New block, a further discussion

[flatheadmurre]

Originally Posted by Henry Floored

My first real step and contribution to this subject is to actually build the best intake port into one of my original blocks. That includes my repositioned intake valve theory. I think there is power to be made there. It will have no effect on outward appearance and will still be compatible with all standard production parts except for the valve guides.

Again this is what I think the first real step towards doing this.

Are you changing position/angle of the valve or just reshaping the runner and guide ?

[Henry Floored]

Originally Posted by flatheadmurre

Are you changing position/angle of the valve or just reshaping the runner and guide ?

A little of both actually. I have a couple sacrificial blocks. I would like to tilt the intake valve towards the cylinder wall margin. This alone will force the intake port to "stretch" a little. I then would like create a gently curved intake port with no air damn in the valve pocket and a much kinder short side radius.

All this relieving business is done simply because it has been found that in a side valve engine we have have to encourage the flow to go sideways just as it passes the valve seat. Then we bounce the charge off the cylinder head to turn the rest of it down the cylinder.

I think I described this once as imagine taking your garden hose and spraying it full blast at 90 degrees to a solid wall. Messy!

No rotate to a 45 degree angle and do the same. What happens?

We are asking the intake charge to change direction of almost 180 degrees right when it's most important to keep momentum up and fill the cylinder.

We all know by first hand experience or by word of mouth that a supercharger wakes up a Flatty. They certainly do for the simple reason is a blower overcomes this basic restrictor in the Flathead's intake flow path.

With a supercharger the Flathead Ford starts to wander up near 1 hp per cubic inch where it should be from the get go.

Guys there is a reason why the best engine builders in the world are only getting 50 or so more hp out of a Flatty than me who sucks by comparison. If there wasn't something inherently wrong with side valve breathing the best would be wringing 300 hp out of a 276 incher.

The way to make any thought of a new block worthwhile to people is to give them the very best breathing they can get from a side valve engine.

Imagine a scenario where this "service block" if you will, just comes close to the best port job by a professional on a stock block. Combine that with being able to toss 100lbs of unneeded weight overboard. What impact would that have on average attainable performance for everyone?

[Fordors]

Originally Posted by Henry Floored

A little of both actually. I have a couple sacrificial blocks. I would like to tilt the intake valve towards the cylinder wall margin. This alone will force the intake port to "stretch" a little. I then would like create a gently curved intake port with no air damn in the valve pocket and a much kinder short side radius.

Just wondering, how much would you like to see the intake valve angle changed? What would be done to compensate for the out of parallel between the deck and the valve seat, would a "mini-relief" so to speak, be required? What else would need to be corrected/changed?

[Henry Floored]

Originally Posted by Fordors

Just wondering, how much would you like to see the intake valve angle changed? What would be done to compensate for the out of parallel between the deck and the valve seat, would a "mini-relief" so to speak, be required? What else would need to be corrected/changed?

Good questions and thank you for asking.

Yes moving the intake valve over towards the cylinder margin would require a minor notch or "relief" since (you're right) the valve head would no longer be parallel with the deck.

Imagine looking up through the cylinder from the bottom and actually being able to see the edge of the valve at or near max lift.

This, I feel would require a lifter bore machined inline with the valve stem. In other words the lifter bores would be staggered from intake to exhaust.

I realize this sounds a little "out of the box" but I don't think it's out of the realm of realistic possibility.

[Henry Floored]

Of course I think any new "service" block should take advantage of the biggest practical bore diameter possible. I think 3 5/16" is a no brainier and 3 3/8" or even 3 7/16" should be at least looked at.

You see at this point I feel that PTAW cylinder walls would be a great and reasonable way to do this in an otherwise aluminun engine.

This process is relatively cheap and very well perfected. Ford Motor Company used this process in production on their 5.8 liter Trinity engine that was built to produce over 600 hp.

The Modular platform that the "Trinity" is based on are very limited in bore spacing. Thus it is tough to get a bigger bore by conventional means i.e. a steel sleeve. The PTAW process leaves a very durable surface on the cylinder wall and it's only a few thousands thick.

They did not have to overbore the block in order to accommodate a thicker walled sleeve in this aluminun in block.

If you doubt the process I suggest you read up on it. Engine rebuilding companies are beginning to use this process to refinish worn engines to original bore specs.