bonz

I want to do something to add a little more horse and I am thinking a cam would be the best way to go. Will I be able to change the cam with the engine in the car. Looks a little tight so I figured I better find out. Even with the radiator out. I would like to get as big as cam as possible and not screw up the computer. It is basically. What kind of gains will I get also. I dont really want to spend the money on new air runners and headers since I plan on buying a different TA in the near future. Not sure if I want to stay with the third gen or maybe a 78-81.


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1989 Trans am 305 TPI Automatic, 2.73 rear, K&N filter, underdrive pulleys, air foil, tb bypass, low restriction exhaust

FruityOne

You can change a cam while the engine is in the car. It requires you to remove the radiator, and A/C condensor though.

As for what cam would be best, I'm afaid I couldn't answer that. I would guess a cam with no more than 220 duration @ .050 for streetability and tuning ease.

I'm no genius, so I could be totatlly off-base about the camshaft spec issue.

fb305svs

stay under 430ishlift as well.. .pushrods wont clear the guid holes inthe heads

bonz

Well ive been lookin at cams and find a Crane PowerMax in Summit. Its just a little more cam thats in the 305 manuals and 350 autos. Intake and Exhaust have 204/214 duration and lift is .423"/.446". Now thats a little over .430 but will it still work. Also is it a pretty big job to change cams with the engine in. I know I can get it done but just wondering what I can be lookin forward to. THANKS

FruityOne

Those cam specs are very similar to the L98 cam. What is the LSA?

Intake and Exhaust have 204/214 duration and lift is .423"/.446"

L98 cam is (for 89's at least)
207/213 duration @ .050
.415"/.431" lift w/1.5 rockers
117* LSA

bonz

Yeah its just a little bigger. Not sure on the lobe seperation. Maybe it shows it on their website.

paul_huryk

i'll be honest here - its not even worth it to just replace the cam for a few hp - maybe you will get 25hp out of it. You have to rip most of the motor apart and put it back together correctly - not something a novice should do. You may also make things worse by touching a well-running motor.

I know you don't want to spend much money - but there are a few areas you should look into first before even remotely considering a cam swap:

Change rear gears to 3.23 or 3.42 (gear swap or rearend swap)
Good 3" cat-back exhaust
Headers (not the cheapo Edelbrock ones either)
Nitrous oxide (75-100hp)
Higher stall TQ converter

I will steer you toward the nitrous because as long as you have decent fuel pressure and the motor is running well, it should be able to take 75-100hp. I would suggest a shift kit and big trans cooler with that - otherwise you will be getting a rebuild very soon.

ShiftyCapone

iTrader: (7)

Before you jump into a cam swap you want to make sure you have a fulkl exhuast and intake. You are blessed with a good fuel pump to handle a swap of this kind. You are also going to want to look into a custom chip. It will maximise your new cam when the time comes. You should look at L98 and LT1 cams. They are within the limits of the stock heads and are proven performers for a 305.

bonz

Well I wouldnt say I am a novice. Ive done plenty of work on cars to know what Im doing. As for the horse power gains I would expect it to be a little more than that. Since the 305 manuals are rated 35 more hp then mine and this cam is a little bigger than that cam. I know theres a lot to change it but its nothing over my head, and if it was there is plenty of people around here that can help me out.
Since my tranny is going out on it also and I will be getting mine rebuilt or another one rebuilt to put in it I was going to get a shift kit and a higher stall converter but the guy doing it said that it wouldnt be the best idea since the 700r4 isnt that great of a tranny.
I really dont want to mess around with nos either, since Ill have to do work on the ignition system.
I want to get into chip burning but not sure on what I all need to do it, but plan on looking into it more since I want to buy a different 3rd gen that I will do more work on the engine.
THANKS for all the help.

fb305svs

well here's something you can go by...

cam was a compucam 2030 (little more duration than the one you said, i think it's now a power max 2032... )

anyways, it was a lfat tappet cam, so a roller one might run more lift.

I put 232hp and 273ftlb all to the wheels with a 230k 305, with rebuilt heads (86 motor). it had a performer intake, edlebrock shortie headers, and a slp cat back with no cat, and a holley carb on it... nuthin special, the intake probably wasnt worth anything, and a carb is a carb as long as its tuned well..

those numbers given, the torqyue curve was phenominal (flat as hell).

so there is a lot of potential- i figuer it was about 275hp and 315ftlbs of trq at the crank-- not too shabby for un ported heads... i'll tell ya what, hog the heads out, extended the slots for the pushrod guids and drop a 47-480ish lift cam in with better springs and you could have a solid 300hp 305..

Kontrax

to get the full potential of the cam you will need to breathe better. id go for intake over cam 1st. if your TPI then go for some runners or port out the plenum. TPIS makes some nasty tpi stuff. you can even change out the bellows that go to the throttle body. those are very restrictive in the TAs. if you do a search or ask around, you can get some pictures of people with some nice looking home made bellows

you will notice a big difference if you swap out those 2.73s...

force350

does the lift restriction of .430-.446" only apply to stock heads or all heads in general for chevy?

ShiftyCapone

iTrader: (7)

Most stock GM heads fall under this restriction. Not all though. LT1 and LS1 heads can go much higher. This is normally designated for GEN I heads. Aftermarket heads can go much higher. Then again so can stockers with the right machine work.