Safeside

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Safeside

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rusty vango

ah, WHAT question???

Safeside

Im about to swap my 1990 peanut cam for the following.

http://www.summitracing.com/parts/cca-12-402-4

Was wondering what kind of gains I could expect? I also have the matching Comp Cams, rockers 1.52, pushrods, retainers, keepers, lifters, and new valve seals.

Also, what, if any mods should I do to the computer? Apparently this cam is stock computer friendly.

Safeside

and new matching comp cams springs

rusty vango

if all goes well ,you can expect around 250 maybe 300 hp. IF you have flat top pistons. and run 1.58 long tube headers. don't expect a TPI to make high RPM hp they are all done by 4800 rpm. but until then... they are a bunch o fun!!!

NowhereFast

That cam is for a flat tappet block; it will not work AFAIK. You already have a roller set up, the best choice without doing any kind of tuning would be crane 2032 or crane XE262.

Safeside

So should I scrap the flat tappet cam and matching lifters?

Can you switch from roller to flat tappet? I know most peoples eyes will pop at the thought of that too. Also, the XE262 cam I looked at is a flat tappet cam, and the crane 2032 cam will require an adjustable fuel pressure part as well.

Basically, im looking to swap the cam will as little impact as possible. Not trying to be cheap, lets not get confused. Ill glady spend the money on a great cam and lifters that wont require much beyond install and go. Wheather roller or flat tappet, idc.

Idk, the more I dig and dive, the more questions I come up with. Frustrated.

midias

Get a roller cam

Safeside

Say something like this perhaps?

http://www.summitracing.com/parts/cc...8/applications

eseibel67

It will run well with that 08-300-8. No computer changes required, but it will be even better if tuned. Not sure how much performance you will gain, but you will feel it.

A bigger than stock cam will move the RPM up. AS the RPM's rise, there will be benefits to increasing torque converter stall speed and lowering the gear axle ratio.

Safeside

Thanks for the inputs. I'm still digging and researching and learning. Main thing is, and I feel this is how a lot of users on here feel, is that we want to be sure that we are sure when we go to make changes and purchases on new parts and changes. A lot of people know and understand how changes effect performance and second and third order effects too. Just wanna be as sure as possible.

With that, I scored an LT1 cam out of a 45000 mile 4th gen.

Hey, what's good for the goose is good for he gander right?!?!?!?

rusty vango

you may not want to raise the rpm level that some cams do. with all that hi stall TC bs. you can quickly end up with a car that is totally un drivable on the street. choose your parts according to what you want from your car. too many people tout "race" parts with out thinking of the "practical" side of things.

w41duvernay

Guys,
I need some help here. I have a 1986 Pontiac Firebird S/e Lg4 305, w 700r4 auto. I have just put a comp cam 260H in the engine, 212 duration @ .050s. I'm trying to figure out what would be proper gear ratio would be for this cam.
I did note this cam I put in there is a close match to the L69 cam. is 3.42 to 3.73 ratio a proper range(with 235 60 r15 tires) ? Can I get away up to 4.10 ratio w/ 255 60 r 15s?

rusty vango

street ,daily driver ? or weekend toy ?? a 3:73 gear, will limit your freeway cruising speed . and can have a negative impact on fuel economy. i wouldnt go lower than a 3:42 for a car you have to drive daily . and 4:10s ?!?! out of the question for a DD

w41duvernay

Thanks, Rusty. I forgot. I have the Pruis to drive regularly. It's a build for a street/strip.

86LG4Bird

iTrader: (1)

What transmission do you have? ie. What is the overdrive ratio?
If a 700R4, then I think 3.73's are the optimum street/strip ration for the 255/60/15 tire size. 4.10's would be strip-optimized only, no added fun on the street. If auto trans, what stall converter are you running?

jokerZ71

^^^^^ x 2
Gearing & stall should be chosen in how the vehicle will be used,tire size,transmission gearing.It should not be chosen to help crutch up a bad choice in camshafts.

w41duvernay

Sorry, a 700r4 tranny guys.

