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Post by David7355 on Mar 8, 2009 11:48:48 GMT -5
Tried out my new(used) Computech EGT meter yesterday. Forgot to turn it on first pass. Second pass(92 jets) it read 1342 degrees. Changed to 94 jets and the next pass it read 1357. First 2 passes were 10.189 and 10.190. After jetting up it slowed to a 10.23.
I personally think the thing is junk. Whatta ya'll think??
I'm about ready to just order a brand new one from family or biondo and pitch this used one on the shelf.
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Post by bigblue466 on Mar 8, 2009 12:19:23 GMT -5
How far is the sensor from the head?
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Post by David7355 on Mar 8, 2009 13:32:36 GMT -5
1 1/4" from flange...# 4 cylinder... SBC
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Post by bigblue466 on Mar 8, 2009 15:10:48 GMT -5
Jet it back to 92 and leave it, maybe a high speed air bleed issue try going smaller one size with the 92 and see, my BBF likes around 1250
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Post by David7355 on Mar 8, 2009 18:22:05 GMT -5
1350° seems awfully high to me. Was just wondering if it's REALLY that high or if the EGT meter I got hold of is junk.
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Post by bigblue466 on Mar 8, 2009 18:58:32 GMT -5
It does not sound like it's bad I think Heath runs around there, but mine don't like it that high. I think it is showing you are lean and thats way it slowed down.
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Post by Eric Bowling on Mar 8, 2009 19:35:26 GMT -5
I personally dont recommend running it that high, Heath and his boys run Heads Up stuff and try to get as much out of their equipment as possible, (Correct me if I am wrong Heath). What motor are you running again Dave? Mine runs about 1270 going through the traps, 1350 seems pretty high. You may try just buying a new probe and trying that. What air bleeds you running? Fuel Pressure? What % is the E85 you are running?? Header size?
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Post by David7355 on Mar 8, 2009 20:13:15 GMT -5
Air bleeds are whatever Heath sent me. Not sure without looking. Engine is a 13:1 383 SBC with Dart Pro-1 Heads(aluminum). Fuel pressure is set at a little less than 7. E85 is somewhere in the 85-87% range. I tested it 3 times. Headers are stepped 1 5/8" to 1 3/4" ...3" collectors... ...running through 3" Dynatech race mufflers.
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Post by ericbowling on Mar 8, 2009 20:17:37 GMT -5
Check to see if they are 25's if not Put them in, Take your fuel pressure up around 7.5-8spi, make a pass and see what it does, what is your idling temp? Timing? Air Mixutre screws?
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Post by Heath Daniel on Mar 9, 2009 9:52:08 GMT -5
Eric, bigblue, how you guys doing? David's got .024 hs and .061 idle bleeds so that should not be the issue. As far as the egt reading goes, I think I need a new probe now too. My screen always says OL which means out of limits when I finish a run but it's still running GREAT and we're not hurting anything so I'm not messing with it. I think everyone knows how I feel about meter readings. If you jet up and it slowed down, go the other way (2 sizes at a time) as long as it's picking up then when you hit the slow down point in that direction, back up one size at a time until the best mph is achieved and that's it. After you get you jetting right play with the timing the same way. What's your total timing set at again David? We have found a ton of et by backing off the timing on several combinations that we have tested lately.
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Post by David7355 on Mar 9, 2009 10:25:42 GMT -5
... David's got .024 hs and .061 idle bleeds so that should be the issue. ....... Did you mean to say the bleeds should NOT be the issue Heath?  ?? Timing is locked out at 35. I guess I'll just put the 92's back in it and go racing. Might buy or borrow another egt meter later and check it again. I really think somethings wrong with the one I bought. |
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Post by Eric Bowling on Mar 9, 2009 11:27:49 GMT -5
I run 30 Degrees Total timing in mine slows down anything above that. 406 sbc.
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Post by Heath Daniel on Mar 9, 2009 12:05:01 GMT -5
Should NOT be an issue is correct David. I just fired my proof reader, oh wait, that's me, never mind.  |
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Post by David7355 on Mar 9, 2009 12:40:10 GMT -5
I run 30 Degrees Total timing in mine slows down anything above that. 406 sbc. Interesting. I'll definitely play with timing after I get my jetting where I want it. |
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Post by hobbesnmina2001 on Mar 10, 2009 0:30:41 GMT -5
You might want to double check by borrowing or using your meter on someone elses engine first. It may be your meter is off, or it could be you have a lean cylinder due to uneven distribution.
Is there a reason you chose #4?
Actually #4 should not be a lean cylinder unless there is a problem. Usually #1, #2, # 7, #8 are commonly used on Chevies as they tend to be the lean cylinders. Some people feel #1, #2 are going to be affected the most by acceleration, the idea being if you tune the leanest cylinder it should keep you out of trouble.
Carlos
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?? 