502procharger

ok i would really like to put egt(s) on my motor in the boat. my issue is i have water jacketed cmi headders and have no idea how to gewt the probes in. if i got the really thin probes i might be able to drill through the area not jacketed but it would thin it way out. does anyone make some sort of an alum. spacer, or could i have my machine shop fab one out of like 1/2 alum then tap the probes into them? do i need 8 or can i just take a cyl off each side of the motor like whichever cyl. tend to run the leanest. any ideas or help would be great. i think with a blown motor running 9lbs of boost it would be a benifit to have them.

merlin540

i have egt's in my cmi's on my blower motors in the #4 cyl on each engine. we fab'ed a sleeve to put in the header as close to the head as we could get it. so far so good and it works great see ya charlie amann

articfriends

When i dynoed my motor the shop had 1/2 in spacers that sandwhiched between head and headers (because we were using cmi elbowtops) w/probes in them. When i ordererd my lightning headers they were able to build them w/probe sockets. I went with probes on #7&#8,which is what i hear everyone does. I chose to use a Gaffrig egt gauge and probes because they matched the rest of my gauges,i DO NOT get a accurate reading from them (they read 250-300 degrees too hot) so if you buy some i wouldn't recommend gaffrig's. With water cooled headers you will have to mount probes closer to ports than is ideal but at least you will have some kind of reference.

Mr Gadgets

Years ago, I did the egt thing and ened up drilling holes in the head right at the edge of the exhaust port. It was too close to the valve, but I was able to balance the cylinders to some point. I used a quick reacting thermocouple to get quick response. I hooked them to a Fluke temp meter. The hand held meters can be had fairly cheap and if I had it to do over, I now have CMI tube tops, I would put a spacer in between the upper and lower and poke them in there. I had CMI add O2 bungs to my headers, but I think they are too close to the collector plate, but it is all relative. I am running a pair of AF ratio gauges and it tells me that the motor is rich or lean, not very accurate, but I have burned anything down yet.. yet I say. Eventually I want to go to wide band O2 and tie it into my efi..
Good luck with it..

Tinkerer

I to drilled my heads right next to the exhaust flange and use just the thermocouple not the threaded part.
Mine are in #6
I have one in each engine and also use the FLUKE duel meter and turn it on to so that it automaticly jump back and forth between the two engines.

I have one burnt out thermocouple. Anyone know where the best place to buy them is???