Lifter Shootout which lifter and why? Everyone's opinions welcome
11-30-2015, 11:51 AM
#201
There is a ton of "lobe" talk in this thread, as rookie in valve train knowledge.
I have a BTR stage 2 turbo cam in my to-buy cart... Where is it listed what type lobe it is?
I have also in my cart BTR .660 spring kit and Morel 5315s
I have a BTR stage 2 turbo cam in my to-buy cart... Where is it listed what type lobe it is?
I have also in my cart BTR .660 spring kit and Morel 5315s
11-30-2015, 12:57 PM
#204
TECH Veteran
That's somthing how a smaller cam with less lift can make more power/torque over a bigger wilder cam.
11-30-2015, 06:56 PM
#206
Im wondering if I should change my lifters now from the Morel 5290's. I still want a link bar setup though.
Currently a Martin Smallwood cam.
239/244 .674/.653 111+4
TFS215's 59cc with shimmed pac I think 1207 or 1206 .700'' springs.
2.04'' stainless valves Changing to turned down 2.04'' hollow stem LS3's
Harland sharp rockers Changing to Yella Terra Ultra lites
Morel 5290 Link bars
Comp 5/16''x.105'' push rods Changing to a 3/8'' pushrod
forged bottom end around 11.7 comp.
Ported Fast 92 possibly change to a ported 102.
Whats the opinion?
Currently a Martin Smallwood cam.
239/244 .674/.653 111+4
TFS215's 59cc with shimmed pac I think 1207 or 1206 .700'' springs.
2.04'' stainless valves Changing to turned down 2.04'' hollow stem LS3's
Harland sharp rockers Changing to Yella Terra Ultra lites
Morel 5290 Link bars
Comp 5/16''x.105'' push rods Changing to a 3/8'' pushrod
forged bottom end around 11.7 comp.
Ported Fast 92 possibly change to a ported 102.
Whats the opinion?
11-30-2015, 08:17 PM
#207
Caleb, back in 2001 I back to back tested a .500" lift cam in a 8000 rpm NMRA Pure Street setup on my chassis dyno. Both cams came from Comp, both had .500" lift, and both cams were within 1 degree of open/close points. The existing cam had BBC Extreme Marine lobes and would go 8000 rpm. The new cam from a well known cam guru had faster lobes, but made less power EVERYWHERE, and floated the valves so hard that at 7600 rpm, which is where they went through the traps at, the engine was down 90 rwhp.
So for me it was 14 years ago, not a decade, that I personally witnessed this. In the years to follow I was involved in tons of testing, as I am to this day, making the fastest pass in NMCA Real Street this year at 180 mph with a hydraulic roller cam is a testament to that.
We back to back tested a lot of cams on the engine dynos at TFS, and most times the cams with less lift and/or slower ramp speed actually made more power. Bear in mind almost everyone of these combinations had heads with VERY good midlift airflow, so I can see where the engine may not need the valve opened faster, as so much more airflow is available at the same lift compared to a poorer flowing set of heads.
I have not seen a Pro Stock lobe, but a good friend of mine Pat Topolinski just moved from KB Racing to the Power Nation TV Engine Power show. At KB Racing he was in charge of valve train, and did a lot of testing, of course. If you think Pro Stock uses the fastest lobes available, then you'd be wrong...
There's another saying I have, you can lead a horse to water, but you can not make him drink...
So for me it was 14 years ago, not a decade, that I personally witnessed this. In the years to follow I was involved in tons of testing, as I am to this day, making the fastest pass in NMCA Real Street this year at 180 mph with a hydraulic roller cam is a testament to that.
We back to back tested a lot of cams on the engine dynos at TFS, and most times the cams with less lift and/or slower ramp speed actually made more power. Bear in mind almost everyone of these combinations had heads with VERY good midlift airflow, so I can see where the engine may not need the valve opened faster, as so much more airflow is available at the same lift compared to a poorer flowing set of heads.
I have not seen a Pro Stock lobe, but a good friend of mine Pat Topolinski just moved from KB Racing to the Power Nation TV Engine Power show. At KB Racing he was in charge of valve train, and did a lot of testing, of course. If you think Pro Stock uses the fastest lobes available, then you'd be wrong...
There's another saying I have, you can lead a horse to water, but you can not make him drink...
Hell, you know my combe well....you did the heads and manifold....
I just like to fully understand the concept and theory.
Thanks for the time Brian....I know your a busy man.
.
12-01-2015, 09:21 AM
#208
He told me the story of the 2nd issue with combo, new valve train needed after every race as the 1.100" lift camshaft was pretty rough on parts. After they lined out the first problem, fuel management issue he tackled the reliability with the camshaft. A mild change in duration and reduction of .300" of lift, yes I have the period in the correct place, the engine lost peak HP of 20, gained some mid range torque. The huge gain was reliability and this was a very competitive Pro 5.0 car hold dome records.
Bigger is not always better. Brian and I both understand this...we were both born vertically challenged!!