690 FWHP DLRE, MMS, Cam Motion, LLR, FAST 102 W MID LENGTH RUNNERS
06-13-2017, 11:11 AM
#41
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One thing I see people say repeatedly is; "This head or that head needs duration spread of x amount of degrees." Yes, the head does influence the valve events, but that thinking does not take into consideration RPM, power levels or the vehicles exhaust system. So, it is a failed generalization.
06-13-2017, 02:36 PM
#43
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Hey Dan.
Just saw your post! Thanks for the cam card. When accounting for the hot lash both your cam and Big Hammer's are surprisingly small for the RPM range and size of the engine. The stock-ish stroke length makes a big difference vs a 4" arm.
An equivalent hydraulic would only have 11 and 17* of duration for your two cams. My drag LS3 with a Victor Jr. has 25* of overlap - 239/251 110+2. It has a flat peak from 7000-7400. It is actually very mild to drive around, but is carbureted and has a 5800 stall converter and a glide lol.
I did let it slip in the other thread that I picked up a mid length Fast. I drove out to Tony's shop and picked up an already Mamofied one he had on the shelf. Super nice guy! Had a fun chat bs-ing about stuff for about an hour and of course left with a gorgeous intake!! That does mean I spent my solid roller budget on induction though...I'll be using short travel hydraulic Johnson lifters.
I have nottttt received the SPS heads yet. Nothing against Gavin. Ran into some delays getting the custom sized hollow stem valves - he got a little screwed over by the mfg'ers. I was part of the initial batch of heads that were going out and the valve delays ran into his planned shop expansion/move...so got a little backed up. He started working on my head and noticed something odd...the CNC wasn't done properly and instead of hand blend fudging it he's starting with a fresh casting.
I wish I had the money to slide a few different cams into my engine when I finally get to build it. I've been kind of obsessively playing with the cam timer to try and nail the best compromise. Your guy's builds are making me think I can go smaller, but then again I do have a 4" crank which will need more duration to achieve the same rpm range given the higher piston speed at the same rpm.
I do think I want to get a 243 (hydraulic) intake lobe in mine, but that starts getting real big. 243/258 112+3 seems real good if I could stomach the 26.5* overlap. Looking at your cam a smaller split 243/250 110+2 is also pretty enticing with the same overlap. 239/246 111+2 would also probably run great at 20.5* overlap.
I think the short runners will really run well with a tight center - IVO at least 10* BTDC - preferably 12*+.
Just saw your post! Thanks for the cam card. When accounting for the hot lash both your cam and Big Hammer's are surprisingly small for the RPM range and size of the engine. The stock-ish stroke length makes a big difference vs a 4" arm.
An equivalent hydraulic would only have 11 and 17* of duration for your two cams. My drag LS3 with a Victor Jr. has 25* of overlap - 239/251 110+2. It has a flat peak from 7000-7400. It is actually very mild to drive around, but is carbureted and has a 5800 stall converter and a glide lol.
I did let it slip in the other thread that I picked up a mid length Fast. I drove out to Tony's shop and picked up an already Mamofied one he had on the shelf. Super nice guy! Had a fun chat bs-ing about stuff for about an hour and of course left with a gorgeous intake!! That does mean I spent my solid roller budget on induction though...I'll be using short travel hydraulic Johnson lifters.
I have nottttt received the SPS heads yet. Nothing against Gavin. Ran into some delays getting the custom sized hollow stem valves - he got a little screwed over by the mfg'ers. I was part of the initial batch of heads that were going out and the valve delays ran into his planned shop expansion/move...so got a little backed up. He started working on my head and noticed something odd...the CNC wasn't done properly and instead of hand blend fudging it he's starting with a fresh casting.
I wish I had the money to slide a few different cams into my engine when I finally get to build it. I've been kind of obsessively playing with the cam timer to try and nail the best compromise. Your guy's builds are making me think I can go smaller, but then again I do have a 4" crank which will need more duration to achieve the same rpm range given the higher piston speed at the same rpm.
