XXO/BVGC '38 Chevy Coupe Build

[38flattie]

What does the other side of the head look like??
Rex

I would pass as well, gotta keep at least ONE ace up yer sleeve

Well, there's clearly two routs about .525 deep.  

Now if we can get a good look at the pistons, we might be able to figure it out.

Rex, Tman, I don't think I want to play poker with this guy . . . .

Haha! It's not that big a secret- think modified Harley KR/Navarro heads, with popup flat tops.

Dr Goggles, Jimmy- In BVGCC we will have a bellypan, and in BVGALT, we
will have a step pan, so both will act as a 'skidplate.

Jimmy, remember, BVGC is no longer an option, with 14% setback.

Tom, I can't remember the new base circle, but the small diameter is
now 1". Stock was 1.375"

Littleliner, that's the one!

Ok, I received the preliminary stock flow numbers from Joe Abbin. These
numbers are with stock valves, no port work, and our custom chamber
head. Next up is port work, valve guide relief, and a 1.76" exhaust
valve. we will test both a 1.94" and a 2.02" intake valve.

Dale and I were chatting, and so far, it seems that if you look at the graphs, it sure looks to be very port constricted. On both the intake and the exhaust the amount of additional CFM that it flows between
.278 and .500 drops off drastically. In effect, you can raise the valve just
about all you want and it just doesn't matter all that much. This is why
getting the valve open early and keeping it open (duration), a blower and
porting will be very big components of horsepower.

From looking at the block, doing extensive work in the bowls, short-side radius,
etc - should make a big difference. My guess is that the overall size of the
port won't be the limiting factor (up by the intake manifold), but what happens
when the ports turn and get constricted into the bowl and the overall size of
the bowl area.

While these numbers are laughable by OHV standards, they excite the hell out of me! They show 20-25% more flow than a stock Ford, according to Joe Abbins flow bench tests.

So, we're off to a very good start!

[Tman]

I figured the Harley heads weighed in there with the folks helping you

[desotoman]

I figured the Harley heads weighed in there with the folks helping you

I got a chuckle out of that statement. Back in the early 1980's when I was doing my Flathead project, I met Dale and he was the one that told me about the HD heads. So yes they would have that information also.

With a Flathead you can take so many different routes when designing a head, especially with a blower.

Tom G.

[Tman]

I figured the Harley heads weighed in there with the folks helping you

I got a chuckle out of that statement. Back in the early 1980's when I was doing my Flathead project, I met Dale and he was the one that told me about the HD heads. So yes they would have that information also.

With a Flathead you can take so many different routes when designing a head, especially with a blower.

Tom G.

Yup, and since they were working with Abbin I made the connection

[38flattie]

I figured the Harley heads weighed in there with the folks helping you

I got a chuckle out of that statement. Back in the early 1980's when I was doing my Flathead project, I met Dale and he was the one that told me about the HD heads. So yes they would have that information also.

With a Flathead you can take so many different routes when designing a head, especially with a blower.

Tom G.

Yup, and since they were working with Abbin I made the connection

Haha! Nope- you just thought you did!

Joe has nothing to do with the design. I simply took everything, after it was done, to Joe for flow numbers. Since his published Ford numbers are everywhere, we could get an apple to apple comparison with the Caddy to Ford numbers.

Dale has been preaching the attributes of the Harley heads for years, so this was his idea (and Navarro's), with Chris Daniels doing the CAD work.

For the record, out of all the members, I believe only John Speer and myself have Harleys!

[desotoman]

Dale has been preaching the attributes of the Harley heads for years, so this was his idea (and Navarro's), with Chris Daniels doing the CAD work.

No offense but to set the record straight Navarro did not have the idea for his Hi Dome heads.  I went to Navarro after reading a column in a Hot Rod Magazine that was written by none other than Bruce Crower. Bruce had written an article of how fun building a flathead Ford might be the second time around, changing up the head design. So really it was Bruce's ideas coupled with many other peoples input, the results from the flow bench, and the result was a new head.

