Steve, have you noticed those that build no actual real engines, or do any testing, and have no data of their own, are the most vocal opposition to those that do build real engines?
Randy
Moderator: Team
Steve, have you noticed those that build no actual real engines, or do any testing, and have no data of their own, are the most vocal opposition to those that do build real engines?
Be it on the dyno or the race track, the scoreboard holds no bias and tells the truth, why do they not participate?
It's always been the case of of more CR equals more duration. Or more specifically, a later IVC. This was directly linked to the dynamic compression and that became the target value. This was irrespective of port flow or peak HP RPM.Stan Weiss wrote: ↑Sat Feb 15, 2020 2:02 amKevin,skinny z wrote: ↑Fri Feb 14, 2020 5:20 pmThis is exactly how I'm learning the program works. And for my intents and purposes, it's giving me what I'm looking for with the engine parameters that I have. It's also interesting to see how one plays out against another. That's how the CR vs duration conversation came up in the first place.Stan Weiss wrote: ↑Fri Feb 14, 2020 4:56 pm Torque Master is not a complete engine simulation program. There are a limited number of inputs.
If just CR is increased (and peak HP RPM has remained constant) the duration shown is reduced but the est HP still has increased.
For the program to want / show the same duration with the higher CR as it did with the lower CR the peak HP RPM would needed to be raised.
Stan
What was the results from the other software that you used for recommended cam duration verses CR?
Stan
In my reply to Stan regarding virtual results from other software I mentioned that there's always a strong connection between CR and duration/IVC. Typically I can see this being the case but not always.randy331 wrote: ↑Fri Feb 14, 2020 7:54 pm... I did a back to back raise the comp test. Same day on the dyno I pulled the heads and angle milled them enough to raise comp about 1 full point, put the heads back on and re pulled it. There was no noticeable change in where it made peak tq/hp at and there wasn't the power gain most think would happen with that increase in comp.
Randy
Their claims were angle milling the head after port work and valve job could show little to no gain and could actually hurt power, Judson said in one case they had to rework the chamber to get the power back and give up the compression?
you got links to any of that?GARY C wrote: ↑Sat Feb 15, 2020 5:23 amSo this one test makes it conclusive?randy331 wrote: ↑Fri Feb 14, 2020 7:54 pmNo it doesn't. I did a back to back raise the comp test. Same day on the dyno I pulled the heads and angle milled them enough to raise comp about 1 full point, put the heads back on and re pulled it. There was no noticeable change in where it made peak tq/hp at and there wasn't the power gain most think would happen with that increase in comp.
Randy
SAM, BES, Wells and other Engine Builders have done similar test and concluded that angle milling a head as an after thought was not a good idea if one wanted to take advantage of an angle milled head.
Judson was the only one I read and all of his links are gone since changing their web page, Tony and Dennis told me when I was consulting them on engine builds.gmrocket wrote: ↑Sat Feb 15, 2020 5:17 pmyou got links to any of that?GARY C wrote: ↑Sat Feb 15, 2020 5:23 amSo this one test makes it conclusive?randy331 wrote: ↑Fri Feb 14, 2020 7:54 pm
No it doesn't. I did a back to back raise the comp test. Same day on the dyno I pulled the heads and angle milled them enough to raise comp about 1 full point, put the heads back on and re pulled it. There was no noticeable change in where it made peak tq/hp at and there wasn't the power gain most think would happen with that increase in comp.
Randy
SAM, BES, Wells and other Engine Builders have done similar test and concluded that angle milling a head as an after thought was not a good idea if one wanted to take advantage of an angle milled head.
Yes that was my understanding on the valve seat part and milling into the topcut could effect pressure recovery I would think?
Keep adding more compression and see what happens with the duration recommendation.skinny z wrote: ↑Fri Feb 14, 2020 5:20 pmThis is exactly how I'm learning the program works. And for my intents and purposes, it's giving me what I'm looking for with the engine parameters that I have. It's also interesting to see how one plays out against another. That's how the CR vs duration conversation came up in the first place.Stan Weiss wrote: ↑Fri Feb 14, 2020 4:56 pm Torque Master is not a complete engine simulation program. There are a limited number of inputs.
If just CR is increased (and peak HP RPM has remained constant) the duration shown is reduced but the est HP still has increased.
For the program to want / show the same duration with the higher CR as it did with the lower CR the peak HP RPM would needed to be raised.
Stan
For the program to behave predictably, as in higher CR calls for additional duration and overlap, the other target values have to adjusted accordingly. It's easy to manipulate in the data fields.
So we are back to the 280/230 deg lobe thats been done over and over againI have only 255 so dialing back the RPM to 5500 gets 279 on the intake with heads needing 257.
Touché, Orr.
Are you aiming for some specific DCR?skinny z wrote: ↑Mon Feb 17, 2020 1:42 pmTouché, Orr.
Well sir, it's certainly coming around that way. Perhaps a little tighter LSA than the norm.
Back in another forum I was trying to gain traction for "over-camming" the engine with respect to CR and peak HP RP and there was no contribution from anyone when I referenced a similar DV build with Edelbrock Performer heads and cams in the 284/240 range. The traditional approach was far too strong.
So, yeah, it may be I'll end up in the old school camp. Randy 331's thread, Pseudo racing engine surprise, is similar is some respects. CR is a little high and the RPM are also but still a fine example for me to duplicate (like many before).
FTR, best suggestion through TM is 284 single pattern on a 106 with 72 degrees of overlap or a dual pattern 284/288/106 with 74 degrees. That should make peak power around 5600 and use up all of my cylinder head capability. Decent DCR of 7.7 and cranking compression of 190+. I've built and tuned engines with that kind of spec so at least I've got that covered.
Not specifically but I am avoiding those I've found too high and those that are too low.