[b-man]

Originally Posted by pmd400

With an iron headed 9.5:1 455, what is the cut off point where roads lifters would be beneficial. With a 068 cam I assume rhoads wouldn't be needed. What about a summit 2802 or crower 60243 cam?

I wouldn't use Rhoads lifters with any of those cams in a 455, and especially not with the 068 in any size engine. Using Rhoades lifters would invite detonation by building cylinder pressure too early. The 455 can easily handle those cams and still have plenty of low-end grunt without using variable-duration lifters.

Once you step up to the RAIV cam or something bigger I'd start thinking about using them in a 455.

[glhs#116]

OK, so let's just cut to the chase. Let's say a guy had a fairly stock 1971 455 HO engine with the 197 heads and the RAM AIR manifolds and HO intake and 71 455 (though not "HO") carb. Let's assume 3.42 gears and automatic (with future plans to go manual) equipped 1971 Trans Am with no weight reduction. Given all I'm reading here what realistically prevents me going from my 068 to the Old Faithful grind? I'm not seeing much downside and it looks like there should be some good upside!

Also, as a complete non-initiate into the whole Pontiac cam world, what is the Old Faithful grind and where would you get one?

Lastly, I guess my main concern would be that I wouldn't want the car running hotter at idle than it does. I have a big aluminium radiator but I also have to drive half the year in heat and humidity you guys would NOT believe.

Thanks in advance and loving the thread!

Sam

[pmd400]

Originally Posted by b-man

I wouldn't use Rhoads lifters with any of those cams in a 455, and especially not with the 068 in any size engine. Using Rhoades lifters would invite detonation by building cylinder pressure too early. The 455 can easily handle those cams and still have plenty of low-end grunt without using variable-duration lifters.

Once you step up to the RAIV cam or something bigger I'd start thinking about using them in a 455.

How would idle, throttle response and cruising change between a 2802 cam with standard lifters and a 041 with rhoads?

[b-man]

Originally Posted by pmd400

How would idle, throttle response and cruising change between a 2802 cam with standard lifters and a 041 with rhoads?

I would expect both to be close to the same. Given the choice I'd opt for the RAIV cam with Rhoads lifters.

[Will]

Originally Posted by glhs#116

OK, so let's just cut to the chase. Let's say a guy had a fairly stock 1971 455 HO engine with the 197 heads and the RAM AIR manifolds and HO intake and 71 455 (though not "HO") carb. Let's assume 3.42 gears and automatic (with future plans to go manual) equipped 1971 Trans Am with no weight reduction. Given all I'm reading here what realistically prevents me going from my 068 to the Old Faithful grind? I'm not seeing much downside and it looks like there should be some good upside!

Also, as a complete non-initiate into the whole Pontiac cam world, what is the Old Faithful grind and where would you get one?

Lastly, I guess my main concern would be that I wouldn't want the car running hotter at idle than it does. I have a big aluminium radiator but I also have to drive half the year in heat and humidity you guys would NOT believe.

Thanks in advance and loving the thread!

Sam

"Old Faithful" is a hydraulic roller cam available from SD Performance. With your setup it should work pretty good but without a good converter in the equation I think I'd stick with SD's "Stump Puller" grind.

Originally Posted by pmd400

How would idle, throttle response and cruising change between a 2802 cam with standard lifters and a 041 with rhoads?

Probably be pretty similar. Rule of thumb is that Rhoads shave off about 8-10 degrees of duration at idle.

[72LuxuryLeMansLa.]

Originally Posted by glhs#116

OK, so let's just cut to the chase. Let's say a guy had a fairly stock 1971 455 HO engine with the 197 heads and the RAM AIR manifolds and HO intake and 71 455 (though not "HO") carb. Let's assume 3.42 gears and automatic (with future plans to go manual) equipped 1971 Trans Am with no weight reduction. Given all I'm reading here what realistically prevents me going from my 068 to the Old Faithful grind? I'm not seeing much downside and it looks like there should be some good upside!

