tell me about this cam/head combo...
#3
Safety Car
Thread Starter
Re: tell me about this cam/head combo... (Ganey)
i dont really understand that...
more info???
what would this combo be like together?
is it a good combo?
when somebody says "what are you running for a cam?" what is the correct lingo to describe it?
and the heads...
are they decent?
more info please???
more info???
what would this combo be like together?
is it a good combo?
when somebody says "what are you running for a cam?" what is the correct lingo to describe it?
and the heads...
are they decent?
more info please???
#4
Melting Slicks
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Re: tell me about this cam/head combo... (SIGNGUY)
Well, it looks like your lift is .440 on your intake and exhaust-provided you are using 1.5:1 ratio rocker arms. You can switch to 1.6:1 rockers and get more lift(.469). It looks like your duration is 268 degrees. What that means, is your valve is lifted off of the seat for 268 degress( this is measured when the valve is lifted-in your case- .004 of an inch). This doesn't make much sense unless you look at characteristics of several cams. Usually, the more lift and duration you have, the higher the hp, but the hp usually comes at higher rpms. I use a smaller cam(Comp 256), because it has a little bit more torque at the lower rpms. I can get more hp, but I wanted max torque and my engine will rarely see above 5000 rpm-well at least until I build a 383. There is alot more to cams than what I just described, but that is the basics of what most people talk about. Keep in mind that alot of people will talk about a "268" cam and have no idea what that means. You need to first decide what you want the car to do. Do you want it to sing at high rpms? Do you want to run nitrous or a supercharger? What rpm range do you want to run in? According to the spec sheet you provided, that cam starts to make power at 1600rpm, so it MAY be a dog in the lower rpms(driving around town).
[Modified by 79VetteMike, 6:55 AM 3/13/2004]
[Modified by 79VetteMike, 6:55 AM 3/13/2004]
#5
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Re: tell me about this cam/head combo... (79VetteMike)
As for the heads.....They are 67cc heads. If your bottom end(engine) is stock, then these may be overkill for you. If you have the stock pistons, then with those 67cc(cubic centimeters) your combustion ratio(CR) may be a paltry 8.7:1(that's just a guess). Unless you are running a supercharger or nitrous, you want a higher CR for max hp. Your heads need to be matched to your pistons. In other words, your pistons and combustion chamber on your heads determine your CR. Look in a Summit or Jegs catalog and look at rebuild kits. You can see that they sell pistons according to what CR they provide with a given cc head. I'm not sure what those S/R torquers flow, but you need to know that also. Typically, more torque equals lower flow(170-190cfm); whereas, higher hp equals higher flow(190-230+), but higher the hp you want, the higher rpm you have to turn-which can equal to more broken parts. BTW- the same goes for valves- smaller=more torque; larger =more hp. Decide what you want the car to do. That cam and heads will work fine, but you may want to go with the 268 as Ganey suggested to get the most potential out of those heads(provided you want to work in the rpm range the cam spec sheet says you are in. As a final note, to determine the best possible combination, the rest of your drivetrain needs to be identified. What gears? What trans? Before anyone starts to try to tell me I'm wrong, these are general statements that are fairly suited to small block Chevys. Good luck
#6
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Re: tell me about this cam/head combo... (SIGNGUY)
i dont really understand that...
more info???
what would this combo be like together?
is it a good combo?
when somebody says "what are you running for a cam?" what is the correct lingo to describe it?
more info???
what would this combo be like together?
is it a good combo?
when somebody says "what are you running for a cam?" what is the correct lingo to describe it?
Comp Cams HE260H
212/212 .440/.440 110LS
XE-256 is similiar w/ more exhaust duration
212/218 110LS
I rec. More cam for manual trans. esp. if someone drives hard. Min.
Comp Cams HE268H
218/218 .454/.454 110LS
Again XE-262 is similiar w/ more exhaust duration
218/224 110LS
These cams rock the curve up over the first ones, giving up some low rpm HP & making about +20 more at higher rpm, all else same.
Heads are about 170cc as are Edelbrock RPM & Vortec, very good for street 350. Since the L-82, 72cc would put over 9 C/R.
Mike
He gave trans. in sig.:
5 Speed Tremek...
otherwise would be needed first as you said (& I have said many times).
[Modified by Ganey, 11:25 AM 3/13/2004]
#7
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Re: tell me about this cam/head combo... (Ganey)
i dont really understand that...
more info???
what would this combo be like together?
is it a good combo?
when somebody says "what are you running for a cam?" what is the correct lingo to describe it?
Cam duration at .050, lift & LS
Comp Cams HE260H
212/212 .440/.440 110LS
XE-256 is similiar w/ more exhaust duration
212/218 110LS
I rec. More cam for manual trans. esp. if someone drives hard. Min.
Comp Cams HE268H
218/218 .454/.454 110LS
Again XE-262 is similiar w/ more exhaust duration
218/224 110LS
These cams rock the curve up over the first ones, giving up some low rpm HP & making about +15 more at higher rpm, all else same.
Heads are about 170cc as are Edelbrock RPM & Vortec, very good for street 350. Since the L-82, 72cc would put over 9 C/R.
Mike
He gave trans. in sig.:
5 Speed Tremek...
otherwise would be needed first as you said (& I have said many times).
more info???
what would this combo be like together?
is it a good combo?
when somebody says "what are you running for a cam?" what is the correct lingo to describe it?
