[gearbanger]

Just because you use a higher flowing head and a biiger cam doesn't mean you are losing power on the bottom. You may lose a little or you may make more, but with the correct combination it is pretty certain you will make more power in a higher rpm range. I read all of Cliff's posts for a long time and pretty much what he has always said was, he can shift at a higher rpm and not gain anything, so why turn it harder. To me that means his car has a very flat power curve that extends well above 5500, but he has no use for that power because it doesn't make the car go quicker.

I just got back from a trip in my GTO, and I can tell you that it is plenty streetable. I have been in the car for probably 10 hrs over the last two days and logged probably 500-600 miles. I have 310 cfm heads and a 242-250 hydraulic roller. I can't see why anyone needs more bottom end power than this thing has. It is a stick car so that will pretty much let you know if you are bogging it down. Anything from about 1800 rpm and up, it just goes. If it was an automatic like Cliffs and others, it would never get below that rpm I would think.

[Skip Fix]

I knew some reference to my 4.10s being "race equipment" would be made making it higher rpm. That's only roughly 10% more gear than 3.73s what ALOT of "street" guys run. They are still in the car from the 400 and roller motor. The car has seen only 2 outings and 7 runs since the new motor. The 3.42 are in the garage to be put back in when I get the time, and the A/C. From the feel of the car I doubt it will suddenly become a "PIG" and have no low end off idle power. The motor makes over 410 ftlbs @ 2100rpm! To even get the dyno load to read low rpm we couldn't do full pull. It can easily haze the street tires in first or second, so the decreased torque multiplication will improve that. Do I really need more torque at 1500, especially with a convertor that goes past that quickly. Maybe if you have a TKO stick and leave in in high gear, but that's why God gave you a gear shift.I've ridden/driven in alot of different combinations(including Jim's wagon) and know the feel of bottom end and throttle response.

By the way let's look at the rest of the pump gas "race" combo that just clicked off 10.99 @ 124.5 and drives 40 miles to car shows. 0.030 455 no stroker crank or long rods. A 239/247 flat tappet hydraulic (5 degrees bigger than Jim's) Jim's is a little bigger than Cliffs, the same on Floyd Hand used for awhile.Torker II that many feel is worse than a RPM or cast iron(Shaker hood) out of the box Holley 850(Cliff runs the same or slower with a massaged one) with a 2.75x13.5 air cleaner and Shaker base. 10" Hand convertor -out of the box-same as Cliff, Jim and Floyd and many others here.Headers 3" full exhaust with mufflers and tailpipes. Ported Eheads-has to be a race car high rpm no bottom end.

You missed my point Cliff did back to back with similar cam specs and ran faster(yes I know Cliff's combo) with the BIG heads. The extra weight of the hydraulic rollers could even be a potential detriment. He's said the car is at least as responsive as before. TCSGTO in the street section ran faster with out of the box E heads over ported D ports. Several others ran faster still in streetable range. I've always contended MOST of our street/strip Pontiacs can use more airflow and still have so much bottom end torque you won't notice. I think most of these guys are showing that.

example a stage 2 ported cast iron head flows in 240cfm will be so much crispier-razor sharp bottom end over a 310 cfm head., "AGAIN only low speed part throtle drivability" . Look at the bottom end number off the Kasse motor from last years Engine Master with the HUGE Tiger heads more bottom end than my motor! Tell me that motor didn't have a crisp bottom end and it was all over by 6500.

The variables of the different port shapes, chamber shapes don't make an apples to apples on just port ccs. A 6X-4 head has a smaller diameter chamber than a 6X-8 head why they are 93cc vs 98cc. That has to affect flow into the cylnder , quench slightly differently even if the port is the exact same. A 62 head has the same shape chamber but much shallower (.200) so even different flow into the cylinder, and has a different shape port than the 6X in the intake and exhaust floor. The we have the RAIV, and HO/SD "open Chamber shape" that os totally different. We'll leave the RAV out with its different chamber not too many to comapre with. We are stil talking iron heads with many variables (enough Pete Mcarthy had numerous articles documenting) and haven't even gotten to the different port shapes or chamber shapes of a aftermarket head.

