TPITuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
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Hi!
I have a rebuilt a 355 engine this winter and am about to install this things: HSR intake,ZZ4 hotcam, 522 TB,Trickflow heads 64CC,pistons whith a comp of 10.5.But i heve now read this on the TPIS homepage and wounder if the ZZ4 cam arent any *** for my combo,please replay about this if you have any suggestions.
Here are the TPIS post::
Q: I have a 95 LT1, it has LT4 heads and intake, LT4 fuel injectors, 1.6 roller rockers, 52mm throttle body, 1 3/4'' SLP headers, GM Performance Parts Hot Cam, ACCEL 300+ Ignition and K&N fuel injection performance kit. Idles good, but when I hit the throttle it is slow to respond, and when it does, it isn't very impressive. Do I need a re-programmed computer? A larger fuel pump or an adjustable fuel pressure regulator? Any help you can give me would be greatly appreciated.
A: The Cam is too big for a 350 motor. I get this question all the time with the LT4 Hot Cam. If you look at the duration @ .050 it doesn't look bad , but it must be huge everywhere else in it's lift range. It would be fine in a 383 or bigger motor with a lot of compression, and a deep gear. Also the intake port volume of the heads are big for a 350 street motor. In order to use these pieces you would want to stroke the motor and or raise the c/r, or add a supercharger. When you go with big cams and 1.6 rocker ratio, and add big heads you will lose a lot of your bottom end power and most of your mid-range power. What happens is the velocity of the air slows down that's why you go slower. The whole set up is still on the big side for a 383 ci motor. You will make more power but it will be all up top.
TPiS
__________________ Firebird cab-92 355 HSR TPI
Mods: Hooker Headers.AFR 195 eliminator heads,LT4 Hotcam,1.6 rr, 58mm TB,Magnaflow 3"exhaust cat back.custom chip, 180" stat,,open element whith a K&N,,accel 8mm 4.10 gears, 3000 stall.GTA tires/M/T street radials.Auburn posi,
Th700R4 rebuilt
Accel 8mm wires.Speed density.
365rwhp 11,83 184 km/h in 402m
7,53 in 200m
Originally posted by Firebird sweden Hi!
I have a rebuilt a 355 engine this winter and am about to install this things: HSR intake,ZZ4 hotcam, 522 TB,Trickflow heads 64CC,pistons whith a comp of 10.5.But i heve now read this on the TPIS homepage and wounder if the ZZ4 cam arent any *** for my combo,please replay about this if you have any suggestions.
Here are the TPIS post::
Q: I have a 95 LT1, it has LT4 heads and intake, LT4 fuel injectors, 1.6 roller rockers, 52mm throttle body, 1 3/4'' SLP headers, GM Performance Parts Hot Cam, ACCEL 300+ Ignition and K&N fuel injection performance kit. Idles good, but when I hit the throttle it is slow to respond, and when it does, it isn't very impressive. Do I need a re-programmed computer? A larger fuel pump or an adjustable fuel pressure regulator? Any help you can give me would be greatly appreciated.
A: The Cam is too big for a 350 motor. I get this question all the time with the LT4 Hot Cam. If you look at the duration @ .050 it doesn't look bad , but it must be huge everywhere else in it's lift range. It would be fine in a 383 or bigger motor with a lot of compression, and a deep gear. Also the intake port volume of the heads are big for a 350 street motor. In order to use these pieces you would want to stroke the motor and or raise the c/r, or add a supercharger. When you go with big cams and 1.6 rocker ratio, and add big heads you will lose a lot of your bottom end power and most of your mid-range power. What happens is the velocity of the air slows down that's why you go slower. The whole set up is still on the big side for a 383 ci motor. You will make more power but it will be all up top.
TPiS
OEM LT4 engines in Corvettes are 350 cube motors. Why someone would say that the LT4 heads and intake are too big for a 350 is odd.
The LT4 Hot Cam Kit was designed for......a 350. So saying that the cam is too big for a 350 is also odd.
I don't know why someone else was having problems with their set up but your engine should run great. I'd be suprised if you weren't happy with it. I know I like mine.
__________________ They say violence doesn't solve anything BUT it sure does make me feel better.
Thanks for the replay!
I just needed some positive feedback on my combo, its coming together next week.
I cant see why the TPIS cam ZZ9 would be so much better for me anyway.
Also it's a ZZ4 cam or a LT4 HOPTCAM . Not a ZZ4 Hotcam
Happy moddin'
__________________ PROJECT UGLY DUCKLING
1989 10:1 353 L98Edlebrock base and runners ( really ported)ZZ4cam ,1 3/4 SLP shorties 083 heads ...cleaned up andstuded w/1.52 rr , LT4 valve springs and retainers and a 3 angle valve job
suspension mods (Hotchkis LCA's PH bar, KYB shocks and struts)
T-5 3.73
T-62 turbo to be installed next ...Exhaust clip ...gota let it load.... http://media.putfile.com/My-exhaust-clip
there is nothing wrong with the hott cam,the zz9 tpis cam or any other cam in that field they flat out work
i would put way larger cams in my old cars to test them out and my fav.is still the old comp 286hr10 it pulls to 6800 with ease has a nice idle(the way a cammed car should sound)3000 stall or a t5-t56 tranny and 3.42-4.10s this cam is an idiot on the n20 150 or more infact:91 z28(many years ago(14)
trick flow 23*1.5 crane r.r.
mini-ram
30 lb svos
58mm
headman 1-5/8
2.5" y-pipe,true3"w/flo
perf.resource chip
2800stall/700r4
3.42 geared 10 bolt
stock shortblock(32000 mi.)
ran 12.40 motor, on the 150 shot it NEVER hooked, on and off the button it ran 11.50 STOCK shortblock,double roller chain and a cam,the key to a thirdgen is cam,intake(LTR to the dumpster)i will get flamed for that but its true!most of all ya gotta have gooooood head or it aint worth a dam!
