Most of the time you never will when it's doing the real damage at higher rpm.
Ailing engine (Updated after teardown)
- Thread starter Coyote Jack
- Start date
-
Jack, I think that's not a bad idea, BUT I tell you what. I'll be danged if I'd put it back together without studding it. You have it apart. Now's the time. The extra clamping force might make the difference. It's a small cash outlay for the benefits. Just a thought.
Also......and I'm just spitballin here now. I wonder if you could attach the vacuum advance (if you have one) to manifold vacuum. That would in effect act as a boost retard. The more load the engine would see, the more it would reduce the vacuum signal to the advance can and retard the timing.
Newbomb Turk
Well-Known Member
This post actually got my head out of my arse and remember that with boost he may want to look into a boost referenced fuel pressure regulator.
That way as boost goes up it will add fuel pressure to help keep the fuel curve correct.
So a timing curve, boost retard on the ignition and a boost referenced regulator would make his tune up window much bigger.
MopaR&D
Nerd Member
Food for thought... My daily driver 2000 Buick has the 3.8L V-6 with an Eaton M-90 Roots supercharger from the factory. It has a pretty sophisticated (for the late '90s) ignition timing control and knock sensor system. The knock sensors can tell the severity of detonation and the computer will retard the timing accordingly then slowly (over the course of a few seconds) advance the timing back to the base value spec'd in the tuning map. I have a connector and tuning software on my laptop for that car. I've run live data scans monitoring the knock retard and total timing advance and when first getting into boost (around 1/3 throttle) it gets momentary knock and I've seen it retard the timing as much as 12°. Never once have I ever actually heard pinging from the engine, and it's a very quiet engine with stock exhaust so I would hear it if it was there.
The max advance I can run under WOT before the knock retard pulls timing back out is only about 18°, granted it's a smaller-bore engine than a 360 SBM but still. That engine has 8.5:1 compression and runs 6 psi of boost, ramping up to 8 psi from about 5000-5800 RPM as the airflow efficiency of the engine goes down. Running 93-octane premium gas too.
The max advance I can run under WOT before the knock retard pulls timing back out is only about 18°, granted it's a smaller-bore engine than a 360 SBM but still. That engine has 8.5:1 compression and runs 6 psi of boost, ramping up to 8 psi from about 5000-5800 RPM as the airflow efficiency of the engine goes down. Running 93-octane premium gas too.
Last edited:
I am running a FiTech EFI dual 4 setup and control the fuel with it. At idle my afr is 14 to 1. At cruise not under boost I go to 13 to 1. When under boost it is 11 to 1. This is a pretty rich setup that helps to cool everything down. I also run my temps at 156 degrees. The only time it goes higher is in hot weather in city type traffic and then it might push 180 degrees.
Jack
Outasite
Well-Known Member
Hey Jack.What radiator,fan,shroud combo are you running.Those temps sound like its workin for ya.Wide or narrow radiator.
Last edited:
I have a Champion 3 core aluminum radiator. I believe the width and height are the same as a stock 340 radiator. I have a very narrow flex fan and no shroud, no room for a shroud. My fan is only about 3/4 of an inch from the radiator. Close, but not touching. I ran an electric fan system at first but it didn't work as good as this setup and drew lots of power. I am real happy with it now but it took some custom fabbing of spacers to make work.
When I put his combo together I did a lot of research and calculating to make it work. I know there a lot naysayers about some of the things I have done but I know it works and works well. I talked to people that do nothing but boosted engines and they can't find any real problems with my setup. I have addressed possible problems in some unconventional ways but it does work.
Jack
Outasite
Well-Known Member
Thanks for the information.Ive been running a 1st gen bronco 3 core cross flow,and thin direct drive flex.worked OK but not great.This time I went with a champion 4 core and 18” electric.No shroud,we’ll see. I do still have room for the thin flex if needed.
Life finally got out of the way and I was able to put the engine back together today. Everything went well until I went to start it up. I have no idea how it happened but the ECU on my Fitech system decided it was time to pack it in. Absolutely not power to it. All fuses were good so I don't know what happened to it. Luckily I still had my old ECU and I installed it and was good to go. I checked the compression pressures and they were all between 120 and 128 psi. So I guess that is the normal for my engine. It fired right up and YAAAAHOOOO, no blowby and no blue smoke out the exhaust. It looks like I caught this in time before any serious damage occurred. My wife was not impressed when I started it up with open headers though. It did sound rather nasty. lol This is the first time I ever had a head gasket blow out on me and if I learned one thing from it, it is. If you notice something abnormal about your exhaust or vapors coming out of your dipstick tube, your engine is telling you something is not right and you better investigate before something serious happens.
Jack
Jack
Glad to know you're up and running again.
Glad you got it goin again, Jack!
Outasite
Well-Known Member
Dodged a bullet! Glad all went well. Next 500 miles will finish the story.No idea what caused the Fitech to croak?
Took it for a shakedown run of a few miles today. All seems well. I'll know more after a few more miles. Who knows with the Fitech. I will be calling them tomorrow as it was still under warranty.
Jack
Well that's good. Now we'll get to see what kind of integrity they have. Keep us posted.
-
