URGENT: Help to Select the RIGHT CAMSHAFT
#1
URGENT: Help to Select the RIGHT CAMSHAFT
Engine: CURRENTLY STOCK L98 5.7L V8 350 TPI, 3:23 rear, rebuilt 700r4 auto tranny with all new performance parts (kevlar bands for instance), and shift kit, stock manifold... I will be having it remanufactured (All parts machined to factory specs, new water pump, oil pump, filters, pistons, wires, hoses, gaskets, seals, bearings, distributor, spark plugs, rotor, cap, thermostat, belt, timing set, frost plug, rings, lifters). They will then be installing New pistons with apparently flat heads, and a new camshaft.
The problem with the camshaft will be AIRCARE!! Yes, I live in BC and we have Aircare every 2 years. Mine in next year.
I want to find a cam that will:
1. Excellent LOW end range
2. Excellent MID end range
3. REALLY WANT THIS - Have LOPE.. the MOST I can possibly get.
4. Keep the stock chip
5. Still stay with the 92octane gas I use
6. MOST IMPORTANT: PASS AIRCARE!!
But I don't know HOW to possibly figure out WHAT CAM to get that will meet ALL my expectations.. How do you figure out what specs will work? How do you know what specs will give you so much lope? and HOW can you figure out what WILL and what will NOT pass aircare? Plus do all this on the first try?
I need to know this BEFORE MONDAY as the car goes into the shop MONDAY!
The problem with the camshaft will be AIRCARE!! Yes, I live in BC and we have Aircare every 2 years. Mine in next year.
I want to find a cam that will:
1. Excellent LOW end range
2. Excellent MID end range
3. REALLY WANT THIS - Have LOPE.. the MOST I can possibly get.
4. Keep the stock chip
5. Still stay with the 92octane gas I use
6. MOST IMPORTANT: PASS AIRCARE!!
But I don't know HOW to possibly figure out WHAT CAM to get that will meet ALL my expectations.. How do you figure out what specs will work? How do you know what specs will give you so much lope? and HOW can you figure out what WILL and what will NOT pass aircare? Plus do all this on the first try?
I need to know this BEFORE MONDAY as the car goes into the shop MONDAY!
#2
more lope tends to mean less chance of passing emissions.
maybe look into something like the LT1 hotcam
or just go call the tech line at TPIS...they've been doing those engines for years...i'm sure they hve and emissions legal cam
maybe look into something like the LT1 hotcam
or just go call the tech line at TPIS...they've been doing those engines for years...i'm sure they hve and emissions legal cam
#3
Another option is to call Comp Cams tech help. They do this every day, all day. Twelve people whose job it is to figure out which of their cams would best fit your application.
Comp has a new series of cams called the "XFI" series, and I would expect that they have something in that line that'll fit your need. Now, unfortunately you are still running the stock TPI system that really limits your engine's ability to rev. In stock form, TPI is good to 5000 RPM. In highly modified form, it's good to 6000 RPM. Thus, whatever cam you choose at this point, it's pointless to pick something that makes power beyond 5000 or 5500 RPM.
Most of today's performance cams that are designed to shift torque and power to below 5500 RPM will offer lots of vacuum signal and will probably have very little in terms of stuttery cam sound. However you might be able to coax some lope out of some of them. Just be realistic: You want to use the stock chip, stock runners, stock injectors, stock throttle body, stock intake manifold, stock cylinder heads, etcetera. This limits you to just the first couple of performance cams on the menu: Expect a recommendation that you stay below 212 degrees of duration at .050" lift, and a lobe center of 113 to 115 degrees. Probably a split profile, like 206 on the intake, 212 on the exhaust, with 113 LSA. Anything bigger and you'll probably fail emissions and worse: lose performance at the low end of the operating range where TPI shines so well.
Call Comp Cams tech help, they are the experts, not me.
Comp has a new series of cams called the "XFI" series, and I would expect that they have something in that line that'll fit your need. Now, unfortunately you are still running the stock TPI system that really limits your engine's ability to rev. In stock form, TPI is good to 5000 RPM. In highly modified form, it's good to 6000 RPM. Thus, whatever cam you choose at this point, it's pointless to pick something that makes power beyond 5000 or 5500 RPM.
