Pontiac - Street No question too basic here!

          
Reply
 
Thread Tools Display Modes
  #1  
Old 09-03-2009, 03:03 PM
wrea3_98 wrea3_98 is offline
Senior Chief
 
Join Date: Mar 2007
Posts: 418
Default Comp 274XE cam

Who's using this cam in a 9.5 to 1 455 and what are your likes, dislikes and results? I see it used alot in a hot street 455 buildups lately. I have some JBP ported #96 heads (1971) flowing 240 CFM on a fresh 30 over 455 right now without a cam, intake or carb. Going in a '67 bird with 3.55 gears (optional changeout considered) and a 4-speed. Your thoughts? Suggestions?

  #2  
Old 09-03-2009, 03:44 PM
screamingchief's Avatar
screamingchief screamingchief is offline
Ultimate Warrior
 
Join Date: Nov 2004
Location: S.E. Wisconsin
Posts: 12,788
Default

My thoughts?

There are better cams out there.

My suggestion...

I dunno,"off the shelf" choice,maybe the Crower #60243 or something of that sort.

Myself,I'd opt for a custom ground bumpstick.

JMO

BP.

__________________
This space for rent...

In the meantime,check out the cars HERE.

  #3  
Old 09-03-2009, 04:01 PM
roadrage david roadrage david is offline
Ultimate Warrior
 
Join Date: Jun 2004
Posts: 1,420
Default

XE274 is a ecselend cam for that engine. my frind hase it in his formula car thuse 12.12 sec in the 1/4 and he drives lots of street miles as wel with a tr2004r trans and 3.42 rear ratio, ................. http://www.youtube.com/watch?v=kghSCRQDSyc

  #4  
Old 09-03-2009, 04:10 PM
PONTIAC DUDE's Avatar
PONTIAC DUDE PONTIAC DUDE is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: West Central Florida
Posts: 14,756
Thumbs up

I like it. A nice all round work horse cam for street performance. Has good vacuum too.
Have installed dozens and sold still more over the years.
The 041 cam of the new millenium.

  #5  
Old 09-03-2009, 07:44 PM
Mr. P-Body Mr. P-Body is offline
Ultimate Warrior
 
Join Date: Aug 2004
Posts: 3,690
Default

Agreed with David and Ken. In a lower-compression engine, where you would have used the "041" (Ram Air IV) in a 10.5:1 application, the XE274H is the best choice.

Jim

  #6  
Old 09-04-2009, 07:12 AM
Cliff R's Avatar
Cliff R Cliff R is offline
Ultimate Warrior
 
Join Date: Nov 2000
Location: Mount Vernon, Ohio 43050
Posts: 18,153
Default

Here's my 02 cents, again. Small cams on 110LSA's have proven themselves to me to NOT be the best direction to go, IF you want to make the most power from your medium compression ratio 455 engine.

The XE274 cam would be OK in a "low" compression 455 engine, but it will give up some upper mid-range and top end power compared to a longer duration cam on a wider LSA.

If you want your "low" compression 455 engine to idle well, and pull hard in the lower rpm's, it's an alternative for you, but there are a LOT better choices out there these days.

At 9.5 to 1 static compression, 455-472cid, no problem at all managing more camshaft than 274 degrees. I like to see 290 to about 310 degree camshafts in those applications, and prefer to sqeeze the engines just a bit more as well. The result(s) will be better everyplace than the XE274 grind.

Here are some numbers, very respectable sent to us by a customer we set up a carburetor for. 230cfm 6X-4 heads, ported iron intake, 463cid, 10 to 1 CR, 4 tube headers, XE274 camshaft. Peak HP 414 @ 4900rpm's, peak torque 587ft lbs at 3400rpm's. Looks pretty good at a glance....right?

Same set-up using the Crower 60919 camshaft, 455.4 hp @ 5600rpm's, 540 tq at 3800rpm's. This was my own engine dyno'd for the HPP head swap article when we went to the KRE heads. After installing the KRE heads, HP jumped to 494.

Here's the trump card folks, the XE274 cammed engine was clear down to 412ft lbs torque at 4900rpm's. My engine was still making over 500ft lbs torque at 5000rpm's! It also made more average torque, and HP across the rpm range, by a considerable amount.

The tight LSA grind, short seat timing, less overlap, etc, pulled the power down lower in the rpm range, and it made less power. This would NOT show up in a "seat of the pants" assessment, but will show up on an engine/chassis dyno, and at the track. Matter of fact, pulling all the power down to lower rpm's usually fools the driver of the car into thinking his engine is making MORE power. The small/tight LSA grinds are brutal down low, spins tires easily, very responsive off idle, etc.

