408 SBF with AFR’s latest 220 cnc heads – what power?

General engine tech -- Drag Racing to Circle Track

Moderator: Team

427dart
Expert
Expert
Posts: 910
Joined: Thu Apr 02, 2015 3:23 pm
Location:

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by 427dart »

David.. what are your thoughts on the TFS High Port 225 heads and have you used these in any builds?
induction apprentice
Expert
Expert
Posts: 796
Joined: Sat Jun 30, 2012 3:12 am
Location: Canada

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by induction apprentice »

Happy new year gearheads.
Lenni AMC
Member
Member
Posts: 82
Joined: Mon Nov 28, 2011 3:05 am
Location: Iceland

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by Lenni AMC »

David I´ve been reading your stuff for couple of years but I have read and own How To Build Horsepower Part 1 & 2 and they have helped alot with some tricks of getting more power on my builds.

One thing I would really like you to do is do an AMC build just one build for us AMC nuts. I know alot of the AMC enthusiast would enjoy that article or book.
Is that something you are open to do sometime in the future ? :shock:

Best Regards and a happy new year from Iceland
Lenni
David Vizard
Guru
Guru
Posts: 1787
Joined: Thu Jan 15, 2015 12:19 pm
Location:

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by David Vizard »

blykins wrote:David, no need to private message me with anything. I just thought it would be a good exercise to try another dyno. It's not very often that you pull parts off the shelf and make 1.5 hp/ci...

Most engine builders/dyno operators aren't out to jip the general public with bogus numbers, but I've seen where an innocently misplaced weather station could offer up quite a few free ponies. There are 3 dynos in my area. There can be up to 70 hp difference between them and they are all calibrated....

Would you mind offering up the correction factor and the weather station data from this dyno session?

Actually i think it would be a good idea to PM you. There is some interesting Ford stuff on your site and I am doing a Ford book. I think we should talk.

Yes having a sensor in the wrong place can make for some optimistic #s.
A few years ago I was asked by Aston Martins historic race division to help break the 400 hp barrier with the 3 litre engine that was introduced back in the fifties and powers such cars as the Bond 007 car. The dyno curve I was shown when I got there indicated we only had to bridge the gap form 386 hp to 400. A step of a mere 14 hp. However on looking at the printout I noticed that the dyno testing was done in january and that the recorded ambient air temperature was in the low 80f range!!!!! Turns out the temperature was being taken from a point directly over the exhaust pipes! A check with the weather records revealed the true ambient temp to be about freezing point so the numbers were optimistic to the tune of some 40 hp. That meant I was supposed to find 57 hp not 14. A new set of ports and chambers plus some wet flow refinements with the Weber carbs and the intake manifold plus six months work resulted in a big torque increase plus 411 hp peak output. All would have been good but now the block life was reduced to an hour or so at the most.

Yes I will look through my paperwork to find what you need here. I may be a few weeks as I have quite a bit of preparatory stuff to be done prior to possible surgery at the base of my skull due to an accident at Brands Hatch in 1989 (44 G and no Hans device!). The dyno tests posted were done just before I had a series of run-ins with the ER department of which one resulted in emergency heart surgery. This year I only made it to PRI by the skin of my teeth. My good friend James Harris, a fire fighter with medic experience had to be with me the entire time. As a result I got to go to the show but was operating at half speed. I had on my list to visit Chris Straub but just simply ran out of time (sorry to have missed this opportunity Chris).

Just thought of another point concerning the flow curves I posted on the AFR heads a page or so back. Usually AF heads have above average intake valve discharge coefficients in the range right off the seat to about 0.250 lift. With average CD #'s a cam advance of typically 4 degrees is most often about it. However with an intake flowing slightly better than average at low lift the amount of cam advance required for max output is usually less. Here we had a situation where the intake valve geometry favored high lift rather than low lift. When the cam was set in at the traditionally accepted 4 degrees of advance it produced, as I expected, way less output. Making full use of the Jesel belt drive unit I use for dyno testing the cam was advance until the optimum was found. This proved to be right about 6.5 degrees advance. Power adjusting the cam advance to what the engine wanted rather than the cam companies best guess resulted in some 14 hp and 12 lbs ft to the better.
David Vizard Small Group Performance Seminars - held about every 2 months. My shop or yours. Contact for seminar deails - davidvizardseminar@gmail.com for details.
David Vizard
Guru
Guru
Posts: 1787
Joined: Thu Jan 15, 2015 12:19 pm
Location:

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by David Vizard »

Lenni AMC wrote:David I´ve been reading your stuff for couple of years but I have read and own How To Build Horsepower Part 1 & 2 and they have helped alot with some tricks of getting more power on my builds.

