Houstons Engine Service H.E.S.
#8628
Joined: Jan 2011
Posts: 4,121
#8629
i send engines out with 5.5 turns lsn and 4 turns hsn . great starting point
#8630
9853ss 41005 is awesome on 5 ports in truck , 2013 and 2058 work very well but you will not see full potential of runtime and torque imo
#8632
#8634
#8637
Kind of a noobie question, but is it possible to get a stock p5xlt to drop right down to idle at a race tune? I had it running great last night at the track, nice and crisp with a nice steady idle and a trail of smoke at wot. But after a straight it would surge up for a few seconds, then drop down to idle. It seemed like if I richened the ls back out it would get to boggy in the slower sections.
I've seen a few other p5s that seem to do this as well so I'm just curious if that's the nature of a long needle carb or what. On the other hand I've heard people say that a properly tuned engine should drop straight back to idle.
I'm running a 2096/41021, Byron 30/11, c6 plug
Settings were pretty close to 3.75 hs, 5.25 ls and a .5mm gap
I've seen a few other p5s that seem to do this as well so I'm just curious if that's the nature of a long needle carb or what. On the other hand I've heard people say that a properly tuned engine should drop straight back to idle.
I'm running a 2096/41021, Byron 30/11, c6 plug
Settings were pretty close to 3.75 hs, 5.25 ls and a .5mm gap
#8638
Kind of a noobie question, but is it possible to get a stock p5xlt to drop right down to idle at a race tune? I had it running great last night at the track, nice and crisp with a nice steady idle and a trail of smoke at wot. But after a straight it would surge up for a few seconds, then drop down to idle. It seemed like if I richened the ls back out it would get to boggy in the slower sections.
I've seen a few other p5s that seem to do this as well so I'm just curious if that's the nature of a long needle carb or what. On the other hand I've heard people say that a properly tuned engine should drop straight back to idle.
I'm running a 2096/41021, Byron 30/11, c6 plug
Settings were pretty close to 3.75 hs, 5.25 ls and a .5mm gap
I've seen a few other p5s that seem to do this as well so I'm just curious if that's the nature of a long needle carb or what. On the other hand I've heard people say that a properly tuned engine should drop straight back to idle.
I'm running a 2096/41021, Byron 30/11, c6 plug
Settings were pretty close to 3.75 hs, 5.25 ls and a .5mm gap
Last edited by houston; 07-11-2015 at 11:41 AM.
#8639
If its not loading up , it stays running ,not excessively and making enough power to keep u happy i say its good , fuel pressures from tanks do some funny stuff. The novarossi carburetor definitely needs a good consistent fuel pressure from the tank , ive seen tanks cause inconsistencies, pipes cause inconsistencies, holes in pressure line ,etc. Etc.
#8640
Tech Master
Joined: Jan 2010
Posts: 1,628
Kind of a noobie question, but is it possible to get a stock p5xlt to drop right down to idle at a race tune? I had it running great last night at the track, nice and crisp with a nice steady idle and a trail of smoke at wot. But after a straight it would surge up for a few seconds, then drop down to idle. It seemed like if I richened the ls back out it would get to boggy in the slower sections.
It would either be:
1. Slightly lean top end
2. Somewhat excessive idle screw
3. Fat'ish bottom end
Now my money will be on your bottom end being about 10 minutes fat, since you describe it getting boggy if you richen the bottom end.
It's difficult to explain why this happens, but it does.



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