thoughts on my forced induction cam
08-04-2015, 07:00 PM
#11
I am curious George, what do you dislike about it so much?
For what its worth I just bought a cam yesterday that has a couple degrees of overlap in it for the next step in this truck.
08-05-2015, 08:34 AM
#16
Is this a max effort car? You can pulley for more boost to make more power if you need it. This cam isn't an achilles heel in this motor.
Intake close and exhaust open are in the right ball park, and 0 overlap isn't a bad thing on a street driven blower vehicle. Could it be better if it was a max effort build? Of course. Is it worth swapping? Not at first, that's for damn sure.
What are you really trying to accomplish with this car?
I think the converter is a little loose for my taste with a PD blower. That would be where i'm most concerned with this combo, not the cam.
Intake close and exhaust open are in the right ball park, and 0 overlap isn't a bad thing on a street driven blower vehicle. Could it be better if it was a max effort build? Of course. Is it worth swapping? Not at first, that's for damn sure.
What are you really trying to accomplish with this car?
I think the converter is a little loose for my taste with a PD blower. That would be where i'm most concerned with this combo, not the cam.
08-05-2015, 05:25 PM
#17
Don't look to bad, I don't think the lsa needs to be that wide, a 114 would probably run a little harder at the track but this will actually work out pretty well imo.
So I tried a 108 lsa cam on a pro charger a while back, I honestly thought it pulled very well, sounded nasty too! Some people think scavenging and air speed go out the window once your boosted, not the case at all. Only time you need to really change the lsa is on high boost sc applications, with that much overlap it will just push you boost out the tail pipe!
So I tried a 108 lsa cam on a pro charger a while back, I honestly thought it pulled very well, sounded nasty too! Some people think scavenging and air speed go out the window once your boosted, not the case at all. Only time you need to really change the lsa is on high boost sc applications, with that much overlap it will just push you boost out the tail pipe!
08-05-2015, 07:25 PM
#18
on a 114 LSA he would have 8* of overlap and the intake lobe would likely be brought in too far... it wouldnt rev high enough for a 408. 8* of overlap is likely not too much, but likely more than you need to increase exhaust scavenging and clear the chamber of spent gasses.
This is just my opinion, and I don't live in the large cube with an even larger blower world, but ideally you want just enough overlap to accomplish nearly completely clearing the chamber of spent gas out the exhaust, and increase exhaust scavenging so when the exhaust valve opens on the next go around it pulls out the spent gasses even harder. Depending on the RPM range you want to live in that can be done with just a couple degrees of overlap at ".050 valve lift. Now, if you live in a world where the blower is massively over sized for the engine, more could be better. Again, that's not where I play.
To assess a cam swap in this car specifically you will need to think about a few things
1 how fast does the blower spin and how close to over spinning it are you?
2 are you in the blowers sweet spot for efficiency
3 how much boost do you run, and again does it fall in a sweet spot for efficiency
4 how much engine RPM do you run? Is it enough for you? Do you like the way the power curve feels?
5 how does the converter feel? My guess is its too loose... not sure why that was the go to converter in this car. Unless its rated at that RPM for the power you make... then I'll eat my words.
This is just my opinion, and I don't live in the large cube with an even larger blower world, but ideally you want just enough overlap to accomplish nearly completely clearing the chamber of spent gas out the exhaust, and increase exhaust scavenging so when the exhaust valve opens on the next go around it pulls out the spent gasses even harder. Depending on the RPM range you want to live in that can be done with just a couple degrees of overlap at ".050 valve lift. Now, if you live in a world where the blower is massively over sized for the engine, more could be better. Again, that's not where I play.
To assess a cam swap in this car specifically you will need to think about a few things
1 how fast does the blower spin and how close to over spinning it are you?
2 are you in the blowers sweet spot for efficiency
3 how much boost do you run, and again does it fall in a sweet spot for efficiency
4 how much engine RPM do you run? Is it enough for you? Do you like the way the power curve feels?
5 how does the converter feel? My guess is its too loose... not sure why that was the go to converter in this car. Unless its rated at that RPM for the power you make... then I'll eat my words.
Last edited by 03sierraslt; 08-05-2015 at 07:48 PM.
08-05-2015, 08:03 PM
#19
Formerly ScreamingL
Would not say 3500 is loose for that combo
This setup is gonna be far from a street daily so might as well set it up to run hard
Imho id have a procharger instead of i was gonna be serious about a blower on that setup
This setup is gonna be far from a street daily so might as well set it up to run hard
Imho id have a procharger instead of i was gonna be serious about a blower on that setup
08-05-2015, 08:18 PM
#20
But it doesn't, so we were talking about the cam.
I would choose a Procharger for that setup also, but it has a KB on it. The converter wouldn't worry me, but I would be careful spinning that KB too high as they start pumping some serious heat when over spun. how high do you plan to spin this motor?
I would choose a Procharger for that setup also, but it has a KB on it. The converter wouldn't worry me, but I would be careful spinning that KB too high as they start pumping some serious heat when over spun. how high do you plan to spin this motor?