Originally Posted by Roadknee
Look like a cast-iron fast burn style chamber to me.
http://www.summitracing.com/parts/DRT-10021171/
Look like a cast-iron fast burn style chamber to me.
http://www.summitracing.com/parts/DRT-10021171/
Have a look at my table and try it if you want. Its pretty in graph but might be amateur lol. EDIT: My bin is $OE so you'll have to use correct XDF to see it properly.
Last edited by brian617; 06-08-2014 at 01:29 AM.
89 K1500 Scottsdale 5.7L 5spd 3:42 RamJet cam Dart iron TBI heads 427 PCM swap
95 C2500 Cheyenne 6.5L turbo diesel 4L80e 4:10 DB2-4911 Manual pump conversion 0411 PCM trans control 2Bar COS
05 Outback XT 2.5L turbo gas auto
I'm going to try it. I just ran my current able modified with Marks, runs great, but manifolds are glowing still just the same. even with the timing up at 40, not sure what is causing it but I guess I will be digging deeper. I'm certain it is mechanically fine, but I'm not sure whats going on. Can an oxygen sensor appear to be working fine but let it run lean? BLM's are much better, no more in the 140 and then 108.
BLG
Dam fine looking table!
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
The only thing I can see to make your exhaust glow/engine hot... is to much spark at idle and off idle? I've never had to run them that high. 23* is about tops if your cam needs it. Now there are cams that need more more lower RPM idles.
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
My Express idles at 700 RPM and 32* timing @ 45 KPA. The headers do not glow.
I wonder if his valves could be lashed too tightly, not allowing the exhaust valves to fully seat.
I'm torn on what could be causing it. I know I have had no enough timing in the past cause this issue, so I'd figure I'd go all out and max it out to eliminate the timing. Using your timing tables as they were I was having them glow...so I have something going on. I was thinking about everything from tight exhaust valves to vacuum leaks to running lean. I did do a compression test when I changed plugs...180-185 psi across the board.
I've never had this cause it, but could the colder plugs be screwing with me? I can't say I remember them glowing with I was running the R44LTS plugs. I am currently running R42LTS plugs. I like to run coldest plugs without fouling, but this isn't exactly a performance/race motor so maybe I need to get that old school mentality out of here. I thing I did notice when I changed plugs, the engine went mega rich and the BLM's on the starter tune went way down into the 108-110 area as where before they were always 114-116 at the very lowest. I didn't change anything but plugs at that time. Perhaps I should switch plugs back and see what happens, maybe it will make difference, maybe not. But either way, I am mega lean or I have fuel burning in the manifolds...I just have to fine out now.
BLG
I thought about that, I have them set 3/4 turn preload, plus my compression is awesome, so I ruled that out. I may still run the valves again just to be sure.
Try 1/2 turn instead, never run more than that myself. Generally looser lashed motors make more power.
Could restricted exhaust or defective cat cause the manifolds to glow?
yes.
anything that slows down the stream of exhaust gasses will cause more heat to get transfered into the exhaust components themselves.
1995 Chevrolet Monte Carlo LS 3100 + 4T60E
There is a lot to spark plug heat range, read this article. Maybe those cold plugs are not properly burning all the fuel mixture and the residual is getting into the exhaust.
http://www.ngksparkplugs.com/tech_su...2.asp?mode=nml
Just remember NGK heat range numbers are inverted from AC Delco.
89 K1500 Scottsdale 5.7L 5spd 3:42 RamJet cam Dart iron TBI heads 427 PCM swap
95 C2500 Cheyenne 6.5L turbo diesel 4L80e 4:10 DB2-4911 Manual pump conversion 0411 PCM trans control 2Bar COS
05 Outback XT 2.5L turbo gas auto
I have no cat and it's 3" new dynomax exhaust.
Here's a more aggressive timing table you can try. Worse thing that can happen is you see knock counts and then you'll know for certain there is too much timing. Don't use the whole bin. Just copy and paste the table into the current bin you're using.
You mentioned you ran a compression test, but have you ever run a leakdown test? I wonder if leaking exhaust valves could be the cause of high exhaust EGT's.
Last edited by Roadknee; 06-08-2014 at 10:37 PM. Reason: Loaded correct Bin file
I will give it a shot once. I am currently going to back the fuel pressure down to where it was when it ran the best, which was 21. I ran logs at 19,20, and 21 and once I got to 22, I didn't see any increase in performance. Go I could be way over fueling this thing which would explain a lot.
Based on my best 1/8 mile time on the GTECH and double checking it with the Wallace racing calc, the engine is around 300hp, so if I throw that into witch hunter's calc, I need around 80lbs of fuel or so, with my current InjDC%. with my current pressure I am around 90lbs. So I figured I will get the pressure down to 21 again. Plus when I changed plus the engine went rich and the ECM was pulling fuel, so I will give this a shot and see what happens after dark.
No matter what I changed(injectors and fuel pressure), the InjDC% never drops below 90-92. I changed the flow rate once but that didn't work so well. I am figuring on those numbers aren't quite accurate perhaps. I don't know.
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