Sorry you feel this way and your engine builder friend. 30 years ago I worked in a shop that used the sweep method. That was 30 years ago. The engine builder now uses the "Thread Method.". He has learned over the 30 years.

 

Paul, you were looking at a high lift, duration cam, bigger stroke, 7000 RPM shift points, Peak HP above 6000 RPM and road racing with extended upper midrange to redline operation. Engine requires more air flow. The OP is looking at a sub 6000 rpm street engine that likely will spend 95% of it's life below 4000 RPM, stoplight to stoplight performance is the goal. 195 to 220 is a 12% difference in port size. 406 to 427 is a 5% difference in CI displacement. It is all about what the engine demands to operate efficiently based on CI and operating range, intended use, cam specs, demand. With your specs a 195 head will restrict your build, it will hit a ceiling, doesn't accommodate the demand of your specs. A 245 head will leave bottom end and midrange power levels down like when your accelerating out of a hard turn, doesn't accommodate the demand of the build. Every build is a series of compromises throughout based on demand for intended use and specs. An ideal head for you might be a 195 at the bottom end and a 235 at WOT at redline. That head don't exist so you compromise. Anything you gain up top on RPM and peak power you sacrifice on the bottom and visa versa.

 

Mouse...are we reading the same thread here? The whole thread is about the 195 being "too small" according to the "resident experts".
Quote: (and this is what I was responding to)
last time. It's not a small head for a 406 @ 6000rpm and I've shown why, BY THE NUMBERS, not just my opinion. If you want to grow or turn more rpm, get a bigger head. If you want to make a lot of peak power and give up lower rpm performance, get a bigger head. If you just want to brag about how big your heads are, get a bigger head. Heck, I'm not even saying a bigger head won't work, I'm just saying the 195 is plenty of cyl head for this build and will perform better than a bigger head, all things considered.

 

Racing shops design and build racing engines. Street engines have different demands. I drag raced in my younger days. We didn't have the availability of dynos, head and cam availability, technology and access to information then. EVERYTHING was trial and error at the track and the knowledge gained from that. When your in that realm your building for max 1/4 mile high rpm power generation. You become jaded to the effects it has on low RPM performance and your thinking narrows.

 

No i don't think they were saying that, saying more there's not much room for growth and you might end up spending for different heads.

I personally think a 210 could have worked OK for Pauldana with a 6300 rpm goal but he sure has not hurt himself with the 220 and if he wants Straub to make him a cam that goes a little higher in rpm range for some more power he has the heads to do it. Im talking about in the range hydraulic rollers are best for, still dependable.

I thought when pauldana talked about 500 hp at the rear wheels it would take more like 6,800 rpm to accomplish it said so at the time. But i have to hand it to straub he made it happen at 6300.

But he needs to go back to that edelbrock cam you fixed it now he's tearing his car up has no traction will probably get worse with traction lol.

 

I can remember years ago cruising the the Crane Catalog and seeing the same grind in the Drag Race and Circle track sections of the catalog. I said then how can you use a drag cam in a circle track?

One of mentors was John Reed. John told me one day an engine doesn't know what it is...ie drag, marine, street, circle....all it knows it has to make power in a given rpm range. An NHRA 500 Pro Stock engine needs a powerband that is 800 rpm wide. A street driven C3 needs a wide powerband under the max rpm the customer wants to make max HP.

 

The bigger head and cam and you lose bottom end is just a fairy tale, but keeps coming up again and again like a bad dream. I built a 406ci 10 years.

It had Eldebrock Vic Jr heads measured to 219cc's and a XR280R solid roller with a Vic Jr single plane and a 825 Drag Race Demon to top it off.
These parts according to out "new experts" are way to big for a 406ci I would be losing the cruicial low end grunt for driving around town.

Against all the new "small cam, small heads" posts recently this motor should be a dog down low. I knew different and this is not what happened. I got a nice easy to drive on the street engine with gobs of low end torque over 350 ft/lbs at the wheels @ 2100RPM and the torque curve is flat across the board with max torque @ 3600RPM.

The proof is in the puddin' in the graph below, (stopped early from a sensor problem. I don't think anyone can say this would not be a killer street engine and you take it to the track and run good numbers. The best of both worlds here for sure and for some reason I never even thought about putting a smaller cam and smaller heads on it to make more power

My new 427 is the same with a tad more power

 

So we correct your numbers with 20% for being on a chassis dyno and we come up with th 473HP and 502#/ft torque.

The AFR190 headed 406 with a hyd roller that is 237/243 .548/537" lift on a 108 makes 519HP at 5800 and 547#/ft at 3800 to 4000 rpm. On a chassis this would be 415HP and 437.6#/ft

Thank you for the dyno sheet.

