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Post by muttsnuts on Apr 5, 2024 15:57:28 GMT 1
Been doing some tweaks on one of my bikes recently, being doing a bit at a time as I get chance etc, pretty pleased with the improvements, although one part did involve 10hrs of porting work ! Got more stuff to do/try etc, but so far its pretty good for a 350cc YPVS motor  |
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Post by lcmarky on Apr 5, 2024 16:09:54 GMT 1
Nice work. I was hoping for > 70 with my 400cc motor. We will see later this month Dave!
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Post by midlifecrisisrd on Apr 5, 2024 16:20:48 GMT 1
Nice result
Steve
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Post by arrow on Apr 5, 2024 16:32:29 GMT 1
That's impressive.
What's also impressive is it makes 50hp just shy of 7.5k.
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Post by srhiskx on Apr 5, 2024 16:45:29 GMT 1
Impressive gains!
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Post by muttsnuts on Apr 5, 2024 16:50:54 GMT 1
thanks guys, I've kept a log of each change I made along with graphs etc, once I get chance I'll do a write up on each change and what gains/improvements each part did
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Post by jon on Apr 5, 2024 17:18:03 GMT 1
What is more impressive to me is the area under the curve. Sure it’s easy to get a higher top BHP figure at the expense of bottom end, but not in this case. A gain all through the Rev range and getting rid of the annoying 5500 flat spot.
Now it’s easy to rig dyno graphs by using a poor setup to start with, but if the dyno is accurate it was a healthily 54 BHP to start with for a 350.
Jon
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Post by foxyjohn on Apr 5, 2024 17:20:16 GMT 1
Fahron 370 slayer really good spread of power
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Post by muttsnuts on Apr 5, 2024 18:48:33 GMT 1
What is more impressive to me is the area under the curve. Sure it’s easy to get a higher top BHP figure at the expense of bottom end, but not in this case. A gain all through the Rev range and getting rid of the annoying 5500 flat spot. Now it’s easy to rig dyno graphs by using a poor setup to start with, but if the dyno is accurate it was a healthily 54 BHP to start with for a 350. Jon my dyno is very accurate.........no fudging of figures, it does what it does, anyone who's been to my dyno for setup will tell you its all correct and above board, plus its calibrated once a month and is only 18 months old, so its not worn out or knackered or a home made jobbie ! |
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Post by 4l04ever on Apr 5, 2024 19:00:17 GMT 1
What is the basic spec of the engine used for testing? What exhausts, carbs etc?
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Post by urbantangleweed on Apr 5, 2024 19:43:47 GMT 1
Impressive that Dave, nice work.
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Post by muttsnuts on Apr 5, 2024 20:32:33 GMT 1
What is the basic spec of the engine used for testing? What exhausts, carbs etc? engine is a 350 on 0.75mm O/S Exhaust are my F2 performance pipes Stock VM26 31k-00 carbs (different internals though) VF4 reeds Ignitech Ported barrels Skimmed head - but running head gasket Stock ignition coil Stock stator and flywheel Running oil pump Next traunch of mods will include; Dynacoil ignition coils Modified cyl head to my spec Fitting 28mm PWK's and billet manifolds (no crossover pipe) Power dynamo kit Possibly 32mm or 34mm carbs depending upon time, money and how its all looking upto this point I am also thinking of revisiting my F2 pipe design as its been 7+yrs since I did them and I've completely changed my porting, so I could be losing some BHP there, but not modelled it yet to know for sure |
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Post by donkeychomp on Apr 5, 2024 21:13:24 GMT 1
That's amazing for those mods and still keeping it as a 350. Nice one indeed matey!
