cam/rocker question L98 mod
03-26-2009, 12:59 PM
#1
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cam/rocker question L98 mod
I posted a thread awhile back to get opinion on increase HP. I appreciate the input. So, I got a L98 stock. I just bought trickflow heads #30300006 ($1200) from summit, ported the intake, got SLP runners/ported plenum, headmean headers , ect...
Now the question is since im putting on new heads, may as well change over the cam. My machinist doesnt think a cam swap is all too important for the car at this time. He believes that most of the power will be made with a good head replacement/porting. I kind of agree, but I believe a cam swap would increase a mild but noticable performance upgrade. Im thinking a ZZ3 cam or a comp cam #12-466-8 or a #08-466-8 (or other comparable roller cam). The other question is that I read a article that upping the rockers to 1.6 may not be necessary if keeping my engine around 400hp or below. I am leaning to keep my stock 1.5 rockers.
I really dont want to spend any more money on parts aside from the heads/cam.
So questions
1. Should I exchange the cam to a mild-mod upgrade?
2. If I do up the cam, is it necessary to get 1.6 rockers or just keeping the stock 1.5 rockers will do?
FYI: The L98 engine only has 20K miles on it (bought it crate new from GM less than three years back.)
Now the question is since im putting on new heads, may as well change over the cam. My machinist doesnt think a cam swap is all too important for the car at this time. He believes that most of the power will be made with a good head replacement/porting. I kind of agree, but I believe a cam swap would increase a mild but noticable performance upgrade. Im thinking a ZZ3 cam or a comp cam #12-466-8 or a #08-466-8 (or other comparable roller cam). The other question is that I read a article that upping the rockers to 1.6 may not be necessary if keeping my engine around 400hp or below. I am leaning to keep my stock 1.5 rockers.
I really dont want to spend any more money on parts aside from the heads/cam.
So questions
1. Should I exchange the cam to a mild-mod upgrade?
2. If I do up the cam, is it necessary to get 1.6 rockers or just keeping the stock 1.5 rockers will do?
FYI: The L98 engine only has 20K miles on it (bought it crate new from GM less than three years back.)
03-26-2009, 04:03 PM
#2
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Either of those cams will work fine, and would give you 400 HP.
To keep it "milder" per say, I wouldnt use 1.6 rockers...use 1.5's.
Call Comp and make sure that cam you have listed for a 305/350 TPI motor will work with a stock converter. I didnt see you list them you had a stall so you want to make sure the cam will work with the stock stall, or buy a stall converter.
I would recomend buying a small stall either way, like a 2400 or so. As well as up the gear ratio to 3.42 or maybe 3.55. That will take away any "lazyness" of the stall and make the car more street friendly.
Just my opinion
To keep it "milder" per say, I wouldnt use 1.6 rockers...use 1.5's.
Call Comp and make sure that cam you have listed for a 305/350 TPI motor will work with a stock converter. I didnt see you list them you had a stall so you want to make sure the cam will work with the stock stall, or buy a stall converter.
I would recomend buying a small stall either way, like a 2400 or so. As well as up the gear ratio to 3.42 or maybe 3.55. That will take away any "lazyness" of the stall and make the car more street friendly.
Just my opinion
03-26-2009, 08:18 PM
#3
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Thanks Rice. I think I like the ratio of the GM Performance cam (ZZ3). This seems to be a dependable cam swap with modest low to mid RPM power. I also agree that 1.6 rockers are overkill for this modification. My stock 1.5 are relatively new and according to GM and summit should work well. For now im keeping the 3.23 gears. After this engine mod I will be looking towards drivetrain.
I agree a stall converter 2400 up but no greater than 2800 would be great in the near future.
So it seems that the trickflow heads and GM performance cam should be a good combo without any real modifications aside from the mild porting. With the gaskets it round to $1500 (1200 for head 200 cam and 100 gasket set). Im hoping over 300 to RHP and ill be satisfied.....at least for now.
I agree a stall converter 2400 up but no greater than 2800 would be great in the near future.
So it seems that the trickflow heads and GM performance cam should be a good combo without any real modifications aside from the mild porting. With the gaskets it round to $1500 (1200 for head 200 cam and 100 gasket set). Im hoping over 300 to RHP and ill be satisfied.....at least for now.
04-12-2009, 05:43 PM
#4
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I say if you're doing the heads, you might as well add 1.6 roller rockers. The rockers are cheap and the labour is essentially free. Why not? Less friction. Easier revving.
If you're doing heads & cam, you're going to need headers to get the full effect. I'd add a shift kit and cooler as well to protect the transmission from the added power. These are going to increase the cost of your build significantly.
Are you set on the ZZ3? Have you considered the ZZ9?
ZZ3 = 208/221....474/.510 (1.5).....510/.544 (1.6) 112deg
ZZ9 = 212/226....483/.520 (1.5).....515/.554 (1.6) 112deg
If you're doing heads & cam, you're going to need headers to get the full effect. I'd add a shift kit and cooler as well to protect the transmission from the added power. These are going to increase the cost of your build significantly.
Are you set on the ZZ3? Have you considered the ZZ9?
ZZ3 = 208/221....474/.510 (1.5).....510/.544 (1.6) 112deg
ZZ9 = 212/226....483/.520 (1.5).....515/.554 (1.6) 112deg
04-12-2009, 08:37 PM
#5
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Location: MI
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Roller rocker arms are never overkill for any engine. Gord said it best, they are worthwhile for a lot of reasons. More power from less friction and more aggressive valve action/more lift. It will benefit those cams which probably aren't on the cutting edge of cam technology. 
Sounds like a good bunch of parts. Once it's tuned properly you should have traction problems galore. A 2800 stall and shift kit are very worthwhile but hopefully you can include some sticky tires to make it all hook. A TPI car is a bore if it can't hook up when you hit the throttle. 245/50/16 MT ET Street Radials work good. Goodluck!
Sounds like a good bunch of parts. Once it's tuned properly you should have traction problems galore. A 2800 stall and shift kit are very worthwhile but hopefully you can include some sticky tires to make it all hook. A TPI car is a bore if it can't hook up when you hit the throttle. 245/50/16 MT ET Street Radials work good. Goodluck!
04-14-2009, 05:06 PM
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Well. The engine has been put together. I kept the 1.5. Its being tuned as we speak. FYI, i got the trickflow 30300006 heads, a little disappointed on how rough they were in the inside, they got polished and ported as well. Added some upgraded rapid fire #5 plugs and MSD plugs while I was at it. I have to admit I love how the SLPs look on a TPI template.
I agree with that my next list of mods will be drivetrain and suspension. At this time I spend a small fortune (hopefully my wife wont figure that out
.
In reference to Gord's comment on headers I had some hedmen shorties, but those piece of SH#@ warped in 6 months...got some flowtech ceramics on at the same time (Im glad Hedman has a lifetime warrenty....will get refunded). I ditched the pseudo dual verts and got a single large magnaflow with 3" all the way to a flowmaster 40 series and monza tips (like those resonators in those monzas).
Its funny, by the time im done with my mods I would have spent over 5X over its worth.
I agree with that my next list of mods will be drivetrain and suspension. At this time I spend a small fortune (hopefully my wife wont figure that out
.In reference to Gord's comment on headers I had some hedmen shorties, but those piece of SH#@ warped in 6 months...got some flowtech ceramics on at the same time (Im glad Hedman has a lifetime warrenty....will get refunded). I ditched the pseudo dual verts and got a single large magnaflow with 3" all the way to a flowmaster 40 series and monza tips (like those resonators in those monzas).
Its funny, by the time im done with my mods I would have spent over 5X over its worth.
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