I went to everyone who was still making Flathead heads in 1980, and only Barney was willing to try and update his heads. He built a flow bench and I ran it. After talking to many people including Dale Hays, Bruce Crower, Don Ferguson Sr. Ed Iskederian, Jerry Branch, and many more people, including getting blueprints of the harley heads, and a couple HD heads I borrowed from Dale, we came up with a design which flowed pretty good. But I did not like the way the piston shape was, which was basically a 9/16 inch pop up piston, which I had Arias put a 240 Z type relief on. The piston was way too heavy even with internal milling.

As luck would have it of the first 10 heads made in this configuration only 4 were good. I told Barney we needed to make the piston a dome with a radius and he balked saying the head machining would have to be done on an EDM machine and it would be prohibitively expensive. So one day I was looking at some old tooling and found an old hemi dome cutting tool. It happened to be the exact radius for what was needed, so I said why can't we use this. So that is how the head went from a pop up piston to a dome with a radius piston. The patterns were taken back to the pattern maker and had metal added to the area over the piston so the dome tool would work. I will leave the 4-71 manifold story for another day.

Tom G.

PS. Are you using the pop up design or the heart shaped design for a flat top piston?

[38flattie]

Tom,

Kudos for the design, and the story!

I knew, looking at the Navarro heads that they were based on the KR head. I had NO idea how the designed transpired!

Man, you should have never told me how involved you were in that- hasn't anyone told you what a PITA I can be when I'm searching for info? Lol!

Do you remember or have any of the bench flow info?

We are going with the flat top popups.

I love when stuff like this is revealed in a thread!

[Tman]

I just remember you mentioning Abbin on the HAMB or maybe I remember thinking about asking you guys if you had seen the Harley head info.....................not knowing what/who Dale was other than a guy that I had seen online for a long time!

regardless of how I got there, I had my suspitions!

[Milwaukee Midget]

Staring into the crystal ball, checking out the future . . .

I like the Phase 2 head, but I'm wondering why the big bend in the bowl.  Looks like about an 85 degree turn, right at the point where you need to smooth out the flow.  If you're starting from scratch, you could straighten out the ports by cutting the intake face at an angle, along with the exhaust, and raising where the port enters and exits from the both sides.  You'll increase the radius and smooth out the flow, yes?  It's not like you're trying to match it up to an existing manifold.

My 2 cents, and worth about half that . . .

Also curious about the bowls in the block - how much room you have to play with on those ports.  Any pics?

[desotoman]

Do you remember or have any of the bench flow info?

I love when stuff like this is revealed in a thread!

I still have all the information on the flow results. But you have to remember this was in the early 80's. We did not invest in any manometers or gauges. We did it pretty simple since our goal was to measure flow increases not actual flow.

Don't laugh OK, but here is how we did it. Barney had a large vacuum motor and variable rheostat that he built for this project. We took an old block I had that had been ported and relieved to the max, and we set it up on top of the unit. We sucked down through a cylinder in the block and sealed if off with large O Rings. Then we had plastic tubing hooked up in various spots with water in them for fluid.

One tube was taped on a piece of wood as I remember about 8 feet long. It was laid down on an old Ford Axle housing made into a stand, at about 20 or 30 degrees, with one end hooked to the machine and the other was in a tuna can filled with water to  the same height each time. This tube measured our inches of vacuum, which we started our tests at 6 inches water vacuum. The other tube was a U tube which we measured the flow from. So using modeling clay we filled the relief back in the block to make it stock, put one of his Aluminum aftermarket heads on the block, and tested it by bringing the water vacuum up to 6 inches and measuring the separation in the U tube Plastic tube. This was the base line for all of our tests to come. So the more distance we would separate the U tube the more we were flowing. We ended up reaching max port velocity, and it did not matter if the valve was in or out of the block. But you must remember this was for our setup, everyone's will vary depending on short side radius, head, etc.  

Some would ask why we put the Aftermarket heads on a block without a relief, since they would choke the transfer area more than an original head. The reason was we wanted to see all the different stages of development for both block and head, since they both make up the chamber.