Most of today's performance cams that are designed to shift torque and power to below 5500 RPM will offer lots of vacuum signal and will probably have very little in terms of stuttery cam sound. However you might be able to coax some lope out of some of them. Just be realistic: You want to use the stock chip, stock runners, stock injectors, stock throttle body, stock intake manifold, stock cylinder heads, etcetera. This limits you to just the first couple of performance cams on the menu: Expect a recommendation that you stay below 212 degrees of duration at .050" lift, and a lobe center of 113 to 115 degrees. Probably a split profile, like 206 on the intake, 212 on the exhaust, with 113 LSA. Anything bigger and you'll probably fail emissions and worse: lose performance at the low end of the operating range where TPI shines so well.
Call Comp Cams tech help, they are the experts, not me.
#4
Ouch! I called the Comp Cam customer support number and damn.. NOT a good first impression. I explained that I was getting my engine remanufactured to factory specs and then adding flat top pistons and a cam but don't know which cam to get. I found him to be quite rude:
"sigh.... Sir I just finished going over this with the last person so I'll tell you too".. He told me I had to know ALL the specs and exactly WHAT they are doing to the engine.. What the ground down specs will be, what type of grounding, what parts they are doing, what compression they will be using, etc..
I told him that I wouldn't know that as that is what the mechanic is doing and he is the one who suggested I call you guys to see which cam would be best for my application. They send the engine out so even they wouldnt know what specs the ground would be. And they told me that the compression would be based on the cam..
He then told me that I have to find out everything they are doing to the engine, all the specs they are doing, brand name parts and their specs before they can determine a cam..
As a result that was a complete waste of my 25 mins on hold.
"sigh.... Sir I just finished going over this with the last person so I'll tell you too".. He told me I had to know ALL the specs and exactly WHAT they are doing to the engine.. What the ground down specs will be, what type of grounding, what parts they are doing, what compression they will be using, etc..
I told him that I wouldn't know that as that is what the mechanic is doing and he is the one who suggested I call you guys to see which cam would be best for my application. They send the engine out so even they wouldnt know what specs the ground would be. And they told me that the compression would be based on the cam..
He then told me that I have to find out everything they are doing to the engine, all the specs they are doing, brand name parts and their specs before they can determine a cam..
As a result that was a complete waste of my 25 mins on hold.
#5
Another option is to call Comp Cams tech help. They do this every day, all day. Twelve people whose job it is to figure out which of their cams would best fit your application.
Comp has a new series of cams called the "XFI" series, and I would expect that they have something in that line that'll fit your need. Now, unfortunately you are still running the stock TPI system that really limits your engine's ability to rev. In stock form, TPI is good to 5000 RPM. In highly modified form, it's good to 6000 RPM. Thus, whatever cam you choose at this point, it's pointless to pick something that makes power beyond 5000 or 5500 RPM.
Most of today's performance cams that are designed to shift torque and power to below 5500 RPM will offer lots of vacuum signal and will probably have very little in terms of stuttery cam sound. However you might be able to coax some lope out of some of them. Just be realistic: You want to use the stock chip, stock runners, stock injectors, stock throttle body, stock intake manifold, stock cylinder heads, etcetera. This limits you to just the first couple of performance cams on the menu: Expect a recommendation that you stay below 212 degrees of duration at .050" lift, and a lobe center of 113 to 115 degrees. Probably a split profile, like 206 on the intake, 212 on the exhaust, with 113 LSA. Anything bigger and you'll probably fail emissions and worse: lose performance at the low end of the operating range where TPI shines so well.
Call Comp Cams tech help, they are the experts, not me.
Comp has a new series of cams called the "XFI" series, and I would expect that they have something in that line that'll fit your need. Now, unfortunately you are still running the stock TPI system that really limits your engine's ability to rev. In stock form, TPI is good to 5000 RPM. In highly modified form, it's good to 6000 RPM. Thus, whatever cam you choose at this point, it's pointless to pick something that makes power beyond 5000 or 5500 RPM.
