Aluminum and Iron Head 455 Builts- Parts and power comparisions

Larry,

I don't think you would have any issues with the brakes at 14* of @.050 overlap, as long as you had your tuning right.

In my experience, there are two things that significantly affect performance, when it comes to camshafts.

1. Intake duration
2. Lobe center

I have had some pretty good results with a straight pattern cam with alum heads.

Somewhere in my archives, I have done a direct test, with the prototype Level 1 motor, with both a 288-94H and the 288-92H.. Those two cams are the same basically, except for lobe center, and 8* less exhaust duration with the 92.. intake dur was nearly the same, 230 vs 231..

As I recall, the upper and lower power numbers were very similar, but it was actually mid range power that was significantly better with the tight lobe center cam.

I will have to see if I can dig up those test results. I thought I had posted them a while back. I think that stuff is on a hard drive in my old computer at home, I will have to put that drive in this machine, or see if I can locate the paper copies, or the discs..

I would say that you need 30-50 more HP to get your car solidly in the 11's, and I am not so sure that just the LC will do it, and I doubt you will see any great difference with such a small duration change.. I am unsure when it comes to the lobe center change, because I don't believe I have ever tested a 118 cam.

JW

 

In the interest of fair reporting, I have to correct myself here..

In digging thru my old records, looking for a specific set of dyno tests for Larry, I came across flow sheets from before and after our upgrade bowl and chamber work, for the TA SE STG 1 heads. I said I had not seen 269 cfm out of the intake at .500 in the out of box TA heads, but I was incorrect, I had seen exactly that number. This was a set of heads for a board member, bought from TA with that BPG special he did a few years ago. He sent them to us for the port work and I did a before and after flow study.

Here's the sheets.

Out of box




After the upgrade




JW

 

Jim, I'm interested in this. Can you elaborate with some specific details please? I have the 308s and HEI now but I happen to have a points dist, a new MSD magnetic pickup and MSD 6AL box in the garage with nothing to do. I was thinking of buying a MSD reluctor and adapting it and the pickup to the points dist. Have you seen that done? (just answered that question, Dave does it for $135) Seems pretty straight forward. I was also thinking of hiding the MSD box on the inside of the RH fender behind the overflow tank. I could run the wiring along with the blower resistor wires and then forward inside the fender to the box. What do you think?

 

Jim can we back up to your entry level cam and engine combinations. every one seems to prefer the c113 or c118 cams, i chose the ta292-02 because of the higher lift and the tighter center and could use the stock rockers. have you ever done any comparisons on this cam??

 

Awesome read!

I also picked the 292-02 cam on a 9.8:1 mild port 70 stage 1 head, and was wondering how this cam would react if changed to manifolds instead of headers. Would it completely kill the power/driveability, or cause tuning issues? The Packard should end up being around 3800#, what rear gear would be a good street fit in your opinion? This engine may just end up in the 66 lesabre with some 3.08/3.42s, or do you think that's wishful thinking for the size of the car?

Thanks for all the great info!!:TU:

 

With otherwise stock manifolds, I hate to say it but I think the point at which the camshaft will be coming on strong is about the same point the manifolds would start to hold you back.

I drove my 308S cammed 462 to the fab shop on manifolds...it was downright sad. Sounded great at idle but had no mid range or top end.

The drive home from the shop after custom headers/exhaust was done was a revelation. I couldn't believe what an animal the thing became after the exhaust was improved.

Devon

 

I Still have the headers from the regal and am thinking that I could rework the front primary pipe on either side to work on the lesabre, but the packard would have to be manifolds.

 

i run MSD 6al with pro billet distrib> mounted just behind passenger side headlights in front of battery. battery blocks view of it- can't even see the box unless you bend over and look in there.

 

A very respected cam designer stated once that he believed that low-flow numbers should not be improved because they helped promote reversion durng the overlap period.

 

this is cool:beer

 

Andy..

