Seeing I need a new cam...I was thinking I would have my builder grind to those specs. Thanks ahead of time.
Interesting,,,I thought that most performance cams were installed at "0" degrees (no advance), as the advance was built into them- not true on the Poston cam I guess?
This what I thought!!! I tried to get an answer to that earlier this year but no one could really respond with confidence. Guys, thanks for the help.
Yes, the advance is built into them, but just because you use the 0 key way on your timing gears doesn't mean that it will degree at 4* advanced. In a perfect world, you put it in dot to dot, and you would have a cam that was installed 4* advanced from it's LSA. That is why it is mandatory to degree a cam.
LOL!!! That was the response I received!! When you read this cam card it leads you to believe that the advance is not built into the cam. So what you are saying (this is more my understanding than your saying) is that 1st you have to confirm that dot to dot is REALLY = to ZERO. Then you can add your 6% with confidence...right?
6%? No, I'm saying that with virtually any cam you install these days, you need a 9 key way timing set, and you should disregard the markings on it and use whatever key way it takes to get the readings to match the cam card. You can start dot to dot, but you'll likely not end up there.
Larry, I have an unknown aftermarket cam in my engine that was visually in excellent condition. It is probably a TA cam, as that is where most of the other engine parts were purchased from during the rebuild. If I want to degree that cam, can I do this without a cam card? If not, then what can I do? Thanks, David
I'm afraid about all you can do is find a shop that runs Cam Doctor software and take the cam in. They can "read" the lobe profiles and the relationship between the I/E profiles, so you get the specs through reverse engineering. It's then up to you to decide at which position you want to run it, because you don't have any way to know the original grinder's nominal numbers that were targeted. Devon
Wow, that's a Bummer. I don't think I'm gonna pull the cam out to solve this mystery, though. It'll have to stay in until a 455 replaces it, somewhere down the road..... Thanks.
This is from the T/A website. It makes my head spin. Some people will refer to the Billet timing sets as being 4 degrees inaccurate. However, it is the stock timing set that is technically inaccurate, stock timing sets had 4 degrees of advance built into them. TA Performance was deeply involved in the development of the Billet, 9 Key Timing Sets. During the development of these sets it was determined to make them true straight up keeping with industry standards and giving the most flexibility for degreeing camshafts. So all but the TA Billet 9 Key sets will have 4 degrees built into them. Oversized gear sets are available for align honed/bored engines.The compensation is NOT in the chain it self,but in the two gears. The gears are larger diameter to take up the slack that would otherwise be in the chain. If you need an oversize you will need an entire gear set. Replacement chains are the same wether the gears are standard size or oversized. Also note that the gears can not be mixed and matched, due to the phasing of the teeth and chain. TA offers special billet crankshaft gears with the nine key way flexibility. Just like the gears used on our Billet timing set series they utilize 0,2,4,6 & 8 degree increments for advance or retard of the camshaft. Unlike offset crank keys which not only alter the timing mark location, but throw the engine completely out of balance which can cause severe damage. Offset keys will advance or retard the cam AND the balancer at the same time, and dont forget that Buick engines are external balanced. These crank gears are compatible with all TA double row sets (excluding over sizes) as well as other manufacturers double row sets.
Yes, I have the TA Billet oversized gear set with multiple keyways. I installed it, set at "0", not having any info for my cam. I feel that I have lost some low end grunt, but starting at 3000 rpm, the engine is a real monster. The gear set I pulled out to replace was installed with 4 degrees of advance (it was on the 4 degree keyway). Now I understand why I lost some low end power- I lost (maybe) 4 degrees of advance (assuming the cam was installed correctly to begin with). I miss-read the TA literature when I installed it, and thought the zero keyway was 4 degrees... so, thanks for posting this. Oh God, I guess I'm gong back in there soon to set it at 4 degrees.... and of course, all the while not really knowing what the cam timing truly is...
Do you have a question about the TA info or need some clarification? I probably can't help much but I'm sure there are a number of members that can mke it more understandable.
Thank you, but no- I understand it now. I read the cardboard insert the wrong way one dark night, while installing my new TA timing set. I'm gonna just have to pull the cover and set it at 4 degrees and live with it for now. Glad bird posted that- I never would have known otherwise...
I am not clear on this 4 degree thing that is supposed to be built into engines...is this only applicable to Buick? Does this say when u r dot to dot on a buick engines that you are actually at 4 degree advance?
The cam should be degreed in. If you have to you can buy an offset crank key and use it on the cam. Long ago I used one from a 440 crank and grinded it to fit. Worked well but it was a 4* key for the crank. So for the cam it moved it 2*. Ray
Dismiss the 4 "built in" notion completely. Buick instructed the engine assembly line to do the "dot to dot" to get the engines put together in a timely fashion. We don't know what the tolerances were in that assembly, some may have hit the streets +3, some -2. The stock grinds were so conservative, the differences may have made no difference in how each car performed. The aftermarket cam suppliers have a lot more interest in being precise about their cam profiles and how they should be installed. If you're buying one of their cams, they figure you are too, and want you to make sure it's installed per their recommendations...in other words, slap the degree wheel on and do it right in order to expect the results they advertise. Devon
