That's what I thought too, (see my reply to BearKiller's post above,) until I read, then re-read apwatson's post and thought about it a bit . What he's saying is that in advancing the timing, the fuel is injected earlier, and combusted earlier, so it takes longer for the heat to exit out the exhaust valve. Because it takes longer, (and yeah, we are talking milliseconds) some of the heat in the gas will conduct in to the cylinder walls and the piston. That heat will not be read by the pyro, because it doesn't leave with the gasses through the exhaust valve.
Because we're talking milliseconds, (it takes 30 milliseconds, or 0.030 of a second for one 360° rotation of the crank @ 2000 rpm) it's hard to know how much that heat actually affects the pistons. I guess we'll all find out sooner or later when it comes time to pull heads and roll rod and main bearings!

 

I don't think too many people who just "play" with their trucks melt pistons. Because and only because when you are playing you may run 1400deg exhaust but only for a few seconds because at that point you run out of road, or there are red and blue lights in your mirrors.

Now if you "use" your truck as in towing, then there is a big difference pulling a grade with stock timing and "pump pushed to the head" timing. THAT is when you will be more likely to melt a piston. Because now you may be running 1200deg exhaust temps for 5-10min.

 

For the record. Stock non i/c injectors, timing 3/16s advanced.

I pulled 1350ish for about 5 minutes straight. Water temp stayed the same. When the head was off the pistons still looked brand new. I think 1250 is quite conservative. Lots of guys (including myself) run their pyro to 16-1800 degrees regularly while playing. I'm scared of running over 1350 for any period of time tho, personally.

 

my non i/c engine runs 900* at 70 mph pullin the steep passes here in 5th gear. and i mean 8-900 degrees for 5-10 min and my timing is to the head. i pulled my head off to do a head gasket and my pistons were fine. the hottest mine gets while playing is 1300. thats as far as i push it, and i have an Hx35/H1C hybrid, 3" intercooler piping and a 24v i/c and intake horn. pulling 8k i could run 5th gear but EGTs are 1100 or so. so i drop it to 4th and she backs off to 800* at 55-60 mph. my coolant needle just rises slightly (non i/c rad too)

im lookin into a HT3B and a 60mm upgrade to lower the EGTs and keep my stock sticks

 

Wow. I am definitely getting an intercooler. Anyone fit a 3rd gen cooler?

 

I'm impressed with those numbers, and no sign of wear! It's a good thing. But both Big Stinky and W150CTD are running stock injectors, although I don't know how much you guys have turned up your pumps. Nevertheless, it's all good. As I wrote earlier, I don't know how much, if any, long-term badness may happen, (and hopefully none 'cause I haul stuff too! ) so it's good to know that at least some of the folks out there have no sign of meltdowns. Thanks for your input guys!
I don't know if this clears anything up or muddy's the water for you more, Schamran, but it ain't going to hurt anything by hunting down an I/C!

 

I think it will help my mileage as well, so I see it as a pretty good investment. I would like to know if a 3rd gen cooler will fit, however. They look pretty big, like they would be awesome if they would fit.

 

Just a little FYI for you guys on here wanting to put larger IC's in your trucks. The #1 reason no one puts a 3rd gen IC in there truck is not because its too wide or too thick. Its because its too tall. ANY professional radiator/heat exchanger shop will cut off how ever many rows you need for it to be whatever hight you want it to be, and then they will tig weld the tank ends closed and pressure test it for you to what ever psi you specify. The average price for this work is $75, not a bad deal IMO. I'm getting custom end tanks made for a 2nd gen cooler so its full 3.5" flow, getting a pinhole leak fixed, and pressure tested to 60psi, all for around $80. So dont let height stop you, just get it altered to your liking.

 

Thanks for the tip. Is there a way to get the paint off of them without harming the aluminum? Or would it just corrode without any coating?

 

paint thinner, preshure washer.

 

You'll have to cut off the front of your frame that sticks out past the radiator... you'll have to do something different with your bumper mounts. Someone has a picture on here of it mocked up with the front of the frame hacked off. Tall is the issue as mentioned.

And a note that Non I/C trucks have bigger injectors than the IC trucks stock. They can push the fuel MUCH more than the IC's when the pump is breathed on. My 89 could run circles around my dually untill I upgraded the sticks...

 

well on the fuel note, my pumps maxed. denny T pin, fuel screw 1 turn from run away, star wheel bottomed, and i softened the boost spring. i backed the smoke screw all the way out because of crappy milage, high idle screw MIA, throttle linkage moved and adjusted so if u breathe on it the rpms rise and including the timing to the cyl head. and i have no reason to turn it down for the life of it lol

 

Where is your probe installed ??


On the short quick steep hills all around here, I had to turn my fuel back to factory setting to keep the pyrometer from going wild.

Timing is not messed with.

I tow HEAVY, as in big gooseneck cattle-trailer heavy, and it is very easy for me to bury the pyro needle without even trying.

 

They can remove the paint at a radiator shop too, I'd be a little worried about bending the fins with a pressure washer. And yes the bare aluminum will corrode. I'd get it at least dipped to protect the heat sinks.

I first leaned this a few years ago when I wanted to put a Dmax intercooler into a turbocharged 1500 Silverado. Everything would bolt right in like it belonged there, except it was 2.5" too tall. So I took it to a shop and they did a great job. I then took the 2.5" of intercooler they cut off and had them cap it off too. Then I drilled and tapped it, and it made an awesome trans cooler for my old 89'W350. LOL

 

Good work!