Itinerant Air-Cooled

I apologize if this is the wrong forum for this message, but I'm pretty sure it belongs here.

I've been debating buying a QUAD cht gauge and was wondering if anyone here had any experience with em? I've never understood the reasoning behind having just a single cht gauge. Yes, chances are #3 is more likely to fail due to restricted airflow but who's to say the others wont fail as well?

For those curious, the beast of which I speak can be found here:
http://www.aircraftspruce.com/catalog/i ... quads2.php

Thoughts? Comments?

BlissfullyCrusin wrote: I've been debating buying a QUAD cht gauge and was wondering if anyone here had any experience with em?
Yes, chances are #3 is more likely to fail due to restricted airflow but who's to say the others wont fail as well?

A quad is optimal. Go for it. #2 is the problem cylinder with Type 4 engines.
Colin

I had CHT gauges on #1 and #3 for quite a while. #3 ALWAYS ran hotter than #1, so I got rid of the #1 gauge.

But I agree, monitoring all four cylinders is optimal.

Tim

That exact gauge has been on my list for a while. When I make my custom gauge cluster.

Amskeptic wrote:Go for it. #2 is the problem cylinder with Type 4 engines.

Why is this? When I adjusted my valves after the Death Valley trip I thought I had the engine turned the wrong way at first, because there was hardly any clearance at all on Number 2.

covelo wrote:

Amskeptic wrote:Go for it. #2 is the problem cylinder with Type 4 engines.

Why is this? When I adjusted my valves after the Death Valley trip I thought I had the engine turned the wrong way at first, because there was hardly any clearance at all on Number 2.

More evidence still, huh?

My guess is this:
The air comes blasting out of the fan housing outlet and pretty much shoots over to the underside of the cylinder cover at #1. Like standing under a waterfall and finding yourself pretty dry, #2 is actually getting robbed of air. As important is the fact that #2 connecting rod journal is at the end of the connecting rod bearing oil path. Connecting rods get their oil from the crankshaft galleries. #2 gets its oil from the gallery feeding the #3 and #4 main bearings. #2 piston is always the first one to seize during a lubrication failure event. I strongly recommend that we all notch our connecting rods to help the cool the undersides of the pistons, particularly with 2.0s (it is harder to control the expansion rate of the pistons/cast-iron cylinders of the larger engines)
Colin

Amskeptic wrote:I strongly recommend that we all notch our rods

Is there anything less drastic that can be done? Should I set my #2 clearances at .007 next time before a long hot trip? Break down and get a CHT gauge?

[quote="covelo
Should I set my #2 clearances at .007 next time before a long hot trip? Break down and get a CHT gauge?[/quote]

Clean, well-tuned < ! keep revs up when working it up the grades, adjust your valves in a timely fashion, and you will do fine. NO LEAK-INDUCED LEAN MIXTURES.
Colin
(consistent .007" is getting in "hammer-the-valvetrain" territory)