IF this is what you want, and how you evaluate the performance of your street car, it makes the XE274 cam a fine choice for your medium compression ratio 455.

IF you want to make quite a bit more power, and spread the power out some, with a strong upper mid-range and top end charge, install a larger camshaft on a wider LSA.

There are also other benefits from going to a larger cam on a wider LSA. If you go back up to the dyno results, notice that the XE274 cammed 455 made a very high peak torque number at a relatively "low" rpm. My own engine made about 30 ft lbs less across that rpm range, but kept the torque production over 500ft lbs clear out past 5000rpm's.

What this means is that the XE274 camshaft produced quite a bit MORE cylinder pressure at peak torque, and concentrated MORE cylinder pressure in a narrower rpm range. This is, and can be a recipe for detonation with currently available pump fuel(s).

My engine lived at 10 to 1 SCR for many years, and hundreds of track runs, managing low octane fuel without the first hint of detonation anyplace. It would easily run on 87 octane fuel, we ran it continuously on 89 octane, and when torn down for inspection after years of street/strip use, showed no indications anyplace of detonation, the bearings looked like you just installed them.

Our current engine is 11 to 1 compression, and manages 89 octane fuel without any issues anyplace. Yet there isn't a week goes by that we don't see someone throw a thread up talking about the perverbial "brick wall" of 9.5 to 1 SCR on pump fuel. This immediately leads to folks jumping all over the topic with great information about lowering the SCR, then making up the lost power with a smaller/tighter LSA, "modern" camshaft to bring all the power back.

Consider this, IF this were true, and ALL the power did come back, then the cylinder pressure at every rpm would be exactly the same as the engine running MORE compression and MORE camshaft.

Reality check. The "modern" lobe profiles do NOT bring back all the power.

They do NOT make more power over the same rpm range as the larger cam having more overlap, and more off seat timing, wider LSA, etc.

The do produce more vacuum at idle, and pull the power curve into a lower rpm range, and narrow up the power curve considerably.

The result is very good "felt" power by the operator of the vehicle.

Go to the dyno and you will find that the power production at high rpm's is off considerably. No magic tricks here folks, smaller cams on tigher LSA's make less top end power, all else being equal.. ....Cliff

__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran!
https://cliffshighperformance.com/
73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile),
  #7  
Old 09-04-2009, 07:55 AM
PONTIAC DUDE's Avatar
PONTIAC DUDE PONTIAC DUDE is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: West Central Florida
Posts: 14,756
Post FWIW

I Track tested the same cam profile with a different LSA. The 110 LSA ran quicker then the 112 LSA.

66 bonne with a [email protected] Comp Cam and out of the box heads ran 11.50 in a 4000 lb car with a 110 LSA.

Sometimes bleeding off compresion with a wider LSA will kill mid and limit the power band. But it won't ping. LOL.

If you have a killer set of heads requiring more rpm, then yes a wider LSA and longer duration IS needed to make the top end intake and heads work.


Last edited by PONTIAC DUDE; 09-04-2009 at 08:00 AM.
  #8  
Old 09-04-2009, 08:35 AM
wrea3_98 wrea3_98 is offline
Senior Chief
 
Join Date: Mar 2007
Posts: 418
Default RE

I'm only playing around with 95CC heads (approx 9.38:1 compression) and a .030 455 shortblock, stock stroke and flat tops. I have run stock 7K3s with a .030 455 with several different cams (Ram air IV, Comp 292 and Summit 2802) all yielding mid to high 12 second timeslips with virtually no major tuning. Now with the ported heads and a better cam choice and carb, I'm looking for high 11s or better in a '67 Bird. Should be possible but I also want driveabilty without worrying too much about idle quality, vacuum etc. I appreciate all the info so far.

  #9  
Old 09-04-2009, 09:04 AM
ponjohn's Avatar
ponjohn ponjohn is offline
Ultimate Warrior
 
Join Date: Mar 2002
Location: Fort Myers, Fl.
Posts: 9,715
Default

I run a 35 over 455 with 220 cfm 96 d-ports.

With the xe284 the car has gone an 11.98 at 3680.
It is a lumpy idle at 1000 rpm in gear.

This combo may have made more avg power with the xe274 but I anticipated a head change. I would think the 274 probably has better idle qualities.

Point is- you have 20 more cfm I would think about a cam this slightly bigger than the 274.
Might even consider a suitable Hyd roller to avoid the issues with flat tappets.

  #10  
Old 09-04-2009, 09:30 AM
wrea3_98 wrea3_98 is offline
Senior Chief
 
Join Date: Mar 2007
Posts: 418
Default RE

I am really considering a hydraulic roller as I have been thru the wiped cam issues myself. Never used one and always wnted to try one out. Any recommendations with my setup?