Cam duration at .050, lift & LS
Comp Cams HE260H
212/212 .440/.440 110LS
XE-256 is similiar w/ more exhaust duration
212/218 110LS
I rec. More cam for manual trans. esp. if someone drives hard. Min.
Comp Cams HE268H
218/218 .454/.454 110LS
Again XE-262 is similiar w/ more exhaust duration
218/224 110LS
These cams rock the curve up over the first ones, giving up some low rpm HP & making about +15 more at higher rpm, all else same.
Heads are about 170cc as are Edelbrock RPM & Vortec, very good for street 350. Since the L-82, 72cc would put over 9 C/R.
Mike
He gave trans. in sig.:
5 Speed Tremek...
otherwise would be needed first as you said (& I have said many times).
#8
Emerging Vendor
Re: tell me about this cam/head combo... (79VetteMike)
I had good success running split duration cams as the Chevy small block can usually benefit from more lift and duration on the exhaust side.
I've ran the Crane 272 with 454/480 lift and 216/228 duration on a 9:1 350 4 speed car and it was a very good street cam.
I've ran the Crane 272 with 454/480 lift and 216/228 duration on a 9:1 350 4 speed car and it was a very good street cam.
#9
Safety Car
Thread Starter
Re: tell me about this cam/head combo... (corvgreg)
WOW...thats a lot of information...!!! thank you, thank you, thank you... :D
as a matter of fact, now i feel like a :conehead
i have to admit that although i do understand some of what you have said...
there is a lot that i do not understand...
so...lets take a different aproach...
my car really does run great now...
but...
im just not sure that i am on the money with my cam/head choice for what i want it to do for me...
what i want is bottom end tourqe...put you back in the seat power...
i dont give a hoot about going 130 mph...
im looking more for a lot more 0-60 mph *****...
the cam is obviously the lesser expensive thing to change out between the two...so lets see if there is a better cam out there for me...
or...if my cam is good enough for me and what i want from my engine...
BTW...these heads were quite expensive so i hope i didnt screw up by buying them...whataya think?
ok...heres what i have...
Federal Mogal double eyebrow pistons...
the block is the original 4 bolt and was bored .030 over...
Scat cast crank...
Proform distributor with 50k volt coil...
Performer intake w/Lars tuned Speed Demon 750 carb...
Dynamax headers...
Tremec 5 speed and 3:73 rear gears...
here is a link to the engine kit that i purchased...
on the choices at the bottom i chose .030 over on the pistons and rings...
and i chose the 266 Dur .444 Lift cam...
http://www.northernautoparts.com/Pro...ctModelId=1666
whataya think i should do?
change the cam or stay where i am?
or something completely different?
thank so much for your advice and opinions... :)
[Modified by SIGNGUY, 8:02 PM 3/13/2004]
as a matter of fact, now i feel like a :conehead
i have to admit that although i do understand some of what you have said...
there is a lot that i do not understand...
so...lets take a different aproach...
my car really does run great now...
but...
im just not sure that i am on the money with my cam/head choice for what i want it to do for me...
what i want is bottom end tourqe...put you back in the seat power...
i dont give a hoot about going 130 mph...
im looking more for a lot more 0-60 mph *****...
the cam is obviously the lesser expensive thing to change out between the two...so lets see if there is a better cam out there for me...
or...if my cam is good enough for me and what i want from my engine...
BTW...these heads were quite expensive so i hope i didnt screw up by buying them...whataya think?
ok...heres what i have...
Federal Mogal double eyebrow pistons...
the block is the original 4 bolt and was bored .030 over...
Scat cast crank...
Proform distributor with 50k volt coil...
Performer intake w/Lars tuned Speed Demon 750 carb...
Dynamax headers...
Tremec 5 speed and 3:73 rear gears...
here is a link to the engine kit that i purchased...
on the choices at the bottom i chose .030 over on the pistons and rings...
and i chose the 266 Dur .444 Lift cam...
http://www.northernautoparts.com/Pro...ctModelId=1666
whataya think i should do?
change the cam or stay where i am?
or something completely different?
thank so much for your advice and opinions... :)
[Modified by SIGNGUY, 8:02 PM 3/13/2004]
#11
Safety Car
Thread Starter
Re: tell me about this cam/head combo... (comp)
it just feels as tho the "power band" is way up on the rpm range...
not down bottom where i want it...
dont get me wrong...it does have tons of ***** down there now but it feels as tho i make more power up the range on the rpms...
not down bottom where i want it...
dont get me wrong...it does have tons of ***** down there now but it feels as tho i make more power up the range on the rpms...
#12
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Location: Marshalltown Iowa
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Re: tell me about this cam/head combo... (SIGNGUY)
The heads were a nice choice with 67cc chambers and 170cc runners.
I would recommend you get a copy of Desktop Dyno and play with the cam selection until you find the powerband you are looking for. My setup dynoed out within 1hp of the software and my friend was within 1/2hp. This is close enough for me! For $50 you cannot go wrong and you will know what to expect.
I would recommend you get a copy of Desktop Dyno and play with the cam selection until you find the powerband you are looking for. My setup dynoed out within 1hp of the software and my friend was within 1/2hp. This is close enough for me! For $50 you cannot go wrong and you will know what to expect.