With the intake being aluminum, you would Jet-Hot it??? :confused:

I had the uppipe from the manifold from the turbo on that WRX coated... it cost me around $50 I think it was for JH 2000. The pipe is about 18" only, not too bad so I don't think those I&E manifolds will be nearly as bad as we're thinking.

If I have a pair off to ditch EGR (which I should) I'll have them done for sure.

Dave.

I spoke to the manager of the truck stop today, of where I had the car weighed. She explained that the weight of the car is in the margin of error for 80 lbs + -. Guaranteed. It is a full-length platform conforming to applicable standards of Handbook-44.

So there's the range. Either as low as 3880 lbs, or as much as 4040 lbs.

Sorry to partially hijack this thread, but the proper moving weight is important when plugging in proper numbers for the accelerometer.

Brian...this is my thinking...Jethot is a ceramic coating it has insulation properties...when used internal and external it should reduce heat transferred to the intake charge from the intake which does get plenty hot, even just 10 degree drop on intake temps on a gasser makes a noticible difference in power...My honda has a 1/4" thick phenolic intake isolator and the same on the throttlebody...(which is heated to avoid icing in winter) these two drop intake charge temps a very large number....but I don't remember the numbers to be honest......in the summer its very notcible.

So yes while it looks nice, I believe the Jet Hot coating is dipped not sprayed, so its coated internally as well as externally and you are going to reduce intake charge temps from an uncoated intake.....put your hand on that intake when you've been driving a while...or better yet don't becasue you will burn yourself.

Now I am talking the 617 engine...but it will apply to the 603 that is also being discussed in this thread.

If Jethot's thermal-resistant properties are as impressive as reported, then coating the intake manifold may actually be worth it on a non-crossflow design like the OM617. On my OM603 w/mid-size intercooler, I can place my hand on the intake manifold after a hard run (with good high velocity airflow over the IC) and it's cool to the touch (ambient or lower), so Jethot probably wouldn't be as necessary. It might help to avoid manifold heat-soak during stop and go traffic though.

My direct experience on the 603 has been limited to looking under the hoods of Brian Carltons and Hattarasguys beautiful SDL's....which is nearly none.

Here is the question:

Is the air temperature outside the intake manifold higher than the air temperature of the charge? If so, by how much? This higher temperature air, caused by the exhaust manifold will serve to heat the intake manifold if it is significantly higher.

But, with the charge temperature estimated to be over 250 degrees at maximum turbo speed, I'd be surprised if the manifold is running this hot via heat transfer from the exhaust manifold. :confused:

Anybody ever use an infrared gun on the intake at idle after a decent run?

The intake manifold soaks most of the heat right from the head...and with the 617 adjacent exhaust ports don't help at all either.

The same applies to a gasser...there is no good way to thermally isolate the 617 intake due to how its mounted....but internal ceramic coating will reduce heat transfer to the intake charge.

If the head stays below 250°F. and the intake charge is 250°F. (est.), how will the internal ceramic coating reduce heat transfer to the charge?

The head must be considerably higher than 250°F. at the intake ports, due to the proximity of the exhaust for this coating to be effective? :confused:

Well, anything that will minimise heat transfer to the incoming air is going to help...none of this is a majic pill....I would guess the intake is going to sink major amounts of heat (being aluminum) from its proximity to the exhaust and being aluminum it will relase large amounts of that heat to the intake air charge. Think of a heat pipe or a heat sink. That intake can get hotter than the head temp on a OM617, but not the crossflow OM603. DO I have hard numbers? No... But like I said...improvements are incrimental...there is no single glaring design flaw.

I reduced my egts a bit. What I did was cut the egr stump off of the trap replacement pipe because it was up against the piping exiting the turbo. I have attached pictures of before and after. I just welded a plate over the hole.

Before it use to climb up to 1250-1300F by 80mph and go slightly over if I kept into the pedal up to 110mph when I would back off immediately.

EGTs rise slower and stay just under 1200F at full pedal up to about 90mph. When I stay on it up to 110-115 for a while it slowly creeps up to just under 1300F.

I bought some insulating tape for the air piping that I am going to install next to see if egts are reduced more.

Nice job. What welding method/technique did you use to weld the cast iron TO log?

I just cut a round piece of 14 gauge steel, tacked it on and put a bead around it with my migwelder. The log is actually fairly soft. I used a cutting disc to cut the protrusion which got me 95% of the way because of clearance issues. I used my screw driver to bend it which was easy, then a few gentle blows with the hammer and I bent it off with my hands.

So, I should have no problems following your lead with my own mig welder? I just thought welding cast iron was especially tricky, and I'm no ace welder by far.

the stresses imposed on welding Cast iron without the oven destressing immediately afterwards MAY cause it to crack in the future. Its not a sure thing...but the possibility is now there.