XXO/BVGC '38 Chevy Coupe Build

[Jack Gifford]

I'm enjoying looking at your work.
Are the chambers top-secret? (sorry for not searching back through posts). I'm curious whether they might resemble what I carved from billet for a couple of garden tractor pullers- much-modified Kohler 16 HP flatheads on alcohol. I think the claimed 100 HP was a WAG, but they were happy with the heads.

[38flattie]

Ok, I said aluminum spindles, but I meant hubs!

Pontiac Jack, I won't show the chambers until after we try them, but think Harley KR chambers.

[Peter Jack]

I'm much happier hearing hubs than spindles. Keep up the good work! 

Pete

[Jack Gifford]

... think Harley KR chambers...

Stock KR chambers are, um, quite mundane; unless there's some "massaged" form that you're referring to? While keeping the original gasket-outline on the Kohler head surfaces, I managed to undercut barrel shapes around the walls of the valve pockets- for maximum flow improvement with minimal chamber volume increase. I ground radius-end toolbits for the offset boring head of my manual mill, for more consistent results than hand-die-grinding (although consistency would be much more important for a multi-cylinder like yours, than for a one-lunger). I just wish that my customers had followed through with flowbench time to science-out the seat area details; I suspect there's much to be learned there.

[38flattie]

Do you have any pics if the work done on the Kohler heads?

Yes, the KR chambers are 'mundane', in appearance,but appearances are often deceiving!

The KR head design breaths well, and with some massaging, I suspect they are as good as anything out there. Look at Navarro heads-he has at least one design based on the KR.

Although, Bob Brooks has a dual plug set, of  Aussie designed chambers, that I'm curios to see results from!

[Jack Gifford]

I doubt that I have any pictures, but I'll try to remember to look.
What's the depth of the block porting?
Are you close (literally and figuratively) to someone with a flowbench? Has he ever tackled a flathead- setting up the whole block/head assembly on the bench?

[38flattie]

I searched everywhere, and was unable to find anyone willing to flow it. Joe Abbin flowed a stock port fior us, but that's as far as we got.

We'll just have to see what the dyno tells us, and go from there. I wouls like to get it on a flow bench, as I suspect we may have some HP hiding there.

[gas pumper]

I quess the problem with guys that have flow benches it that they are just concerned with flowing heads. You need to find someone that wants to get involved in setting upa block with the head on the bench to flow the combination, right?

So you need to find a flathead guy that has a flow bench.

Do the 1/4 midget and JR dragsters still run flatheads? yup. That's where you need to look. There's some big bucks spent on the kid's hobby racing.

[desotoman]

You don't need a block to flow a head. If you have access to a junk block cut one cylinder out of it. Skill saws work great with a cutoff saw blade, don't ask how I know. LOL.

But now I will throw a curve-ball out. Since you are supercharged, pressurize the intake, your results may vary from typical suction in a cylinder. Just something to think about.

Tom G.

[38flattie]

Tom, I agree that we really don't know how the supercharger will effect flow- we only know that we will pack more air in the chamber.

I wanted to get the ports flowed, so that we could get the most out of the port work. All 4 intakes on one side are different, so it's important to be able to get numbers on all, and try and 'even' out the flow.

I have junk blocks, and a single cylinder head chamber that I could get tested, to compare this chamber design against others. Until I can find someone willing to do all the ports, though, I feel like I will be wasting the effort.

Maybe I'll build a flow bench next winter....

[dw230]

To refresh your memories - Tom worked with the late Barney Navarro on flow work with flatheads at the shop in Glendale, CA. Ask Tom the right questions and you will get the answers.

DW

[38flattie]

Good point Dan! Tom? Tom!? Lol!


I received the aluminum hubs from Garry today, and they look great! This will allow us to get rid of the Chevy hubs and rotors.

[38flattie]

Guess I forgot to mention the plans for the water.

We're going to take a page out of the 50's, and introduce water into the engine through the casting plugs, or freeze plugs-whatever you want to call them! We'll probably just do the back two plugs,on each side, where the heat will be the biggest issue. Also, the front motor mount makes it hard to get to the front one.

This is how Garry ran his, and how the engine that ran Bonneville (pictured) in the 50's, was done.

[38flattie]

Damn, it's starting to look like an engine!

Dale sent me these pic updates, of work accomplished this weekend!

[BoredAndStroked]

You don't need a block to flow a head. If you have access to a junk block cut one cylinder out of it. Skill saws work great with a cutoff saw blade, don't ask how I know. LOL.

But now I will throw a curve-ball out. Since you are supercharged, pressurize the intake, your results may vary from typical suction in a cylinder. Just something to think about.

Tom G.

Hey Tom . . . how the hell are yah!   Are you by chance going to make it to Bonneville this summer - would be great to see you again . . . has been about 20 years.   Let me know and we'll be sure to hook up.   We are planning to go to El Mirage in the spring - will keep you posted on that as well.   Who the hell would think I'd end up in Ohio - just so I could get back to racing on the West Coast.   But Hell . . . we now have the 'Wilmington Mile' -- out my way . . . gives us some new possibilities!

As far as the ports go -- given that we're blown,  the supercharger can overcome a lot of 'flathead sins' . . . the more port volume the better for what we're doing.

Dale