Also, as a complete non-initiate into the whole Pontiac cam world, what is the Old Faithful grind and where would you get one?

Lastly, I guess my main concern would be that I wouldn't want the car running hotter at idle than it does. I have a big aluminium radiator but I also have to drive half the year in heat and humidity you guys would NOT believe.

Thanks in advance and loving the thread!

Sam

Your heads will need new valves and machine work to handle the lift associated with a cam like Stump Puller or Old Faithful. Dave at SD would be the man to consult since he picked the lobes for those cams and knows what the heads need to use them. It is easiest to contact him through the email links on his site: http://www.sdperformance.com/viewPro...productID=1816

[ponyakr]

"Probably be pretty similar. Rule of thumb is that Rhoads shave off about 8-10 degrees of duration at idle."

"I would expect both to be close to the same. Given the choice I'd opt for the RAIV cam with Rhoads lifters."



Isn't this amazing ?

After many pages and over 225 posts about 455 cams, with some refusing to even offer any specific cams, without EXACT minute details of the combination, at least one saying they had a bad experience with Rhoads lifters, some saying go roller, and LOTS of other ideas, we're right back to the 041 / Rhoads combo.

It seems that some guys will hold out for "new technology", regardless, thinkin it has to be better than that stuff that was designed nearly 50 years ago. Even after all the drag strip testing done by Jim and Cliff, well documented for all to read, proving that the 041 / Rhoads combo is hard to beat, many just simply refuse to accept it. These 2 guys have probably done more testing with the 041 / Rhoads combo than everybody else on this forum combined.

So, my conclusion is that for a STREET driven(mostly 600-5000 rpm range) hyd flat tappet cam, the 041 / Rhoads may just be the best combo available for MANY 9:1 CR & up 455-474 cube engines.

For those who may not have read it, Jim tried several cams that were real close to the 041 specs, and discovered that none of them were quite as good from idle to his shift point as the 041 / Rhoads. Those that made just a hair more top end, wouldn't idle quite as well as the 041.

And, since the 041 / Rhoads will idle so low, for street cars with hard street tires, you don't even need to buy one of the high dollar converters. This combo idles smooth at 800rpm or lower, has instant torque, from the 1st stab of the throttle, and will pull strong to past 5000rpm. Unless you will accept nothing less than 500-600hp, my question is, what else could you ask any HFT cam to do ? Will any of these other HFT cams that have been mentioned, idle as smooth and low, with good vac, as the 041 / Rhoads, AND still have as much or more top end power ?

So, if you are planning a mild 455 / auto street build, and have never tried the 041 / Rhoads, try it before you bad mouth it. Then, if you don't like it, at least you'll have something to compare your next cam to. And you can report back about what cam / lifter combo you used that was actually better than the 041 / Rhoads.

If I'da said this much on the site I got kicked off of, they'da crucified me and set fire to the cross. But at least here, I have Jim and Cliff's testing to back me up.

[Skip Fix]

Originally Posted by wovenweb

I agree with your premise, but we're in the street section where I think the general point of this thread is that an "old" grind cam, iron headed street vehicle can still take you into the 11's(competitive with the fastest production vehicles made today) on today's pump gas.

Does it take a lot of work and tuning, yes.

Even in a "street car" (what is the exact premise? working PB, A/C-different thing to different folks)-My point was how many of them(11 second cars iron heads 041 or similar HFT) are out there vs very "similar" combinations that are in the 12s/13s? Walk through the pits at any big Pontiac race and I bet in the staging lanes the mid to low 11s car with iron heads and an 041 are very very few. Yes there are some like Jim and a few others that are there but a whole lot more in that 12-13 second class lane.

And if "new technology" is not as good why are so many guys running good even with iron heads and HR or "hybrid combination like Cliff's? I guess we need to kick Cliff and many of Dave Bisshop's combinations out of the discussion since they use that HR "new" technology. I'll bet 50 years ago they weren't using the coating Cliff is talking about experimenting with for a flat tappet try again either.

