cam timing

I recently built a 455 bored new pistons rings whole nine yards. I bought a ta 212 cam when I ordered parts I just got a standard timing set and installed it straight up. Would this result in low power and low vacuum? Any comments might help.

 

That's a pretty small cam. With 218*-230* I wouldn't expect to much from it on power but you should have at least 14 in hg. Installing it straight up verses 4* advance will make some diference.

Assuming you're engine is .030 over, 9.1 compression, Stock small valve heads, 750 CFM carb, daul plane intake and stock exhaust manifolds and muflers with TA 212 cam Dyno 2000 says it will make 346HP @ 4000 and 499 TQ @ 3000. That should be about 285-295 at the wheels.

 

This is a 70 sf engine with 10 to 1 pistons. I am only getting 8 to 11 on vacuum.

 

Are you sure that you have no vaccum leaks, my 455 holds 18 inches of vaccum with a Poston GS116 which besides lobe displacement is very similar to the TA212.

Dave Berryo No:

 

Hello. I have the same cam in my car. TA told me to advance it 4.*

 

8 to 11" at idle seems way low to me I'm running a TA290-94 (a good bit larger cam) and I have 13-16" at 725rpm idle. I did install mine 4 degrees advanced (106 ICL) per JW and the cam card. As mentioned above I'd triple check for vacuum leaks, but advancing the cam 2-4degrees would likely smooth up your idle and bring your vacuum up.
What static timing advance are you set at? What's your idle rpm?

 

I had about 15* Initial timing at abou 850 rpm cannot get to run very well any lower than that. I was worried about vacuum leak too went over it pretty close and actually replaced the valley gasket. No obvious leaks. Maybe something I am missing. I have been messing around with the dist considering having ignition man rebuild it and set it for my application. Also mabe while this is taking place I will take it apart and get a keyd timing set and do it as TA said to.

 

Have you driven the car since the cam change? If not could be the vaccum line is loose at the trans, or maybe the power brake booster is leaking.

Dave Berry

 

I have got a TA 212 in my engine and initially the cam timing was at 0 degrees. After many attempts at tuning the carburetor and getting around 8 to 10 inches of vacuum I advance the cam timing at the recommendation of TA to +6 degrees. I am now getting between 12 & 14 inches of vacuum. The theoretical difference when you advance the cam timing is that you move the effective power band up or down depending on which way you go. Advancing it will lower where the power band is and should give you better idle performance. You may also have to go to around 10 degrees of initial ignition timing and a no load idle of around 1000 rpms for good low end performance. If you are running an automatic you may need a higher stall converter, depends on what you have. Don't forget that carburetor adjustments will be necessary when you make changes such as with the different cam.

If you go to the Crane cams website there is a good explanation about cam timing. I think that there was a link in this forum not too long ago. Good luck and have fun.:grin:

 

Well having Dave convert your distributor is a good move no matter what else is going on with your car. I went from points to his small body hei, I immediately saw cold start up and idle improvements even with less static advance than with the points.
While it's a major PITA I would jerk that timing cover and get that cam degreed properly, combine that with a well built distributor and I'll bet it runs much better.

 

Thanks for the advice guys!