New block

[Tod]

Originally Posted by rotorwrench

It sounds like the porting flow would have less of a sharp turn to make so that might do well as long as it still leaves room for valve installation and adjustment in the tappet valley which it should if I understand your approach to this.

Folks have done all sorts of stuff in the bowls over the years to reduce the right angle turn nature of them. They've added bondo, epoxy, and who knows what else to make a better curve in there. Some also braze up part of the contour of those large guides to get them to blend into the curve that they end up with as well as whittle a bit off one side of the guides to allow a bit more room to flow for an entry ramp. It will be interesting to see what you come up with.

Flow Bench and Dyno testing have been done by innumerable people for as many design changes as you can imagine for these damn intake & exhaust ports. JWL & Ol Ron are some that I'm sure have experience with this. It would also be interesting to talk to Kenny Kloth about some of his testing if he ever would. Many of the guys that did a lot of this like DJ "Flat Dog" on the HAMB are already gone to us so their secrets will remain except for those that new them well. Some changes even if just subtle might have better effects than others.

I made some good progress yesterday in opening up the "window" under the valve. My initial work was done on the center exhaust port. I am happy with the results so far. Next I will apply the enlarged design to the other exhaust ports and then also the intake, while at the same time increasing volume and doing something about the sharp turn. Part of this will be eliminating water between the intake port and the deck. The 4 holes for water flow into the head will be gone.

Tod

[Tim Ayers]

Originally Posted by Tod

I made some good progress yesterday in opening up the "window" under the valve. My initial work was done on the center exhaust port. I am happy with the results so far. Next I will apply the enlarged design to the other exhaust ports and then also the intake, while at the same time increasing volume and doing something about the sharp turn. Part of this will be eliminating water between the intake port and the deck. The 4 holes for water flow into the head will be gone.

Tod

Hey Tod:

Sounds like you are moving along on this.

Curious about the change of the water holes in the block. With this design, will you need to use a special head gasket covering the holes in the head?

The water holes that are removed from block will still be in the heads and with water flowing in them and using a traditional gasket, the water is going to want to go somewhere. I can imagine this would be an area of potential leaks.

[Bored&Stroked]

Originally Posted by Tim Ayers

Hey Tod:

Sounds like you are moving along on this.

Curious about the change of the water holes in the block. With this design, will you need to use a special head gasket covering the holes in the head?

The water holes that are removed from block will still be in the heads and with water flowing in them and using a traditional gasket, the water is going to want to go somewhere. I can imagine this would be an area of potential leaks.

I can see no issue with this - having holes in the heads and not in the deck will not cause an issue - as the water still has plenty of other places to flow and is not under high pressure. I'd use stock style head gaskets (as long as they could support the final bore size) and not be worried about it. If the block can support a 3.5" bore, then I may have to go to custom copper head gaskets (due to the compression rings on the stock gaskets hanging into the bore). With that said - those of us who want 'maximum cubic inches' . . . will be prepared to 'pay to play' . . . just as we always have! LOL

Keep up the great work Tod - you have a lot of folks watching and I for one will be happy to sign up for one of your first blocks!

Dale

[Admiral]

Originally Posted by Tod

I made a little more progress today despite having to mess around with one of my machines some and also doing some of the last 1st OP machining on a Cleveland block. I have a bunch of machining to do coming up so design work will take a back seat to cash flow.

Pics of the basic model so far. It is not finished so please be understanding. If you see what seems incomplete that would be because it is incomplete and do me the courtesy of assuming that I see it rather than figuring I'm a clueless moron (even if that much is true!).


Tod

Even in an incomplete stage it's a thing of beauty! Keep up the great work!

[Ol' Ron]

I don't think the holes in the head will make any difference, this will allow a much better intake flow to the cylinder. I like it. Just think, for the averaged guy that wants to build a nice engine for his early daily driver, he can now have a 258/258 ci engine with just the cost of pistons. A set of angled milled heads and 8:1 CR. Cruse with the best of them and get better gas mileage as well. I should live so long to see this.

[Tim Ayers]

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Ol' Ron and B&S, thanks for the explanation. I'm not knocking Tod and appreciate this herculean effort. I was just mulling over the proposed design change.

I guess with all things, its a tradeoff. If the tradeoff increases performance, so be it.

[Tod]

Today while machining some parts I was able to get to the other exhaust ports and I like the opening up of the port under the valve as well as the more smooth flow. I eliminated the sharp corners and turns as well as adding a dip to the bottom similar to the center port. I did this because I also dipped the top a little to aid in the deck thickening plan. I made better progress than I figured I would so now I will be able to do more water jacket work with that port geometry pretty much complete.

Tod

[Tod]

OK. Here are pics of the ports under way. As you can see, I increased the size of the area under the valve, more so on the intake than the exhaust. I also followed the idea of the center exhaust port where it dips down on the bottom side. I tried to make the intake less abrupt than stock. None of this is finished, but you can get the gist of it, I hope. I did the exhaust at work today and the intake this evening after supper.

Tod

[Henry Floored]

Tod those airflow improvements look great!

[rotorwrench]

I'm not sure how the divergence in the exhaust ducting is going to affect things in there. The velocity decreases a bit until it gets to the port where it will speed back up again. This is where I know I missed out on the engineering education I probably should've had. Maybe I worry too much but it seems it might have an effect on scavenging. I'm no rocket scientist though and it might be OK. Maybe others who have played with this stuff can give their ideas. Ford didn't have a very straight duct in there but it was uniform in cross sectional area pretty much all the way through. A drop in the roof proportionate to the drop on the floor might be necessary.

It will likely improve things on the intake side though since it should increase the velocity at a point where that could be an advantage.

