Carb Jetting advice please
08-26-2018 | 08:00 PM
#32
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From: Grand Rapids, MI
Back of intake.
I run 1" into the bottom of my headers.
-10 back of intakes to the top of the headers and they do have ~1/4"+" flow restrictors in them. You can dump out if you'd like to.
08-26-2018 | 08:21 PM
#34
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From: Sodus MI
Oh and the same buddy that recommended square jetting also recommended locking my timing at 28 degrees....if what you were saying MT that my timing is coming in too early then wouldn't locking the timing amplify that and make it worse??
08-27-2018 | 08:36 AM
#35
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From: chicago
08-27-2018 | 08:45 AM
#36
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From: chicago
Id definitely find out why youre seeing 140* water temp with no thermostats. Your guide issue may have been stemmed from a water flow issue. Do you have water psi gauge?
28* timing is low at wot. 525sc ran 35 deg total. Retarding the timing excessively raises exhaust temp, and hurts power.
28* timing is low at wot. 525sc ran 35 deg total. Retarding the timing excessively raises exhaust temp, and hurts power.
08-27-2018 | 09:04 AM
#37
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From: Sodus MI
Could very well be caused by the -12 an Libra like you pointed out already....plan to def look into that further once it’s back together...
Makes sense what you’re saying with the timing for sure...I’m not a total newb and understand how timing works to a point...just my first go at an actual run hard blower motor lol...just for my own knowledge...are you saying no go to locked timing as a whole or just at the 28 degrees?? Just trying to learn is all...of course you can read anything on the internet but I read a lot of info about locked timing vs not and it seems like it may help smooth out the idle and run a little better down low if it’s locked out?? Like I said just trying to get some knowledge so please don’t think I’m not listening cuz trust me I am!! And also I do understand every motor is different and there’s no end all be all to tuning just trying to figure out the best route as I don’t have Endless funds to keep rebuilding this thing lol
i do not have a water pressure gauge to answer that question...honestly I felt fuel pressure and oil temp were more important so I put my money into those gauges instead...I could get one if I have to don’t get me wrong just haven’t made room for it in the budget yet
Makes sense what you’re saying with the timing for sure...I’m not a total newb and understand how timing works to a point...just my first go at an actual run hard blower motor lol...just for my own knowledge...are you saying no go to locked timing as a whole or just at the 28 degrees?? Just trying to learn is all...of course you can read anything on the internet but I read a lot of info about locked timing vs not and it seems like it may help smooth out the idle and run a little better down low if it’s locked out?? Like I said just trying to get some knowledge so please don’t think I’m not listening cuz trust me I am!! And also I do understand every motor is different and there’s no end all be all to tuning just trying to figure out the best route as I don’t have Endless funds to keep rebuilding this thing lol
i do not have a water pressure gauge to answer that question...honestly I felt fuel pressure and oil temp were more important so I put my money into those gauges instead...I could get one if I have to don’t get me wrong just haven’t made room for it in the budget yet
08-27-2018 | 10:51 AM
#38
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From: chicago
I personally prefer a timing curve. I did run locked timing and it worked. But after seeing how less timing in the midrange made more power than locked timing, it was a no brainer to me.
Id rig up at least a temporary mechanical psi gauge to see what kind of water psi you are seeing in the engine. If youre seeing 140* at the front of the engine, its quite possible youre seeing close to 200* at the back like rookie said. Which is no good for sticking valves, detonation , etc.
Id rig up at least a temporary mechanical psi gauge to see what kind of water psi you are seeing in the engine. If youre seeing 140* at the front of the engine, its quite possible youre seeing close to 200* at the back like rookie said. Which is no good for sticking valves, detonation , etc.
08-27-2018 | 02:47 PM
#40
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From: Sodus MI
What do you mean by fuel burn?? I didn’t have it dynoed...just had it built and put it in the boat
i can for sure try to rig up a pressure gauge...something just occurred to me as well...my temp sensor is located on the port side rear of the intake right in the water passage...that being said my exhaust runs together about 5-6 inches above it and dumps out of the center of transom right behind the distributor...I do have the tails wrapped as they are pretty much dry and get pretty hot so it may be a possibility that I’m getting some residual heat from them in the temp sensor??
Back to timing....should I be running less of a curve?? My base timing is 10-11 and all in being 30 at 28-2900....is it too much advance?? Should I try to change bushings and springs and get my base timing up and still be all in around 3000?? Or for the time being to get rid of a variable should I lock it at say 30-31 degrees and tackle the timing curve once I get the carbs figured out??
I know now this is a lot of topics covered in one thread and I appreciate you guys hangin in there and helping me out!!
i can for sure try to rig up a pressure gauge...something just occurred to me as well...my temp sensor is located on the port side rear of the intake right in the water passage...that being said my exhaust runs together about 5-6 inches above it and dumps out of the center of transom right behind the distributor...I do have the tails wrapped as they are pretty much dry and get pretty hot so it may be a possibility that I’m getting some residual heat from them in the temp sensor??
Back to timing....should I be running less of a curve?? My base timing is 10-11 and all in being 30 at 28-2900....is it too much advance?? Should I try to change bushings and springs and get my base timing up and still be all in around 3000?? Or for the time being to get rid of a variable should I lock it at say 30-31 degrees and tackle the timing curve once I get the carbs figured out??
I know now this is a lot of topics covered in one thread and I appreciate you guys hangin in there and helping me out!!
