heres the setup im looking at:

-siamesed TPI base
-AS&M runners
-LT4 hot cam
-1.5 roller rockers
-home ported L98 heads

would this combo work on a TPI motor with intake and exhaust mods? is the Hot cam to radical for a LTR setup, or would the reduced rocker ratio make it work? with a siamesed base, the engine should make power in the operating range of the cam (1500-5500). im looking for an alternative to the expensive ZZ9 cam from TPIS, which is suppossed to be one of the best cams for TPI.

 

An lt4 hot cam using 1.5 rockers would bring the lift down to .492 on the exhaust as well as the intake . Sounds O.K. to me .

 

Private message "3.8TransAm" otherwise known as Jeremy. He's the moderator of the NW Indiana/chicago board and he's done a setup VERY similar to what you are suggesting.

Only difference I can think of is he has Vortec heads.

 

In my opinion your shooting it down by lowering the lift. Don't be suprised if your disapointed with the whole darn thing. It's design is better in use with a LT1 type intake, carb or stealthram. Something a prom guru can work with the fuel curve on to better the performance and utlize the ability to roll it up to valve float without being air starved. Since your staying with the TPI set up I like a small duration with a lot of lift. Builds great torque and quickness out of the gate. Take advantage of your port volocity and give it some 2.02 intakes and 1.6 exhaust valves to run through. Some great exhaust and hold on.. The ability to let it breath is one thing. The air starving can be misconcieved.

My cam of choice might be someone elses paper weight but I'm preping a stealthram to go on here soon and I am staying with my Ramjet cam. The engine I have is ultra quick on the street and plays hard in the powerband the system was built to use.

oh and 1.6 rockers.....


- 355ci, WS6, 5speed -
* Ported & Polished Big valve Cylinder Heads (Cast # 993)
* 2.02 & 1.6 Manley Pro-Flo Valves
* Harland Sharp 1.6 Ratio Roller Rockers
* Crane Valve Springs and Retainers
* G.M.P.P. Ram Jet Roller Cam
* Crane Roller Lifters
* Speed Pro/TRW 1.25 Dome Forged Pistons
* Windage Tray
* Lightweight Nodular 16lb Flywheel

* Induction - Ported and Gasket Matched
Plentum
Manifold
Runners
52mm Holley Throttle Body
Custom Built Adjustable Fuel Pressure Regulator
#19 GPH Injectors running at 50lbs

* Exhaust All New
Edlebrock Chrome T.E.S. Headers
High-Flow 3" Carsound Cat
Dynamax 3" Exhaust Tubing and Tail Pipes
Flowmaster American Thunder Muffler

 

Yes it will work and make pretty good power. Mine is quite similar to what you have planned.... Go with 1.6s though.....

-Siamesed stock TPI base
-SLP runners (worked over)
-LT4 Hot Cam (w/ 1.6 rockers)
-TFS heads (box stock)

No numbers as far as power, but I turned 13.60 @ 105 with some horse-poop lack of traction 60 foot times (2.2+)..... So it is making pretty good power (I just can't drive!!! ). And I haven't put a wide band on it or dyno-tuned it to really eek out the last few ponies (and I won't be since the 355 will be coming out soon).

 

I had a stock TPI car going 13.5 on a 2.0 60ft with the 1.6rockered hotcam. I was only trapping 101 with stock parts.

 

13.5 with just a hotcam kit ? That sounds good to me !

 

Well I don't wanna get your hopes up, I had full exhaust and a 2400 stall also. The LTR setup itself was stock.

 

You will be much happier with a LPE 211 or 219 cam over the hotcam with TPI. The LPE cams promote much more low end tq because of their valve timing. What's the point of using a cam that's made to run up top if your intake can't flow enough to support the cams needs?? LPE211=excellent low-mid range tq. Hotcam=okaymidrange tq&good top endhp. Spend the money and get the right cam for your application

 

Yeah, but he is talking about using it with a siamesed base (like what I currently have)...... It is no longer a LTR setup - or at least not like it would be in stock form. Look at my MPH. It will work. A perfect match? Probably not. But if he is looking to save some money he won't be disappointed with the LT4 HC on that setup and likely can't afford to buy that perfect match cam anyways...... IMHO, of course . Tough to beat a brand new roller cam for ~ $190 though .

p.s. Watch the classifieds on Camaroz28.com and you can probably get a low mile LT4 HC for about $100 .

 

Good to hear your opinion camarojoe. The hot cam is not a true TPI cam by design. It places the torque curve in the wrong place through valve timing. Results, a loss. A LT1 or Steathram sure.. TPI, I'm betting there is more power to be had with the correct LPE, TPIS or even a ramjet cam. The hot cam is a prime example of a car becoming air limited with out the need. It's all about calibration. Air limited happens when the car tries to produce power where it isn't designed to run. The higher RPM scale. Torque is and will always be the winner with stock style TPI without a adder. The guy with this 406 Vette has got it right. No adder, 406 that moves massive amounts of air as quickly as possible with a superram. 437 horses at 5100 RPM but look at torque. never drops below 450 as it crosses HP at 5100. Thats what it's all about. There is another dyno sheet there that the HP and torque never meet. The need for torque for volumetric efficiency is the bottom line. Ride the wave into the horsepower line and you have efficiency. Get the figuers in order and you got the real deal. This vette's for real.

https://www.thirdgen.org/techbb2/sho...hreadid=180840