  #11  
Old 09-04-2009, 08:07 PM
ponjohn's Avatar
ponjohn ponjohn is offline
Ultimate Warrior
 
Join Date: Mar 2002
Location: Fort Myers, Fl.
Posts: 9,715
Default

Truth be told, Cliff has reported his findings with fact.

If I were to try another hyd flat tappet I would certainly give the 60919 a try. Maybe get a little better idle quality and more avg power.

  #12  
Old 09-04-2009, 10:35 PM
screamingchief's Avatar
screamingchief screamingchief is offline
Ultimate Warrior
 
Join Date: Nov 2004
Location: S.E. Wisconsin
Posts: 12,788
Default

Quote:
Originally Posted by ponjohn
Truth be told, Cliff has reported his findings with fact.
Ok,lets consider the word fact for a moment John.

From wikipedia:
A fact is a pragmatic truth, a statement that can, at least in theory, be checked and confirmed. Facts are often contrasted with opinions and beliefs, statements which are held to be true, but are not amenable to pragmatic confirmation

One persons findings are relative to that persons perception of said given set of data.

Another fella looking at the same exact findings may come to another (or completely opposite) conclusion.

Facts are established when the outcome is consistently found by all others using the same set of data.

I got a feeling were not quite at the "fact" stage with regards to this topic.

We have all read Cliff's findings on the subject,and no doubt he is accurate with much of his data,and I actually respect his contributions on these topics myself.

Contrary to what many folks here seem to think.

Cliff himself included @ times.

I got no beef with Cliff,nor with any of his preferences or testing results,go back and look at what cam I recommended here.

But accepting his set of findings as "fact" does nothing to explain what others have found to be "fact" as well,those "other" facts being completely contrary to his own facts.

Both sets of "facts" cant be true,can they?

Truth be told,each individual here is depending on but one set of facts,the facts as they've seen them,that does'nt mean they're the only "facts" that count in this sorta discussion.

I can find ya'll plenty of similar (and documented) combos in the HPP shootout series or other members on here using that #60919 cam that have run nowhere near as well as Cliff's combos using that same cam have ran,so no,we cant quite say that the #60919 is a "magic" cam as a matter of "fact".

Does it run well in certain combos,yep sure does,no argument from me there.

But...

Just like the #60919,I can also find more than a few XE-274's combos out there that run extremely well too,just ask slowbird how well their old xe274 combo ran,IIRC that one got into the high 11's too,but again,there is a flip side on this cam as well,that is there are indeed combos out there that showed lackluster results with the xe-274 cam.

We could nit-pick this topic to death,and persoanlly I think we've just about done so @ this point.

Just like anything automotive performance oriented,there are success and disaster stories for just about any single given component out there,none necessarily more valid than the others,they are what they are,examples of how each worked in that specific combo,with that specific tuning.

There simply are no magic cams out there,they just dont exist.

Myself,I dont favor any one cam approach over the other,I tend to play with anything and everything as much as possible,IMHO that's how a fella learns this stuff.

One typically does'nt learn much of anything by doing the same thing over and over again,the same way time after time,all one learns from that approach is how all the "detail" items will add up to make even more gains with that combo.

But that's true with any combo,the more you work with it,the more power you'll find till you exhaust all areas of gain to be found in that combo.

A fella does'nt really learn much of anything by just going around and copying another fellas combo,as he often has no idea how to address all those "details" the first guy has found out about.

Might he achieve his goals,maybe yes,maybe no.

But this specific topic,damned if everytime it comes up,the same guys,take the same sides,and argue the same things,over and over time after time.

It's just getting really weak,,,last few "xe" threads I did'nt even bother commenting on...

I myself could care less,I'll use a 106° to 116° LSA,it really does'nt matter to me,I dont play favorites here.

I can adjust the other cam specs to get the cam pretty much where I want it regardless,now might that sacrafice some areas for other areas,yeah sure,but that's how cams work,they're all compromises.

And lets say a fella does'nt like the xe lobes...

Well,fine by me,then he should'nt use them,there are plenty other lobes out there to use.

Whatever the cam gripe,there are answers for them out there.

I dont have any beef with the xe lobes,do a search,I've recommended them in the past when the combo seemed right for them,and the one seeking advice/input wanted a simple recommendation.

I'll admit I'm not a rabid fan of xe lobes though,especially the flat hydraulic lobes,I just dont care for the noise they seem to make,if I wanted that,I'd just use a flat solid cam/lifters and call it a day.

But I dont despise them either.