I still have all my stuff, and it is 98% done. I only need some roller lifters, and Titanium valves. At the time I ceased this project no one made any roller lifters, and I was so tired of beating my head against a wall, I shelved it.


Tom G.

[Milwaukee Midget]

Tom, how can we not laugh?  That's as hysterical as it is brilliant!

[38flattie]

Tom, that's good stuff! I admit to laughing, at the mental picture of the tuna can, wood, plastic tubes, and a vacuum cleaner!

The bottom line is, though, you found the information that you needed,and it was pure genious!

Joe Abbin, author of Blown Flathead, has bench flowed and recorded a lot of the aftermarket Ford heads in his book. Guess what. His flowbench is powered by a 6hp shop vac! No kidding-been there, seen it!

Tom, what kind of HP were you aiming for?

Staring into the crystal ball, checking out the future . . .

I like the Phase 2 head, but I'm wondering why the big bend in the bowl.  Looks like about an 85 degree turn, right at the point where you need to smooth out the flow.  If you're starting from scratch, you could straighten out the ports by cutting the intake face at an angle, along with the exhaust, and raising where the port enters and exits from the both sides.  You'll increase the radius and smooth out the flow, yes?  It's not like you're trying to match it up to an existing manifold.

My 2 cents, and worth about half that . . .

Also curious about the bowls in the block - how much room you have to play with on those ports.  Any pics?

You're right on the money, on your port comments. Mike had started this design for a banger he was going to convert. We will be staightening, and enlarging the ports as much as possible. We are also looking at changing the push rod angle, to more closely match the stock Hemi angle.

I just made a deal on a pair of 270 Hemi heads, and will send one to mike. He'll convert the chamber info into a CAD file.  He'll then move the valve angles, to be able to increase valve size, and to work better with this engine.

There's a lot of work to do- the FlatCad has had 7 head bolts added, and they still need to be added to the CAD files.In addition to getting the proper porting and valve train workable, we still have to work on the water passages.

Then comes the fun part. Casting one-off items is very expensive. After we are confident we have a good, workable model to start with, we need to design this to be a machinable, two piece head.

I'm at work, and only have some pics with me. They will, however, give you an idea of the bowls in the block.

[desotoman]

Tom, what kind of HP were you aiming for?

As much as possible, for the time. LOL.  I used to visit Tom Beatty and in our talks he told me he thought his old Belly Tank had around 400 HP when he had the flathead in it, and as I recall it ran 212.something with the Flathead. Tom ran Alky for fuel, with a GMC blower. I would ask him questions about cams he ran and he just said he would tell Mr. Winfield how the car ran and Mr. Winfield would grind him another cam and say try this. No spec tags, and Tom would install them as told.

I also wanted to keep the stock ports somewhat stock, what I mean by that is I did not want to alter the block, like Ron Main did on his last Flathead motor. The KISS method works best for me personally, plus one off stuff cost cubic dollars and might not work. JMO.

My aim was to be able to use stock type intakes, stock dimension cam, etc. So with stock location type ports both intake and exhaust, I was hoping for HP in the 500 - 600 HP range. I feel this was very attainable, and a computer modeling engine program confirmed what I thought. So I think I was on the right track but until I put it on a dyno, who knows. I shelved the project around 1988.

Tom G.

PS. No problem with laughing about the flow bench, the mental picture is hilarious.

[38flattie]

[/quote]
My aim was to be able to use stock type intakes, stock dimension cam, etc. So with stock location type ports both intake and exhaust, I was hoping for HP in the 500 - 600 HP range. I feel this was very attainable, and a computer modeling engine program confirmed what I thought. So I think I was on the right track but until I put it on a dyno, who knows. I shelved the project around 1988.

Tom G.

PS. No problem with laughing about the flow bench, the mental picture is hilarious. [/quote]



500-600 HP is a helluva flathead!

Tom, I would have to urge you to finish it! I mean, really, how many flatheads are out there making that kind of HP?

I, for one, live and breath flatheads, and I'm sure I'm not the only one wanting to hear more about it!

Hell, it sounds more interesting than my project!

[Tman]

Yes, this page of the thread has been most enlightening!