One thing I would really like you to do is do an AMC build just one build for us AMC nuts. I know alot of the AMC enthusiast would enjoy that article or book.
Is that something you are open to do sometime in the future ? :shock:

Best Regards and a happy new year from Iceland
Lenni

After all the work has been done and whatever parts can be sold off to help balance in and outging expenditure it costs around $30,000 to $50,000 to write a book on a POPULAR engine such as Ford or Chevy. It takes about 2-3 years to recoup that if it's a popular engine. If i did an AMC book I would never come close to recouping the time effort and money involved. That all said you can probably guess my answer here.

The best I can do for you is to read my flow bench/porting book and combine that with what you have learned from the How to Build HP vol I & II books.

DV
David Vizard Small Group Performance Seminars - held about every 2 months. My shop or yours. Contact for seminar deails - davidvizardseminar@gmail.com for details.
andyf
Guru
Guru
Posts: 1387
Joined: Tue Oct 05, 2004 12:55 pm
Location: Oregon
Contact:

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by andyf »

I wrote my "How to build max-performance Mopar big blocks" for roughly $10K, but I had a head start since I had 10 years worth of magazine articles already in the can. If someone asked me to write a book on something other than Mopar big blocks I'd lose my shirt.
Andy F.
AR Engineering
User avatar
MadBill
Guru
Guru
Posts: 15024
Joined: Tue Nov 15, 2005 10:41 am
Location: The Great White North

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by MadBill »

A friend of mine wrote and self-published a very technical book on race car engineering that was going to take many years to amortize. Printed off 500 copies (retailing at $120.00) and then found a horrendous math error that got carried over from an early version and which undermined much of the remaining text. He recalled and reprinted them all and commented: "Well, there goes my retirement motor home..." #-o
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.
David Vizard
Guru
Guru
Posts: 1787
Joined: Thu Jan 15, 2015 12:19 pm
Location:

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by David Vizard »

andyf wrote:I wrote my "How to build max-performance Mopar big blocks" for roughly $10K, but I had a head start since I had 10 years worth of magazine articles already in the can. If someone asked me to write a book on something other than Mopar big blocks I'd lose my shirt.
Andy,
Finally someone who actually understands the situation. I am going to make a bet that the $10,000 costs you incurred did not count the hours of time spent actually writing the text.

In my estimation there are two principle reasons why more people don't write books. The first is they lack the will and determination to do a proper job and carry on right to the bitter end to finish it.

Secondly - they are smarter than we are in the first place so don't try to start on a questionable money making project with only a marginal chance of success.

DV
David Vizard Small Group Performance Seminars - held about every 2 months. My shop or yours. Contact for seminar deails - davidvizardseminar@gmail.com for details.
User avatar
MadBill
Guru
Guru
Posts: 15024
Joined: Tue Nov 15, 2005 10:41 am
Location: The Great White North

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by MadBill »

I was just a voluntary editor of the book I mentioned above, and still it absorbed an unbelievable number of hours over more than a year. One of the compensations though is that when you start to write about something instead of just talking, you find yourself being far more disciplined: digging deeper, questioning your long-held assumptions, researching more basic science, etc. It forces you to be better at your specialty!
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.
Kevin Johnson
HotPass
HotPass
Posts: 9365
Joined: Tue Nov 22, 2005 5:41 am
Location:

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by Kevin Johnson »

You need to require students to purchase the new iteratively revised text for the course.
Driving Force Online: BREAKING NEWS—Ohio Governor Signs SEMA-Supported Vehicle Freedom Bill Into Law!
User avatar
MadBill
Guru
Guru
Posts: 15024
Joined: Tue Nov 15, 2005 10:41 am
Location: The Great White North

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by MadBill »

Uumm, there is a certain level of that that goes on even outside of achedemia...
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.
ou812
HotPass
HotPass
Posts: 948
Joined: Thu Feb 10, 2005 11:23 pm
Location: SoCal
Contact:

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by ou812 »

David Vizard wrote: A:- Agreed, but I am running 10/1 plus with moves that make the engine less demanding of higher octane fuel.


