L98 Cam.... Which one?
#1
Burning Brakes
Thread Starter
Member Since: May 2002
Location: Albuquerque NM
Posts: 831
Likes: 0
Received 0 Likes
on
0 Posts
L98 Cam.... Which one?
I know this isn't C4 related directly, but close
The 88 GTA L98 that was in my elcamino had a blown headgasket. I've pulled the motor, had it bored .030, new flat-top pistons, crank turned 10/10, world products Pro-torque heads (I think that's them, they are Pro something or other) 1.94/1.6 valves 64cc chambers, mild port/polish. Also have a port matched edelbrock TPI base and edelbrock runners. Using 24# injectors. I'm this far into it and was going to leave cam selection to the builder, but he picked an "upgrade" over what the cam would have been for an '87 el camino. Cam he picked out was nearly identical to a stock 88 L98 Cam. I don't really want to purchase a stall converter, and it still has to pass the sniffer emissions test (No visual, so I don't have the smog pump or AIR injection, but do have dual cats) Narrowed it down to the OE '92 Firehawk Cam, and the GM performanceparts cam that was in the ZZ3. If it matters, I have a 3.42 rear gear.
Specs:
SLP .05" duration 214/224, 1.5:1 lift .470/.490, 115 LSA
GM .05" duration 208/221, 1.5:1 lift .474/.510, 112 LSA
Even with the edelbrock stuff, I figure it will be out of breath by 5500, Any help greatly appreciated.
The 88 GTA L98 that was in my elcamino had a blown headgasket. I've pulled the motor, had it bored .030, new flat-top pistons, crank turned 10/10, world products Pro-torque heads (I think that's them, they are Pro something or other) 1.94/1.6 valves 64cc chambers, mild port/polish. Also have a port matched edelbrock TPI base and edelbrock runners. Using 24# injectors. I'm this far into it and was going to leave cam selection to the builder, but he picked an "upgrade" over what the cam would have been for an '87 el camino. Cam he picked out was nearly identical to a stock 88 L98 Cam. I don't really want to purchase a stall converter, and it still has to pass the sniffer emissions test (No visual, so I don't have the smog pump or AIR injection, but do have dual cats) Narrowed it down to the OE '92 Firehawk Cam, and the GM performanceparts cam that was in the ZZ3. If it matters, I have a 3.42 rear gear.
Specs:
SLP .05" duration 214/224, 1.5:1 lift .470/.490, 115 LSA
GM .05" duration 208/221, 1.5:1 lift .474/.510, 112 LSA
Even with the edelbrock stuff, I figure it will be out of breath by 5500, Any help greatly appreciated.
#2
Race Director
Of the two you list, I vote for the 214/224 cam -- especially with Edelbrock intake. Intake duration is very important for lt runners. And, it's no where near too big for a 5500 rpm motor.
Last edited by GREGGPENN; 05-14-2009 at 11:11 PM.
#3
Either cam will be a decent choice, but you should choose depending on how you want your power delivered. Low-end, or high-end?
The SLP cam will give you a broader, fatter torque curve, and will be a little easier on your tune, since I'm assuming you are running a stock ECM. This is due to the wider LSA, which really is one of the most important things to consider when selecting a cam. This is especially true in a computer controlled car.
The GM cam will give you better overall HP numbers, and will work with slightly lower compression than the other due to the shorter duration, which helps build cylinder pressure. However, 112 LSA is about the 'ragged edge' when using a stock ECM or even a mild tune. (speaking L98, anyway...LSx with a good tune can easily pull off 107 LSA, but that's for another thread...)
I just ordered COMP Xtreme Energy # CL12-268-4 from Summit. It specs out at: 224/230 @ .050", .479"/.480", 114 LSA. This will be decent for now with stock L98 heads, but will really see life with some AFR 190cc heads that are waiting in the wings.
