I have herd the debate about the peanut cam not being a peanut in late model TPI cars such as my 91ta. Question.. if it is not a peanut then can anyone give me the specs that they think the cam is. I would think the only way for sure is to measure the lift of the cam so could someone give me instruction on the proper way to measure it. Cam is installed. I am getting ready to install a new cam once I get back in the U.S. so any help would be appreciated.

 

Measuring the lift you'll need some tools you may not have. Either a micrometer or dial indicator. With the dial indicator, all you gotta do is take off the valve cover, put the end of the indicator on the pushrod end or valve stem and rotate the engine, and read the difference. If the cam is out, you can use a micrometer and measure the smallest and largest diameters, subtract the two, and thats cam lift.

Specs on cam are as follows:
ENGINE: CHEVY SM BLK 305-350
INTAKE EXHAUST
VALVE ADJUSTMENT HYD HYD
GROSS VALVE LIFT .413 .428
.006 TAPPET DUR 259 265

VALVE TIMING OPEN CLOSE
AT .006 INT 8 BTDC 71 ABDC
EXH 61 BBDC 24 ATDC
THESE SPECS ARE FOR CAM INSTALLED
AT 119 INTAKE CENTER LINE

INTAKE EXHAUST
DURATION AT .050 202 207
LOBE LIFT .2750 .2850
LOBE SEPARATION 115.5

The lobe separation is as measured. The spec is supposed to be 114.5, so either they list the spec wrong or the cam I have isnt ground 100%.

The lift on the peanut cam is like .350 on the intake. I'd hope everyone could easily measure the difference between .350 and .413 with a ruler. Its a bunch. I always suggest it, and it seems like nobody does it. EDIT: bonehead subtraction, please step back to 2nd grade please. Would work fantastic if you didnt need exact specs.

 

$amn I did'nt realize the peanut cam was that bad . I need to get a real cam in my car.
Later Barrett

 

Don't you mean a 1/16" ?

A 1/2" is .500

The difference would be .063 or 1/16th.

 

Ok, I knew I was tired today but sheesh...
Thanks.

 

That's ok!

I had a nap after work today......LOL

Later bro.

Darrell

 

I'm gonna have to say you dont have the peanut cam, and here's why: I pulled the cam out of my 91 305 auto TPI camaro, and also out of my 92 350 TPI formula. They were the same cam. The SAME. Not only was the lift the same (and I checked with a micrometer) but they had the same casting number stamped on them. Something like 773 if I remember correctly. The specs listed in the tech data here on TGO are apparently wrong for the late model TPIs.