I've been reading posts and didn't realize until tonight that my 87 305 tpi 5 spd. car had a peanut cam in it. I've read about a number of people replacing the peanut cam with an LT1 cam, but most of the posts talked about an improvement in 1/4 mile times and not anything remotely like autocross, whcih is what I intend to do with the car. My 87 has a cat back, chip, and ported plenum and runners, 3.42 gears with a zexel. I'm seriously thinking about putting on a set of edelbrock nickel plated headers in the next few weeks. I use the car as a daily driver and plan to get back into autocrossing next year. (picked up two sets of race tires today for it)

So, with the intended use I have in mind for the car, would a cam change benefit me very much? And please keep in mind I have to pass emmissions every two years.

 

These are my opinions, I can't back them up, yet.

Autocross requires you to be able put power down at almost any where in the RPM band, to be able to punch out ether low or high speed corners and also be able to scream down strait-aways. To do this I think you'll need a cam that has a flat torque curve but keeps making power through 4500-5000 RPM. With headers and if you run with the SCCA you'll be in E-Street Prepared and the only "legal" cam that you can upgrade to is the L98 350 cam that was put into some later 305's. Another cam that I would look at the LT4 HOT cam, it should make a little more than the L98. The TPI's high end breathing problems is going to limit you choices. You could consider losing the TPI and replacing it with a multi-point injected single plane intake, that should breath better up high and not hurt you too much down low.

I'm running TBI that makes loads of torque down low, but has nothing in the high RPM range. I'm planning on replacing the heads and swapping in a LT1 cam and later a LT4 HOT cam. The intake is switching to a Edelbrock performer dual plane and later I'll experiment with a single plane.

 

I'm actually thinking about going to the mod class. I'm not concerend about what class I'm in anymore. I won a FS championship, and a couple of divisionals back about 11 years ago with this car. It was tough going to do this. Took me almost 4 years to win. The competition was really good, but I finally starting winning and never looked back. Chasing points and trying to win the championship just got to serious back then. Now if I miss an event then I don't care. I'm older now and have five grand kids we do things with on the weekends, and if it's a choice between seeing my grand kids or going racing, then the kids will win every time.

I'd would really like to stay with the TPI setup. I like the way the car runs since I got it back together. The car has 144k miles on it and runs strong for a 305. When the 305 does go, I'll drop a 350 into it for no other reason that the 350 is cheaper to build than the 305. So, I'm curious to see what cam would work best in my situation (off idle to 4500 rpm) and still let me drive it all day on the street and still pass emissions.

I'll try and find some specs on the cams you mentioned and compare them to the cam that's in the motor now. I really appreciate your input.

Thanks
Dan

 

Lift Duration Seperation
Peanut Cam: .350/.384 179/190 109
1988 L98 cam: .415/.430 207/213 117
1992 L98 cam: .413/.428 202/207 114.5
LT4 HOT cam: .492/.492 210/228 112 (with 1.5 rockers)

Here are a few Lunati cam specs
54742: .416/.447 206/215 112 (1500-5200 rpm)
54743: .471/.480 219/227 112 (1800-6000 rpm)
54756: .510/.525 232/242 110 (2000-6500 rpm)

 

If you are going through the trouble of changing cams, I wouldn't put a stocker back in. The comp cams 304 or 305 looks like a good one for you, or the LPE74211, or an extreme energy under 220 duration if you are keeping the stock tpi.

 

Any cam change is going to help you if you have a peanut cam. You shouldn't have trouble finding a cam to satisfy your two goals of having a driveable daily driver and having auto-x car, since in both cases you need a cam thats going to deliver strong low end and mid range torque. With this in mind, keeping the tpi is a good idea. Something like an LT1 cam should be ok, but you shouldn't go too larger than that because this thing is still using stock heads and after that you'd be hurting low end torque anyway with a 305

 

I know it's a bit pricey, but what about a TPIS Super Profile L98 cam? I bought a used one years ago and installed it in my otherwise stock 87' L98 - it really woke up. Instead of falling on it's face at 4400-4500, it pulled to 5200-5300. The reason I mention it - TPIS used this cam in their world challenge corvette. Just my $0.02

 

The 87 305 5-Speed did not come with the peanut cam. The 87 305 Auto did come with the peanut cam.

 

Your 1987 305 TPI 5-speed did not come from the factory with the peanut cam, so breath a sigh of relief. The above post about the peanut cam only going into the 305 auto (where it concerns TPI cars) is correct. Model year 1987 was the beginning of some good roller profiles in the 5-speed 305 TPI/L98 350; the biggest of which is - as Axoid posted - in the 1988-89 305 TPI 5-speed and L98 350 TPI cars. My own opinion is that 207/213 cam is a pretty good street grind, and would be complete with a good set of 1.6 roller rockers.

Dave

 

just to restate what the previous 2 post said....

YOU DO NOT HAVE A PEANUT CAM in your 87 305TPI 5-speed.

Only the 305TPI Auto's got the peanut cam in 87.


I might know from personal experience. Check my sig.

 

I'm glad to hear I don't have the peanut cam. I wasn't looking forward to changing the cam out.

All the posts I read said 87 had them, and made no mention that auto cars were different from stick cars.

I guess I'll concentrate on getting a set of hooker headers now after I get my SFC's installed.

Thanks

 

Alloy, although the question has been answered pretty well, here are the two 1987 TPI cam specs to show you the difference between the two:

1987 305 TPI 5-speed cam profile:

PN: #14093643 (hydraulic-roller)

202/207 duration @.050 (int/exh)

.404" / .415" lift

114.5 lobe sep angle


Now to clarify what your car would have had, if it was an auto. trans car, it would have had this cam:

1987 TPI 305, automatic trans. cam profile:

PN: #10088155 (aka "Peanut" cam; hydraulic-roller version)

179/194

.350"/.384"

109 LSA

Be thankful you do not have a 1986 TPI 305, as that particular year - for some curious reason, probably something to do with emmissions - both the auto. trans and 5-speed cars got the dreaded peanut cam in flat-tappet form. In any case, your stock cam is not too bad, so rest easy.



Dave

 

I am looking for a replacement cam for my TPI swap into my 87' Monte Carlo LS. Im keeping its LG4 and will be using a 87' TPI setup I pulled from a Trans Am.

I also pulled all the roller cam parts to convert it to a roller cam motor....but the car was an automatic so it has the peanut cam .

My question is, would the 5-speed/L98 TPI cam be a good replacement?

The 305 will be mildly modified, with Hooker headers/cat back exhaust(MCSS style) and a K&N filter/cold air induction. Nothing major. Car has the 2004r trans just rebuilt with a 1650 stall convertor and it has 3.08 gears.

Would the 5 speed/L98 cam be good with that combo or would I not see much improvement over the peanut cam?

From what Ive seen/heard I dont want the ZZ4 cam, would be a little too drastic for my setup.

TIA

 

I'd say you have the right idea. Any cam will be a big improvement over the LG4/peanut cam. You could run the GM '88-'89 L98 cam at 207/213, which should work quite well for you.

Dave

 

Thanks for the reply.

How does the 87' L98 cam differ to the 88-89?

Just checking before I buy one.

Whats a fair price range for a good-but-used cam(88-89).

TIA.

 

Scroll up; Axoid posted the 1988 L98 specs (same cam in 1989 also), and I posted the 1987 specs a few posts up.

The TPI 5-speed got the same cam as the L98 350 each year.

Dave