I do think I want to get a 243 (hydraulic) intake lobe in mine, but that starts getting real big. 243/258 112+3 seems real good if I could stomach the 26.5* overlap. Looking at your cam a smaller split 243/250 110+2 is also pretty enticing with the same overlap. 239/246 111+2 would also probably run great at 20.5* overlap.
I think the short runners will really run well with a tight center - IVO at least 10* BTDC - preferably 12*+.
Daniel
I believe you will be very happy with Tony's Mid-Length Runner Fast.
Your 4.00' stroke has 11% greater piston speed then my 3.60"
at the same RPM. Your 7000 RPM = My 7700 RPM.
That said your >2800 lb manual trans EFI street/sports car
would benefit from a wider LSA VS a dedicated carbureted drag
car utilizing a glide with a 5500+ stall converter. An overlap of 20* or
less would be easier to tune and more enjoyable on the street
and just cruising around. If it were my car I would spec
239/247, 112+3 on the small side to 243/251, 114+3, on the
large side. Similar curve to mine with +30-40 lb ft, peaking
~6800, carrying to ~7200 shift point with HR.
Looking forward to your flow #s, build thread, and results.
Dan
06-13-2017, 03:33 PM
#44
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I have to say, this is a pet peave of mine as well. I've started pushing back on these types of generalities by saying "tell me what you don't like about the valve events" If the valve events are right, then everything else is just calculated off the valve events. But I have had people say things like "the valve events look good, but i think that's too much split" That's like saying you like the bore and stroke of an engine, but not the displacement.
To begin, congrats again for building and superbly documenting your
Phenomenal SBE LS1, comparing the LLSR to a HR as well as
comparing MAMOFIED MSD & FAST WAS/IS of incredible
benefit for everyone who took the time to read and digest
the Data you provided.
It is without a doubt the most impressive SBE LS1 I have seen on
LS1 Tech or CF in over the 12+ years that I have been following both forums.
That said there is more then 1 way to spec a cam, (ask Tony LOL).
You used an 8* split which is at the far end of what I have seen
with Tony's Cathedral Heads, and with your RPS Lightened BC2
clutch (I have the same for my C5) your cam is at the far end of streetable
for you, if I have understood some of your comments correctly.
Then Jake Fusion (super hulk smash) says 12* split is the Ideal
for a max effort street/strip cathedral head application.
Would 12* Exhaust Split have been beneficial to your application?
I would bet Not!
I used a 6* Exhaust Split with my LS3 Application, more conventional
wisdom being 12-16*. I reached the exact power curve I wanted,
particularly from 5400-7600 RPM, would a 12* Exhaust Split have
given me any more or a narrower LSA? I am pretty sure not.
My overall point is with top of the line cylinder heads and an optimized
intake & exhaust system (from the very leading edge to the tips of the mufflers)
splitting hairs over a few degrees here or there as long as everything else (displacement,rpm,weight,gears,trans and application) is correct is almost
humorous at times. Not saying the right Cam isn't important it obviously
is, just that more then 1 will usually work very well until you get to the
Absolute Pinnacle of Professional Competition.
06-13-2017, 05:00 PM
#45
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Darth,
To begin, congrats again for building and superbly documenting your
Phenomenal SBE LS1, comparing the LLSR to a HR as well as
comparing MAMOFIED MSD & FAST WAS/IS of incredible
benefit for everyone who took the time to read and digest
the Data you provided.
It is without a doubt the most impressive SBE LS1 I have seen on
LS1 Tech or CF in over the 12+ years that I have been following both forums.
That said there is more then 1 way to spec a cam, (ask Tony LOL).
You used an 8* split which is at the far end of what I have seen
with Tony's Cathedral Heads, and with your RPS Lightened BC2
clutch (I have the same for my C5) your cam is at the far end of streetable
for you, if I have understood some of your comments correctly.
Then Jake Fusion (super hulk smash) says 12* split is the Ideal
for a max effort street/strip cathedral head application.
Would 12* Exhaust Split have been beneficial to your application?
I would bet Not!