So how can we say we are just looking at larger ports? I think that is being way too simplistic. Unless Cliff throws on some ported larger KRE heads or Jim had tested his 6X before his meticulous porting to spare ccs(something not done in most commercial porting jobs) we are not just looking at ccs we have other variables at play so no way its apples to apples. And as I stated before how do we know that a smaller poorer shaped port will have better overall velocity and cylinder filling than a slightly larger better shaped port? I still have a problem believing in a RUNNING engine we don't see high velocity in a port the size many FACTORY first gen SBC use(Vortecs) with 100+ CI more to suck on them, especially with the piston speed a 4.21 or 4.25 stroke puts on the port. The same way a Superflow 600 with more motors can flow more velocity test pressure on the same hole compared to a smaller (fewer motors) 110 Superflow. It can barely pull the cfm at 10" in a moderate head compared to 28" on the big bench on a big head.

In being around some chassis dynos a loose convertor almost negates an accurate torque number. So I don't think Ron's numbers would clarify that unless he has engine dyno numbers.

Those Crower rocker numbers 1.33 break ins 72885
stainless 0.090 offset trunnions 1.8-73689, 1.75 73688, 1.7 73687
aluminum offset trunnion 1.7 72897

[harry k]

Skip Fix: i admire your technical talent you are demostrating here ,but some how you are missing my point ! again & again my point is as Jim Hand called it even
" Better street manners " , you mean after all this, those big heads drive around just like small cast iron heads???? NOT RACED you keep coming back with higher rpm-race WOT scale comparison.

[ponjohn]

Skip- thats the thing it is very difficult to compare.

One engine might have x% of total tqe available at Xrpm, change the heads and the overall tque might climb but the actual tqe available at the same rpm is higher

With the head change it might be a lower tqe% at the same rpm but you can't tell because the overall tque rose. So in effect the "new" combo is flat if you could compare numbers in terms of %.

[Skip Fix]

Yes my car drives similar to a smaller head car. I've had now 6 different motors different CIs with various heads cams, gears and convertors in this car. Come hop in it. we can blinfold you and ride in both TAs and see which you think is sluggish.Cliff has said his car has the same street manners. It's not just the head cc that impacts it! The higher end WOT is what everyone else says the big heads are only good for.How many guys does it take to say they are still using the same rpm range-not higher and they feel no change in low end "streetable manners"? It isn't just one or two guys.

How do you describe "street manners"?? 1000-2000rpm goose. 20-40 mph part throttle acceleration how much part throttle?Idle quality-at what rpm, running power brakes, A/C?My BIGGER RAIV iron heads on a 400 with a 304/312 hydraulic ran power brakes and A/C, was that streetable? Needed more gear than a 455 so apples to oranges. Did my 409 with a huge cam and an aluminum flywheel have a good bottom end-nope not until 2500 when it turned on.

410 ft lbs at 2000 is 410 ft lbs regardless of big heads or not, the flywheel doesn't know which it is. Can street tires tell 30 ftlbs when they are already broken loose? Yes maybe if we are towing a boat and need that greater low end from a dead stop idle to 2500, but guess how GM does that in their trucks- bigger motor with bigger heads! And how big are GM 454 heads?? The smallest oval ports are 280-290 cc for their truck torque motors!What were they thinking? Most of us aren't building truck pull motors-but even those are usually blown and on different fuel! We drive cars that go from idle to 5500-6000, and I'll bet little time is spent at 1200rpm.

The high end guys are seeing all the different variables besides ccs and using wet flow benches. They are seeing same size ports same dry flow cfm showing totally different wet flow patterns. And what we are ASSUMING with the theoretical better velocity on a smaller port is better air AND fuel filling cylinders. Yet chambers, port shape, port surface,swirl, tumble, boundry layers all affect that even on similar heads. That's why they use the wet flow to optimize the whole package.

Ponjohn you are right there are still variables, looking at average torque as well as peak or numbers at different rpm. But less variables using the same exact head type. Still look at Kaase's average torque!

[speedshopmike]

for myself, street manners are the ability to start and idle on it's own in wintertime, get double digit gas mileage, run power brakes, not overheat in traffic.
most importantly, i like low end pull - if i can't drive around at 1200 rpm in traffic in top gear i won't be happy.
and that's where small heads will beat big heads - part throttle response under load; peak torque doesn't matter much if you're at 1/8 throttle chugging along.
however, this is not something you will ever see on dynos, cause most can't pull a torque motor down that low, and nobody tests part throttle on engine dynos anyway.
it's also hugely more relevant - like day and night - with stick cars vs automatics, because as noted above, torque converters cover a whole mess of bad behavior.

[ponjohn]

Originally Posted by speedshopmike

for myself, street manners are the ability to start and idle on it's own in wintertime, .

WOW - in winter?

You have a much wider set of "street" guidelines than I do. My car never sees rain let alone be driven in the winter. With no choke, headers and full 3" exhaust it takes a fair amount of time for it to warm up unless I let it heat soak.

