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View Full Version : zz4 cam in an l05 tbi engine.



one92rs
02-23-2012, 02:53 AM
who is or has run a zz4 cam in a 350 tbi engine. mine is an l05 from a buick roadmaster that is roller. im going to be running the stock heads and intake. of course ultimate tbi, headers, and catback. also planning on going to a 427 ecm when i do my 350 swap. if you have how hard was it to tune. i have an lt1 cam-202/207 @ 0.050" .450"/.460" Lift, LSA 116

zz4 208/221@.50 474/510 lift 112 lsa

woody80z28
02-23-2012, 05:14 PM
Will the stock heads accept that much lift? You have a couple of things going against you with that cam...there's a decent amount of exhaust duration compared to stock LO5, and the LSA is a little tight. Your o2 sensor might not be accurate at low RPM and the MAP reading will be reduced.

I put the LT1 cam in my LO5 with Vortec heads and TBI. The Vortecs have made mine some work to tune...but the LT1 is less cam than the ZZ4. I never played with the stock swirl port heads on mine.

EagleMark
02-23-2012, 06:49 PM
May have to tune idle/low RPM open loop. MAP will be low so it will be adding fuel thinking there's a load on engine, but that can be tuned. The duration and Lobe seperation will be sending O2 unburned fuel at/near idle/low RPM is why open loop idle/low RPM will probably be needed. Would be easier on a manual trans car as you could set idle up to 1000-1200 or so. Just pushing boudries of low RPM cam...

May want to check with some engine builders and see if that engine will even be able to breath that much. What is the RPM range in specs?

woody80z28
02-23-2012, 06:56 PM
LO5 TBI's with the stock swirl port heads make good torque from idle to about 4000, and choke almost completely at 4500. The swirl ramp in the intake port becomes a restriction. This is why I built mine with Vortec heads. They leave very little torque on the table down low, but make much better power as RPM increases. The Vortec-headed 355 in my Camaro with a 230/230 .480/.480 cam pulls hard past 6000.

PJG1173
02-23-2012, 08:47 PM
I have had good luck grinding the ramps out of l05 heads. the engine I had them on would pull up to 6k. cam selection does play into this also. The vortec 355 in my toyota has good torque down low and will keep pulling in the upper rpm range with a extreme energy 4x4 cam 230/234 @ 0.050, .474/.474

woody80z28
02-23-2012, 09:06 PM
I have had good luck grinding the ramps out of l05 heads. the engine I had them on would pull up to 6k. cam selection does play into this also. The vortec 355 in my toyota has good torque down low and will keep pulling in the upper rpm range with a extreme energy 4x4 cam 230/234 @ 0.050, .474/.474

How was the low end without the swirl ramps on the TBI heads?

Was that a Comp XE 4x4 cam? The XE grinds I've seen are usually pretty aggressive, and with those duration and lift specs it would actually have a softer ramp than my old Magnum 280H grind which isn't very aggressive. Are you sure those specs are right?

PJG1173
02-23-2012, 11:21 PM
How was the low end without the swirl ramps on the TBI heads?

Was that a Comp XE 4x4 cam? The XE grinds I've seen are usually pretty aggressive, and with those duration and lift specs it would actually have a softer ramp than my old Magnum 280H grind which isn't very aggressive. Are you sure those specs are right?

they wern't too bad at the bottom they were on a 327 I had which really arn't torque motors, but it didn't have any problems hitting 6k. I never got them flow tested because I was in a hurry to get them on. matter of fact we didn't even get the hood back on before we left for the race we were in such a hurry.

the cam I'm running in my 355 is this one. supposedly they are specifically designed for 4x4's.
http://www.compcams.com/(S(5xt3rx55f12cifn53hcsfa55))/Company/CC/cam-specs/Details.aspx?csid=167&sb=0