of the year. :x

[Junkers]

Exhaust manifold is the same as regular SOHC, but intake is different.

No the DASH engine uses a split pulse exhuast manifold, pretty sure it has a 'tubular' design aswell. They're also supposed to reach an extra 1000rpm before hitting cut (7000rpm) because of the higher profile cam.

[MrBishi]

No the DASH engine uses a split pulse exhuast manifold, pretty sure it has a 'tubular' design aswell. They're also supposed to reach an extra 1000rpm before hitting cut (7000rpm) because of the higher profile cam.

OK to be more specific they are interchangeable - where the inlet manifold definetly is not.

[AB]

They also use a TD05-12a turbo (Japanesse imports only?), a different larger throttle body, larger staged injectors, computer controlled ignition, optical dizzy, no MAP sensor and are all factory intercooled.

They have two inlet valves one is quite small and the other is quite large. Only the smaller one is used at at low load/rpm to maintain a high intake velocity, the second larger one is used at higher rpms to increase the intake flow. There is a large 'step' at the end of the runner for the larger valve which blocks off a signifcant amount of the cross sectional area of the runner. This is possibly there to maintain a high intake velocity and/or limit total power output?

[MelbStazz]

hmmm i now am the proud owner of a dash engine in my stazz.
:D i'd like to know more about them too.
I've had the turbo high flowed and the std dash computer has mods though i'm not too sure of what they are yet as the cars not running 100%
i know that they have a different cold idle setup to the orig stazz's. as well as better pistons but thats the extent of my knowledge.
i can tell you that its alot nicer engine to drive, there is a different exhaust note, good power. Hmmm fun.

[fr335tyl3r]

as well as better pistons

I was under the impression that the dash head used the same pistons as the std head (std block has heart shaped pistons too so it is able to accomodate the dash).

Admin, please move this to tech.

[AB]

as well as better pistons

I was under the impression that the dash head used the same pistons as the std head (std block has heart shaped pistons too so it is able to accomodate the dash).

Admin, please move this to tech.

The DASH engine has pistons with four valve recesses, I think the standard ones only have three?


MelbStazz, I know a bit about these engines, what else do you want to know?

[Sargeant_Khan]

if it were a 12 valve wouldnt the piston tops have 3 grooves? 2 for inlet side and one for exhaust like the man said?

[AB]

The pistons have four valve recesses because the exhaust valve is either on the left or the right, depending on which cylinder it is. If they had three valve recesses mitsi would of needed to use two different piston casts and then have two of each piston in the engine. I guess they decided it was easier to make all the pistons the same.

That is also why an 8 valve engine has pistons with three valve recesses. The intake valve is always in the middle and the exhaust valve is to the left or right.