Fast355

iTrader: (2)

For something that gets driven mostly city that you want to accelerate quickly, go with 4.10s. If you want it to be a highway cruiser, go with 3.73s. With 4.10s in OD with a 255/60r15 you would only be turning 2,500 rpm @ 70 mph. I run a 350/4L80E/3.73 in my Express van with a 255/70R15 and I turn it 2,600 rpm @ 80 for hundreds of miles at a time. It actually runs better at 75-80 mph than it does at 55-60 mph because the RPM is higher and the engine load is less. However my personal preference is to drive a slightly overgeared vehicle rather than an undergeared vehicle. I cannot stand a car that has the downshift blues on the open road.

86LG4Bird

iTrader: (1)

3.42's if you it to be a highway cruiser.
4.10's to optimize strip performance.
3.73's for street/strip.


Hey "Mr. Counterpoint" Fast355, trying to draw an analogy between gearing required for acceptable performance in a van weighing a ton more than a 3rd Gen is pointless.


w41, What TC are you planning to use? Hopefully nowhere near stock with that much cam in a 305. I think it will need every bit of 2800 (9.5" rather then 12") if you're serious about it performing well.

Fast355

iTrader: (2)

No I am just going off the amount of gear it is going to take to put that cam in the right cruising RPM range and the right RPM range to run through the traps in the 1/4 in the 100-105 mph range. Lugging the engine is lugging the engine regardless of vehicle weight and aerodynamics.

I am running more cam (Lunati HE 268) than that with a stock 4L60E converter in a L30 in a 99 Tahoe.

jokerZ71

If the cam we're talking about is the 260H,it has an operating range of 1200 to 5200.Not that it wouldn't help for strip performance,but,it doesn't NEED lower gears,or,higher stall to perform well.This is a small torque cam,not a racing cam.It will drive & cruise fine with stock gearing & stall.

Fast355

iTrader: (2)

Those RPM ranges are based on a 350 CID engine. In a 305 the powerband will shift up about 10%. With the Lunati 268, you can tell the engine/cam wants more stall and more gear than the factory converter that is stalling ~1,600 and 3.73s. The power really does not start to come on strong until the 3,000+ rpm range. I have played with several 305 setups and even 100% factory engines enjoy more stall speed and more gear. I have put several 3.73 G80 setups from S10s into F-cars in place of 2.73-3.08 gears and it was never a regret. I have installed numerous 4.3 torque converters with the 2,025 stall rating as well.

86LG4Bird

iTrader: (1)

Sure it will drive and cruise with any TC or gear, but he did say street/strip. It will be a disappointment at the strip with anything less than a 9.5" 2800 TC, regardless of gearing. TC choice has a more significant effect on 60' and 1/4 mile performance than gearing does. Without considering strip performance at all, the above mentioned S10/4.3 converter is the bare minimum to keep that engine in its powerband for spirited acceleration on the street. Under heavy acceleration, it will almost feel like a bog when it upshifts if he uses the stock converter.

Fast355

iTrader: (2)

In my experience gears are equal in importance to torque converter in terms of 60' and 1/4 mile. When you are geared too tall, you end up only being able to fully make use of 2 gears for the 1/4 mile. Geared correctly for the 1/4 mile, you will fully use all 3 non overdrive gears in the 700r4. You actually even want to go through the traps about 5-10% over peak HP RPM. If you engine peaks at 5,000 rpm, you generally want to cross the traps at about 5,250-5,500 to make the most use of your HP. I have also found that if you lockup the converter at higher rpm in the top of 2nd and 3rd you can gain some MPH on the top-end.

cardo0

Thx for posting Fast355. Right now im having problems w/wheelspin at launch w/3.23 gears. Curious what are your 1/4mi times (60' also) and your cam specs on your 383 TPI strocker? Im betting u have your 4L60 shifting better than mine.

w41duvernay

I've got to rip out the tranny anyway. When the OEM brakes locked up, I burnt up the tranny. I've been thinking of going with a 2400 rpm stall converter w/a rebuilt 700r4. Also going with a posi and whatever gear ratio seems good after this thread is resolved.
LG4 bird, I'm curious if you went to a non-stock intake manifold and IF so, how did you solve the air cleaner problem. I've been thinking about either a 80's corvette air cleaner housing or a spectre housing.

Fast355

iTrader: (2)

Best pass was a 14.1 @ 99 but it was also a 5,000+ lbs brick

Wheelspin with that tall of a gear means you need some chassis/suspension help and or better rubber.

w41duvernay

Will I have to reprogram the chip for the axle ratio change? I probably have the 2.77 gears in it now.