Operating temperatures with Evans NPG+?
Advanced Tech Moderator
Joined: Aug 2001
Posts: 2,262
From: Nashville
Let me poke my nose in and throw in 2 nice general questions 
Chuck would you recommend this on a street car, and two is it really worth it or just one of the last things to do when modding a car?
Thanks
Chuck would you recommend this on a street car, and two is it really worth it or just one of the last things to do when modding a car?
Thanks
Registered User
Joined: Nov 2001
Posts: 2,985
From: In a house by the bay
This stuff is interesting. I read an article here a few years ago about a group of engineering students who built a (I believe) 502 big block Chevy. The engine was to run on 87 octane fuel and the goal was to make 700 lbs-ft of torque. They went about this with a static compression ration of 12.5:1! The cylinder head design was a small 2-valve head with a centrally located spark plug and was supposedly designed to produce awesome torque numbers with excellent octane tolerance and "no-swirl"! The intake was a tuned runner Accel and the cam was a very mild grind designed to make strong inertial tuning effects with the manifold. The engine management system was an Accel unit also.
Anyhoot, the guys got the engine running and they found a bit of pre ignition at high engine loads. The backed timing off and lost a bit of power so the next step was to try this Evans NPG stuff. They did, and from there found that they could dial the timing back in without any of the pre ignition they were seeing before the Evans.
Like I said, pretty interesting and there are some guys around here who swear by the stuff. I still a little skeered but like Chuck said... that's because I don't really know squat about cooling systems except what I learned 20 some years ago.
-Mindgame
Anyhoot, the guys got the engine running and they found a bit of pre ignition at high engine loads. The backed timing off and lost a bit of power so the next step was to try this Evans NPG stuff. They did, and from there found that they could dial the timing back in without any of the pre ignition they were seeing before the Evans.
Like I said, pretty interesting and there are some guys around here who swear by the stuff. I still a little skeered but like Chuck said... that's because I don't really know squat about cooling systems except what I learned 20 some years ago.
-Mindgame
Registered User
Joined: Feb 2000
Posts: 473
From: Lexington Park, Maryland, USA
Chuck, can I pick your brain for a sec?
(promise I will not debate).
Question 1. As far as our LT1 motor and cooling system is concerned, Will NPG+ cool as well or better than 100% water?
Question 2. What is it that helps the engine to not detonate? (when talking about the cooling system).
I'm asking here beacuse I've asked about this about 1 year ago and got no response. I'm trying find out if NPG+ is as good or better than 100% water.
Thanks in advance,
Karl Ellwein, 95 Impala SS, Cast crank, stock rod 383LT1 with ported LT4 heads and mild Crane SR cam. 12.10 @ 112 mph all natural.
(promise I will not debate).
Question 1. As far as our LT1 motor and cooling system is concerned, Will NPG+ cool as well or better than 100% water?
Question 2. What is it that helps the engine to not detonate? (when talking about the cooling system).
I'm asking here beacuse I've asked about this about 1 year ago and got no response. I'm trying find out if NPG+ is as good or better than 100% water.
Thanks in advance,
Karl Ellwein, 95 Impala SS, Cast crank, stock rod 383LT1 with ported LT4 heads and mild Crane SR cam. 12.10 @ 112 mph all natural.
Registered User
Joined: Jan 2001
Posts: 2,148
From: Bay Area, CA
QuickSS, I think this is the info your looking for.
Cheers
Cheers
Originally posted by Mr. Horsepower
I don't know if you are familiar with the term "terminal molar heat" (TMH). TMH is the ability of a fluid to draw heat from a surface and is usually expressed in BTUs. Water for instance has a TMH of roughly 9,350 units where as the propylene used in NPG has a rating close to 15,000 units. Therfore it's not too much of a stretch in seeing the effectiveness of propylene's heat transfer abilities.
That said, you will see higher "coolant temps" and better thermal efficiency overall. The temperature of the "engine itself" while an issue, is not the most important. What is important is how effective the coolant is at thwarting nucleate boiling temperatures. Localized boiling (at hot spots) is the issue that needs addressing, not necessarily overall engine temperatures, if that makes any sense?
I don't know if you are familiar with the term "terminal molar heat" (TMH). TMH is the ability of a fluid to draw heat from a surface and is usually expressed in BTUs. Water for instance has a TMH of roughly 9,350 units where as the propylene used in NPG has a rating close to 15,000 units. Therfore it's not too much of a stretch in seeing the effectiveness of propylene's heat transfer abilities.
That said, you will see higher "coolant temps" and better thermal efficiency overall. The temperature of the "engine itself" while an issue, is not the most important. What is important is how effective the coolant is at thwarting nucleate boiling temperatures. Localized boiling (at hot spots) is the issue that needs addressing, not necessarily overall engine temperatures, if that makes any sense?
Thread
Thread Starter
Forum
Replies
Last Post
95z_28_camaro_4_Ivan
General 1967-2002 F-Body Tech
13
Oct 3, 2015 07:27 PM