I want, no detonation, not overheat and not to loadup while idleing. No power accessories on my car so a big nasty idle is ok.

I also run 4.10 gears so am I out of the street category? (prob go down to 3.73's over the winter)

John

[gearbanger]

speedshopmike, you are just off base if you think you can't do that with 300+ cfm heads. I have been driving mine around all weekend here in Kentucky and TN, with 310KREs and I fired it up on Sunday morning with a big thick frost on it and it idled fine in about 30 seconds, and I don't even have a place for a choke. (Proform body) I have cruised my car all summer hard and been stopped in traffic for hours in cruises in 90 degree+ and it sits at no more than 190. I logged almost 17 miles per gallon yesterday on the 3 hr trip home, and I can smoke the tires (295/45/18 Nittos) in second gear by just pushing the gas at 1500 rpm.

I have alot more torque than my 389s and 400s ever had with any cam grind from stock to RA IV and heads from stock to moderately ported. The bottom line is, for the street, there is no replacement for displacement. Cubic inches rule.

[Ron H]

Harry, don't forget that with the swap i went from 9.4 to 1 with the 6x heads to 11.1 to 1 with the KRE heads. This has given me power all the way through the range. The throttle is as crispor better but I am making a bunch more torque and way more HP with these heads.
I was a bit lean with heavy part throttle and WOT. I switched to a 77 jet from a 75 jet on the primary side. I went to a .037 rod on the secondary from a .043. It is a bit fat on the light cruise with the APT all the way down but it still seems a bit lean heavy throttle and WOT I am around 13.5 to 14 A/F ratio on my Edelbrock monitor.
I did the rocker swap and it has more power above 3000 rpm for sure. I still need to tune and I detonated above 5000 yesterday and seem a bit lean still. Timing is around 30* total. I need to mark my balancer better and check it again. I don't think the MSD is helping much. I need more fuel again since swapping rockers? Plus the air is alot better now. Once next spring and summer comes around ecverything will change again.
I don't think the throttle is as crisp now after the swap. But I am fatter now cruising with the jet swap. And I still need to tune it some more to the new conditions. I think the more lift was wanted by the heads etc. My air cleaner isn't helping me.
I port matched my RPM intake to the 2.3" height and it was at the 1.18 width already. I blended it back over an inch.
I think I need to go to a single plane intake. I run 3.90 gears so a bit of torque loss will have no effect on my combo. I can't get any traction on the street anyway if i try to launch the car.
I attached a copy of the dyno sheets. they are crude. The KRE head one doesn't show much. The dyno was screwibng up. He had to ease the thriottle all the way to 5000 rpm and then punch it from there. The RPMS were jumping all over the place.
The last pulls we didn't bother printing as it was worse. Though on 1 pull it showed the 452 HP peak the lines were squiggly and actually wne tbackwards and in circles,lol.
I am going to try a different dyno for the hell of it but again I have now swapped the rockers. I don't think they made as much difference as I thought they would. But I haven't finished tuning it yet.

[Skip Fix]

OK guys something I have brought up in previous discussions but no one has ever addressed or refuted- the factory did the apples to apples for us in 71-74 with 455s!

They had D port 455s and HO/SD 455s. The D ports averaged around 150ish ccs the round ports close to 180ish. They were similar compression,similar cams(unlike the RAIV 400s vs D port 400s) and iron vs iron. The round ports flowed more air(tested too many stock ones and D ports) and the increased (almost 30cc) port size did NOT turn them into high rpm race motors. They made more hp and had similar torque curves,look at the factory numbers. So how can that be possible if adding 30cc makes the motor a non streetable pig with no velocity? What's the answer guys-look at the factory specs. Airflow over loss of velocity wins out here too.

How about you fairly stock HO drivers is it a high rpm race motor with those giant heads? It's go no bottom end right??

Yea John those 4.10s make you a race car.But I do agree they are a pain on the freeway,why I'm looking at the 3.42s again.

[ponjohn]

Yes, I only spin it 2500-2700 on the highway and that is close to 55. I want to keep the spool so the lowest (numerical) gear i can to is a 3.73 with 30" tire.

