Why Degree A Cam Shaft?

[Deuce]

Also every Comp Cam I've seen degreed is spot on.

I would have to agree with this.
Comp do the Harley cam's, and on the twin cam engine (and most others H-D I believe) it is impossible (or very near so if I am wrong) to degree the cam during installation. And you certainly are not removing the engine for a cam install - which doesn't make degreeing much easier anyway.
Every cam just goes in, gets dynoed, and spits out near enough the same hp/tq as every other similar combo on the same dyno.

Real world experience. It is what it is.


But always degree on my on V8 for my piece of mind that I've done it right.

 

[vc commodore]

So on one hand immortality you say if you don't degree a cam you're not doing the job right. This comes at the expense of extra time and you have to remove the heads too.
But taking the extra time to do a few more dyno pulls and swap the gear around a few times is not more work?

I can give you a gold plated guarantee that shops doing the old "spin the cam to raise the lifters" trick aint degreeing the cam in.
If I'm going to do head gaskets on an LS with lots of road use I'll usually pull the engine. This is to make it easier to prep all the gaskets and seals as on older and more used engines when you pull the timing cover it disrupts the sump gasket. Then you pull the sump which upsets the rear plate gasket and to do the rear main you should be pulling the rear plate to linish the crank.
So to re-seal the engine you need to scrape and scotch bright by hand all the gasket surfaces so it's easier on an engine stand.
Then if you're doing the job properly you should check the cam bearings which will be out because LS (great engines) so I send all cam bearings off to the machinist.

Now we put the sump on rear main on cam in and degree the cam put it all back together. Big job.

Or you do what some shops do and pull the timing cover do the spin trick lifting the lifters onto their buckets slaz the sump gasket whack it in and send it.

Or you can pull the engine and do the job properly as per above but don't use slaz in the corners for the timing cover fill with water (which it should be on new head gaskets) and do a dyno pull the quickly whiz the timing cover off. Gaskets are fresh so can be re-used the cover is clean quickly change setting whiz back together with the air ratchet use the old crank bolt. Run another few pulls rinse and repeat. When it's all done brake clean the gaskets add the slaz at the corners for final assembly use new crank bolt fill with coolant and send it.

Now your jumping around again, trying to deflect the topic at hand.

Truth is, to do a job properly, degree the cam in whilst it is going back together the first time....This saves money no matter how quick it is taking a timing case cover off....If you don't do this, it proves you're a rip off and/or bodgy and should be avoided at all costs....

 

[Immortality]

I don't think it's that much work.
With the two piece timing cover you mention even if you have to remove the water pump you wouldn't have coolant in only water.
When the gaskets are new it's easy to pull apart and put back together.

Much work? Maybe not but you aren't paying the bill and it's all time and money when you could have degreed the cam when you installed it!

And you don't need to remove the heads to degree a cam.

Pulling the engine now for what you originally termed a simple cam swap and tune for a road car....

Stop trying to muddy the waters.

 

[Immortality]

Ohh, and BTW, if you had degreed your cam when you installed it and worst case scenario happened and you did need to move the timing you wouldn't need to go through the whole setup again because if you know where the cam is!

 

[shane_3800]

Much work? Maybe not but you aren't paying the bill and it's all time and money when you could have degreed the cam when you installed it!

And you don't need to remove the heads to degree a cam.

Pulling the engine now for what you originally termed a simple cam swap and tune for a road car....

Stop trying to muddy the waters.

So how do you stop the piston rocking in the bore with the head on?
The video you posted clearly shows the guy pushing on the piston on one side to load the skirt.
The amount of rocking the piston does in the bore could equal a degree or two.

I posted a video of a SB2 V6 engine showing how he uses a dual gague deck bridge. That is so you know your on TDC and takes out the variable of piston rock.

One of the most important aspects of cam timing is intake to piston clearance. If you have too much you're just wasting efficiency due to pumping loss so ideally you want to bring that valve as close as possible so adjusting for this make the whole degree step redundant. But that is a performance race type deal for street use just send her.

 

[vc commodore]

This is Shane...Head first with everything

 

[Immortality]

Depending on the cam or engine type piston to valve clearance comes down to how big the cam and/or how much lift it has. We are talking about a street commodore with a simple cam swap/tune. Good try though....

A shop that does these types of cam swaps regularly will know what cams will fit without valve to piston clearance issues or cams that will need to have pistons fly cut to suit. Knowledge that comes with experience....

 

[shane_3800]

Watch this video. You can clearly see the power differences are fairly minimal compared to the effects of the exhaust. Like he states 95% of people just match the dots and send her.

The internet: you need to degree your cam so you don't loose low end power and torque.

Also the internet: use a single plane (even though it kills about 5 times the low end power and torque)


One other thing is that the slotted gear in the first video may be the culprit for the cam being out. I would like to see what the results were with the stock gears.

 

[shane_3800]

Depending on the cam or engine type piston to valve clearance comes down to how big the cam and/or how much lift it has. We are talking about a street commodore with a simple cam swap/tune. Good try though....

A shop that does these types of cam swaps regularly will know what cams will fit without valve to piston clearance issues or cams that will need to have pistons fly cut to suit. Knowledge that comes with experience....

You missed my point. You're talking about making clearance for a valve to stop interference. That is different to setting correct PTV clearance.

 

[Immortality]

Again, more youtube videos from your hero trying to obfuscate....

Holdner the dyno queen!

edit: getting the cam timing right is about the torque and power curve, i.e where it makes that power!

If you were a half decent mechanic/engine guy you would know that but now you are trying to hide that and bring on a video that involves exhaust design and wave length tuning instead.