I used a 6* Exhaust Split with my LS3 Application, more conventional
wisdom being 12-16*. I reached the exact power curve I wanted,
particularly from 5400-7600 RPM, would a 12* Exhaust Split have
given me any more or a narrower LSA? I am pretty sure not.
My overall point is with top of the line cylinder heads and an optimized
intake & exhaust system (from the very leading edge to the tips of the mufflers)
splitting hairs over a few degrees here or there as long as everything else (displacement,rpm,weight,gears,trans and application) is correct is almost
humorous at times. Not saying the right Cam isn't important it obviously
is, just that more then 1 will usually work very well until you get to the
Absolute Pinnacle of Professional Competition.
To begin, congrats again for building and superbly documenting your
Phenomenal SBE LS1, comparing the LLSR to a HR as well as
comparing MAMOFIED MSD & FAST WAS/IS of incredible
benefit for everyone who took the time to read and digest
the Data you provided.
It is without a doubt the most impressive SBE LS1 I have seen on
LS1 Tech or CF in over the 12+ years that I have been following both forums.
That said there is more then 1 way to spec a cam, (ask Tony LOL).
You used an 8* split which is at the far end of what I have seen
with Tony's Cathedral Heads, and with your RPS Lightened BC2
clutch (I have the same for my C5) your cam is at the far end of streetable
for you, if I have understood some of your comments correctly.
Then Jake Fusion (super hulk smash) says 12* split is the Ideal
for a max effort street/strip cathedral head application.
Would 12* Exhaust Split have been beneficial to your application?
I would bet Not!
I used a 6* Exhaust Split with my LS3 Application, more conventional
wisdom being 12-16*. I reached the exact power curve I wanted,
particularly from 5400-7600 RPM, would a 12* Exhaust Split have
given me any more or a narrower LSA? I am pretty sure not.
My overall point is with top of the line cylinder heads and an optimized
intake & exhaust system (from the very leading edge to the tips of the mufflers)
splitting hairs over a few degrees here or there as long as everything else (displacement,rpm,weight,gears,trans and application) is correct is almost
humorous at times. Not saying the right Cam isn't important it obviously
is, just that more then 1 will usually work very well until you get to the
Absolute Pinnacle of Professional Competition.
I agree with you, a 12 degree split would not have been right for me, but mainly because I like to have the overlap split at TDC to take advantage of the "fifth cycle" jump-starting the cylinder fill. So a 12-degree split would put my EVO at 61 degrees, which would be too early IMO. I guess we're saying the same thing in a different way. But I always look to the valve events first. Duration and LSA are just calculated off the valve events.
Does that mean looking at the splits and durations aren't a good gut check? No it doesn't. Of course they are very good gut checks. but if I can't identify how I'd like to change the valve events, then i'd leave the duration and LSA untouched. That's why I say, if you figure a mid to high 40's IVC and a mid to high 50's EVO and a centered overlap, you're pretty much guaranteed to have 8-12 degrees of split, just depending on where you land.
in your case, the overlap is intake biased a smidge - which obviously worked for your combination!
Lastly - you're damn right about splitting hairs over a few degrees. Some of the "how will these two cams be different" comparisons when you honestly would not be able to tell the difference are kind of funny.
These threads are great though! I love actual tech discussions on tech!
07-01-2017, 10:14 AM
#48
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07-01-2017, 10:41 AM
#49
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Originally Posted by NAVYBLUE210
3/8 by .120 wall thickness Pushrods here. Stiffness is absolutely critical with
7500+ RPM.
7500+ RPM.
07-01-2017, 12:02 PM
#50
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They actually fit no problem with the mast heads. I didn't set out to run a pushrod that big. But after a lot of measuring they came out to the exact size of a common BBC pushrod. Checked eBay and there was 16 Manley 7/16 pushrods the exact length that I needed. So I bought them. I was going to use 3/8 but did it want to wait to get them made
07-01-2017, 02:06 PM
#51
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Talk about convenience! Or divine providence!