The SLP cam will give you a broader, fatter torque curve, and will be a little easier on your tune, since I'm assuming you are running a stock ECM. This is due to the wider LSA, which really is one of the most important things to consider when selecting a cam. This is especially true in a computer controlled car.
The GM cam will give you better overall HP numbers, and will work with slightly lower compression than the other due to the shorter duration, which helps build cylinder pressure. However, 112 LSA is about the 'ragged edge' when using a stock ECM or even a mild tune. (speaking L98, anyway...LSx with a good tune can easily pull off 107 LSA, but that's for another thread...)
I just ordered COMP Xtreme Energy # CL12-268-4 from Summit. It specs out at: 224/230 @ .050", .479"/.480", 114 LSA. This will be decent for now with stock L98 heads, but will really see life with some AFR 190cc heads that are waiting in the wings.
#4
Burning Brakes
Thread Starter
Member Since: May 2002
Location: Albuquerque NM
Posts: 831
Likes: 0
Received 0 Likes
on
0 Posts
Thanks guys, I was kindof leaning towards the SLP because of the LSA and the larger duration #'s, and yeah, still running a stock ecm with a tune from TPIChips.com. That Comp cam you listed ChopperKingPin also sounds like it may be a good choice. I use the elky as a DD, and to haul my motorcycle around or tow a trailer to the landfill, not looking for a race car, but something fun on the streets.
#5
Race Director
For pulling/towing the GM cam's probably best -- because of the cylinder pressure/torque issue. It will definitely feel stronger at the lower-end. Don't consider a 224/230 cam for this same reason.
I'm betting on the duration vs LSA thing being a wash for mid-range. Hard to tell the difference there (but I'd still bet on the SLP cam for timed runs).
BTW: When you do the tune, make sure you tell them whether your 24# injectors are SVOs (FORD-pressure-rated) or not. (If they are, they flow closer to 25.5.)
Last edited by GREGGPENN; 05-15-2009 at 02:18 AM.
#6
Burning Brakes
Thread Starter
Member Since: May 2002
Location: Albuquerque NM
Posts: 831
Likes: 0
Received 0 Likes
on
0 Posts
You think the GM cam will still pull alright to 5500? BTW, I'm using crane 1.6 roller tip rockers.
#7
Team Owner
Member Since: Oct 2004
Location: altered state
Posts: 81,242
Received 3,043 Likes
on
2,602 Posts
St. Jude Donor '05
Either one will work fine and idle like a stocker .
Used the Lunati Voodoo(trying to remember the #, 256???) 213/219 cam on a 350 Iroc, similar build asyours and builds great torque everywhere from idle on up. Idles smooth as silk,passes emissionis easily..
Used the Lunati Voodoo(trying to remember the #, 256???) 213/219 cam on a 350 Iroc, similar build asyours and builds great torque everywhere from idle on up. Idles smooth as silk,passes emissionis easily..
#8
Le Mans Master
Here are the specs for you to compare
How bout the Hotcam ????
The GM cam you choose its the ZZ4 that's the one i have and im very happy with it.
Stock L98 cam
Duration @ .050", 202/207
Lift: .413/.428 ,
114.5 LSA
ZZ4 cam :
Duration @.050 208/221
Lift: .474/.510
112 LSA
1500-5500 rpm range
Hotcam
Duration @ .050", 218/228
Lift: .525/.525 ,
112 LSA
How bout the Hotcam ????
The GM cam you choose its the ZZ4 that's the one i have and im very happy with it.
Stock L98 cam
Duration @ .050", 202/207
Lift: .413/.428 ,
114.5 LSA
ZZ4 cam :
Duration @.050 208/221
Lift: .474/.510
112 LSA
1500-5500 rpm range
Hotcam
Duration @ .050", 218/228
Lift: .525/.525 ,
112 LSA
#10
Team Owner
Member Since: Oct 2004
Location: altered state
Posts: 81,242
Received 3,043 Likes
on
2,602 Posts
St. Jude Donor '05
Bet it works out just fine, good to see somethign different being used than all the typical stuff.