Author Topic: Blair Patrick's latest 506" FE  (Read 31443 times)

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whitea62.7t

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Re: Blair Patrick's latest 506" FE
« Reply #30 on: July 06, 2015, 09:58:57 AM »
Blair  did you ever consider  using a vacuum pump?

CaptCobrajet

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Re: Blair Patrick's latest 506" FE
« Reply #31 on: July 12, 2015, 12:53:33 AM »
Not on that particular engine.  The car it is in is actually a Super Stock car.  We did that engine so the new owner could get some seat time and make some passes without wearing out a bunch of expensive and high maintenence "legal" parts.  It is not allowed to run a vac pump with the legal engine, and there were no brackets or provisions for mounting the pump or the separator, so we just ran pan-evacs on the stroker.  It is externally an identical twin to the 427.  There would probably be modest gains from a pump, but well placed pan evacs will pull on the crankcase also.  If it were an aluminium block, the pump is worthwhile, and needed, in my opinion.  Aluminium blocks, with all of the correct prep, just do not seal as well as iron.  The power vs. weight is just about a wash, although a vehicle will tend to work better on the track with an aluminium block due to the weight reduction on the front of the car.
Blair Patrick

machoneman

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Re: Blair Patrick's latest 506" FE
« Reply #32 on: July 12, 2015, 08:46:30 AM »
Not on that particular engine.  The car it is in is actually a Super Stock car.  We did that engine so the new owner could get some seat time and make some passes without wearing out a bunch of expensive and high maintenence "legal" parts.  It is not allowed to run a vac pump with the legal engine, and there were no brackets or provisions for mounting the pump or the separator, so we just ran pan-evacs on the stroker.  It is externally an identical twin to the 427.  There would probably be modest gains from a pump, but well placed pan evacs will pull on the crankcase also.  If it were an aluminium block, the pump is worthwhile, and needed, in my opinion.  Aluminium blocks, with all of the correct prep, just do not seal as well as iron.  The power vs. weight is just about a wash, although a vehicle will tend to work better on the track with an aluminium block due to the weight reduction on the front of the car.

I get that aluminum blocks produce less power and maybe Blair has partially answered my question: why? If the deck was flexing, they'd lose head gaskets. The ductile iron liners are pretty stout as is the modern aluminum block material. Yet, is it mainly the greater heat rejection of aluminum or moving liners that actually cause the power loss or maybe both? Something else?

I've never really heard why.   
Bob Maag

whitea62.7t

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Re: Blair Patrick's latest 506" FE
« Reply #33 on: July 12, 2015, 10:40:16 AM »
The wealth of knowledge you guys have is the reason i keep reading this forum
Its great that you guys freely pass it along.
Thank all of you
Sean

BigBlockFE

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Re: Blair Patrick's latest 506" FE
« Reply #34 on: July 13, 2015, 12:50:56 AM »
Not on that particular engine.  The car it is in is actually a Super Stock car.  We did that engine so the new owner could get some seat time and make some passes without wearing out a bunch of expensive and high maintenence "legal" parts.  It is not allowed to run a vac pump with the legal engine, and there were no brackets or provisions for mounting the pump or the separator, so we just ran pan-evacs on the stroker.  It is externally an identical twin to the 427.  There would probably be modest gains from a pump, but well placed pan evacs will pull on the crankcase also.  If it were an aluminium block, the pump is worthwhile, and needed, in my opinion.  Aluminium blocks, with all of the correct prep, just do not seal as well as iron.  The power vs. weight is just about a wash, although a vehicle will tend to work better on the track with an aluminium block due to the weight reduction on the front of the car.

If the car has a 50 50 weight distribution, could an iron block be an advantage to lower the center of gravity for around a track, it seems most FE builders I have talked to all prefer the iron block over aluminum...

Barry_R

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Re: Blair Patrick's latest 506" FE
« Reply #35 on: July 13, 2015, 06:45:49 AM »
I have always heard that aluminum blocks make less power than iron in comparable applications.  The folks that I speak with who have done the back to back comparison say the difference is noteworthy - on the order of 20HP.  They attributed the variance to the dimensional changes that occur with heat - aluminum expands at a far greater rate and in oft unpredicted directions dictated by the metal's mass and cross sections.

One thing worth noting is that the guys I referenced are racing in categories that limit compression ratio to a fixed value.  If you build both an iron engine and an aluminum version to say - 12:1 and get them warmed up you will find that the aluminum engine will develop .005 or so more valve lash.  Now consider what that same dimension does to compression and quench volume.