[speedshopmike]

ponjohn, yes in winter; i'm not working this hard to only drive my **** when it's nice out; i dont live in arizona.
gearbanger, i never said a word about not being able to do that with 300plus heads; the flow number's quite irrelevant to what i wrote.
all i stated was what i personally need from a street car.
"cubic inches rule" - ummm...duh.
skip, fwiw, even the round port heads are too small by "modern standards".
look to ford's various lousy street hot v8 combos for evidence of why just making a port larger doesnt work.
boss 302? - ever actually driven one? - unbelievable dog.
but same displacement 302 chevy is pretty snappy on the street.
351c 4V - not till it gets well up in rpm is it fun
boss 429 - no power anywhere from stock; major mismatch head/cam package.

closer to home - ok, 396 chevy with rectangular heads - don't start working till 3000 rpm.

you can go too big on a head - it's just that pontiacs are so underheaded to begin with it's hard to do it.

i'm running 3.73's on my TA; big fun around town, hideous on the road.

[harry k]

"How many guys does it take to say they are still using the same rpm range-not higher and they feel no change in low end "streetable manners"? It isn't just one or two guys"

well one of those guys is infamous-Pontiac expert mr.Jim Hand that counts for lot !

"The smallest oval ports are 280-290 cc for their truck torque motors!What were they thinking?"
well a head like that is being used with a SMALL cam @50 in low 200 figures to do the cylinder fillings and top of it now a days f.i. systems to make the engine whole lot responsive.

bottom line is Skip ,i just wanted to compare & address my 310E head theory 10.3 compression with HR288 cam (236-242) with what Ron did , and what i seen with cars i work on ,again & again smaller cast iron heads are all whole lot more pleasure driving around and not RACED ,so i thought he will have that happening to him ,then again when hes stating the compression jumped almost 2 points well that makes some difference i guess

Ron: i cant understand anything from that printout ,its not legible as a Dynojet Winpep graph prinout i use ,come down to Ca. and ill give you free dyno pulls .

official www.pontiacdragdays.com dyno sponsor

[Ron H]

The graph is screwy because the pulls were too. You can see an normal dyno graph for the 6x head. But the KRE head does not.

[gearbanger]

Originally Posted by speedshopmike

gearbanger, i never said a word about not being able to do that with 300plus heads; the flow number's quite irrelevant to what i wrote.
all i stated was what i personally need from a street car.
"cubic inches rule" - ummm...duh.
skip, fwiw, even the round port heads are too small by "modern standards".
look to ford's various lousy street hot v8 combos for evidence of why just making a port larger doesnt work.
boss 302? - ever actually driven one? - unbelievable dog.
but same displacement 302 chevy is pretty snappy on the street.
351c 4V - not till it gets well up in rpm is it fun
boss 429 - no power anywhere from stock; major mismatch head/cam package.

closer to home - ok, 396 chevy with rectangular heads - don't start working till 3000 rpm.

you can go too big on a head - it's just that pontiacs are so underheaded to begin with it's hard to do it.

i'm running 3.73's on my TA; big fun around town, hideous on the road.

Okay, sorry speedshopmike.

I thought you were saying that if you put ported heads on a pontiac, it makes them dogs. From what I can tell, overcamming a pontiac is where most people got the idea that you could kill the torque of a pontiac. If you take a restrictive head like a pontiac head and couple that with a big cam, you have a dog. Much worse than putting a smallish cam into an engine with a pretty good flowing set of heads.

I agree about those Boss 302s, they are pretty sick.

[Skip Fix]

Yes you can got too big. The Clevelands/302s are the perfect example. But our Pontiacs are so underheaded as you say, a 215 cc head is a drop in the bucket for a 460 ci motor.

Harry, I agree for Jim's combination his 6X head worked better than the KRE but we had those other variables. If other guys are having different results that also points to a different set of variables involved. So they can work and still be streetable.the compression is a variable as well as the aluminum to iron variable we really don't know. That's why I brought up the round ports.

I think cams add more variability in the mix that we think too.

My wife's 73 low compression 454 truck didn't have EFI and I guarantee it had more bottom end than my TA did at the time! Didn't even know that horse trailer was back there. But that 7mpg towing and only a 20 gallon tank wouldn't get you too far.

[Skip Fix]

Harry you're doing exactly as you should comparing everyone's combination and how they feel about it. The HR cam is another variable but I think a good choice given our current oil situation out there. Ithink if you pick all the compoents you''l have a good streetable car.My E head motor is sittign at about 10.25 20cc dish, 75cc chamber. Didn't pick up any on the dyno using octane boost over 93.

[Jim Hand]

Skip,
Just to clarify for everyone what those other "variables" were when I replaced iron heads with the KRE heads, will list them one more time:

1. KRE heads flowed an average of 273# .55 lift. The iron heads that were replaced flowed an average of 253# .55 lift.

2. The iron heads averaged 165cc port volume. The KRE heads averaged 186.5cc port volume

3. The iron heads provided actual CR of 10.08. The KRE heads provided actual CR of 10.38.

4. The KRE heads weighed a total of 42# less then the iron heads as installed.

5. With no other changes to the engine, trans, converter, rear axle, or shift point of 5500. the car ran between .15 and .2 seconds poorer in the 1/4 with the KRE heads.