Like everything,there is good and bad to be found if one looks hard enough.



(Was that diplomatic enough???)

Bret P.

__________________
This space for rent...

In the meantime,check out the cars HERE.

  #13  
Old 09-04-2009, 10:43 PM
Steve C. Steve C. is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: Liberty Hill, Tx. (Austin)
Posts: 10,923
Default

A hot street build with ported heads, 4-speed and 3.55 gears. Intake unknown. Car weight unknown, presuambly not a pig with that year f-body. Idle quality, more avg power a must here ?

  #14  
Old 09-04-2009, 11:24 PM
screamingchief's Avatar
screamingchief screamingchief is offline
Ultimate Warrior
 
Join Date: Nov 2004
Location: S.E. Wisconsin
Posts: 12,788
Default

Joepapa had the crower #60211 in his '69 bird with the 406 & 4spd,and that ran pretty well,but he had more gear and compression than this 455 has.

I'd expect the weight for a '67 bird to be around 3600 lbs. or so give or take just a bit.

My "off the shelf" cam suggestion was on the conservative side no doubt at this point,mostly due to the 4spd and 3.55 gears,and the somewhat moderate compression ratio.

Now that the goal of 11's (or better) is known,,,I might make a different set of recommendations...

I really pondered this comment:

Quote:
Originally Posted by wrea3_98
Now with the ported heads and a better cam choice and carb, I'm looking for high 11s or better in a '67 Bird. Should be possible but I also want driveabilty without worrying too much about idle quality, vacuum etc.
I have a few reservations.

One typically does'nt get a bunch more power from a cam without losing some degree of idle quality and driveabillity.

Honestly I dont think any cam mentioned in this thread so far will run solidly into the 11's with this sorta combo.

It's gonna take more cam,and I'd like to see more gear too.

I'd look into something like the FT hydraulic Crower #60244 now with that set of criteria.

Or a HR cam in the mid 230's intake,mid 240's exhaust @ .050".

Or possibly a FT solid like the crower #60311.

HTH.

Bret P.

__________________
This space for rent...

In the meantime,check out the cars HERE.

  #15  
Old 09-05-2009, 07:14 AM
Cliff R's Avatar
Cliff R Cliff R is offline
Ultimate Warrior
 
Join Date: Nov 2000
Location: Mount Vernon, Ohio 43050
Posts: 18,153
Default

Perhaps we should stick to posting facts from our own direct testing, rather than confusing everyone with a bunch of nonesense, just my 02.

Fact, we've got ONE, yes, that's ONE decent track run posted from ONE board member using an XE274 camshaft.

Fact, every single car that particular person is associated with, runs WAY faster everyone else doing the same thing. I commend them in the ability to set up their cars for excellent track runs for the combination(s) of parts.

The actual number of folks running mid to high 11's with the XE274 camshaft are rare, if not non-existant.

One of my customers with a near identical car to my own, using just about every single component that I do, aside from 3.73 gearing vs 3.42's/apprx 300lbs lighter, ran an XE274 cam in a 455 with KRE heads, and couldn't get into the 11's. He hit a brick wall at 12.0's.

He changed the cam, and nothing else, and busted DEEP into the 11's. It was a small hydraulic roller but the specs escape me. Really doesn't matter, I've had enough folks call in that were extremely UNHAPPY with that particular cam in the 455 engine, that we have avoided them like the plague.

I've also had two dyno charts sent here, and we had one posted up here a few months back, which all provided nearly the exact same results, WAY off on power and power ending quite early in the RPM range.

I think the topic is going quite well, it would go even better if folks would stick to posting usable/accurate information on the subject, without using my name specifically surrounded by a bunch of crap that is meaningless to the reader, and does nothing but further complicate and already complicated topic.

I haven't even started on the FACT that these cams can and will cause valve train instability due to the excessive seating velocity of the ramps. The last time I brought up this fact, the thread went WAY off track and got canned.

Bottom line from where I'm sitting, NOTHING impressive about that particular cam in a 455 with ported or unported iron heads that I've seen.

I also witnessed a dyno test with the XE284 cam in a 455 using 7K3 heads. Despite the very best tuning efforts, it took all day to get that engine to make 430hp, most pulls were right around 400hp, and it never did make over 500ft lbs torque anyplace. There's a FACT, as we had to wait our turn for the dyno as they pissed around most of the day trying to get that engine to make more power than a 2802 cam would have made in exactly the same application...FWIW......Cliff

PS: My purpose for putting information on this website is to help folks, not "bash" a particular line of parts. When we have information that isn't well accepted from folks who happen to use these particular parts, sorry about your luck....

