Azmio,
I hate to come across like a dodo, but I wasn't able to find anything on either Kolbenschmidt's site or Gehring's site. All I did find was a paper outlining the design and manufacture of the Cayenne's V8 cyl block, as well as briefly going over the ALUSIL process (nothing new to me) I...
To answer my own question, I just heard that rubbing the bore surface with a leather swab dipped in acid/etching solution is supposed to melt away the aluminum matrix on the surface thereby exposing the silicon crystals... However, I was hoping for a little more detailed information on the...
Another question for you guys,
What is the proper way to bore/hone Alusil blocks, the ones made out of 390 aluminum, where the surface aluminum is supposedly "etched away revealing the hard silicon crystals to provide the necessary wear resistance"?
From the literature I have seen, the best ring coating for Nicasil bores in Titanium Nitride coated rings, followed by Chromed rings, which are slightly inferior, and plain cast iron, which is waaay behind.
Azmio,
I did a bit of research yesterday and according to a Ward's Autoworld article...
Azmio,
Thank you for your input. I'm glad you brought up Sulzer's Plasma Spray coatings, as I've been doing quite a bit of research on Plasma Spray,HVOF, and Arc-Spray coatings lately, as frankly, I find the idea of paying >$300 per cylinder bore for Nicasil plating quite ludicrous. My question...
What I want to know exactly is whether Nicasil coating is applied directly to the (cast) cylinder wall or via a dry liner made of wrought aluminum. I've heard that cast Al surface doesn't make for a very reliable bond with the nickel-SiC matrix, but I've also heard otherwise... I was hoping you...
Actually, there was a pretty interesting discussion on that very same topic over on AtlasF1, you can check it out here:
http://forums.atlasf1.com/showthread.php?s=&threadid=67536
This is for a boxer-6. The 330-380 was the spring rate, and the seat number would be in the region of 130lb, giving an open rate of say 360-400lb with 0.7" valve lift
Slightly off topic... Can an OHC belt drive be used with multiple valves and high(ish) spring loads, or would that compromise durability too much? I was thinking of spring loads in the region of 330-380lb/in for a 24V engine...
From what I understand the Davies Craig water pump has some problems. Autospeed (www.autospeed.com) tested one, and DC were so displeased with the results they threatened legal action, or something along those lines... You wouldn't happen to have any personal or anecdotal experience with them...
Forgive me for going slightly off topic here, but would bronze valve seats be compatible with EV-8/21-4N Steel valves? If so what particular alloy of bronze would be best?
Wouldn't a polished port give you less intake charge heating (due to lower surface area) which increases power and reduces the tendency to detonate? I would imagine this would (theoretically) show up as a high-rpm power gain, as port wetting isn't as much of a problem at higher rpms.. or is it?
What about average wall thicknesses for aluminum block castings? I've seen/measured anywhere from 4mm to 6mm, with another 50% around bosses and stress concentrations...
Very interesting features indeed,
I like how they've integrated the cylinder heads and barrels. I see plenty of advantages in doing so, not least of which is dispensing with the troublesome head gasket, and replacing it with a regular gasket or sealant between the lower part of the cylinder...