I bought this brand new 413 flat tappet cam off of a member that he purchased about 3 years ago. It didn't come with a cam card so TA is sending me a cam card that they think is close to the numbers i'm seeing. I have the 9 key Rollmaster timing set on the outer 4A mark lined up with the cam gear dot like the timing set intructed for 4* advanced. I'm trying to degree the intake lobe to 109* and i'm at 110* right now. If I throw this cam in at the 6* advanced I'm affraid I will be too far off in the other direction. Can I slip the cam gear one tooth to get closer to 109*? This cam appears to be smaller on the intake duration and larger on the exhaust duration than some of the cam cards for the 413 that i've seen. This cam is an upgrade from a TA288-94H cam. Let me know what you think of this cam and if I should leave it where it's at. Thanks INTAKE -Lobe center 110* -Lift .319" -Opens 6* -Closes 46* -Duration 232* EXHAUST -Lobe center 114* -Lift 321.5" -Opens 57.5* -Closes 9.5* -Duration 247* Intake/exhaust overlap 15.5* Intake exhaust lobe center 112*
Right now you are 2* advanced with the gear at +4 and that sounds typical for a TA cam and the billet gear set.(112* LSA/110* ILC) No reason not to place it at the +6* position and then the cam should be in at 4* advanced. Right where it should be IMO. I'm not sure why you want to split it at 109* ILC other than the cam should be at 113* LSA. Go with your readings which seem to be in the ballpark. As I said this looks like typical numbers for the billet set (+4 or +6) and a very good reason to always degree the cam in when using that set. Always go with advance in a typical street setup unless you have steep gears and a big converter/manual trans or possibly you're shifting at 6000+.
I’m using the +4 advance key way. I don’t understand how that ends up at 2* advanced? Cam ILC at 113 with 4* built into it to be set at 109*. Every post I’ve seen says to set the intake lobe to 109*.
It doesn't matter where the gear set is at, it just matters what measurements you come up with and you've come up with some that are close to what the cam card will say so I'm figuring your measurements are OK. (You made accurate measurements right?) At this point I don't care what the cam card says. I'm going by your measurements. According to your readings the ICL is 110* and the LSA(or lobe centers) is 112*. Therefore your cam is advanced 2*. If you want 4* advanced,which is what they generally call for, you want to use the +6* keyway. If your numbers exactly matched the cam card your ICL would be 109* and the LSA would be 113*. That is why you actually measure the cam and that is why you have a +/-8* degree keyway, to make up for manufacturing tolerances. Any way you look at it you are are not far off and it seems to me it would only take a few minutes to slip the crank gear to the +6 slot and remeasure. As Ben says changing the cam gear one tooth would change the cam timing 15* but where did you come up with that idea? The lower crank gear is not being changed by one tooth. When you move to the +6 slot the tooth you use will only move slightly compared to where it was. If you start where the picture is right now and slide the crank gear off carefully without disturbing the cam positioning when you slide the whole assembly back on with the crank gear now at +6 you will have to rotate the cam clockwise slightly to get the bolt holes to line up which advances the cam 2*. Then recheck your cam timing.
I thought that going from 4* to 6* on the timing set would have moved my ILC from 110* to 108*. Here are my numbers on the 6* keyway. I'm at 109* ILC now. INTAKE @ .050 -Open 7* -Lift .319" -Closed 45* -Duration 232* -ILC 109* 7+45+180=232 232/2=116-7=109 EXHAUST @ .050 -Open 58.5* -Lift .320" -Closed 11* -Duration 249.5*
I have had to b4 jump the cam forward then retardvthe crank to get where I needed to go.........my last motor came in +6 to be cam card numbers.... 110*.......so no way to go plus 4 with only 1 slot left......I wanted to try 106. So by moving only the cam it jumped to 95*. Going 0 I got 101.......then -4 retarded got 105 and minus -6 was 107......I tried both and saw bo difference in performance from each other...........or from the 110 I started at for that matter. So in my case I had the cover off several times.....lots of hrs of work, no change
I know this is probably a dumb question but I've seen this done. How did you determine TDC for your pointer? I've seen the harmonic balance TDC mark used, which is many time off. Same with front cover.
Good point Gary, on my new cover and romantic balancer........true tdc is 3 degrees off on the balancer. I always use a piston stop to find tdc
My heads are on so I used an adapter for a compression tester, a #’s drill bit, and a dial indicator. The drill bit fits perfectly inside the adapter that I screwed into the spark plug hole. The drill bit rises and falls without binding or side to side movement. I set up the dial indicator on the drill bit that’s flat with a slight chamfer on both ends. With dwell and .050” rise and drop of the piston I’m getting 11.5* on each side of my degree wheel with the pointer at TDC. Then I run it again to double check my readings. I know this isn’t the preferred way with the heads on.
They make a piston stop that screws into the spark plug holes. It's better to stop the piston below tdc........as it get hard to feel the true dwell at tdc........ but stopping with something solid b4 tdc you can find true tdc on you wheel much more easily and acturately. You can use the same tool to check how truely close to tdc your dampener and indicator are https://www.summitracing.com/parts/...9QLq0iJhO2YlLg43HMuPJiWkZQrYVw78aAtpNEALw_wcB
Thanks. If I consistently get 11.5* on both sides of my wheel @ .050” piston rise/fall from the TDC mark on the wheel and pointer it should be accurate. That’s how I did it with the heads off and a dial indicator. I can build a piston stop and try it that way to verify. Thanks
A piston stop in the head works, then half way between reading on the degree wheel finds tru TDC. I made a stop from an old spark plug.
I used a piston stop this time and installed a +.005” Rollmaster 9 key timing set because my chain had too much play. Installed the crank timing gear @ +6A and here’s what I came up with. - IO 7* - IC 45* - Lift .320” - 109 ILC - 232* duration @ .050” - 288.5* advertised duration - EO 58* - EC 4.5* - lift .320” - 121.25* ELC - 242.5* duration @ .050” - 297* advertised duration - 11.5 overlap - 112.875* lobe center separation - .512” lift w/ 1.6 ratio rockers
The attached cam card is the closest I could find to my cam for reference. Next question is would this be the best cam choice for my street car? I want just enough vacuum for brakes. Would it be worth trying a TA290-08 or 290-08HL instead. See my signature for my build specs. Thanks guys
You are within 1 to 2 deg On everything It's a 413 I'd run it,its a great street/strip cam and has enough vacuum. The hydraulic rollers are excellent with vacuum and enhanced performance. Comes with a price however,including valve springs
Other than writing the wrong ELC(116.75) everything looks great. Right now it is advanced +3.9* and you can't get better than that. Done!