CaptCobrajet

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Re: Blair Patrick's latest 506" FE
« Reply #36 on: July 13, 2015, 11:22:50 AM »
From what I can tell, the diff on a modern FE iron casting and aluminium is about 30 hp.  The diff between an OEM block and aluminium is 15-20 hp.  We have done several engines that have identical or nearly identical parts, and those are the margins that show up, over and over.  The Ford OEM 427 is not as much better, but the Pond, Gen, BBM iron blocks are "more" better, just because of the more rigid cylinders.  As far as "in car" goes, you can chase a dyno figure, and an iron block will show more, but the power is just about exactly offset by the weight difference.  It takes about 30 horsepower to overcome the 150 lbs.  In a drag car, 150 lbs off the nose is ALWAYS better.  The chassis can be better optimized with less weight on the nose..........always.  I remember when we were allowed to replace the OEM seats in Super Stock with lightweight race seats.  Even at the same total weight, my car picked up about .03 in the 330 ft time from taking 80 lbs out of the middle of the car and relocating the weight to the rear.  That was in the middle of the car, and about half the diff in the iron and alum blocks.....

To Barry's point on aluminium....I totally agree on the growth. I always run the deck a little tighter, and also bump the static C/R a little, to allow for the growth.  The last Shelby block we did had .008 cold lash, and about .025 at running temps.  They definitely grow more.  As long as you know that, and allow for it, it is no problem.  Aluminium engines just need to be massaged a little different than the iron.

If you are traction-limited, or nose-heavy, the aluminium block offers added benefits to getting the car to hook and "work".  Small tires and/or leaf sprung Cal-Trac cars with big engines will like the benefits of the lighter block more than they like the power diff of the iron and the weight it puts on the front tires.  A tenth gained in the 330 ft is a "mile" in high gear..............
Blair Patrick

machoneman

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Re: Blair Patrick's latest 506" FE
« Reply #37 on: July 13, 2015, 12:18:32 PM »
Thanks Barry and Blair!  :)
Bob Maag

turbohunter

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Re: Blair Patrick's latest 506" FE
« Reply #38 on: July 13, 2015, 01:21:04 PM »
Thanks Barry and Blair!  :)

No kidding.
Thank all of you FE guru's that qive us mere mortals your insights and knowledge.
That's pretty darn cool of you, and it IS appreciated.
Marc
'61 F100 292Y
'66 Mustang Injected 428
'66 Q code Country Squire wagon


Nightmist66

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Re: Blair Patrick's latest 506" FE
« Reply #39 on: July 13, 2015, 02:56:26 PM »
X3  :)
Jared



66 Fairlane GT 390 - .035" Over 390, Wide Ratio Top Loader, 9" w/spool, 4.86

Putts428

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Re: Blair Patrick's latest 506" FE
« Reply #40 on: July 18, 2015, 11:47:04 AM »
X4. It is amazing the information shared on this site!! ;D

whitea62.7t

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Re: Blair Patrick's latest 506" FE
« Reply #41 on: July 18, 2015, 11:56:57 AM »
I wish this was around when i was running a 390 Cougar at MIR in the late 80's early 90's

PinnaclePeak

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Re: Blair Patrick's latest 506" FE
« Reply #42 on: September 08, 2015, 12:19:50 PM »
Blair,
Have you ever tried the Blue Thunder FE Heads on any of your engines?
Interested in the flow numbers on your Edelbrock heads.

PinnaclePeak

CaptCobrajet

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Re: Blair Patrick's latest 506" FE
« Reply #43 on: September 08, 2015, 09:58:58 PM »
Appreciate your interest.  I choose not to publish flow numbers out on the interweb.  There is a lot more going on with a good working pair of heads than the max flow number.  I generally try to get a feel for what a customer is trying to accomplish, and then try to provide a cylinder head/manifold combo to reach the goal.  Sometimes a well suited combo will run and hide from a "big numbers" head........it really depends on what a person wants to do.  A couple of years ago, a fine gentleman had me build an engine with heads he supplied.  About one year ago, we freshened the engine and put on some of my heads.  With less max flow, we made almost 100 more hp, and almost 100 ft/lbs torque.  Working strictly from flow numbers, he would have never tried my heads.   The port and the prep vary depending on the end-use.  Flow numbers are a much better tool when tweaking a combo, and taking note of all of the variables that affect the results.  Comparing head "X" with head "Y" from two different sources, only by flow numbers, may or may not tell you what you need to know.
Blair Patrick

Qikbbstang

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Re: Blair Patrick's latest 506" FE
« Reply #44 on: September 09, 2015, 02:52:31 PM »
Just when you think you understand motors it all goes up in smoke.  I'm laughing at my first thought to Jay's quote:

" I have never seen an 800 lb-ft FE except for my big SOHC, and that engine was 585 cubic inches.  This engine is only 506 cubic inches.  That is a very, very impressive torque number."

So I'm thinking this baby of Blair's must have 14:1 CR! 

Then in the next paragraph Jay writes:
 "Apparently it is basically one of his Super Stock FEs, but with more cubic inches, less compression, and a smaller cam."..........

............Doh! there goes my high compression idea flying out the window. But there is saving grace Jay continued: "Apparently it is basically one of his Super Stock FEs, but with more cubic inches, less compression, and a smaller cam.  His normal 427-based super stock engines turn to 9000 RPM to make this kind of horsepower.  Compression ratio on this engine is 13:1,"


IF 13:1 is "less compression" then a Super Stock what the heck CR's do they run in Super Stock?......