GH Pigma. VR4 Head + Forged Stroker..

redzone · Post by **redzone** » Mon Sep 14, 2009 8:38 pm

fuck. similar problem i had with my gemini motor before jambo. on mine the cam dowel wiggled forward out of the cam drive. fix for mine is a longer dowel and a washer to hold it in place so it cant move...

commiserations dude i know how it feels

Anchor · Post by **Anchor** » Mon Sep 14, 2009 9:35 pm

redzone wrote:fuck. similar problem i had with my gemini motor before jambo. on mine the cam dowel wiggled forward out of the cam drive. fix for mine is a longer dowel and a washer to hold it in place so it cant move...

commiserations dude i know how it feels

Yeah it was going so well. Was having fun with a 1000 kawa on the way down.. Massive double legger through first 3 gears too..

Fyi - starion 5 speed and locked scorp diff can handle 340rwhp.. haha. Although i never sidestepped the clutch. Didn't need to. Power on ftw.

quest · Post by **quest** » Tue Sep 15, 2009 10:07 pm

you really did go all out!! Good to see serious SOHC efforts
Had to read over this thread again, as it has some really good technical info buried throughout. A few questions..

is that a custom CAS adapted to a staz dizzy or modified oe electronics from another mitsu application ?

I want this thing to hold 2nd gear limiter launches...

...with a staz gbox ? must have wrong diff gears then. What ratio is it?

New head has a cam. Ralliart copy, 35/70 70/35

was OLDie's head from a 2.4L ?
Anyone recall the chamber cc size ?
Is "Surecam" the grinder ? ...not heard you guys mention them before.

Picked up my head/studs/adj cam gear off Rad last night.

Used proper headstuds this time, not twincam ones.

Any part number for the 'proper' sohc head studs ?

Doug @ NPC is re-drilling my flywheel to fit a skyline size clutch. 5 puck brass button ceramic... $825 later haha

Probably could have gone from the 225mm up to the 240mm used on our widebodys, and used an inexpensive proven clutch from the states. If they stand up to the torquier 2.6L in the heavier starquest pig, they should suit you fine.
Dunno about those 2nd gear launches tho :)

296.5 rwhp on 11psi, creeping to just under 13psi

so 2.4L made same power at approximately half the boost, same turbo. Wow!
Pity your dynos hardly ever show the ft-lbs torque plotted vs the rpm scale, so one can really tell what a motor is doing

really cool setup!

Anchor · Post by **Anchor** » Tue Sep 15, 2009 10:52 pm

quest wrote:you really did go all out!! Good to see serious SOHC efforts
Had to read over this thread again, as it has some really good technical info buried throughout. A few questions..

is that a custom CAS adapted to a staz dizzy or modified oe electronics from another mitsu application ?
The CAS is a mitus item, we had to get a new one as it died on us during tuning. I can get pics close up and part numbers if you wish sometime this weekend.
I want this thing to hold 2nd gear limiter launches...

...with a staz gbox ? must have wrong diff gears then. What ratio is it?
On the back of the diff it says "G4 3.308" and some jap writing. Scorp Diff. Now CIG. Was in very good condition when we pulled it apart last week
New head has a cam. Ralliart copy, 35/70 70/35
was OLDie's head from a 2.4L ?
Anyone recall the chamber cc size ?
Is "Surecam" the grinder ? ...not heard you guys mention them before.
Yep was a 2.4L. Surecam made the custom cam i bought off him. Didn't use the ralliart copy. No idea on chamber cc size sorry.

Picked up my head/studs/adj cam gear off Rad last night.

Used proper headstuds this time, not twincam ones.

Any part number for the 'proper' sohc head studs ?
You'll have to ask Rad, they were just wrapped in a dishcloth when i got them. Had to grind out the tappet cover a bit so it'd fit. But they definately are longer.

Doug @ NPC is re-drilling my flywheel to fit a skyline size clutch. 5 puck brass button ceramic... $825 later haha

Probably could have gone from the 225mm up to the 240mm used on our widebodys, and used an inexpensive proven clutch from the states. If they stand up to the torquier 2.6L in the heavier starquest pig, they should suit you fine.
Dunno about those 2nd gear launches tho :)
Probably could have, but i like this clutch so far. Very very harsh, especially with the locker but i was getting used to it after 1500km.

296.5 rwhp on 11psi, creeping to just under 13psi
so 2.4L made same power at approximately half the boost, same turbo. Wow!
Pity your dynos hardly ever show the ft-lbs torque plotted vs the rpm scale, so one can really tell what a motor is doing
Leave it with me, i'll try get that for you :)
really cool setup!

Bolded is my replies, easier that way lol.

Now i need to figure out what went wrong :(

OLD FART · Post by **OLD FART** » Wed Sep 16, 2009 4:08 am

The head is a new 4G63 that I had ported a few years ago with cc'd chambers + 3mm os ex valves and ports ( same size as a 64 ) with stock inlets
Surecam is a grinder that relocated to Sydney from Brisbane a couple of years ago and has the masters for my old Ralliart copy cam
Chamber sizes DOHC 63 =48CC sohc 63 = 50 cc ???? 64 =60cc ???
Head studs are 4G54 's and they need an app 10 (3/8 th ) washer on the top DOHC studs are to short
The motor is a 2.3 = 64 crank in a 63 block

quest · Post by **quest** » Thu Sep 17, 2009 12:33 am

thanks for the info guys.