If I may ask, what moves do you make to achieve an engine that's less demanding of higher octane fuel? Our here in Ca., we have really poor fuel with 10% ethanol. I've been wanting to experiment with 87 octane fuel but not with customer's stuff....
Thank you!
Brian Hafliger
IMM Engine & Dyno

Image
http://www.immengines.com
http://www.neilhepburn.com
User avatar
MadBill
Guru
Guru
Posts: 15024
Joined: Tue Nov 15, 2005 10:41 am
Location: The Great White North

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by MadBill »

One problem with running high-ish octane pump fuel (e.g 94 R+M/2 here) with the max possible 'safe' CR is that if you ever loan your vehicle to a GF or pal, he/she'll tank up with 87 and detonate the whee out of it... #-o
Felix, qui potuit rerum cognscere causas.

Happy is he who can discover the cause of things.
ou812
HotPass
HotPass
Posts: 948
Joined: Thu Feb 10, 2005 11:23 pm
Location: SoCal
Contact:

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by ou812 »

MadBill wrote:One problem with running high-ish octane pump fuel (e.g 94 R+M/2 here) with the max possible 'safe' CR is that if you ever loan your vehicle to a GF or pal, he/she'll tank up with 87 and detonate the whee out of it... #-o
LOL!
Brian Hafliger
IMM Engine & Dyno

Image
http://www.immengines.com
http://www.neilhepburn.com
David Vizard
Guru
Guru
Posts: 1787
Joined: Thu Jan 15, 2015 12:19 pm
Location:

Re: 408 SBF with AFR’s latest 220 cnc heads – what power?

Post by David Vizard »

ou812 wrote:
David Vizard wrote: A:- Agreed, but I am running 10/1 plus with moves that make the engine less demanding of higher octane fuel.


If I may ask, what moves do you make to achieve an engine that's less demanding of higher octane fuel? Our here in Ca., we have really poor fuel with 10% ethanol. I've been wanting to experiment with 87 octane fuel but not with customer's stuff....
Thank you!


Just got to your post here. lets see If I can do a quick answer before I have to hit the road.

#1 chamber designs that scavenge better than average. This gets rid of more hot exhaust residuals and allows for a lower temp charge at the time of ignition.
#2 Assuming the right spark plug the exhaust valve is the # 1 cause of detonation. Thermal barrier coatings on the face cut valve temps. So do sodium cooled valves and coated sodium cooled valves are even better yet.
#3 Minimize exhaust valve stem clearances just short of what will seize for sure as closer clearances dump a lot more E/valve heat into a bronze guide.
#4 Use bronze guides not iron.
#5 Use aluminum heads not iron.
#6 The intake valve absorbs more heat than the exhaust valve during the combustion cycle because it is of greater area. that heat is then transfered into the intake charge which is not good. Coat the Intake valve face as an absolute minimum.
#7 Use a good thermal barrier on the intake port and manifold runners
# 8 Better fuel atomization is needed with thermal barrier coated ports. Dyno test alternative boosters in the carb if the atomization is too coarse.
# 9 if the fuel atomization is at or near optimal the spark timing needed will be less. This means the end gases (which is the part of the charge that is last to burn and most likely to detonate) will have received less radiated heat. This reduces the temperature and increases detonation resistance.
#10 Use an intense spark (Might want to read what I have on this in my Holley book ref Amozon.com)
Run the engine block at no more than 170 degrees F.
#11 If it is convenient run reverse cooling
#12 draw in cold air from outside the engine compartment
#13 I am sure there are still more little details I/we do but off hand I can't think of them.

As it happens all of these moves also increase torque.

DV
David Vizard Small Group Performance Seminars - held about every 2 months. My shop or yours. Contact for seminar deails - davidvizardseminar@gmail.com for details.
Post Reply