Going down the babbitt hole

[Los_Control]

As a old wood butcher .... I'm surprised to see this task accomplished with a hand held router & a carbide bit ..... I guess it works.

 

The only idea is to move air quicker sideways ...... Overhead valve were way ahead of the game.

 

The Legend goes .... speed kills. Drive a Ford & live forever.

 

I have a newer Ford engine then what @Snipershows ..... I'm not sure I'm brave enough to relieve the block myself ... No question about it .... that was a big thing to get more power out of a flathead.

[Hickory]

That's what I envisioned but wanted to make sure. Never thought of doing that since most head gaskets seal 360 around the cylinder bore but the flat head gives that freedom.

[Hickory]

That's actually a hand held drill and a carbide bit from the Bridgeport machine. It was easier by hand than rigging the block in place. It made quick work of it.

[Los_Control]

IIRC, Ford actually had a few blocks they did this from the factory ... for racing ..... or large truck blocks.  the idea is the same for any flathead. Just improve airflow.

 

While I can not point to any Dodge racers that did the same trick .... sure there are a few.

 

I really thought it was incredible to watch a Dude do it free hand with basic power tools used on wood.

It took 2 or 3 passes to get them where they wanted to be. When finished you could throw the tools away .... they did their job.

[D35 Torpedo]

9 hours ago, Hickory said:

Mr torpedo let me understand what you are saying about the piston wall or cylinder wall?  I'm doing the valve runners and a little on the valve stem boss. Explain the top ring portion better for me please.

Relieving the block is not what I refer to. I call that " shaving the eye brows" I don't think it's really effective on a Chrysler. What I mean is rounding the top of the bore with a carbide bur. Give it a good radius. Like a 1/4" radius. Only on the side that spills into the valve area. And don't go too deep into the bore to effect the top ring. It won't affect compression much. The increase in flow should more than make up for it.

Edited April 22, 2023 by D35 Torpedo

[Hickory]

So I have checked on decking the Chrysler block with freewheeling tony smith. He says there is no real advantage to doing so on a Chrysler since the valves are above deck compared to the fords and Hudson's which were below deck level.

[D35 Torpedo]

12 hours ago, Hickory said:

So I have checked on decking the Chrysler block with freewheeling tony smith. He says there is no real advantage to doing so on a Chrysler since the valves are above deck compared to the fords and Hudson's which were below deck level.

That is what I mean when I said relieving the deck on a chrysler has no effect. Radiusing the turn into the cylinder will.

[Hickory]

Thank you for clarifying that. I still have spoken to freewheeling for some advice on such tricks. I am starting to clean up the valve pockets some but don't want to get to crazy.

[Hickory]

[Hickory]

Got some more work to do but I got a general shape to all of them.

[Hickory]

I am disassembling the updraft carburetor also. I know a lot of people have bad things to say about the Stromberg U1 carb but I think it's an attractive carb. Lots of character.

[D35 Torpedo]

When it comes to porting, the biggest gains are made right below the valve head. Blend below the seat into the port( the bowl). Narrow the valve guide boss. Its ok to take material from the bottom of the bowl on either side of the guide boss. I've ported over head valve engines but never a flat head other than lawnmowers. The same principles apply. But there are some flat head only features. Keep the good work coming. You're not going to hit water unless you go way way overboard...no pun intended.

[Sniper]

The biggest gains are going to be removing as much of that tree stump of a valve guide out of the port. 

[Hickory]

I know the valve stem is the biggest issue, but how much can I remove from that without effecting the valve.

[Sniper]

That is a tough number to find. I'm on the road right now so I can't look it up but I found a formula online to calculate they minimum guide height. And if I remember correctly take a half an inch off the stock guide

[Sniper]

Ok, I am home, here's the formula and the thread I found it in.

 

Quote

I normally like to keep the guide as long as possible... but you don't want the guide tight down on the short side either.

My general rule of thumb to be OK w/ a relatively low RPM engine (under 8k) A simple rule is anything greater than 15% of the over all valve length times the diameter you should be fine for a good straight guide.

So assuming you have a good straight valve guide and your over all lenght is 5" and .343 guide...

5 x 1.15 x .343 = 1.97"

so I would not go any shorter than 2"

 

https://www.speed-talk.com/forum/viewtopic.php?t=19767

 

Mind you they are talking about OHV heads that have a side load on the valves, we do not have that issue.

 

So in our 218/230 usage

Valve length is 4.845

Stem diameter is 0.3405

 

That works out to

4.845 x 1.15 X 0.3405 = 1.897" long

Stock guide is 2.813" long

So could remove 0.919" off the stock guide.  Obviously, you want a bit to stick out into the port so that might be your limit there.

 

Remember you want a minimum of 0.050" guide to retainer clearance at max lift so you may be able to push the guide deeper into the block and keep more of it's length, depending on what your clearance is.

Edited April 28, 2023 by Sniper

[Hickory]

That's a good idea, I have very little lift. A non performance 29 has a lift of .37 ish. I have a lot of room to drive it deeper into the block. On Monday I will check it out.  I will also need to see if they are available if they are different. I remember replacing the guides in my 49 that 2 of them shattered on me.

[Hickory]

Got my valve stems down to where I'm happy. Now a little sanding and then I'm good.

[Hickory]

Got some new toys today. Thank you egge.

[Sniper]

I wonder what the weight difference is?

[Hickory]

Allot. I don't have a digital scale anymore to check. (It was for air conditioning if your wondering) but I'm thinking close to double. So that is my next issue.....

[Hickory]

I'm wondering if it's worth checking rotational balance. I've never had this done but it sounds expensive. And I'm not sure how to do it with the bolt on weights. I guess I could have the fabricator in my shop make heavier ones if needed. Tell me what I should expect to pay for balancing.

[Sniper]

So I am assuming the new pistons are the weightier ones?

No idea on balancing costs.  Haven't had that done since 88.  Most of my engine builds have been stock type rotating assemblies, or at least the weights were within stock specs.

[Hickory]

I found a scale in the paint room and it's not as bad as I thought. Oid pistons are 490.6g with pin. New pistons are 554g with pin. So 64g difference might be workable.

[Hickory]

Just got off the phone with the babbitt place, (is he called a babbitter????) My bearings are next in line and will be prepped on Monday and poured on Tuesday. Should be ready for shipping wed or thur.  It's time to take the block to the machine shop to have it bored out and have the head decked. I have picked a happy .080 on the head. Then when I get the bearings it will be time to line bore.....