 

Peak power was 550HP and 510TQ when I took the engine out and put it on a engine dyno. At the time as most forum members remember( 8 years or so before you showed up) I did this to find the loss between gross and wheel HP and Tq. and the percentage I got was 23 percent, you do the math now, I always have videos and dyno sheets to back up what I say.

This was also 10 years ago and I did not have the money for AFR heads but if I did I would have made more power. AFR 195's now flow about what my "huge" runner Vic jrs. flow Do you get any work done or work just kinda a hobbie and losing arguments on the internet your major activity

 

So with a baby hyd roller and smaller heads, the engine Chris posted makes 37 more #/ft torque, probably more average power and would smoke your engine on the street in a 3500# car.
LOL...great argument.
How much compression was your 406? I would be embarrassed with those parts and those numbers but hey, to each their own.

 

10:1 run on 91 Octane same as my 600+HP 427ci. Two against one, no fair, and a my $%@ is bigger that yours childish way of trying to debate a subject and a great way to represent your company, I am sure others will be impressed

 

IF it made 550/510 and difference between was 23% then it should make 423RWHP and 393RWTQ.

 

Actually you stated Big heads Big Cam Big.....is the way to go. I'm trying to follow this path of thinking.

How does your 427 compare to Mr. Paul's dyno sheet. You say 600+ and you always dyno your engines. I would be interested in seeing the combination.

 

You said down low as a comparison that this thing hangs there. Your engine torque wise looks about 365#/ft at 3000 rpm. If we use your conversion of 23% to FW that is 474#/ft. The 406 with he hyd roller makes 511#/ft. That is 37# more in a very usable rpm for a street car when you want to punch it.

 

LOL...That's your respones?? No fair???
Guess those numbers really didn't work out for you, did they.
Have a great evening.

Oh, and thanks for giving us prime example of just exactly what we were talking about and the opportunity to help others understand. Don't want your efforts to go unappreciated.

 

Good point!
Your 406 would have made more power both off idle and top end if you ran the AFR 195 especially if it was cammed to match the head.
Here is a comparison. Compare it to filling a gallon jug. The gallon jug will only hold a gallon. If you have a gallon and a quart it won't fit in the gallon jug. If the 406 has a set maximum demand giving it more capacity than it can accept is counter productive. It cant take more than the capacity. At the other end of the spectrum due to decreased port velocity you lose a portion of the atomization and the "ram" effect needed to maintain bottom end efficiency. The loss will be a percentage of bottom end torque as a relationship to the decrease in optimum velocity. You don't lose it all, just a pecentage. LOOK AT THE DIFFERENCE @ .400 lift!!!

Flow @ ------------.200 -------.300 ------.400 ------.500

AFR 195----------146/119---201/166---274/197---275/213

Victor Jr. 215-----119/112---177/153---226/188---265/207

 

When I was planning the upgrade for this engine the first thing I did was decide what kind of engine I wanted, and what RPM range I wanted to work with.
It came to me that I wanted a sporty street motor, that ran from 2000-6000 RPM, with a dual plane intake, that I could hand over to my wife and she could run to the store and back without any issues.
My original setup (vortec heads,performer intake,and a Qjet) ran very well.....even to 6000 RPM. I was Quite happy with it as it was.
Now the vortecs are allowing some oil by the seals, and the valves aren't as tight in their guides as they should be. I don't want to put any more money into those.....they've been good to me but it's time to move on.
I guess the deciding factor was the requirement to go with a single plane intake if i stepped up to the 210's......that was not going to happen. I want great throttle response, great mid range torque, and the ability to run to 6000 and rarely to 6500 rpm. The 195's give me all that and more.
During my racing days on the circle track, I was the only car with a Performer RPM airgap intake, everyone else had a Victor Jr. or similar. On restarts nobody could touch me, I usually had them by 1/2 a straight after a lap. It was only a 3/8 mile track so rpm's were under 7000. Vortecs and RPM airgap worked well for me....My point is I had way more torque than everyone else at our starting RPM of around 2500-3000, and thats what I want in my street motor.
If plans change again, I can always buy some 210's 220's or a bottle.
Ohh.....I wanted to take my car to the track and run it like it is now, and then run it after the head change, but the tracks will be closed by the time I get home from AZ. I'll do it next summer. I'm not sure of any chassis dynos where I live. I'll look around.

 

I have a single plain on my 406 with L98 heads, it'll never be short on torque.

 

trying to decide between two different heads which one to get sometime next yr decided it will be a 377 have to buy a dart block. Staing with a 331 build just causes me to much grief.

int. lift flow 200=156 300= 222 400= 280= 500=330

ex lift flow 200=128 300= 175 400 = 238 500 =275

other head

int. lift flow 200=152 300=218 400=275=500=318

ex. lift flow 200=126 300=175 400=235 500= 262

 

For the street, the smallest MCSA calculated for engine CID and rpm is the best choice. Velocity rules. I know this....I was the fat kid...never won a sprint race in school.