[Ol' Ron]

My grandson helped me flow am intake manifold using a computer program. I'm sure he could do the same with these ports. I'll forward this to him and ask, how he did it.

[Henry Floored]

Hot exhaust gasses want to expand. This is why you see very high volume exhaust manifolds on engines used in such applications as heavy trucks and boats.

The difference here is the exhaust flow is effectively "supercharged" by the exhaust stroke of the pistons. I don't things like velocity and cross sectional area of exhaust ports is as important as the intake side so long as it is more than adequate.

The intake side relies on pressure differential in order to move flow. This is why velocity, momentum, reversion and other phenomena are important to getting the highest performance possible.

[rotorwrench]

Scavenging helps draw in the intake charge before the exhaust valve closes so it's important that there is no interference in flow on either side of the equation. A divergent duct where flow it taking place, increases pressure and decreases velocity. It's all Bernoulli's principle. The opposite, a convergent duct, reduced pressure and increases velocity. The proposed port design diverges in the middle then converges toward the end so I don't know what that will do there. All I'm mentioning is that it might not allow enough scavenge effect as a duct that has no divergence or convergence to it. Someone that knows this stuff better than I should take a look at this.

The center port has a tendency to do the same thing so some folks put those dividers in there to decrease the effect but the way the firing order is, it doesn't seem to affect it except at higher flow rates or higher RPM. This might be part of the reason that flatheads drop off at around the 4000 to 5000 RPM range. The other part would just be the size of the ducts. Ford only made them so big in order to fit into the overall design.

[Ol' Ron]

Some information on ex ports, and Flat dogs intake port. I have trouble posting pics, but you get a chance to see some of our work. In the latest intake port the waterjacket over the intake port is filled with Devcon liquid steel. In a future port I will fill the intake bowl with liquid steel as well. Just to see how it works. Another improvement to flow is in the heads. The exit of the transfer area should be increased to a 45.60 deg angle. I have some more pics.

[Yoyodyne]

On the subject of ports, is there an often chosen size of intake port at the manifold/block surface for mild street engines? Best makes a "Big Port" intake gasket, and it seems I've seen many recommendations here to just open the block and manifold to match that gasket. http://www.bestgasket.com/engine_cat...59A%20Std-Bore.......[511]

I bought a manifold for my project that has already been cut to that size, so I need to open up my block to match. If Tod's block had that size port already, what harm would there be in putting a stock port size manifold on it? I do understand why not to go from large to small, and I understand about potential turbulence from the small to large mismatch, but it gets done on OHV engines every day, sometimes even large mismatches. Some even claim a benefit from anti-reversion effects.

BTW - Here's a thread with some info on what rods will fit through what diameter bores. https://www.fordbarn.com/forum/showp...03&postcount=7

A friend built a B engine with aluminum rods, he had to install the rods onto the pistons from the bottom, after the pistons and rings had been inserted into the cylinders, and before putting the crank in. Is that possible in an 8BA? Has anyone here ever done that?

[Ol' Ron]

I don't think you can improve the ports for a street engine. Plus there is more to porting than just making it bigger. One of the best running street engines was in Richarrds from fls 276 53 HT. with atock ports I drove the car and was surprised at the performance. All this porting and other mods to combustion chambers happen over 4000 rpm. I do believe the port matching is a good idea, but have no knowledge to prove it one way or another in our flatheads What does help in the CR of the combustion chamber and the piston to head clearance. I believe that is more important in a street engine than porting..

[40 Deluxe]

Originally Posted by Yoyodyne

On the subject of ports, is there an often chosen size of intake port at the manifold/block surface for mild street engines? Best makes a "Big Port" intake gasket, and it seems I've seen many recommendations here to just open the block and manifold to match that gasket. http://www.bestgasket.com/engine_cat...59A%20Std-Bore.......

If you open the intake ports to match the "Big Port" gasket you need to open up the entire port from carb to intake valve to keep the port size consistent. Air does not like to have to speed up and then slow down (flow is lost). Plus, the smallest diameter section of the port is what will limit flow. Where is the smallest cross section in a flathead port??

[Tod]

I was able to start on the driver's side water jacket yesterday and made better progress than I figured I would. It would be nice to have this ready for core work by July.

Tod

[Tod]

In between relaxation time today and running some errands with my wife I was able to rework and finish the intake port. I like it even more. I also inserted one intake and exhaust port into the water jacket and started incorporating that geometry into the jacket. It's no wonder these things run warm. There is so much junk in the way of water flow it has to get hot. They almost need 4 water pumps!

For the sake of coolant I am only increasing deck thickness to .430 instead of .500. I'm eliminating water above and between the intakes but keeping as much as possible around the upper exhaust port areas.


Tod

[Henry Floored]

Can't wait to see the images for the porting inserted into the block.

It sounds like you're designing really nice ports and also leaving material there for the folks that want to take it to the next level.

Thank you sir for taking this project on and for being so open about it.

A quality Flathead replacement block WILL take the nostalgia hot rodding world by storm. It will bring people to the fold that previously would not have considered Flathead power due to its perceived weaknesses.

In addition giving engine builders something that doesn't have to be hunted down and squirreled away for future build projects will save a bunch of time and money.

I feel like, as a part time Flathead engine builder, I could reasonably expect to offer a block such as this as a viable alternative to car owners looking for a refreshed power plant.

In many ways relating to preparation labor this block will save them money while delivering added performance.

If the outside bits bolt on and most of the stock Ford rotating assembly still works you are going to have a slam dunk success with this.

I can tell you from years of observation that every gear head is fascinated by the look and sound of a dressed up Flathead.

I think a new block will open doors to guys that have been heretofore afraid to trust a Flathead whether or not those fears are based in reality.

Thank you Tod.