What is the max PR dia. that a stock LS can handle, as far as you know?
What is the max PR dia. that a stock LS can handle, as far as you know?
07-01-2017, 02:50 PM
#53
TECH Senior Member
OK thanks!
07-01-2017, 03:51 PM
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Originally Posted by big hammer
Going to a larger diameter adds a lot more strength than increasing wall thickness
07-31-2017, 11:44 PM
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Small update:
Ring & pinion, lightened Auburn diff & Transmission Internals going to
Abel Chevrolet Wednesday for assembly.
Then install with MAMOFIED RPS BC2 Clutch, Trans & Diff, along with
ECS Brace, Pfadt trans Brace and suspension bits.
Will start another thread for driveline efficiency/losses.
Ring & pinion, lightened Auburn diff & Transmission Internals going to
Abel Chevrolet Wednesday for assembly.
Then install with MAMOFIED RPS BC2 Clutch, Trans & Diff, along with
ECS Brace, Pfadt trans Brace and suspension bits.
Will start another thread for driveline efficiency/losses.
08-01-2017, 12:31 AM
#57
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That'll be awesome! Same engine on engine dyno and chassis dyno!
08-14-2017, 09:48 AM
#58
Steve,
Hope you don't mind me asking a couple questions in your thread,
After all it is directly responsible for my decision to use a
Cam Motion LLSR for my build, and subsequently my recommendation
For 64 Post to get one as well, in fact the Exact Valve Events you
Specified.
So my question regarding my build.
Given 20/20 hindsight with my specs & Dyno curves/results along
With BigHammers curves/results (although rear wheel results).
Given that we have very similar Airflow (Heads & Intake),
Bore/Stroke and desired Peak operating range (6000-7500).
243/249 115+3 VS 239/253 112+3.
1 If I were to change lobes from .395/.375 to .405/.395
Increasing lift to ~.696"/.680" up from .680"/.645" gross with
My 1.72 ratio roller rockers. What valve Events (durations, LSA & Advance
Would you specify if I wanted to reduce my peak from
7100-7300 to 6900-7100,
2. And alternately increase to 7500 Peak with
Shift points 400-500 RPM past peaks.
Feel free to answer here or in my 690 FWHP Dyno Results Thread.
Thanks
Dan
Hope you don't mind me asking a couple questions in your thread,
After all it is directly responsible for my decision to use a
Cam Motion LLSR for my build, and subsequently my recommendation
For 64 Post to get one as well, in fact the Exact Valve Events you
Specified.
So my question regarding my build.
Given 20/20 hindsight with my specs & Dyno curves/results along
With BigHammers curves/results (although rear wheel results).
Given that we have very similar Airflow (Heads & Intake),
Bore/Stroke and desired Peak operating range (6000-7500).
243/249 115+3 VS 239/253 112+3.
1 If I were to change lobes from .395/.375 to .405/.395
Increasing lift to ~.696"/.680" up from .680"/.645" gross with
My 1.72 ratio roller rockers. What valve Events (durations, LSA & Advance
Would you specify if I wanted to reduce my peak from
7100-7300 to 6900-7100,
2. And alternately increase to 7500 Peak with
Shift points 400-500 RPM past peaks.
Feel free to answer here or in my 690 FWHP Dyno Results Thread.
Thanks
Dan
I'm curious for your thoughts.
08-14-2017, 06:00 PM
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I don't feel my results are lacking by any means, just comparing
Curves & Peaks given that our Head/Intake combos are very
Similar with quite different cam specs (or valve events Steve).
If I was speccing today with 20/20 hindsight I would go
Same durations, LSA 114+3 (1* Tighter, same Advance)
and increase lift + .016/.035 to .696"/.680" gross,
Keeping the same springs. The Goal being to
Peak 200 RPM earlier with just a little bit more.
Just curious what Steve would have specced.
And the other cam being for a 7500 Peak shifting @~8000 RPM.
I would go 249/257 115+3 with the aforementioned lift
Increases. Just Hypothetical scenarios here not planning to
Change my cam LOL.