Colloquial cam spec interpretation
Thread Starter
Racer
Joined: Jun 2017
Posts: 343
Likes: 18
From: Newport News VA
Colloquial cam spec interpretation
Ok... Over summer I bought a 89 L98 Z51 vette that had the L98 rebuilt, bored 30 over, new cam and pistons, and crank. It came with the 113 aluminum heads that circulated on the L98s in the later years. I've beat my brain to death trying to track down cam specs for this newer aftermarket cam the PO had installed in the car. He didn't save any info from the build and the only thing he keeps saying is "it is one size over stock". The only thing I can think of is that it has 1 degree tighter LSA??? I know the stock "113" aluminum heads can only accommodate so much additional valve travel, lift, etc.
But my question to the group is: if you told someone that your cam was one size over stock, what in your mind would that mean? Just trying to get some grip on this mystery cam. Car runs great and has a nice mild cam lope, nothing like a thumper or anything. Just not wanting to tear down the front of the block to read the specs on the front of the cam. Any and all help would be appreciated!
But my question to the group is: if you told someone that your cam was one size over stock, what in your mind would that mean? Just trying to get some grip on this mystery cam. Car runs great and has a nice mild cam lope, nothing like a thumper or anything. Just not wanting to tear down the front of the block to read the specs on the front of the cam. Any and all help would be appreciated!
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
That kind of talk could mean ANYTHING.
IF you really want to know what you have you don't have to do anything crazy.
Pull a rocker cover, use a dial indicator on the rocker arm and a degree wheel on the harmonic balancer..... measure the cam for lift and where the opening and closing points are at .006 lift and .050 lift (on the push rod side of the rocker).... you can know everything printed on a cam card in about 45mins....
Will
IF you really want to know what you have you don't have to do anything crazy.
Pull a rocker cover, use a dial indicator on the rocker arm and a degree wheel on the harmonic balancer..... measure the cam for lift and where the opening and closing points are at .006 lift and .050 lift (on the push rod side of the rocker).... you can know everything printed on a cam card in about 45mins....
Will
Safety Car
Joined: Apr 2016
Posts: 4,648
Likes: 1,059
From: N.E. Ohio OH
Finalist 2020 C4 of the Year - Modified
Harbor Freight has usable 1" travel dial indicators and magnetic bases for not too much money. Granted they are not as good as the ones I used for actual machine work, but they are good enough and accurate enough to work out your cam specs.
Thread Starter
Racer
Joined: Jun 2017
Posts: 343
Likes: 18
From: Newport News VA
That kind of talk could mean ANYTHING.
IF you really want to know what you have you don't have to do anything crazy.
Pull a rocker cover, use a dial indicator on the rocker arm and a degree wheel on the harmonic balancer..... measure the cam for lift and where the opening and closing points are at .006 lift and .050 lift (on the push rod side of the rocker).... you can know everything printed on a cam card in about 45mins....
Will
IF you really want to know what you have you don't have to do anything crazy.
Pull a rocker cover, use a dial indicator on the rocker arm and a degree wheel on the harmonic balancer..... measure the cam for lift and where the opening and closing points are at .006 lift and .050 lift (on the push rod side of the rocker).... you can know everything printed on a cam card in about 45mins....
Will
Maybe this just gives me an excuse to get those old pulleys off there, pull the timing cover, get the specs, install nice new pulleys and a lightweight bracket system
Thread Starter
Racer
Joined: Jun 2017
Posts: 343
Likes: 18
From: Newport News VA
The shop name he gave me was bought out end of last year and demolished in place of a strip mall. I tried to track down some other contact info for them and have been unsuccessful. The two main reasons I want to know are: yeah curiosity, but also I want to know if the cam is sufficient to be able to delete the EGR system reliably as well as future tuning specs/needs. I know EGR can be tuned out regardless of cam spec. But it would be nice to know if the cam is scavenging enough to keep the head/chamber temps down. The power is nice, runs real strong. Just sorta want to baseline what I have as I think about future wants
