the old L03 is feeling a little worn,

I have a 350 in the garage, it has world sportsman II heads, 9.0:1 compression, and a comp cams 08-306-8 cam

cam specs as follows:

duration @ .050" Intake 230 exhaust 244
lift .510 intake, .540 exhaust w/ 1.5 rocker.
112 lobe separation

I would like to keep the car TBI, is that do-able?

 

it's do able. but you'd have to get into chip tuning.

 

thanks.

what kind of power and torque should I be expecting at the crank? any Ideas?

 

I'm not a TBI expert, but that seems like a huge cam for TBI. Maybe it's do-able though.

 

I like big cams

 

Stock TBI ECM will not support that much overlap. Based on description this cam is better suited with a TPI and 2500 RPM stall converter (and modified ECM). I am venturing a guess that it will have low idle vacuum which will make MAP sensor very unhappy.
Also, with this much overalp and only 9.0:1 SCR that engine will feel lazy even with a carburetor.

//RF

 

how much higher should I bump my compression up? I was planning on converting to Mass air flow, do you see any issues with that cam and MAF?

 

Question is do you want to spend the time to make it work? And do you value keeping EFI? As stated requires tuning, larger injectors, larger TB unit, a swap of fuel pump. knock sensor, ign module(?), and probable addition of a WB02 sensor.

RF: Why could he not run open loop and lose the NB02 running fueling off VE tables and WB02 feedback to ECU?

See what I mean, to want to make it work. MAF I believe is said to be easier to tune. Yet many MAF users convert to SD with MAP sensor.

 

I do value keeping it EFI, not really sure why, but I just don't want to go carb. if the car had a carb from the factory, I wouldn't mind, but since it came injected, I'd like to keep it that way. as far as tuning goes, it's something I'd like to learn to do, so I think it's worth the hassle.

 

Ronny

Sure - I would disable CL at idle first and get my VE and spark tables dialed in to give this engine combo what it wants. Once this engine can maintain idle I would start looking at WBO and NBO correlation at various idle speeds looking for false exhaust lean areas. Based on experience dialing in idle is about 50% of conversion headaches! Nothing more embarrassing then a car that will not hold idle and stalls at stop lights! To do so requires ECM reprogramming and appropriate skill set.

Every time some of my friends come by and ask me for an opinion, after going to the bottom of the cam companies catalog page, as to which cam they should install in their high priced rides I always ask them what are their goals and expectations. Most of the time it either DD or WR! Hence, cam that is more docile (mid page) is usually appropriate choice. Note that you have to consider the whole package (car, engine, drive train, the driver).

Switching to MAF introduces another set of problems. There are threads that cover MAF vs. MAP pluses and minuses. I am not going to venture into that abyss!

//RF

 

it's a DD right now, but when I finally blow up the L03, that will be another story!

 

Is the 350 a roller or non-roller. Not to say that non-rollers are not tunable, just not as forgiving as rollers.

Just to make sure you know, you need closed loop only if you are running a catalytic converter. Luckily for me, I converted to stick and do not have much problems with idle. I had it idle at close to 15Hg but messed with some stuff not it flutters around 10.

I see you have an 83 as well. I just went through a whole 350 upgrade to my dd while my 83 still remains not running. Take my advice and either get rid of the 83 or just keep the L03 running and get your racecar complete. Like me, too many projects, not enough time or money.

 

I am non emishions with no cat-con. I ran OL for a season and gas mileage was terrible. Here in WI it can be 45 ded in morn and 75-80 in late afternoon. Running CL accounts for those swings in temps.

 

It's a roller 350, I'm considering selling my '83, I'm not sure yet though, I do know, that I want to finish my paint and my inteior on my '91 before I build a motor, I'm sick of driving ugly cars! I don't have emissions check here in Florida, so thats not an issue.

RFmaster:

you mentioned I should bump up my compression, how high do you think I should go?

 

Eric
With your roller cam that has a decent overlap of 74.50 degrees, advertised duration 290/307, I would consider going to 9.5 to almost 10.0:1 on premium pump gas since you have modern heads to boot (they flow). With hydraulic roller tappet both intake and exhaust valves are lifted during overlap (same as with flat tapet). With fast ramp rates afforded by roller based cams valves are lifted faster and provide more cross flow during overlap effectively reducing dynamic compression. Check this handy calculator here:

http://www.wallaceracing.com/dynamic-cr.php

An extensive explanation can be found here:

http://members.uia.net/pkelley2/DynamicCR.html


Every 1 point increase in static compression ratio (SCR) will increase your torque 3-4%. Again - you always have to ask what is your goal and budget!

/?RF

 

well, thanks for all of the help, looks like a piston swap should be in order than.

what do I need so I can start data logging?

I know it won't help much for the 350 til it's in and running, but I'd like to learn to tune on my 305 so I have a foot in the door when I go to put the 350 in.