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

[avengerengines]

Sure.

Would be interesting to try it on another dyno. Frankly, the numbers just seem really optimistic for a 408 inch engine, hydraulic roller, on 87 octane. I don't doubt for a second that the AFR heads aren't top notch (use them myself), but 1.5 hp/ci and 1.4 lb-ft/ci on an "off-the-shelf" build just seems odd to me.

There's no way that motor would make that kind of power on my dyno. I have a DTS and it reads lower than a lot of others but certainly not that much lower.

[David Vizard]

Sure.

Would be interesting to try it on another dyno. Frankly, the numbers just seem really optimistic for a 408 inch engine, hydraulic roller, on 87 octane. I don't doubt for a second that the AFR heads aren't top notch (use them myself), but 1.5 hp/ci and 1.4 lb-ft/ci on an "off-the-shelf" build just seems odd to me.

I have no doubt about your concern here but consider these hopefully relevant points.

#1 the dyno is calibrated on a regular basis and the beam test always shows the torque meter to be within 1/2 %.

#2 My dyno numbers have an accumulative audience of about 1,000,000 people a month. A substantial percentage of those are professional engine builders with their own dyno's. I give very precise details of how to replicate my builds. Virtually every week I get some communication or other from someone who has built a replica of one of my engines. The standard comment I get is along the lines of " it worked just like you said it would". I have never had anyone say that they built a replica that did not produce.

#3 Cosworth trusted me to do some of there dyno testing because out of all the shops they sent engines to for output verification i was the only one that produced curves deviating less than 1% of those they got on their environmental controlled dyno's.

#4 About 3 years ago we took and engine directly off one of the dynos at UNO that was used to test EMC engines a week or so before. 3 days after testing at UNO this engine (a 525 inch BBC) was tested on Terry's dyno and delivered results 2.7% lower.

Look, this list could involve a few more hours of typing. I have a protective client visiting this afternoon and I am still not finished tidying up rlom the flood we had a couple of days ago.
How about I send you a private message with my phone number and you can grill me on dyno results and how they work out on the track? Then you can go ahead and post whatever your thoughts are on the subject.

You sound like you more than know your way around performance engines. As such I am sure i will learn something of value from you so from my point of view it will more than likely be a production conversation.

DV

[RevTheory]

David,

I think the last time we spoke, you were mopping up the shop. The time before that, you were mopping up the shop. The time before that, you were mopping up a dyno cell when a crank finally gave up the ghost.

I'm starting to see a pattern here

[user-9274568]

I believe the power. As an example I have several as-cast 205cc SBF Pro-Filers on pump gas/HYD 347-351's that make 575+ and 470+..

[427dart]

If you are not in a Engine Masters competition what really matters is how it performs in the vehicle with exhaust and intake height constraints.
Figuring trap speed to weight is a better indicator of how it really runs!

[David Vizard]

David,

I think the last time we spoke, you were mopping up the shop. The time before that, you were mopping up the shop. The time before that, you were mopping up a dyno cell when a crank finally gave up the ghost.

I'm starting to see a pattern here

So you are starting to see a pattern here eh! This only goes to show you are observant as there is one.
Unfortunately we have , in the last two years, had some really heavy rainfall that overwhelmed the area drainage. My shop is in the house basement so if it floods outside I get to experience the consequences inside.

As for the broken crank - well I am surprised it was a crank. Usually it's a block.. Although it's not a major deal, on my book production agenda some reliability issues are always going to rear their ugly heads. Consider this - the better and engine builder is at getting power the more likely they are to find reliability issues sooner that those making less power. I am certain my readers would rather I found what breaks rather than letting them find what breaks. In the last three years the tally of broken blocks has been three SB Ford Windsor style blocks, 3 post 87 SBC 350 blocks (whole side of the block came out on all three occasions) and one 496 BBC block. (this suffered some serious cracks but only after a about 5 years of dominate track performances. I take what I do very seriously. If it involves the expense and time out as a result of parts breakages so I can better service my readers then so be it.

I sense an element of humor here - I certainly smiled - hopefully this puts your observations in prospective.

DV

[induction apprentice]

The Dyno sheet of this build projects very closely what I would have expected from a quality build like this from a expert engine designer and builder. For those who question the results. Keep in mind. Some guys boast they can assemble an engine like that in an afternoon. I could easily spend months assembling an engine like that. There are a lot of details that can be considered. Or ignored during a build. In both cases they will usually run.

All that mopping is great! A spotless shop says a lot about ones seriousness, respect and dedication to quality control.

[RevTheory]

...I sense an element of humor here - I certainly smiled - hopefully this puts your observations in prospective.

DV

It's always in good humor with me. I have a friend in Texas that had his shop swamped out a couple of times with all the rain the last year or so. I believe the crank was the one you detailed clear back in the 1st edition (blue) SBC book that finally let go.

Anyways, keep doing what you're doing and keep the combos coming.