With that 87 Regal we put the prototype level 2 motor in, it originally was set up with a Stinger S4 ignition. Since it already had the mag pickup distributor in it, and that beast needed a rev limiter in it something fearce, we decided to upgrade it to a MSD 6AL. I thought it would be neat to see what the difference was in starting and idle quality, and we were able to do a direct replacement plug and play deal, without touching the distributor.

The difference was substantial.. much easier starting and a much smoother idle.

And yes, I built probably a couple dozen MSD pickup distributors every year, from the points style bodies. Also have used Dave's, and they work well.

JW

 

Steve,

I have not had an occasion to test that particular cam, but I would expect the power to be very similar to the 288-94H. I use the 94H cam because I typically have been working with ported heads and headers, and don't need the extra 5 degrees of exhaust duration.

I would expect that cam to be very similar to the 113 or the 94H, I doubt there's 10HP one way or the other between any of them.

JW

 

Your going to lose some torque and HP, but not a ton.. I would use whateve exhaust is easier to fit in the chassis. I don't think you will have any tuning issues.

I would like to see a 3.08 to 3.42 gear in your car with this cam.

JW

 

Two things to consider here.

At speed (say above 3000rpm) charge dilution via reversion is no longer a factor. The engine is simply running too fast, making reversion a mute point. There simply isn't time to dilute the incoming charge. To put it simply.. the valves aren't open long enough.

To illustrate the point, many years ago we had a 430 that we raced. We over revved it once, and slightly bent all 8 exhaust valves. The car ran high low 11's at 120mph. We had been testing and tuning, reducing ET and gaining mph steadily with a number of changes.

But after the rev incident, wouldn't idle for crap anymore.. We suffered thru that for 4 or 5 test sessions, before it occured to me that we may have tickled the valves.

We pulled the heads, and found the leaking valves, and got all excited because we thought we were going to set the world on fire..

Got it back together, and thought for sure that we were going to get it into the 10's..

It ran exactly the same.. even factoring the air differences out.

But it, of course, idled better.

Moral of the story.. valve sealing, reversion and other issues are muted tremendously at speed. It's a factor of time. There is simply not enough time to leak the air. The valves are opening and closing too fast.

Secondly,

I have had two experiences, with engines that did not perform as I thought they should. Both engines had heads done elsewhere, and had no chamber work done. While the upper valve opening numbers were similar to my level 1 heads, the lower numbers were 10-20% off.

And the real difference with the chamber work, back cutting the valves, and the valve job, is low flow numbers.

I don't accept the designers conclusion. While strictly relating to camshaft events he may be correct, but in the engine, the more air the better. Especially with the bore size and cross sectional area available with our 455's.

I also have been told similar stories by my dyno operator. That shop does two things mainly, hand porting of cylinder heads for all makes, and dyno testing. So they can directly relate one to the other, and their conclusion is solidly that low valve lift head flow is an important, and often overlooked part of the package.

JW

 

I'll try it and see what the difference is between the MSD 6AL and the HEI with the MSD module. I have my timing locked at 34* and my starting has never been a problem hot or cold. You know how the 308s idles and I don't expect or want that to change but if I could get a stronger idle and or more vacuum that would be a plus. As it is now I have to turn it up to 1300 in neutral to get a strong 900 idle in gear. This is with a custom 3400 stall conv. When the a/c is turned on in drive it stalls so I was planning an idle solenoid. I was going to get the new MSD HEI module that has an adjustable rev limiter. Worst case, this way I can get the limiter, get rid of the ugly HEI and get more of a stock look.

 

Hi John,

Sorry, Missed your question here..

Yep, we will go 10-1 with your motor and the heads are better than the typical Level 1 heads, so I would expect your motor, built the same, to come out around 460-475HP ..

Maybe we will go with that 292-02H and get some numbers on it..

JW

 

Jim, Thanks for the advice and expertise! :Smarty:

Looking forward to the numbers on the 292-02 setup!

 

Lots of good info here, thanks.

 

Cricket,
If you are interested in the numbers on the 292-02, go ahead and send Jim the balance of what I owe him and he can get started on it right away! :TU: