Bigger valves and better cam

[8v-of-fury]

I'm not sure polishing is an issue here, since a diesel doesn't rely the rough surfaces in the intake/port to help mix the fuel and air the way a gas engine does.  I think you would be fine with polished surfaces.

It has been covered, but I cannot recall what the out-come was.

[745 turbogreasel]

I'm not sure polishing is an issue here, since a diesel doesn't rely the rough surfaces in the intake/port to help mix the fuel and air the way a gas engine does.  I think you would be fine with polished surfaces.

True, but the air may find it easier to maintain laminar flow with a small turbulent boundary layer, like the vortex  generators a jet has above the flaps.

[Alcaid]

The 1.9 head has the valves spaced further apart than what the 1.6 heads have so watch out for shrouding with bigger valves if you using that head on a 1.6 bottom end! Also the prechamber doesn't have the optimal location as it should have.

I have a head being prepped for me now showing 62% increase in steady flow, and 71% increase in dynamic (pulse) flow compared to stock AAZ head flow tested on 76.5mm bore. Intakes valves are only marginally bigger than stock.

Consider getting a cam with significantly more valve lift, when these heads are ported they love the extra lift!

[Hoble]

That's what I was thinking, get it in as fast and out as fast as I can

[Hoble]

Had anyone figured out what sized cam works best? I'd love to send one off to get ground to custom. I'm still in search of a shop that will do head work with a good reputation.

[justiz00]

You might contact Giles or Passenger Performance for a head porting source. They should know the major players in the IDI game since they have been around them for a few years.

Justice

[Jetmugg]

If you are interested in a complete 7mm stem valvetrain setup, Techtonics got all the parts for me.  I am building a 1.5L / 1.9 head Franken motor.

Techtonics supplied all the valves, guides, springs, shims, keepers, etc, and lifters to convert from 8mm to 7mm stem diameters.

They were very helpful.

Steve.

[justiz00]

If you are interested in a complete 7mm stem valvetrain setup, Techtonics got all the parts for me.  I am building a 1.5L / 1.9 head Franken motor.

Techtonics supplied all the valves, guides, springs, shims, keepers, etc, and lifters to convert from 8mm to 7mm stem diameters.

They were very helpful.

Steve.

Did you go larger than stock on the valve size? KS lists the stock size as 36mm intake and 31mm exhaust.

[RabbitJockey]

I'm not sure polishing is an issue here, since a diesel doesn't rely the rough surfaces in the intake/port to help mix the fuel and air the way a gas engine does.  I think you would be fine with polished surfaces.

True, but the air may find it easier to maintain laminar flow with a small turbulent boundary layer, like the vortex  generators a jet has above the flaps.

Mirror polish flows less ive seen it on a few write ups.  Like dimples on a golf ball

[Alcaid]

Mirror polish flows less ive seen it on a few write ups.  Like dimples on a golf ball

On that subject, have you seen these valves?



http://www.williamsmotowerx.net/valves.htm

[R.O.R-2.0]

LOL... "replace your valves every 20 hours"

under severe racing conditions?!

[Alcaid]

Its for motocross engines, they don't tend to last very long

[R.O.R-2.0]

Its for motocross engines, they don't tend to last very long

ahh, that makes sense..

i wonder if you can get dimpled valves in a size that fits our diesels?!

[Jetmugg]

[/quote]

Did you go larger than stock on the valve size? KS lists the stock size as 36mm intake and 31mm exhaust.
[/quote]

Stock size on the valves, just smaller stems.  I wanted to keep this on a budget that was manageable for me.  The head I bought had already been lightly ported, but did not have valves or springs installed.

Since I was buying new valvetrain components, I just went for the 7mm stems and guides, along with upgraded springs.

I'm certainly not an expert on AAZ stuff, but did learn that there are several combinations of valve and spring packages that came as factory stock equipment, mainly depending on the model year of the head.

Steve.

[Hoble]

So it's better to have a semi rough intake and a polished exhaust?

I think with my turbo setup and choices ill have problems keeping my head on the block. Has anyone figured out a way to keep these bolted down?