Most of today's performance cams that are designed to shift torque and power to below 5500 RPM will offer lots of vacuum signal and will probably have very little in terms of stuttery cam sound. However you might be able to coax some lope out of some of them. Just be realistic: You want to use the stock chip, stock runners, stock injectors, stock throttle body, stock intake manifold, stock cylinder heads, etcetera. This limits you to just the first couple of performance cams on the menu: Expect a recommendation that you stay below 212 degrees of duration at .050" lift, and a lobe center of 113 to 115 degrees. Probably a split profile, like 206 on the intake, 212 on the exhaust, with 113 LSA. Anything bigger and you'll probably fail emissions and worse: lose performance at the low end of the operating range where TPI shines so well.
Call Comp Cams tech help, they are the experts, not me.
Someone replied with the following on Thirdgen.org:
Lope" and "emissions" are not found in the spec for the same camshaft.
Neither are "lope" and "TPI".
And most especially, neither are "lope" and "stock chip".
Sorry to be the bearer of such bad news; but reality just kind of is what it is.
I'd suggest a Comp "302" grind. http://store.summitracing.com/partde...&view=1&N=700+ That's about all you can run and still have any hope of passing emissions without any programming.
Neither are "lope" and "TPI".
And most especially, neither are "lope" and "stock chip".
Sorry to be the bearer of such bad news; but reality just kind of is what it is.
I'd suggest a Comp "302" grind. http://store.summitracing.com/partde...&view=1&N=700+ That's about all you can run and still have any hope of passing emissions without any programming.
#6
http://www.jegs.com/webapp/wcs/store...53159_-1_10707
The two in the Small Block Chevy 1987-98
305-350(Except LT1 & LT4) O.E. with Hydraulic Roller Camshaft
Were suggested..
Would any of those work? Which would be better?
The two in the Small Block Chevy 1987-98
305-350(Except LT1 & LT4) O.E. with Hydraulic Roller Camshaft
Were suggested..
Would any of those work? Which would be better?
#8
An LT4 Hot Cam would be an excellent decision. Somewhat mild(as you you don't have to upgrade heads and such), really livens the car, can be found for a very decent price(especially used)... I would recommend tuning the car, as you will probably need to re-tune the car with any upgraded cam.
#10
http://www.jegs.com/webapp/wcs/store...53159_-1_10707
The two in the Small Block Chevy 1987-98
305-350(Except LT1 & LT4) O.E. with Hydraulic Roller Camshaft
Were suggested..
Would any of those work? Which would be better?
The two in the Small Block Chevy 1987-98
305-350(Except LT1 & LT4) O.E. with Hydraulic Roller Camshaft
Were suggested..
Would any of those work? Which would be better?
210/218 on a 113 LSA. Nice cam profile, it'll lope a little. UNFORTUNATELY for you, it lists the valve lift as .560 inches on a 1.6 rocker arm. Since you have stock cylinder heads, your heads most likely cannot handle that much valve lift without either coil bind or smashing the retainers into the tops of the valve stem seals. Stock heads support half an inch, tops. HOWEVER, if your machine shop knows that you need .560 inch lift (.525 inch on a 1.5 ratio rocker arm), then they can check the heads before installation to see if .525 inches is possible. Who knows?? Certainly you're going to need new valve springs for this cam, so if they are doing the job of setting up the new springs, they might be able to set you up. All in all, I'd explore it more as I think this cam offers you your best option of actually passing emissions and getting that bit of muscle in the sound of the cam. This is the largest cam I think you'll be able to get away with on a stock TPI.
#12
An LT4 Hot Cam would be an excellent decision. Somewhat mild(as you you don't have to upgrade heads and such), really livens the car, can be found for a very decent price(especially used)... I would recommend tuning the car, as you will probably need to re-tune the car with any upgraded cam.
Do you have any video of your car to hear what your engine sounds like with the LT4 Hot Cam?
#13
ws6transam Is this anywhere similar to what a "his is the largest cam I think you'll be able to get away with on a stock TPI." would sound SOMETHING like? This is the GM LT4 Hotcam. Seems all the Camaro's i've heard with this particular cam have the same overall idle sound. http://videos.streetfire.net/search/...eb013b40c4.htm
#15
If you don't know, then you may be a little over your head. So please don't swap it out by yourself.
Last edited by 89_Irocz; 03-23-2007 at 12:23 PM.