Quick question on the build: I'm guessing the AFR heads didn't back up with .700 lift. Do you find that to be the case with the rest of their offerings?

[bigjoe1]

What makes you think the AFR heads will back up at 700 lift ?? I run an 875 lift cam in my sons drag race engine combo with the AFR 245 heads-- NO PROBLEM


JOE SHERMAN RACING

[RevTheory]

What makes you think the AFR heads will back up at 700 lift ?? I run an 875 lift cam in my sons drag race engine combo with the AFR 245 heads-- NO PROBLEM


JOE SHERMAN RACING

Nothing led me to believe that they did, Joe. I was just curious. I've seen Chad post numbers clear out to an inch of lift and the heads never backed up so it made me wonder.

[blykins]

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?

[JoePorting]

David,

I think the last time we spoke, you were mopping up the shop. The time before that, you were mopping up the shop. The time before that, you were mopping up a dyno cell when a crank finally gave up the ghost.

I'm starting to see a pattern here

So you are starting to see a pattern here eh! This only goes to show you are observant as there is one.
Unfortunately we have , in the last two years, had some really heavy rainfall that overwhelmed the area drainage. My shop is in the house basement so if it floods outside I get to experience the consequences inside.

As for the broken crank - well I am surprised it was a crank. Usually it's a block.. Although it's not a major deal, on my book production agenda some reliability issues are always going to rear their ugly heads. Consider this - the better and engine builder is at getting power the more likely they are to find reliability issues sooner that those making less power. I am certain my readers would rather I found what breaks rather than letting them find what breaks. In the last three years the tally of broken blocks has been three SB Ford Windsor style blocks, 3 post 87 SBC 350 blocks (whole side of the block came out on all three occasions) and one 496 BBC block. (this suffered some serious cracks but only after a about 5 years of dominate track performances. I take what I do very seriously. If it involves the expense and time out as a result of parts breakages so I can better service my readers then so be it.

I sense an element of humor here - I certainly smiled - hopefully this puts your observations in prospective.

DV

Do you think you're getting the broken parts from detonation issues? Maybe try and back off the timing or run better gas. I find a lot of motors run good on 28 degrees timing when using pump gas. When you mentioned that you'd be running this motor with 87 octane with 10:1 compression, I was thinking there was going to be a lot of rattling involved. If I was going 87 octane, I would have kept the compression around 8:1 at the most.

Nice HP numbers. I thought my 575-600 HP estimate was on the high side.

[David Vizard]

Mr. RevTheory sir,

Ref your comment below:-

It's always in good humor with me. I have a friend in Texas that had his shop swamped out a couple of times with all the rain the last year or so. I believe the crank was the one you detailed clear back in the 1st edition (blue) SBC book that finally let go.

If we are going that far back (in terms of my memory that is over the event horizon) then I have broken a crank or two since then. But I have to say that most of the crank breakages I have experienced have been due to some other breakage leading up to the crank failure.

Anyway here are the flow figures for the AFR 220 off my bench. It was checked for calibration both before and after the test. With a 310 cfm calibration plate it was 1 cfm off. Note the graph quality. This is how all the graphs are in the book. None of those wimpy things produced by the dyno or a flow bench program. The numbers are downloaded into an Excel program that automatically generates a graphic output as you see here. To best absorb graph detail the curves need to stat at an angle of 45-60 degrees. If they are flatter than that the differences between two curves is not as easily absorbed.

These AFR numbers are good but I am sure you will see higher numbers from other peoples benches. But as good as they are there is still the issue of port velocity involved. In my upcoming SB Ford book I will be going into what is needed in the way of port velocity to get everything working just so and what you are likely to be giving away by not working within the limits given.

DV

[David Vizard]

Do you think you're getting the broken parts from detonation issues? Maybe try and back off the timing or run better gas. I find a lot of motors run good on 28 degrees timing when using pump gas. When you mentioned that you'd be running this motor with 87 octane with 10:1 compression, I was thinking there was going to be a lot of rattling involved. If I was going 87 octane, I would have kept the compression around 8:1 at the most.


No problem from detonation. I am often called on to do fuel testing so most of the work is done with a det sensor in the system. As i remember it the 408 ran about 5 degrees short of any trace det.

DV

[David Vizard]

I believe the power. As an example I have several as-cast 205cc SBF Pro-Filers on pump gas/HYD 347-351's that make 575+ and 470+..

Chad, I know you and I think along similar lines in many respects. My best pump gas street 347 made 562 hp and 472 Lbs-ft on Terrys dyno. I did run it on a local dyno and it made something like 582 hp and 485 lbs-ft. Have not used that dyno since as I know it is wrong!

BTW I have flow tested your new(ish) Ford heads and I am expecting some really stout results as both flow and port velocity look good. I expect to run these heads on a 427 street build. Down the road the dyno will tell the story but for now those Profiler heads look a hot deal.
DV