I run engines on methanol, however 98 octane is good for up to about 11.0:1 anyway or if you felt it necessary a head shim could be used to reduce it.

And sorry no oval port manifolds

Revcore,

Pretty sure I have a standard cam there, mid dizzy, but it would be an a12. Not sure if there are any differences in profile, if it was going to be used for regrind the standard profile would not matter any way.

If you still want it let me know and I'll dig one out for you.

Ange,

Was a newly built engine at start of last season, has 12 meetings on it plus about 4 hours dyno time. 1237cc

Late a12 block, a12 crank, a12a rods, 75mm pistons, GX head.

All the usual race prep such as debur inside block, line bore, polish rods, arp rod bolts, balance rotating assembly, stress relieve everything (exc. block), full floating gudgeon pins, roll master timing chain kit, extensive head work, stainless valves.

Was last dynoed with 109hp at the wheels, however since then there has been another head developed with more flow and better chamber design.

engine is safe to 10,500rpm however mostly run up to maximum of 9,200.

Not sure how you would go on the street with this as it doesn't really start developing any worthwhile power until it gets north of about 4,000.

Oh and the cam was ground using an early front dizzy cam, didn't worry me as I was using crank trigger system, however if a dizzy is needed to be run the cam will have to be changed.

If you are a serious buyer give me a call to talk price.

Mark

Frank TDT,

Actually have 3 GX heads, all have been extensively ported

I am cleaning out the shed and have some A12 gear to go.

Things like blocks, cranks, rods, sumps, flat top pistons, etc.

Even have a full race engine if someone wants to make the right offer.

Call to find out if I have what you need, you will have to phone me on 0425 806 922 as I will not be on the net for the rest of the day and would rather get some of this gone today

Sorry, I will not package or post anywhere, pick up only from South Eastern suburbs.

Oh, and this is what the engine looked like before a season's of racing....

OK,

remeasured and found head spec sheet

In valve - 40mm
Ex valve - 32mm

Port sizes at manifold (W x H)
Inlet - 32 x 40
Exhaust - 29 x 31

Flows @28" water
Inlet - 166 @ .480"
Exhaust - 106 @ .460"


not using this engine anymore, not worried about giving away 'racing secrets', so here's a pic for you

Keep in mind that different people flow test with different methods.

Rally1200's flows where acheived with 32" water

The head on my race car was done from a GX, it flows 166 cfm @ 28" water @ .480" lift on the inlet with 39mm valve, not sure on the port size though, will take some measurments next time the manifold is off.

Sounds like you are planning on doing it properly, if so should not be considering shortening valves, instead you would be finding out who can supply stainless items IMO.
JTS do these at a reasonable price and at pretty much any size you require.

Here's a starting point for you

2 x 40DCOE
choke size - 30mm
main jet - 120
emulsion tubes - F15 / F9 or F16
air correctors - 170
idle jets - 45f9
pump jets - 35 / 40
aux. venturis - 4.0

This is assuming you have 1500cc, are looking to produce max. power at 6,500 rpm and prefer flexibility across the rev range instead of just looking for highest power output.

It is a starting point only, you should still get them properly tuned on a dyno at the first available opportunity.