How do I identify an unknown camshaft without removing it from the motor ?

[Tynan918]

The best way to nail my correct timing and everything else related to tuning my engine correctly, is to know exactly what camshaft I'm working with..

I have an unknown camshaft and I want to identify it without pulling the camshaft from the motor..

What are you guys' ideas on how to go about that?

I seen this ProForm universal cam checker..part # 68902... what do you guys think about this?

 

[Tynan918]

do you have any pics of your engine and the work you've done? cause it certainly sounds like a lot is going on here with noise, rebuild, cam, timing, idle, etc.
have you popped the front timing cover to see if there is a stamp on the front of the cam?

The camshaft did not have a stamp on it..

 

[565bbchevy]

When they say my vacuum level is 13 HG and people are telling me that's too low for stock camshaft, then obviously I have an aftermarket camshaft that I don't know about that I need to know about if it changes the ball game of setting the timing of my engine.

Who is they? Do you not have your own vacuum gauge that you use for tuning?

 

[Tynan918]

Who is they? Do you not have your own vacuum gauge that you use for tuning?

They meaning the Monte Carlo guys and the Monte Carlo Nation Facebook group.. that was the biggest concern when I posted about it and the group was that the vacuum was too low for it to be a stock engine.

Yes I have an interior vacuum gauge attached to my dash, which is connected to my intake manifold full vacuum port.

 

[86LK]

well, either that cam has no i.d. stamps at all, or they are on the other end 🤬

maybe shoulda pulled it when you had everything open 🤷
right now you're between a rock and a hard place. to me, I wouldn't rely on the measuring device, I would just bite the bullet, pull the intake, pull the camshaft, and know for sure.

 

[bracketchev1221]

Camshaft has no bearing on ignition timing. Advance it until you either have an issue starting it, or it pings. Total timing depending on cylinder head and piston usually winds up between 34-40. In the real world either use an engine dyno to see when it stops gaining hp, or when mph stops climbing at the track. There’s your answer.

If you are looking to raise idle vacuum, then you need to work on ignition curve and try to get as much timing in at idle to keep the throttle blades as closed as possible.

 

[Tynan918]

well, either that cam has no i.d. stamps at all, or they are on the other end 🤬

maybe shoulda pulled it when you had everything open 🤷
right now you're between a rock and a hard place. to me, I wouldn't rely on the measuring device, I would just bite the bullet, pull the intake, pull the camshaft, and know for sure.

Man I asked these guys if I should take out the camshaft to check the ID of it, while I had the timing cover off and the timing chain set off, and these guys told me no not to do it.. these very same guys in the comments right now. I posted my whole procedure right here in this forum.

 

[DRIVEN]

Perfect reply, just keep blaming everyone else.

 

[carnutjw]

Camshaft has no bearing on ignition timing. Advance it until you either have an issue starting it, or it pings. Total timing depending on cylinder head and piston usually winds up between 34-40. In the real world either use an engine dyno to see when it stops gaining hp, or when mph stops climbing at the track. There’s your answer.

If you are looking to raise idle vacuum, then you need to work on ignition curve and try to get as much timing in at idle to keep the throttle blades as closed as possible.

Here's your answer. Set initial timing at 8 degrees, adjust idle speed, drive it. Make it 10 degrees, adjust idle speed, drive it. 12 degrees. If it pings/rattles, or is hard to start hot, back it off one or two degrees. Quit worrying about things that don't matter. Vacuum will be what it is.

 

[ck80]

Man I asked these guys if I should take out the camshaft to check the ID of it, while I had the timing cover off and the timing chain set off, and these guys told me no not to do it.. these very same guys in the comments right now. I posted my whole procedure right here in this forum.

You're looking at this all wrong. Guys increase and pull timing based on ranges of things, including what octane gas you're willing to run, as a way to optimize power.

It's not a one-size-fits-all based on the cam you run for anywhere you go.

The proper way to do it is go for a baseline set then increase or pull your settings based on what the engine likes for how you're setting things up, and your altitude (higher you're running, the more you advance). You've got to make those changes yourself, it's not like owning a 2010 Civic that you just set things to a baseline depending on your cam specs and the computer fixes it all for you. No short cuts with some things in owning a classic car.

 

[CopperNick]

13Hg of vacuum at when? Idle or off idle? Vacuum tends to increase as rpms rise. If the mill starts on the key with little persuasion from the acc pedal and idles nicely and smoothly, and shuts off without dieseling or running on, then your vacuum ought to be about where it should be.

If you are looking to identify the manufacturer, or discover some kind of part number or alpha/numeric code inscribed somewhere on the stick you might just walk away disappointed. Popping off a rocker cover might offer some hints based on the presence of heavier than stock valve springs or beehives instead of straight coils or other non stock valve train components but the only sure way to discover what specs your cam has is to measure the lift and duration using the micrometer tool and the degree wheel and a pointer and compare what you get with the stock specs for a factory issued 305 cam.



Nick