On the back of the diff it says "G4 3.308"

ok... 3.31 is the gear ratio I was thinkin you had.
Should be ideal for this torque level, staz 5psd, tire diameter(tall 15s?), for 1st gear launches.
...unless there was a tire/traction problem ?
Only time I've seen that at the strip is when the diff gear is to short (numerically higher... normally residual from a na to turbo conversion), and 2nd gear launch for compromise.
seems wierd in this case.

Now i need to figure out what went wrong

I think I recalled reading where u checked the block clearance with playdoh. What about the head, for piston-valve interference ?
I know some here run std spec VR4 pistons in their 2L SOHC, but those 7.8:1 concave pistons may provide enough valve/piston clearance, where these 8.8:1 may not. Compounded by a longer duration cam, bigger dia exh valves and valve reliefs scribed for the 4 valve head and not our 2.
Just a few thoughts

This build reminds me of "4g64b"s' impressive 2.4L SOHC staz detailed here.
~350hp @15psi iirc. He ran pretty much a stock 2.4L sohc ute motor, with delco electronics, performance cam(unspecified) and shaved oe pistons (for a slight reduction of stock 8.6:1 comp ratio).
Same path I plan to take after maxing out the 2L (solely for curiosity).

OLD FART · Post by **OLD FART** » Thu Sep 17, 2009 3:42 am

64 & 63 SOHC heads are not interferance heads like the DOHC heads (ouch!!$$$$ ) and I had dohc Wiseco's under that head for 3000k's with the Ralliart cam with a 7200 limiter no worries
It may be that the special stroker grind cam with a bit more lift along with a timing belt jumping was the cause .Strange that it never happened running in or on the dyno :?
Valve clearence flycuts should be the same depth from the piston crown regardless of the comp ratio

Anchor · Post by **Anchor** » Thu Sep 17, 2009 7:08 am

The pistons i ended up using were CP 9.0:1's. As Titan Motorsports stuffed up..
Yeah we wound the motor over every time we added a part just to make sure nothing hit.

Fyi - didn't have to grind anything off the block/crank/pistons/rods. Everywhere had at least 40thou clearance.

The second gear launches are purely a burnout thing lol. Not meaning to launch on track like that. Although first gear is over very quickly and the staz 5sp doesn't like shifting quick. I have to let it come down speed a bit before i shift otherwise it crunches. Still goes in, just tight.

Yeah rad, everyone keeps saying clearance. If it was clearance it would have stuffed up during the million dyno pulls or the 1500km before it happened.. Something has either broke or slipped.

redzone · Post by **redzone** » Thu Sep 17, 2009 5:44 pm

didnt u say a dowel came out? i think the dowel thing is a symptom caused by heavy valve springs, i've seen it on a few different motors now, never with stock springs. the gem for example runs 180psi seating pressure..

Anchor · Post by **Anchor** » Tue Sep 22, 2009 6:46 pm

redzone wrote:didnt u say a dowel came out? i think the dowel thing is a symptom caused by heavy valve springs, i've seen it on a few different motors now, never with stock springs. the gem for example runs 180psi seating pressure..

Still unsure what has happened..

Got my tonsils out and a fair bit of mouth/throat surgery on friday just gone so haven't been doing much.

Pigma gets towed to dyno shop tomorrow, they are gunna fix it for free since it has their sticker covering the back window.

I'm thinking they mistook the 'rattly sohc mitsu 4cyl noise' for the pistons hitting the valves... Albeit very lightly, even if only under great load/stretch.

We'll see, still has full 185psi compression. Just looks a bit messy and bends the tips of the plugs in. Ie, loose metal flying round lol.

Anchor · Post by **Anchor** » Tue Sep 22, 2009 6:49 pm

Got a bit busy the morning of leaving for bris too haha....

And here's the dyno sheet with both tunes that have gone into it so far.
Pretty good curve. Very safe also. Afr's around 11 and go down to 10ish up high.

And a bit of a run on the dyno, excuse the screamer pipe :D And the shitty camera phone that stopped just before the end.

Anchor · Post by **Anchor** » Wed Sep 30, 2009 4:37 pm

soo....

faulty piston?
something in cooler pipe?
iunno, ideas...

None of the other pistons have marks. so no clearance issues.

There was also traces of coolant in the combustion chamber on cyl 3 (fucked one) and the intake port of cyl 3 was super super clean... others were normal, etc...

RiceThief · Post by **RiceThief** » Wed Sep 30, 2009 5:10 pm

Im thinking that your 3rd injector has a problem or the wiring to it is loose somewhere.

Anchor · Post by **Anchor** » Wed Sep 30, 2009 5:53 pm

RiceThief wrote:Im thinking that your 3rd injector has a problem or the wiring to it is loose somewhere.

When it killed the old motor, we tried swapping injectors and the wiring between 2&3 at different times to diagnose the problem. Still stuffed up on the one pot. (This was the motor that had a jet valve head, jet valve leaked oil into mixture, leaned it out, pop hole in valve.)

RiceThief · Post by **RiceThief** » Wed Sep 30, 2009 8:45 pm

Anchor wrote:When it killed the old motor, we tried swapping injectors and the wiring between 2&3 at different times to diagnose the problem. Still stuffed up on the one pot. (This was the motor that had a jet valve head, jet valve leaked oil into mixture, leaned it out, pop hole in valve.)

Let me confirm this, with your new setup you swapped injectors 2 and 3 with each other as well as the associated wiring, i assume your autronic is fueling in batch fire mode? Are you still running the pcv into the inlet?

Austarion

GH Pigma. VR4 Head + Forged Stroker..

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