__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran!
https://cliffshighperformance.com/
73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile),
  #16  
Old 09-05-2009, 08:16 AM
ponjohn's Avatar
ponjohn ponjohn is offline
Ultimate Warrior
 
Join Date: Mar 2002
Location: Fort Myers, Fl.
Posts: 9,715
Default

Bret-

I knew you would take exception to my Fact comment. IF I were referring to your data not being fact based I would have quoted you.

My combo runs in the very high 11's with a head the flows 10cfm over stock. The engine was dynod and it was done by 4900. In conversations with cliff this is a typical characteristic of the xe grind.

I always wanted to know if it would run better with a 60919. I am NOT putting another HFT in this engine, roller is next.

John

  #17  
Old 09-05-2009, 12:08 PM
slowbird's Avatar
slowbird slowbird is offline
Ultimate Warrior
 
Join Date: Jan 2001
Location: Montgomery, IL
Posts: 10,911
Default

We ran 11.8s to 11.9s with the xe274 cam in our street 400. We did put it into our 455 but the lobes went flat before we got it to the track. It seemed to work pretty good in the 455. I know it ran great in the 400.

  #18  
Old 09-05-2009, 12:58 PM
Steve C. Steve C. is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: Liberty Hill, Tx. (Austin)
Posts: 10,923
Default

From a old catalog, the discription for the Ultradyne 288/296 hyd flat tappet with 231/239 at .050 and ground with a 110 lobe separation, .485/.507 lift ....

"Hot street/bracket cam, 3000ss converter or 4-speed. No power brakes. Power 3000-6000."

I believe Lee's best with that cam in his first gen bird was 11.46 at 115.4 mph with a 1.53 60-ft. It was later when he switched to the Ultradyne 247/247 at .050 solid flat tappet ground with a 108 lobe separation that he ran 11.27 at 119.61 mph. It was my understanding the "bigger" solid cam was just as driveable as the smaller hyd cam. I wonder what his comment would be about "no power brakes" with the small 231/239 cam ?

Jim Butler stated the Ultradyne 276/284 (243/[email protected]) soilid flat tappet cam ground with a 110 lobe separation was good for 1.2 bhp/cid with 9.5 compression (540 hp /455cid)


Last edited by Steve C.; 09-05-2009 at 01:08 PM.
  #19  
Old 09-05-2009, 01:33 PM
Skip Fix's Avatar
Skip Fix Skip Fix is offline
Ultimate Warrior
 
Join Date: Dec 1999
Location: Katy,TX USA
Posts: 21,707
Default

My 304/312 FTH UD in a 400 ran my power brakes fine, and even the A/C with a idle solenoid! But was on a 112 LS.

I know we are in the street section but talking to the "stocker" guys they run some BIG cams, as big as alot of race guys rollers, with the stock lift-part of how they go so fast. 400 ci D port early Birds deep in the 10s and well over 120 mph! I'd almost guarantee they aren't worried about that bottom end TQ, they must have enough to launch and get those times as they have to be stock weight.

__________________
Skip Fix
1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever!
1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand
1965 GTO 4 barrel 3 speed project
2004 GTO Pulse Red stock motor computer tune [email protected]
1964 Impala SS 409/470ci 600 HP stroker project
1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs
1964 Corvette Coupe 327 4 speed
  #20  
Old 09-05-2009, 01:58 PM
Brent Flynn's Avatar
Brent Flynn Brent Flynn is offline
Ultimate Warrior
 
Join Date: Jul 2009
Location: Middletown, IN
Posts: 1,431
Default

I had a .480/280 Crane in my 350Pontiac engine in my Suburban and had great power brakes! But, if it were me, i'd try bout a .500 lift/290ish duration hyd in your engine. Im running this type of cam in both my 455's(they both runnin 11 to 1) and they run like crazy up to 5400rpm. U could always advance 2-4 deg if you runnin tall gear.
Your engine will be done by then anyway no matter what cam you put in it, so you might as well build torque, not horsepower. With these cams you get both. 108LSA is in the ballpark, and these cams are absolutely streetable. Use some good oil(Rotella, Amsoil and the like) and you shouldnt have to worry bout wiped lobes if break-in procedure is good. Just my opinion....

__________________
1968 Firebird 10.817/122.33 3600lbs trw 455, iron d-port heads/SD intake/q-jet, 9" tires 1.440 60ft
1962 Catalina 4100lbs trw 455, iron d-ports,perf RPM, 800holley, 9'' tires,([email protected])1.578 60' Oct 2010!!

Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 03:06 AM.

 

About Us

The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. Since then, it has become the mecca of Pontiac technical data and knowledge that no other place can surpass.

 




Copyright © 2017