I'm running the LT4 HOT cam in my stock short-block L98, and I'm pleased. It's my daily driver. Admittedly, I chose the HOT cam because it was at least $100 cheaper than anything else out there. I'm using it with 1.52 roller rockers, and it's pretty mild. I'm still fine-tuning the chip, though, to really smoothen it out. It definitely doesn't sound stock, but I think it has the potential to be a real stop-light sleeper. I might consider putting in 1.60 rockers once I get everything else dialed in just right.
I'm also using 64cc chamber heads on my engine, but with the Edelbrock TPI base with SLP runners. I'm running the stock factory torque converter with my 700R4, FWIW.
I have both the ZZ4 cam in my stock ZZ4 motor and the ZZ9 TPIS cam in my IROC. Both work great. The TPIS ZZ9 cam is a slight mod of the ZZ4 cam, but it feels and sounds like a much more radical mod. Great cam, but it's about $100.00 more than the ZZ4 cam.
Both these cams work excellent with TPI motors!!!!!!
you call THAT a big cam?(see sig) I'm only running a little 355. car still has a/c and gets 16-17 in town, about 20-21 highway unless I'm being stupid, and it's carbed, and has run in the 11's. If people think the hotcam is big I can't imagine what they'll say about my new motor...380ci de-stroker, same cam w/ 1.6 shaft rockers.... .604/.624!
Hey Shagwell, what cam is that? I'm looking for something just like that.
Actually I'd love a solid roller around the .600 lift mark WITH 1.6RR, but i can't find one.
More importantly, what kind of pistons are you running and how is your valve clearance. i'm running speed pro flattops with 2 valve reliefs and am worried about clearance. i also have the 64cc pro topline 200cc as well.
Cruz'N Bruz'R - Doug Herbert billet roller. Cost me something like $280 new, built for the late-model block(machined for the retainer plate, extra $50). Any billet roller can be run as a hyd or solid roller. I'm going solid w/ the 400 block. I highly reccomend to everyone that you look into shaft rockers. They are truly a nice piece, and they make more HP than regular RR's on a sbc. They also make for a quicker revving motor. - Can't remember now my exact valve to piston height, but I'm running the Dynagear zero deck flat-tops, and .025 squash Victor head gaskets. My toplines are untouched 200cc, 64cc chamber angle plug heads. W/ the headmans, I have to pull the driver's header to change #3 plug though, due to the angle plug. - Ask Dans87GTA, this motor is explosive. My car is a tank(4161) and I've run in the high 11's all motor.
also, I usually turn it about 7200 in low gear...and if your running a 350 I wouldn't run 1.6's w/ this cam. It's plenty of cam for a 355 with 1.5's, 1.6's would cost you power...
I'm running a 383. I like the fact that you can use a roller cam with either hyd. or solid roller lifters. I have my eyes set on a sweet solid roller setup with everything, except the cam is huge. It's .630 lift with 1.5, and I probably won't have the clearance to pull that kind of lift.
FYI, on the Pro 200's, i pulled the valves out of mine to port them, and there's no point, they're so clean in there. I kind of feel bad for the guys that spent so much money on AFR's.
.020 bore, ported intake, plenum and pocket port job on the heads and castings in the block. Can still see the cross hatching after 40k on the bore job.
I have no idea as to what the car has for a cam, didnt have it degreed, it's what cam with the car when I bought it. It doesn't sound stock lined up with another stock camaro L98, but it doesn't sound as radical as a hot cam setup.
What would actually have to be done to install a hot cam in an L98 with the stock iron heads? Can I get away without prom tuning and still hit the street till a later time when I can purchase a piggyback tuner like the prominator?
What they should have put on there was that the hot cam is to big for that motor with 1.6 rockers. the lift on a hot cam is .525 with 1.5 rodkers. a 350 can only handle .550 lift stock. when you put 1.6 rockers in your motor with a hot cam, the lift is pushed to .560 or somewhere around in that area.
I can't believe no one has mentioned this yet! It all in the tuning, I'm surprised it even runs with all those mods and the stock tuning. Your 92 is a speed density setup which means any modifcations you make will throw off your VE tables. Even headers can need upwards of a 10% correction. There's nothing wrong with your cam, just need to retune your ECM for the mods. Check out the DIY tuning board, lots of great info and you can be up and running for less than 150$. Don't bother with the mail order trash, if you don't want to learn to tune find some one local to tune it hands on and be prepared to spend major bucks.
. a 350 can only handle .550 lift stock. when you put 1.6 rockers in your motor with a hot cam, the lift is pushed to .560 or somewhere around in that area.
Stock , you can't handle ANYWHERE NEAR 500 LIFT, let alone 550 . My springs are good for 570 lift but stuff had to be done for binding/clearance issues
What they should have put on there was that the hot cam is to big for that motor with 1.6 rockers. the lift on a hot cam is .525 with 1.5 rodkers. a 350 can only handle .550 lift stock. when you put 1.6 rockers in your motor with a hot cam, the lift is pushed to .560 or somewhere around in that area.
I believe the lift on the hot cam WITH 1.6's is 525. It's only 492/.492 with 1.5's. That's from Scoggin-Dickey Parts Center.