6. With the KRE heads, the car ran to the 60' distance between .1 and .15 poorer then with the iron heads.

This was not a "test" of heads. I spent a lot of time and effort getting the KRE heads ready to install and fully intended to leave them on and not worry about cracks or leakage in the ported iron heads. After three trips to the track and all normal tuning optmized for the new heads, it was painfully obvious to me that the car had lost performance. And it also was obvious that it was a loss of low and early mid range power, exactly as every researcher that has tested such changes in port volume has found.

So I ordered a new cam to pick up the low end, a 233/235 on 108. It did, but also lost two MPH for no ET gain!

What I did and found is in no way related to what Cliff Ruggles experienced when he changed heads. I was already running .5 second quicker then Cliff with a car that weighed 300# more. I already had excellently prepared small port good flowing iron heads, as opposed to Cliff's basically stock iron heads. So please don't try to confuse this issue by dragging up Cliff's car.

As a result of the loss of low and early mid range power due to the larger ports on the KRE heads, even though they flowed 20 cfm added flow, and the loss of performance with the car, even though it was 42# lighter with the KRE heads, I yanked them off.

I did a bit more porting on the iron heads which also added a small amount of port size (13 cfm/5 cc) and reinstalled them. The car immediately regained the 60' time, and not only the earlier ET but an additional .1 second! And the added airflow also picked the MPH up equal to what the KRE heads provided.

Skip, why not discuss what actually happens when small port heads with equal flow as larger port heads are compared? We all know that the loss of some low and early mid-range power can be hidden by looser converters, deeper gears, or no traction. And we also know that many folks don't care if it is lost. But none of this changes the basic facts of the effects of port volume/cross sectionall area on real power development.

You can believe that if my new KRE heads had worked as well as my heavier iron ones on my car at the RPM range I run, they would sure as heck still be on the car!

Jim Hand

[Jim Hand]

It so happens that Popular Hot Rodding Oct,, 2006 issue featured a long and detailed article on porting, written by David Vizard. That issue is still on the PHR site at:

http://www.popularhotrodding.com/tec..._head_porting/

I strongly suggest that anyone interested in airflow, port volume, or general head operation review the article, and especially on page 2 where David discusses port volume and effects on power production. He even has a dyno graph showing the very obvious differences in low and mid RPM power between a 200 cc port and a 171 cc port on a Chev 350. And his test numbers correlate very closely with what my car did when I changed from 165cc ports to 186 cc ports.

I would like to quote two sections of his article because it so closely mirrors what I have written in my book, and countless times on this board:

Quote 1 - "Although we are far from done with port shape, let's turn our attention to port size, or more accurately, port area, as this is about as important as shape. The phrase, "the ports have been opened up," is a no-no. Remember this first. The typical hot rodder's viewpoint that if some is good, more must be better (and too much must be just right) may be good when we are talking cubes, but it absolutely does not work when the subject is port area. Sure, a big hole must flow more than a small one, but when a valve is situated at one end (along with the rest of an engine's mechanical complexities) the whole deal that bigger must be better goes right down the drain. An engine relies far more heavily on ram filling of the cylinder and swirl generation than is often supposed. Ram filling is a function of mass x velocity squared (M x V2).

So yes, there is much more to head operation then sheer airflow, and especially peak airflow."

Quote 2 - Caption for the dyno results chart (double click it to enlarge) "FIG. 11-These tests, done on a 350 Chevy, show that though the bigger ports flowed about 5 cfm more at .5-inch lift, the smaller, higher-velocity ports produced a much better power curve. At 2,250 rpm, the smaller ports were up by 30 lb-ft. An engine equipped with the bigger ports would need about 25 cubes more to match the low-speed output of the smaller-port heads."

End of quotes from Vizard's article.

And be sure and look at the dyno chart for actual measured results - again simply click on the smallish chart for a large and detailed graph.


Jim Hand

[Jim Hand]

Pontiac intake port too small? Depends specifically what RPM range you want to run! They are certainly not too small for my application.

Pontiac Dude just addressed that subject in a recent post at:

http://216.178.81.108/forums/showthread.php?t=497831

See post 4.

While he was speaking about airflow, in order to change airflow, port volume/cross section will invariably change also.

Jim Hand