And for what it's worth my 78 TA raced in the old NMCA classes with first a 455 then a 400 with iron heads and the 400 had 4 cams some degreed in different spots , different carbs, intakes and header sizes and ran PB ,PS and A/C with most of the combinations and most were "modern" Ultradyne cams. So a lot of combination dialing in.

[TCSGTO]

I ran the RAIV/Rhoades deal for a long time and it is a really sweet running set up you could drive everyday, and I did eventually get into the 11.90's with it but I don't think the OP cares about ET. For his purposes it would do everything he wanted. You can even keep the stock stamped 1.5 rockers with decent replacement valve springs and limit RPMs to 5500 or less which is all you need.

Not everyone gets carried away like me and a lot of us do, but if the OP gets bored with the RAIV /Rhoades he won't have a ton of cash tied up in it if he decides to move up to a roller valve train.

[ponyakr]

"...And if "new technology" is not as good why are so many guys running good even with iron heads and HR or "hybrid combination like Cliff's? I guess we need to kick Cliff and many of Dave Bisshop's combinations out of the discussion since they use that HR "new" technology..."



I think one of the problems we may be having here is that some guys are talkin about max horsepower and lowest ET's, with streetable ROLLER cams, and some are talkin about daily driver type, or street / strip type HYDRAULIC FLAT TAPPET cams.

To me these are two totally different apps. I think maybe we need to compare apples to apples, as they say. So, compare the HFT cams to other HFT cams, and roller cams to other roller cams.

Is this reasonable or ridiculous ?

[Skip Fix]

Reasonable but many folks have had HFTs go flat, heck even Cliff before has stated be would not build a HFT motor because of that so HR do have a definite street place here, even Daily drivers and almost every modern truck/car uses a HR cam. Cliff considers his car almost a DD and it has a HR in it-"modern".

Heck my current pump gas 455 in the 78 had a HFT but a "modern" Ultradyne lobe, runs power brakes, maybe A/C if I put it back on with "regular" lifters and runs high 10s light wheels and slicks weighing 3750lbs, and 11.50 all day long in the Texas heat with the spare back in it and heavy snowflake wheels and DOT street tires( I figure 3850+) with a lot of the same driveline stuff Jim's wagon and Cliff's car have.

[gtofreek]

A friend of mine on these boards runs a 9.3:1 compressioned 455 in his street car, with a Modern Harold SFT cam[you know, fast ramps, shorter seat timing, 110° LSA], and iron heads that only flow in the 220's[I flowed them so I know]. On pump gas he has ran mid 11's with it pretty effortlessly. He has only been out a couple times, so there is a lot more tuning to be done. Oh, yeah, that cam is ground on a 110° LSA, which is NOT supposed to work in 455's, according to some here. Even though, with lesser parts, he is as fast as those that say this combo shouldn't run good. Whatever!

Can't wait to see what it does when he gets it dialed in. Right now he's as fast as Cliff, with a FT cam, much lower compression, and iron heads! This is running in hot, terrible Arizona air too! Car is not gutted either.

[ta man]

Here is the old HPP article,any new members that haven't read it find a copy.It has sat beside my nightstand for the last 20 years...and routinely gets reread!It is what started my tuning of Pontiacs over 20 years ago..Check out Gary's setup too,slightly milder than Jim's with a 068 cam...but a greet street setup also..

[ta man]

Date of the HPP issue.

[ponyakr]

So, is it a sin today, to have a street driven car that won't run low 11's on the strip ?

[b-man]

Originally Posted by ta man

Here is the old HPP article,any new members that haven't read it find a copy.It has sat beside my nightstand for the last 20 years...and routinely gets reread!It is what started my tuning of Pontiacs over 20 years ago..Check out Gary's setup too,slightly milder than Jim's with a 068 cam...but a greet street setup also..

I can remember first reading that article, and how I was so impressed with the performance of Gary Carnivale's mild combo. A 455 w/stock #96 heads at 9.0 to 9.5:1 compression, iron intake w/Q-jet, RA manifolds, 068 cam w/1.65 rockers, 3.31? gears running between 12.70 and 13.05 at 104 to 107 MPH.

