pbreaction wrote:i didn't build my engine and when i asked him to mark TDC the heads were already on and he said the ecu does it automatically...
My previous remark was in response to the above, posted by the OP. I relied on the absolute wording which, in my interpretation, implied that the ecu would establish TDC "automatically". I continue to contend that the OP was provided erroneous information.
What I will say, without equivocation, is if I don't set my tooth #1 angle correctly, the engine will neither start nor run and knowing the tooth location (teeth between missing tooth and sensor at TDC) is essential to determining the proper tooth #1 angle.
Apparently I have overloaded my a$$ again.
Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/extra 3.4.2 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
TinyIOX from JBPerformance
Well that's the weird thing ... the engine runs... not the greatest... but we did put it on the dyno and it made 315 whp so its running well enough to not blow up on the dyno
And again i got into this car hobby less then a year ago so i don't have enough experience to "listen" to an engine and tell whether its running sluggish or excellent. All i know is my neighbors don't like it when i turn it on... HA
So with out taking off every thing on the front of the engine including timing cover is there a way to find this angle? Maybe with the logger?
Actually, it is quite easy to determine that "tooth offset" without disturbing anything on the engine, but it requires absolute confidence in the crank timing mark and the strobe light. You are using the "piston stop" method for finding TDC, one of the best methods, but I urge you to have somebody else check your procedure to make sure you are doing it correctly. After that, we come back to the timing light issue. Have you used a simple non-dial-back light yet?
pbreaction wrote:Well that's the weird thing ... the engine runs... not the greatest... but we did put it on the dyno and it made 315 whp so its running well enough to not blow up on the dyno
At the risk of being redundant, I find it extremely unlikely that your engine will start/run at 70* BTDC!!!
So with out taking off every thing on the front of the engine including timing cover is there a way to find this angle? Maybe with the logger?
Where in the world are the wheel and sensor located on an LS3, for cryin' out loud??
Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/extra 3.4.2 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
TinyIOX from JBPerformance
"At the risk of being redundant, I find it extremely unlikely that your engine will start/run at 70* BTDC!!!"
Yeah, I think we are all in agreement with you there. There has to be something wrong in how the OP is reading the timing. New eyes on it, good timing light... that's all I can come up with.
billr wrote:New eyes on it, good timing light... that's all I can come up with.
I agree.
I also want to pose an additional question to the OP, pretty much unrelated to the erroneous timing readings he is experiencing....... How did you come up with a 15* Tooth #1 Angle without knowing where the sensor is in relation to the missing teeth?
Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/extra 3.4.2 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
TinyIOX from JBPerformance
billr wrote:New eyes on it, good timing light... that's all I can come up with.
I agree.
I also want to pose an additional question to the OP, pretty much unrelated to the erroneous timing readings he is experiencing....... How did you come up with a 15* Tooth #1 Angle without knowing where the sensor is in relation to the missing teeth?
Ken
,
Thats what I was wondering. Has anyone heard of an LS1 using a 60-2 wheel?
Have you used a simple timing light to verify the MS timing corresponds to the crank, and that it stays constant throughout the rpm range? Until we are certain timing is accurate logs are pretty meaningless. When a log shows running at 10 BTDC we need to know that the #1 plug is firing at 10 BTDC.
Ok well no one i know has a non dial back timing light... but am i wrong in saying the a dial back timing light is a non when set to 0... and 2 timing lights made 15 years apart are reading the same exact thing i am pretty sure its ok to assume that the lights are working as intended.
Ok does anyone know the answer to my previous 55 to 60 question....
also i cant seem to find much info on installing the tooth wheel does it only fit in one position? i am going to take off the starter and crank sensor and start counting teeth tonight.
"Ok does anyone know the answer to my previous 55 to 60 question...."
Most (all?) of us can't comment on that because we have no clue what crank angle it really relates to. The run-log, of course shows a steady 10 degrees BTDC. So what does that "55-60" mean? Are you saying when MS sets 10 BTDC the #1 plug fires in the 55-70 BTDC range? Most (again, all?) of us don't believe the engine can run under any appreciable load with that much spark advance, so are convinced either both those dial-back lights are tripping you up or your procedure for making/reading the timing marks is flawed. Get a good timing light (non-dial-back) and get another set of eyes to check your work. Yes, I'm being just as "redundant" as Ken, but I feel it is the only appropriate comment I can make at this point. Since you have a missing-tooth crank wheel (60-2), I would switch to "wasted COP" and eliminate any possibilities that something in the cam sensing is tripping you up.
Edit: My gut-feeling is that you are reading 55-70 degrees ATDC on the cylinder preceding #1
