haedwork and cam

[GQ Bear]

My tb42e is having a problems of late.

Massive power loss - which could be attributed to 3.9 diff gears turning 35's.

and overheating regularly. - I've recently re-cored the radiator, replaced water pump, thermostat and radiator cap, and replaced clutch fan with twin thermos. still gets hot though.

I'm suspecting a blown head gasket (nobody even mention cracked head at this stage, or it'll be your head that gets cracked).

Started doing a comp. test last night, but this is a day job with efi crap in the way . Anyway cyl 1 read 170psi, cyl 2 about 150psi.

If, and most likely when, i pull my head off i was thinking of shaving it to increase compression slightly. Does anyone know max. that these haeds can be shaved?

Also was thinking about putting in a new cam more suited for low range torque, not economy or high speed work. Anyone got any suggestions who to speak to about this, what specs, or if there's such a cam that suits and what's it out of?

thanks.

any other thoughts on the overheating would be appreciated too. No external leaks, and doesn't use f'all water until red hot.

[BowTieGQ]

Nissan say only 0.2mm can come off head. While it's off, do everything. Ring Quickdrive Engineering in Dandenong 0437698427.

[GU4me]

a friend of mine is and engine builder and has a fair bit of experience with these heads hes happy to talk to u about the mods your after he also does alot of fabricating e.g. rodeo with vs 5.0l and monaro race car with full harrop gear.
contact him at:
hytek body and bike in moorabin
costa 0408559074.

[Fozdick]

The best way with comp ratio is to pick a CR eg 9.5:1(8.7:1 stock) then CC the combustion chamber. eg 75 cc then calculate the swept volume of a cylinder using your bore size and stroke eg 700cc. Then allowing for the thickness of the head gasket , work out how much to take off the head, to achieve your desired CR.
next find out if this is a reasonable figure to remove , i took off 60thou(1.5mm). no probs.. but now need to run premium.

Hope this helps

Shaun.

[cooter]

ring camtech in syd he will grind you a cam to suit your needs

[bogged]

The best way with comp ratio is to pick a CR eg 9.5:1(8.7:1 stock) then CC the combustion chamber. eg 75 cc then calculate the swept volume of a cylinder using your bore size and stroke eg 700cc. Then allowing for the thickness of the head gasket , work out how much to take off the head, to achieve your desired CR.
next find out if this is a reasonable figure to remove , i took off 60thou(1.5mm). no probs.. but now need to run premium.

Hope this helps

Shaun.

did anyone else get a techno-chubby reading that?

[gqtrol]

i had 25 thou decked of the bottom of mine had it matched ported i run extractors elec igntion from aus 4wd melbourne and a bigger gas system put on it has a nice power band between 2400 3100rpm work good for those hills out in toolangi puts out a decent 75 kilowatts at the rears nothing to brag about but it puts hiluxs and landcrusiers to shame in regards to your cam depends on how much you want to spend you could have your one ground or have a brand new billet one made where to go look in the white pages and make some phone calls get some prices first if you really want low down torque get a v8 or diesel donk up ya
glad to help GQTROL