Inspired me later on to try my own even milder 455 combo with Tri-Power, 8.2:1 compression, 068 cam w/1.65s and 2.56 gears. I never really spent time tuning or optimizing my 87 octane combo, but it still managed to squeak into the high-13s at nearly 102 MPH (13.899 @ 101.85) with no posi or traction tires doing a miserable 2.3-second 60' time, 4050# race weight.

Was a great daily driver that started instantly even in cold weather (30 to 40 deg F) with the flick of the key and idled with a noticeable little rumble. Put you right back in the seat taking off at moderate throttle from a stoplight, it was a great feeling!

[72LuxuryLeMansLa.]

Originally Posted by gtofreek

A friend of mine on these boards runs a 9.3:1 compressioned 455 in his street car, with a Modern Harold SFT cam[you know, fast ramps, shorter seat timing, 110° LSA], and iron heads that only flow in the 220's[I flowed them so I know]. On pump gas he has ran mid 11's with it pretty effortlessly. He has only been out a couple times, so there is a lot more tuning to be done. Oh, yeah, that cam is ground on a 110° LSA, which is NOT supposed to work in 455's, according to some here. Even though, with lesser parts, he is as fast as those that say this combo shouldn't run good. Whatever!

Can't wait to see what it does when he gets it dialed in. Right now he's as fast as Cliff, with a FT cam, much lower compression, and iron heads! This is running in hot, terrible Arizona air too! Car is not gutted either.

Most guys I've seen on here that don't like shorter seat timing on tight lobe separation angles, when asked about UD cams designed by Harold will give his grinds a pass saying they work because he doesn't slam the valves shut, bouncing them off the seat if stronger springs aren't used. I've also noticed it is usually 108° LSA cams with less than around 275° seat timing are the ones they complain about. I haven't seen anybody with any credibility say a 110°LSA can't work in a 455. The key being "Somebody with Credibility" ! My ignore list is pretty long! Now I have seen statements like (that same cam ground on a 112°LSA would broaden the curve) but not that a 110°LSA wont work.......

Would you mind posting the specs on your friends UD cam. I'm sure most guys would like to know what cam will get them the power to go 11's with a 9.3:1SCR slightly ported iron head 455! That is pretty damned impressive to me!

[gtofreek]

I'll leave the specs up to the owner of that car, if he wants to post it.

[72LuxuryLeMansLa.]

Originally Posted by gtofreek

I'll leave the specs up to the owner of that car, if he wants to post it.

So, this isn't a shelf grind from UD?

[Cliff R]

"Oh, yeah, that cam is ground on a 110° LSA, which is NOT supposed to work in 455's, according to some here. Even though, with lesser parts, he is as fast as those that say this combo shouldn't run good. Whatever!"

NO ONE ever said that, or even hinted that you can't run well with tight LSA cams in 455's. Go back and read the comments a little closer. What we are talking about here is using relatively "small" cams on tight LSA's with SHORT SEAT TIMING/EARLY CLOSING INTAKE events in huge engines with moderate compression, and how much power you can leave on the table, and end up with an engine with mid 9's for compression that will not effectively manage pump fuel.

The example I put up there shows nearly 90hp left on the table with a piss-poor cam choice, and they "pinged" the engine on the dyno trying to put timing and fuel to it to make acceptable power.

BTW, my car runs quite a bit quicker than "mid-11's", we de-tune, add weight and short shift for 1/4 mile tracks to run mid-11's and stay above the roll bar rule. Look at the 1/8th mile times I've posted in hot-humid weather with the car lightened up a bit and shifting at 5800rpms. 7.20's at 96 MPH will get you DEEP into the 11's and that's at 3500-4000 DA. The "multiplier" for 1/8th to 1/4 mile is 1.56-1.57 for most N/A cars, then subtract about a tenth for every 1000' DA improvement........Cliff