Cam lobe separation degrees, difference from 112 to 114?!
#1
Cam lobe separation degrees, difference from 112 to 114?!
Hey Guys, I have been looking at cams and am trying to learn how two different cams with the same specs besides a 112 to 114 lobe separation degrees will act differently from one another. It seems like most people recommend the 114 for nos or a charger'? Why is that too?
Is the lt4 hotcam a good cam, its the most reasonable priced one and seems VERY close to the 305cc cam, but the lobe degree!!!
lt4= @.050 218/228 .525/.525 at 112 but has a 1,500 to 7,000rpm range!!!
305= 220/230 .510/.510 at 114 degrees, and is only good to 5,500rpm
They seem so close but actually I think I would prefer the lt4 ( which I NEVER hear anyone talk about on here and hear about the 305 ALL the time ).
I noticed my L79 327 is 222/222 .447/.447 at 114 and was confused at the 114 degree choice gm made with that cam too (considering I get her up to 6500 rpm all the time and its fine; opposite of the example above), please clear this up for me
Is the lt4 hotcam a good cam, its the most reasonable priced one and seems VERY close to the 305cc cam, but the lobe degree!!!
lt4= @.050 218/228 .525/.525 at 112 but has a 1,500 to 7,000rpm range!!!
305= 220/230 .510/.510 at 114 degrees, and is only good to 5,500rpm
They seem so close but actually I think I would prefer the lt4 ( which I NEVER hear anyone talk about on here and hear about the 305 ALL the time ).
I noticed my L79 327 is 222/222 .447/.447 at 114 and was confused at the 114 degree choice gm made with that cam too (considering I get her up to 6500 rpm all the time and its fine; opposite of the example above), please clear this up for me
#2
Re: Cam lobe separation degrees, difference from 112 to 114?!
The wider the lobe seperation.. wider meaning the 114 vs the 112... would mean there is less overlap. Overlap is when the intake and exhaust valve is open at the same time so the exhaust valve starts to open before the intake valve is fully closed. As you can imagine in that situation some nitrous and boost would escape out the exhaust which is basically a waste of money and power.
#4
Re: Cam lobe separation degrees, difference from 112 to 114?!
Originally Posted by alwayscode
Thanks , that cleared up the nos/boost question.....I appreciate it!!!!
#5
Re: Cam lobe separation degrees, difference from 112 to 114?!
Originally Posted by Injuneer
"NOS" is a specific brand name for a manufacturer of nitrous kits.
NAAAAAWWWWSSSSS
#6
Re: Cam lobe separation degrees, difference from 112 to 114?!
Originally Posted by alwayscode
They seem so close but actually I think I would prefer the lt4 ( which I NEVER hear anyone talk about on here and hear about the 305 ALL the time ).
#8
Re: Cam lobe separation degrees, difference from 112 to 114?!
Originally Posted by alwayscode
lt4= @.050 218/228 .525/.525 at 112 but has a 1,500 to 7,000rpm range!!!
305= 220/230 .510/.510 at 114 degrees, and is only good to 5,500rpm
-Dustin-
Last edited by Bersaglieri; 07-07-2005 at 01:57 AM.
#9
Re: Cam lobe separation degrees, difference from 112 to 114?!
A tighter LSA cam will produce better torque accross the rpm range with the expense of low rpm drivability. For the wider LSA cams (with same or similler duration), a few lb.ft are lost accross the range but what is gained is a more civil driver.
And no way will a hot cam rev that high.
And no way will a hot cam rev that high.
#10
Re: Cam lobe separation degrees, difference from 112 to 114?!
Thank you guys very much. Bergsaglieri you have been awesome bro. I didnt realize the spec difference from the hotcam to the cc was at a different rocker ratio!!!! That changes alot. I am also greatful for the 846 suggestion because I wanted something hotter than the 305 but not as wild as the 306!!!!
#11
Re: Cam lobe separation degrees, difference from 112 to 114?!
Originally Posted by alwayscode
Thank you guys very much. Bergsaglieri you have been awesome bro. I didnt realize the spec difference from the hotcam to the cc was at a different rocker ratio!!!! That changes alot. I am also greatful for the 846 suggestion because I wanted something hotter than the 305 but not as wild as the 306!!!!