Alex
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Post by chrisg on Apr 5, 2024 21:37:33 GMT 1
What is the basic spec of the engine used for testing? What exhausts, carbs etc? engine is a 350 on 0.75mm O/S Exhaust are my F2 performance pipes Stock VM26 31k-00 carbs (different internals though) VF4 reeds Ignitech Ported barrels Skimmed head - but running head gasket Stock ignition coil Stock stator and flywheel Running oil pump Next traunch of mods will include; Dynacoil ignition coils Modified cyl head to my spec Fitting 28mm PWK's and billet manifolds (no crossover pipe) Power dynamo kit Possibly 32mm or 34mm carbs depending upon time, money and how its all looking upto this point I am also thinking of revisiting my F2 pipe design as its been 7+yrs since I did them and I've completely changed my porting, so I could be losing some BHP there, but not modelled it yet to know for sure Phase 2 will be really interesting, but those figures are impressive as they are. Move over Stan.  |
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Post by 4l04ever on Apr 5, 2024 21:53:38 GMT 1
4L0 or YPVS?
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Post by muttsnuts on Apr 5, 2024 21:56:59 GMT 1
YPVS  think some people thought that was a 350LC engine, best I've done one of them is 68bhp at the moment, need to try and get back on getting one over 70bhp - the thing is I am trying to keep them reliable, the YPVS is only using 66% of ring to bore, which is low compared to the normal 68% to 70% |
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Post by srhiskx on Apr 5, 2024 22:02:27 GMT 1
That is impressive when you are running 31k carbs. Can’t wait to see difference when you bolt on the PWK carbs.
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Post by donkeychomp on Apr 5, 2024 22:44:44 GMT 1
PV? Ah...nuts (Mutts).
Alex
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Post by jon on Apr 6, 2024 7:25:46 GMT 1
What is more impressive to me is the area under the curve. Sure it’s easy to get a higher top BHP figure at the expense of bottom end, but not in this case. A gain all through the Rev range and getting rid of the annoying 5500 flat spot. Now it’s easy to rig dyno graphs by using a poor setup to start with, but if the dyno is accurate it was a healthily 54 BHP to start with for a 350. Jon my dyno is very accurate.........no fudging of figures, it does what it does, anyone who's been to my dyno for setup will tell you its all correct and above board, plus its calibrated once a month and is only 18 months old, so its not worn out or knackered or a home made jobbie ! I wasn’t suggesting your dyno was inaccurate. Merely that 54 BHP was a good start. Makes more sense being a PV rather than an LC, but still a good start engine. Jon |
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Post by muttsnuts on Apr 6, 2024 8:55:40 GMT 1
yeah, when I got the barrels off somebody had been playing, which is one of the reasons it took a while to port them as I was trying to work around what had been done
had an LC engine do 68bhp, but it was a race engine in fairness, not really what I am about when it comes to tuning, prefer to make engines perform but with longegivity as that is what my customers want, this one is super safe at the moment
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Post by bezzer on Apr 6, 2024 9:19:19 GMT 1
YPVS think some people thought that was a 350LC engine, best I've done one of them is 68bhp at the moment, need to try and get back on getting one over 70bhp - the thing is I am trying to keep them reliable, the YPVS is only using 66% of ring to bore, which is low compared to the normal 68% to 70% Incredible to think of 68BHP from an engine with an original design intent of 46 !. Id be ecstatic with 60 BHP and reliable as you state Dave. Superb gains made on the YPVS engine too, looks to be revving really cleanly, right through the range. Top work Squire 😀. |
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Post by Yogi on Apr 6, 2024 9:26:29 GMT 1
Impressive 👌
Looking good Dave. When’s the unveiling 🤔
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Post by muttsnuts on Apr 6, 2024 17:40:12 GMT 1
Impressive 👌 Looking good Dave. When’s the unveiling 🤔 you know the bike already, although its had a fair amount of work done to it and changes, more on it next week too all being well |
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think some people thought that was a 350LC engine, best I've done one of them is 68bhp at the moment, need to try and get back on getting one over 70bhp - the thing is I am trying to keep them reliable, the YPVS is only using 66% of ring to bore, which is low compared to the normal 68% to 70%
