This is actually related to a thread I have in Racing Q&A about /6 Land Speed Racing, but I think this has broad enough appeal to post it here.

In case you don't know I am in the early stages of preparations for a land speed record attempt. The engine is going to be a 170 and since I already bought flat top pistons (was initially going to build a turbo 170) I needed to reduce the combustion chamber size beyond what was feasible with milling. I also wanted a quench combustion chamber. The solution was to weld up the combustion chambers. This is what the head looks like after I picked it up from the welder. The head was shot blasted so it's a bit shiny. The chambers were over filled so there will be a lot of milling just to get the welds level with the existing deck. Of course the shallow side of the chamber was filled and I also asked him to fill the little eyebrow close to the spark plug. After the welding the head is about .020" low in the middle from warpage. Before I have any machine work done I'm going to have the head cryogenically treated to reduce the internal stresses from the welding. Putting a bunch more money into the head just to have it crack would really stink. Who knows, it might even end up a bit straighter. For those that care the welding alone was $160 at Rick's Cylinder Head in Milwaukie, Oregon. They have a good reputation for successfully welding iron heads.

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Joshua

Looks awesome! Way to push the envelope. I hope the head straightens out without cracks, etc. Any idea (ball park) where the compression ratio will end up?

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'68 Dodge Dart 4dr Sedan

Very interesting!

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Patrick,

With the power goal being 300hp (it should come close) the cam and compression requirements are pretty stiff. 12:1 is about the minimum I feel is acceptable. Since the salt flats are a little over 4000' elevation it can be a little higher than it would tolerate at sea level, but I don't think I can even get it that high.

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Joshua

Great stuff, JS, keep us posted. Where and for how much money is the cryo treatment being done? (Anyone out there who hasn't heard of this, Popular Science did a very good article on it in 1987—I believe in the April issue. Blue cover with big headline "FROZEN TOOLS".)

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Nice work so far, Josh. We'll be interested to see how it all comes together. FYI, it is pretty easy to get a stock head down to 30-35cc chamber with milling. $160 sounds like a great deal for the welding.

Lou

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Home of Slant6-powered fun machines since 1988

That is a very creative, and resouceful approach to what has been the major weakness of the slant all along. I hope this proves to be a good, workable thing. Keep us posted. What speed record are you going for? Is this for a specific class, and if so what class? Where are you going to do this? At the salt flats? I would guess you have seen the movie, "The Worlds Fastest Indian". If not, you should rent it and watch it.

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I bought the dvd. If you can, watch it with a good surround-sound system. There are some awesome motor sounds in that movie - give ya chills! The dvd also has the original documentary on Burt Munro that the movie is based on.

I apologize for sidetracking the thread..

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Friends Don't Let Friends Drive Fords.

'64 Valiant 100 '66 Dodge A100

Dan,

The cryo treatment will be done at NW Cyrogenics http://www.nwcryo.com/ and will run $115.

Lou,

I didn't know you could get the chamber that small and still have it hold a head gasket. I know slants don't normally blow head gaskets, but this isn't a normal build either. I think keeping nice thick decks on the head and block will help keep the gasket in place as long as the head doesn't warp when it gets got. That's part of the reason for the cryo treating.

Sam,

The quench type combustion chamber is really only workable on a 170 unless you use dished pistons in a 198 or 225. A 225 would end up with a very high compression ratio with flat tops at zero deck and the welded chambers. Just over 13.5:1 if the head were 35cc. A 45cc chamber would drop that to 12.46:1. With an 18cc dish in the piston would get you down to 10:1.

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Joshua

When you have the chambers machined, will you do it with CNC equipment? If the chambers work well, it would be nice to be able to duplicate them.

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

I have never had a head gasket problem, and have run down to 31cc chambers at 10.5-11:1. That was a 0.100/0.200" angle mill (int/plug sides) with flat bottomed valves. I have that same head running 34ccs now with some slightly dished (lighter) valves.

Good to try this out though. Goodman's team has done this chamber filling with great success (mid 10s in a 2400lb car, NA on alcohol).

Lou

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Home of Slant6-powered fun machines since 1988

Ha, ha! Sorry. Um, no. No plans for a CNC program. If 10 people wanted the same work done it might be worthwhile to set up a program, but this is a one-off custom deal. I doubt I could get 10 people to spend $160 for the chamber welding let alone the machining. The valve seats will be cut and the chambers relieved around the valves before the chamber shape is finalized.

I want it to look something like this, but obviously the spark plug will not be angled toward the exhaust valve and the plug side of the chamber will be a little more open.

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Joshua

Good work Josh! I had done some paperwork while in Iraq and postulated on my long rod that if I could get a quench head made up with a 42-44cc chamber I'd have an ideal build in the works...At $300 for the welding and stress relieving, and then the milling, and getting the head work done...I think it'd be worth it, the price doesn't seem too unreasonable for the work.


Thanks for sharing!

-D.Idiot

Is there going to be an issue with valve shrouding?

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Official Cookie and Mater Tormentor.

I seem to recall an article in a popular mechanics years ago where a Valiant or Dart set a record in that class about 1965, right there at Bonneville. It seems to me it was 137 MPH or so. Would this be a record that was not kept on file, or not officially timed or sanctioned? How do you think your speed will match up to that? Do you have a target you are going for? Any calculations as to theoretical speeds?

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