going to install my EGT gauge tonight or soon, whenever i find a 1/8" NPT tap. installing in stock manifolds. wow i didn't know a 1/8" NPT hole was going to be that big, more like 3/8" ! I suppose there won't be issues with cracking? I was wondering if I need to put any kind of high temp thread sealant in there? Anyone have a pic of their stock manifolds tapped? Just wondering where exactly you tapped it, top or side. I know to do the #5 port and as close to head as possible (1-2"). Someone said to try to suck a the shavings out the tailpipe with a vacuum.... will that really work? I have a tiny 2 gallon shop vac. All tips welcome. Looks like it *might* not be that hard to get to. thanks

 

Sammy -

Drill the hole on the top side of the ex manifold. I installed an EGT in my silver 01 L at #5 cylinder and its not that hard. You must use the proper size drill but witch is just a tad smaller then the tap. I am not sure of the size but a hardware store should be able to tell you. NPT threads are tapered so dont run the tap all the way to the bottom when cutting the threads.

When you install the fitting it should seal itself due to the taper on the fitting and the threads cut in the manifold. Here is an old post I made on the subject.

https://www.f150online.com/forums/sh...&highlight=egt

 

1/8 pipe thread tap uses a 21/64 drill bit. Drill a small hole first and use greas on the flutes of the drill bit and tap to hold the cuttings and clean grease and cuttings often. you can put a piece of small hose and then go down to a small piece of tubing on the end of youre vacume that will go in that hole to pick up shavings. I have heard that a nother way is to put a large magnet near the hole you are drilling to collect the shavings. Are you calling #5 the first cylender on the drivers side???

 

thanks guys. if all goes well i'll be doing this tonight. yes, the #5 as I understand is on the drivers side, the port closest to the front of the truck, correct? haven't looked at a firing order in a long time, guess I should. i hope that' the one b/c its the easiest to get to.

 

Hey Bob,

Where you tapped into the manifold HERE, do you think that you were getting an accurate read there? It's about 8 or 9" from the head but it's really the closest/best place to put the sensor without removing the manifolds from the truck. The steering column is in the way further up and/or those little designs on the manifold would need to be filed down a bit for a smoothe surface. Seems like these cast iron manifolds would hold heat better than headers, plus where you tapped is really close to two other ports. How much heat could it lose from being there anyway, a few degrees that wouldn't even show up on the 2 1/16" gauge?

 

Sammy -

I think it was pretty accurate where I placed it, there is going to be very little difference by placing the sender any closer especially at WOT.

One thing I would need to mention is that EGT gauges are not really all that worth while. They do not react fast enough for you to use as tuning tool and by the time they go off the chart hot the damage is already done. They are mostly for eye candy IMHO.

Bob

 

Bob,

Have you used EGT's in non-iron manifolds (IE tube headers)? The EGT I had in my 94 Cobra with LTs was very responsive and was a great tuning tool. I installed the same unit (not identical, but the very same gauge and thermocouple) in the L's cast manifold and it was useless. It was always too hot (1600 on a WOT blast) and quite sluggish. I think the cast iron may retain so much head and re-radiate it so that it screws up the readings from the Type-K TC. Maybe the TC is too 'pre-heated' in this installation?

Herb

 

that's what i was thinking. what i really got my gauge for was towing. i do a lot of towing through the blue ridge mountains so I see some boost at 70mph for several minutes at a time when towing uphill. Since I'm going with a 2lb towing setup with a fuel heavy tune, i just want to make sure nothing melts! perhaps it will tell me if i need to back off the throttle. i should be able to get some real before and after results.

what do you guys think would be a maximum safe sustained temperature for say 5 minutes at a time?

i figure that on the drag strip, this tiny gauge will perhaps be worthless unless maybe there is something seriously wrong...

 

When you drill the hole coat the drill bit with something like heavy wheel bearing grease. The shavings will stick to the drill bit and not so many will fall into the manifold.

It may smoke some but you will have an easier time on cleanup.

 

Guys -

I just think a wideband 02 would be me much more effective then the EGT. I have had both and prefer the wideband to the EGT by alot. I am not downing the EGT but the wideband is much more reactive and accurate, EGT's get out of control due to lean mixtures and / or really high timing. Hopefully you have some sort of chip or tuner that controls timing especially in a towing program.

I would think you would want it plenty fat for extended boost pulls. If I remeber correctly around 1600deg is getting real close to start melting stuff.

Bob

 

Yeah, 1600 is bad news. From my 5.0 days, we used to target 1450 as a max. I don't really know what was up with the temps I was seeing on my EGT on the L. I would see 1300 at idle! I pulled the EGT and put in a Dynoject WBC O2. I have since picked up a different EGT (dual channel pyrometer with peak replay), so I will by running both.

In therory, the EGT should be the more instant warning compared to the WB O2, but you can have elevated temps for multiple reasons, so it is less 'sure' than a WBO2. Hence, I wanna run them both and compare! Hopefully, it will be with LTs so the cast iron issue will be out the window.


Herb

 

thanks guys. just a follow up on this project... I tapped the manifold tonight, right in the same place as Bob did. slight problem though. the autometer (5744 kit) probe is bottoming out in the manifold. when i screw the fitting into the hole, then put the probe into the fitting, it bottoms out and I need to put it in about another 1/8" so I can screw the fitting cap (?) down over the probe... otherwise it will screw the probe up. this should be fairly easy to fix with a couple washers though. now i realize i could probably have tapped a couple less threads. i may dremel the bottom of the fitting off if I determine its setting too far into the port.

the drilling was fun (not). i highly recommend a drill that is meant for tight spaces, not the normal drill like i had. i just barely got the drill in there. i had to hold it from inside the wheelwell and pull down on it and push up to hit the trigger. i couldn't find a way to hit a punch with a hammer to start the hole so i just started carefully.

typical pain in the azz project. going to go rub some salve on the abrasions on my arms