306 with a tune is not wild by any means. I can't believe how often people say that. Yes you have to spin it a little higher (I only go to 6300ish) but it is very streetable. Shoot, my m6 idles at 650 with no issues. Brakes work, never stalls on me, and pisses off Harley guys.
#12
Re: Cam lobe separation degrees, difference from 112 to 114?!
Originally Posted by Injuneer
Actually, he cleared up the N2O/boost question. "NOS" is a specific brand name for a manufacturer of nitrous kits.
Jsetzer, well the 306 is an option then , hahha......my main goal is a LUMPY lopy sounding cam and you seem to have made me think thats the one to go with?! How do those cams run with a shot of n2o?! I noticed they are 112 degree and not 114 degree. How much is JUST porting from LLOYD and not the entire cam/porting package.....or do YOU think his custom cam will work better with his porting?! Thanks---
EDIT: I'm a noob and hear the WILD 306 from alot of people, so its good to get things straight from a real 306 driver
Last edited by AlwaysCode390; 07-07-2005 at 09:17 AM.
#13
Re: Cam lobe separation degrees, difference from 112 to 114?!
If you are considering doing just the cam and nothing more you'll want to talk to Bret Bauer AKA SStrokerAce. He makes custom cams on this board for members, including Lloyds packages. He is the camshaft voodoo Doctor.
-Dustin-
-Dustin-
#14
Re: Cam lobe separation degrees, difference from 112 to 114?!
It has become popular (on this forum anyway) to grant LCA a lot of importance. LCA, or what more may recognize as LSA means virtually NOTHIN'. To attempt to characterize or describe a cam based on LCA is pointless and meaningless, because it is inaccurate to do so. That number is little more than a 'product' of more important 'events', namely intake/exhaust opening and closing. The reason it is meaningless, is because the same LCA can be achieved using different valve open/close numbers, and THAT change can really change the personality of a cam. A good example, would be to compare the OEM LT1 F body cam, to the OEM LT1 B body cam. That has been done here before, in an attempt at clarifying the true value of the LSA figure. Hell, you may as well use it (LSA) as a catalog #, as it has about the same value. As I see it, if the majority prefer to describe cams by LSA, you may as well go back to the 50s/60s mentality and label cams via buzz words like '3/4 race' or 'full race'. Once you become familiar with cam timing events, you won't put the emphasis on LCA/LSA when describing cams. Of the various aspects of a cam, (IO/C, EO/C, OL, ICL, duration, LSA/LCA carries the least weight.
It may be easier for the novice, to describe a cam via the LSA, and easier to understand, compared to the other aspects, but it is also the poorest method of identifying the character of a cam. BTW, the one 'product' of the valve 'events' that can be considered of importance would be valve overlap.
Seeing that I'm going for the throat, I may as well hit the jugular. It is also popular/accepted to focus in on the intake opening event. To me, that is like giving most of the credit to the quarterback. Without the line to block, the quarterback wouldn't have much time to do what he is expected to do. Yes, the IO is important, but so are the other 3 events. Without those postioned correctly, the IO can do only so much.
It may be easier for the novice, to describe a cam via the LSA, and easier to understand, compared to the other aspects, but it is also the poorest method of identifying the character of a cam. BTW, the one 'product' of the valve 'events' that can be considered of importance would be valve overlap.
Seeing that I'm going for the throat, I may as well hit the jugular. It is also popular/accepted to focus in on the intake opening event. To me, that is like giving most of the credit to the quarterback. Without the line to block, the quarterback wouldn't have much time to do what he is expected to do. Yes, the IO is important, but so are the other 3 events. Without those postioned correctly, the IO can do only so much.
Last edited by arnie; 07-09-2005 at 07:34 AM.
#15
Re: Cam lobe separation degrees, difference from 112 to 114?!
305 and hotcam = waste of time in my opinion unless you want a car that idles about like stock and doesn't have as much potention. I know people have gone far on them and they are good cams but the 306 is better and with a good tune it will be fairly tame but still provide a very nice lumpy idle. Oh ya and stay the hell away from those xe grinds i hated my old 230/236 my new setup will be with a 306.