I am again, hopefully, nearly in a position to upgrade my engine. I have a spare timing cover in the works "just in case". And I plan on buying: a TA timing cover a new cam A pair of TA aluminum Stage 1 heads The summer's half over already, but I am itching to do this before the end of the good weather (or maybe the good weather will finally START!) What cam would you recommend? This car is a driver, and I put the top down all the time- no race cams:grin: My idle right now is butter smooth with a stock cam, the engine looks like an oil painting when running, and I pull 19" Hg. I can sacrifice some idle quality, but only some. I still have to drive this car to and from work, and down my semi-residential neighborhood streets. I had my eye on the TA 212, but I recall reading that the Al Stage1 heads can make some other cam designs work very well. Any input?
Level 1AM? Chris- Did you check out this combination from Trishield? Jim's got cam specs listed there for this aluminum headed motor that has mild manners when it comes to idle. If it's the same cam as the Level 1 iron head (looks like it is), then it's the TA 288-94H.
Hey Chris.I think your on the $$ with the TA212 IMHO.I use the TA290-94H 2 profiles up from the 212.It has a slight rump to it and I use a 2200 stall also.The 212 should give you more oomph over your RV cam and still work with a stock stall.Nice move to those heads by the way!! Later,Tony.
I agree with Tony, the 290-94 is probably just a bit more than you want for a stock converter, I also run it with a 2200 stall (and love it). If your willing to change the converter then I'd definately recommend it.
Well that seems decided: I'll try the TA212 ...and I'll degree the cam this time! Can anyone shed light on the mod the dipstick tube needs for the AL heads??
Chris, Ask Jim Burek, Jim Weise or Mike at TA where to degree that cam. I doubt very much straight up would do you right. Probably 6 - 8* advanced is more in the neighborhood.
If your compression is over 9.75:1, I would be careful about advancing it any more than 4 degrees (with aluminum heads- with iron heads, it would be even more risky). 6-8 degrees is a lot for any cam (some would say too much). Chances are that you will run into problems running a small cam and upgrading to aluminum heads because the smaller chambers are going to bump your compression up quite a bit, and the small cam is going to create a lot of cylinder pressure. Detonation could be a problem. Something to think about.
Chris, If you go with a smaller cam than the 288-94H, then I would go no more than 10.0-1, even with alum heads.. Those small cams make lots and lots of cylinder pressure. That 288-94 H cam is my "wife drives it" cam... so I should not have to say anymore.. it's really docile.. the 114* lobe center gives it a very mild lope. 4* advance would be fine with any of those cams.. only the bigger cams do we advance it more than that in a GS, sometimes I will spin the riv stuff a little tighter, for more low speed torque. On the dipstick, the tab has to be cut off and re-located, as the bolt location is higher off the deck, than with the iron heads. This is due to the re-designed exhaust ports. JW
OK, I can't tell you all how p!ssed I am right now. I just typed up a long and in depth response highlighting exactly what I had done and what I did to the engine, and then I lost my connection and it's all gone. Let's say just that solid machine work is under my build up. I took extreme care building it and it hasn't missed a beat in 5 years, which equals about 35,000 miles, even when the rocker arm shaft broke or the valve keepres failed- still ran like a champ and I thought it was simply out of tune! I don't feel like typing up all the specs again...I built this '73 455 as close as I could to 1970 specs with the exception of the TA RV12 cam ( a mistake), the TA headers, and the 1973 heads which I was stuck with. I made sure everything was blueprinted by a very good machinist, and also that everything was balanced. then I sweated out every second of assembly with a notebook and pre-made torque schedules. I took no chances, and the engine is solid, we can leave it at that i think. I haven't heard anyone say that these heads cause any trouble at all, regardless of cam. In fact, I recall TA saying in an ad that it was a pair of heads that was responsive to small cams as well as large ones. This car is not a crusier or a weekend car. It goes on the road in May, and I drive it seven days a week until the end of October. It must be reliable. I can't have a lumpy cam annoying me as I roast in this car on a summer afternoon in gridlock, on my way home from work. This is a transportation vehicle as well as my hobby. I don't have the money to make this an occasional car. It is a workhorse, and will stay that way. I also can't take the chance on flycutting my pistons with them in the block, so I can have valve clearance with a big cam. As I recall, any cam larger than the 212 and I may have valve clearance problems. Not an option. Also, I can't spend this money to find out it's been thrown away. It has always been my understanding that these heads are a simple bolt on peice. Now I hear about detonation in an engine with factory compression (10:1) and a mod to the oil dipstick tube, which is harder to find than a hen's tooth. What is going on? What is the story? I need to know, I cannot play games with this engine. I had all this stuff specced out last year and had some financial and health troubles. It's taken me almost 12 months to get on my feet again, these parts must be a solid purchase, I don't know when I can spend this money on engine parts again.
Jim- Just read your reply. You must have posted while I was typing! Thanks for your input. I am thinking a simple split shaft collar with a tab welded on it would work for the dipstick tube. You know, one of those two part deals with socket head cap screws holding it together? I see no problems in my mental image... How about dissimilar metal problems with head studs/bolts with the AL heads? Any problem? I use ARP studs, undercut. Also, would that "my wife drives it" cam ( :grin: ( can imagine the looks on the local Chevy guys' faces as I repeat that to them after they lose) be OK as far as valve clearance goes with 1.6:1 ratio rockers? How about a stock stall converter?
Hmm. I just checked the 288-94H specs...it's .504" lift with 1.6:1 rockers...shouldn't that be a no-no with my factory-type dished pistons and no fly-cut?
Chris, Did you zero deck this engine? Stock piston placement (with most of the aftermarket pistons) is well down in the hole, my shop mocked mine up (right at .500 lift cam) and it wasn't really close, I don't recall the measurement but it was significant. I know the combustion chambers are smaller on the alum stage 1's but I didn't think they located the valves any deeper into the chamber?
The lift has very little to do with piston clearance... It's a lot more critical how much duration and on what lobe center. It has been said on occasion here that you would be surprised how big of a cam it takes to run into clearance issues in a 455. As far as the detonation issue, I didn't mean to freak you out. It's just something to consider. There is a good dynamic compression ratio calculator you can download to figure out if your engine will run on pump gas. I have used it to run combo's that Jim Weise posted on the board here, and determined that a dynamic compression ratio around 8:1 with aluminum heads is where you need to be to run on good pump gas. If you have iron heads, you need to keep it down around 7.5:1. This means that you can run the TA212 cam with 9.75:1 static compression with aluminum heads, with 4 degrees advance on the cam. If you move up on cams to the 288-94H, you can run much more compression. I was considering using that cam in a 10.8:1 motor for pump gas with stage 2 aluminum heads. The dynamic compression with 10.89:1 static compression and the cam advanced 4 degrees comes right in at 8:1 (intake on 110 centerline). Keep in mind that setting your pistons closer to zero deck makes the motor more detonation resistant, and that the amount of compression you can run will vary because of that. Jim Weise seems to almost always zero deck his motors, so it's something to consider when you look at the numbers I used above (since they were based on calculations taken from his specs). You might have to cut back on the static/dynamic compression if you have more piston-deck clearance.
