I bought a new cam from Jim Taylor's Engine Service, a 240/240 (@ 0.050")solid mechanical lifter cam. When I degree it, it indicates that the keyway is cut 20 degrees advanced of the advertised 108 intake CL. I am measuring at the lifter, and all the opening/closing is occuring 20 degrees early. The duration, lift and the LSA are all right on. I am using a dial indicator to determine TDC on #1 piston, and measuring all opening/closing at 0.050" tappet lift. I reinstalled my old cam and it is exactly as the spec card reads, but every time I degree the new one, I get 20 degrees advanced. Then I retarded the cam gear on the chain one tooth, which is about 18 degrees, and this gets me real close to what the spec. card reads.

I called Jim Taylor and explained my situation, and he keeps putting me off, saying his $600,000 cam grinder doesn't make errors, etc. What do you think, install it retarded one tooth on the cam gear?

Thanks!

I bought a new cam from Jim Taylor's Engine Service, a 240/240 (@ 0.050")solid mechanical lifter cam. When I degree it, it indicates that the keyway is cut 20 degrees advanced of the advertised 108 intake CL. I am measuring at the lifter, and all the opening/closing is occuring 20 degrees early. The duration, lift and the LSA are all right on. I am using a dial indicator to determine TDC on #1 piston, and measuring all opening/closing at 0.050" tappet lift. I reinstalled my old cam and it is exactly as the spec card reads, but every time I degree the new one, I get 20 degrees advanced. Then I retarded the cam gear on the chain one tooth, which is about 18 degrees, and this gets me real close to what the spec. card reads.

I called Jim Taylor and explained my situation, and he keeps putting me off, saying his $600,000 cam grinder doesn't make errors, etc. What do you think, install it retarded one tooth on the cam gear?

Thanks!

All things considered, I guess it would work. I'd sure want and explination as to why it's that far off though.

If you can duplicate your old cams specs, but not on the Butler Cam then you are probably doing everything correctly. I would send it back to exchange. You should get what you pay for...PERIOD! You can make it work however it will always bother you in the back of your mind.

Also why not a dual pattern cam...do your heads flow very well on the exhaust?

Dean,
Double check your cam card to be sure that you are checking @ the correct lift value. I've seen many times that the advertised duration/lift value is @ .050" for comparison purposes, but the actual lift checking value to be much lower ie. .010".
Good luck,
Herb

My heads do flow high exhaust numbers, @.500" lift, Intake 232 cfm, Exhaust 199 cfm. That is why I choose to go single pattern. Jim Taylor also recommended that I use a single pattern cam.

As far as the Cam Spec. card: Duration @ 0.050" lifter rise: 240/240, LSA 110 deg., Int. opens 12 BTC, Int. closes 48 ABC, Exh opens 52 BBC, Exh closes 8 ATC. Valve lash cold: 0.013". Cam lift 0.320", gross (1.5) 0.480".

You are right, it will always stick in the back of my mind. Espically when Jim Taylor says to just put it in the way it is.

For starters: Sounds like a 400 motor application.

Can I criticise the notion of a Solid cam where a Flat HYD is quite mechanically capable of 255/255 duration lobes?...I just did.

Sorry to hear about the customer support issue.

Let's go over (in brief) the Cam Degree Procedure:

1. Find Motor's CYL#1 TDC. I use a spare 4-Bolt Main cap bolted to the Deck with a main bolt acting as a positive Stop on Piston1. Mark the two Approaching Stops onto the RANDOMLY INDEXED, but tight Degree wheel. Find TDC as the middle of those 2 marks. Set the drgree wheel to that TDC.

2A. Degree the cam Intake lobe. Well this means putting the head on and get the CYL#1 valvetrain intact...thenInstall a Zero'd dial position meter onto the either the Lifter Edge or the Valve Retainer. I figure that positions on the Rocker arm are not "square enough" with movement.

2B. Record Lifter/Valve movements going up and then down the lifter base. Note the Degree wheel position for each lift. The interested student will use REGULAR degreewheel movements and record lift indications...while noting the .003" and .050" numbers on either side of the Lobe.

You will know "which end is up" after that.

Good luck and Have a nice day.

H.I. Stud

Half-inch, you are correct that it is a 400. When I was trying to determine what cam to use, I called CompCams and the tech that I talked to said that you can typicaly expect a 25-30 hp increase with a solid tapped cam vs. hydraulic, considering other things similar. The reason being that the valve is opened/closed at a faster rate.

Thanks for the comments regarding degreeing, when I have been doing it, I have the heads off and I am measuring on the lifter itself. The way that the Cam Spec. Card reads, I believe that is where the measurements are taken. As I stated earlier, I am comming up with the correct duration @ 0.050" and correct lsa, it is just advanced 20 degrees.

If your degreewheel is at the true Top Dead Center, and that is within 2degrees uncertainty. And you can observe the upside and downside ramps open&close points at .003", then you can achieve true knowlegde of the base-circle region. Then you can also determine the Lobe-Center...assuming a SYMETRIC lobe.

BUTT, you make .050" checking points, along with finding the Peak lift point to truely read the cam lobe position. You may have a NON-SYMETRIC shped lobe. Usually Rapid Rise and slower close...

So, it becomes up to you, to read the camcard for the .003" numbers, or the .050 number to know about checking the cam position, then ignoring the Lobe Center information for a moment, see if the cam is on time.

Calculate the symmetric lobe center, and measure the actual lobe center, then grab a beer for added wisdom. Understanding the information will soon happen. You will know what to de next.

Reminds me of an old saying..or at least some old guy saying it to me: numbers don't lie.

Please report back with findings.

Have an nice day.

H.I. Stud

[ April 26, 2002, 05:54 PM: Message edited by: Lady Dude ]

Try checking it at .020 once.
Do all the numbers move for both the same, intake and exhaust?
Also are you using a 3 keyway bottom gear? Make sure your using the right dot to dot/rect to rect or triangle to triangle on the bottom as that will make about 20 degrees difference.

Sorry had to log the Lady Dude out. :eek: