Northstar rebuild: Will style (Page 69/119)
Will JUL 25, 01:17 PM
I dug up my old dyno run file and used the DynoJet viewer to overlay the old and the new.
cptsnoopy JUL 25, 01:24 PM
Looks awesome Will! I too was a little concerned about the oval pipe to oil pan clearance so I had that part of my exhaust jet-hot coated just to be sure. The X-connection is very cool...

Charlie
Will JUL 25, 01:31 PM
Thanks!

In retrospect, I could have used an oval pipe to pass under the pan, but there's *VERY* limited space for the round/oval transitions... I was just barely able to pull it off for the cradle pass-under.

[This message has been edited by Will (edited 07-25-2012).]

FieroWannaBe JUL 25, 01:34 PM

quote
Originally posted by Will:


Thanks!

Actually, it's the other way around. The pipe will cool off far faster than the pan and oil. The pipe is comparatively thin and light relative to the pan and oil. Despite being at a high temperature during operation, it cools quickly. You can try this yourself on your own car... After a drive, your pipe will be cool to the touch well before your oil pan and the oil within.

The car will get an oil/water heat exchanger.

While I also intend to produce heat shields for use in specific locations, I'm far more concerned about the CV joint boot and grease taking on excess heat during operation. I'll be switching to an intermediate shaft axle to move the CV joint out of the high heat area.




Well, to counter, the Chinese 16Ga. long tubes on my GTO would stay hot for quite some time after shutdown, heatsoaking the cramped compartment before I wrapped them.

I didnt see how close toe the CV boot you were until just now, I agree a shield is needed there. Hopefully they don't swell at high speed!
Will JUL 25, 01:40 PM

quote
Originally posted by ALLTRBO:

Will, what the hell are you doing?! You can't fit all those pipes in there! Especially without hacking up the trunk! Double especially without it looking like crap!
You better obey the laws of physics and pull all of that artwork out of there right now before someone thinks that it's actually possible!
Will JUL 25, 03:18 PM

quote
Originally posted by FieroWannaBe:


Well, to counter, the Chinese 16Ga. long tubes on my GTO would stay hot for quite some time after shutdown, heatsoaking the cramped compartment before I wrapped them.

I didnt see how close toe the CV boot you were until just now, I agree a shield is needed there. Hopefully they don't swell at high speed!



Think about it... The exhaust tubing may operate at 1000 degrees, but weighs maybe as much as 20 lbs.

The engine operates at 200 degrees, but weighs 400 lbs or more.

The amount of heat (in terms of Joules) that is held by the exhaust is tiny compared to the heat held in the engine.
FieroWannaBe JUL 25, 07:06 PM
Fair enough. So long as your comfortable with it, thats all that truely matters.

I wouldnt think the heat of the exhaust would destroy anything in the vicinity, your are right on a specific heat basis the engine wins. But I was only considering the localized heat that the exhaust tubing might have on the oil pan, and the film of oil in the near vicinity of the pipe for the small 2 minutes or so it would take to transfer the heat away from the pipe if you were to park it somehow with the pipe at say, 600F just after flogging it. Not enough to ruin anything except maybe soften a seal or boil out some aromatics in the oil. The thoughts in my head were: There is limited air flow when parked, so maybe 8% of the heat from that area is being purely radiated into the oil pan the rest to free convection and conduction to the rest of the system (which isnt that large really so its all around 600F at the time), the oilpan is aluminum, and relative to the steel and oil, it could perhaps be seen only as a transport medium, so imediatly at the pan, it may reach 300 degrees for a small amount of time until the exhaust in free-er air pulls more heat away, so oil right at the base of the corner of the pan by the exhaust may get overheated slightly. Will it hurt the engine probably not, never thought it would. Could the oil life be shortened ever so much, maybe? Im only speculating, your engineering this system, not me. Back to your build. Again, Im impressed and jealous.

[This message has been edited by FieroWannaBe (edited 07-25-2012).]

Will JUL 27, 08:26 PM
I have been considering a heat shield for the pan, as well as the CV joint. I'll likely go to an intermediate shaft axle instead of building a heat shield for the CV joint... avoid the problem entirely instead of mitigating it. A heat shield for the pan will be simple enough, but will need to be very precisely made.

I think the circulation will avoid problems with the oil while the engine's running and I don't think the heat post-shutdown will be a big deal, but obviously less heat into the oil means less heat I have to dump into the cooling system which means less heat I have to get rid of through the stock V6 manual trans radiator, which is a good thing.
Will AUG 25, 10:44 AM
Heat shield for the pan is in progress, as is a bracket to support the housing for an intermediate shaft axle.

I've been driving the car daily. It was doing fine, but gradually became harder to get the initial turn over when starting. The charge voltage from the alternator had gradually gone down. The car runs fine, but the alt doesn't quite charge the battery to a high enough voltage to be able to start it.

I've parked it for the last week while dealing with a family medical problem.

[This message has been edited by Will (edited 08-25-2012).]

Will SEP 03, 02:38 PM
I was wondering how to deal with this. Unfortunately the welder is on vacation, so I couldn't consult him about reworking the location of the v-band clamp. I know it would be a huge PITA no matter what... I would have just asked his advice on how to do it most easily.

However, as I was cleaning a giant load of scrap (old Northstar parts, old TDC parts, old Muncie parts) out of the shed out back, I noticed that I had two Type II IMS's on the shelf. Interesting. I knew that there were two different types of IMS's, but I'd forgotten I had two of the Type II's. I had @$$umed that the Type I and II shafts would be the same length and use the same CV axle assembly. On a whim I grabbed one of the Type II's and compared it to the shaft from the Type I. The Type II is noticeably longer. I pulled the Type I housing out and installed the Type II with the target CV joint tulip and the tulip cleared the V-band clamp. :-D

Installing the Type I would have required removing the axle seal. Even though axle seals are cheap and I bought a spare, I hadn't popped the seal out because I considered that "committing" to a course of action. Since I didn't have a good idea of how I'd make the Type I IMS work, I had not yet done that. The Type II shaft uses the same axle seal as the stock axle, so to install the Type II shaft, I do not have to remove the axle seal. I feel modestly vindicated.

However, I *STILL* have to remove the axle seal. The Type II shaft requires a different bracket than the Type I. Because the bracket for the Type II provides *ALL* of the support for the "remote" bearing, the Type II bracket must not only be much stronger than the Type I bracket, it must be able to locate the bearing fairly precisely in order to avoid wear on the differential side gear and IMS splines due to misalignment. I will have to fully develop my Type I IMS bracket in order to properly establish the relationship between the centerline of the IMS and the bosses on the Northstar block. THEN, knowing that relationship, I will have to *RE*design the bracket to work with the Type II IMS.

PITA, but I now know the path forward.

Rev 0 of the Type I IMS bracket:

[This message has been edited by Will (edited 09-13-2012).]