Well sure. This just isn't going to happen with OEM parts. I have one of the unobtainium Billet cranks. It's the only reason I'd consider poking my nose above 500 hp. Cross section of a 225 crank is nil. Start pushing the limits, and a production crank, even the Forged piece is suspect at that level. The crank comes apart, and the block will undergo an unplanned ventilation. Get into that range with Steel rods, and the OEM main caps are prone to cracking. Billet main caps, a custom forged or billet crank, and a girdle are in order. And those exist. Not in any numbers, but when someone throws enough money at a problem, it can be met. The stock crank has stress risers and they do crack at those places, I've thrown several away. They were never meant to carry loads like this.

Doc told me over beers track-side, "the forged 225 crank is suspect above 550 hp." So long as there are plenty of blocks and cranks, we can push them. So far, we have them available. Most slant people aren't going to have that kind of disposable engine fund though. Scatter a crank, and/or throw a rod, most of the remaining internals, not to mention the block, are trash. Start over.

When I called the company that made the billet crank ten or so years ago, they disavowed any knowledge of it. I was going to order a spare, but with a Flange that was useful. They wanted $2500 and an order for a minimum quantity which at the moment escapes me. They also wanted me to ship them a crank to measure. I wasn't going to order 20 parts, so that price went up to a much higher one. Something like $10k. I don't think they wanted to do it. For obvious reasons. Most Slant-Sixers don't want to spend that much on the whole car.

If someone makes the step to an aluminum head that actually breaths, there are plenty of takers. Right up until they hear the price. Then you can count the takers on two hands. Maybe one.

I'm still generally in for Aluminum if someone can come up with a palatable group buy. It would have to be for a minimum run to make it worth their while. Might be able to work something up, but at the same time, getting slant six racers to agree on a specific design is like herding cats. In order to make it worthwhile, the port configuration has to be reworked. Cooling jackets? How do we come up with a cross flow design with the valve arrangement? In order to make it worthwhile, it has to be able to flow. Still, having a lighter head that is stiffer and has a better combustion chamber is worth something. The Mopar aluminum heads that made it out into the wild have all the same flow limitations that the iron heads have. I don't remember where Josh got to with his full quench modification of an iron head. I think he dropped it about the same time he sold his Bonneville car.

If somebody can come up with some ideas, or solutions, I'm all ears. I've got a couple slant engines north of $10k now. One left that figure behind a long time ago. If I break even one internal engine part in that engine, it will require a custom part be made. Could be 'spensive.

I never heard if all the billet roller cam blanks that OCG commissioned were sold. Likely so by now. I think Dave bought "Several."

CJ

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Part of Tyrde-Browne Racing

The main drawback to a Slant will forever be the tiny bore. You can make a head that flows great on a bench, but will be lackluster on a block. There's just not enough room for a big valve that won't be shrouded by the cylinder wall. Yes, you can notch the wall, but then you lose compression.............

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Official Cookie and Mater Tormentor.

So then you used forced induction, or go on the hose!
Now all we need is a way to keep the head on the block!

CJ

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Part of Tyrde-Browne Racing

I think Will was keeping the head gasket in his.

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Official Cookie and Mater Tormentor.

CJ

Lots on info in your post to digest, can I ask you about a couple items?

"unobtainium Billet cranks", are you talking about the Cower buy years ago?
I understand 6 were purchased.

"When I called the company that made the billet crank ten or so years ago, they disavowed any knowledge of it. I was going to order a spare, but with a Flange that was useful", was this Crower? What crank flange was on your crank? Cheby?

"the forged 225 crank is suspect above 550 hp", to my limited knowledge there are very few slants ever to crack 500 HP correct?

"billet roller cam blanks that OCG", There were at least 3 cam grinders who did rollers during the high water times.
Lunati, LSM, Victoria in OZ, and others. Cams should not be our problem.

And you mentioned "Josh" working on a closed chamber head, who is or was Josh?

Thanks for your input and any comments you want to post.

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Hyper_pak

I am running Josh's closed chamber (welded) head on my 34 Coupe, bought from Bonneville Bob Dally about 8 yrs ago. Shortblock is 10.2:1 with (too small) 234@0.050" lawnmower cam. Makes great power for what is in that motor, but i would not say the head is revolutionary. Lots of porting, and a fair bit of epoxy in it after they hit water. Holding up well on the street so far. I should try it on a racier shortblock with over 11:1 and a big cam. It is likely about the same as my well-ported Jeffrey head with regular (68-up) chambers.

I do not recall many people making big power having head gasket problems, at least once they went to copper. A few engines have cracked 600 HP on boost. Revs kill the crank, not HP, IMHO.

Plenty of talk here... Does anyone really want to go class racing with a Slant 6? Nobody I know. Build stuff and try it out.

I admit I am a street car guy, so if it won't live driving around then I'm less interested. Personally, I think about 450 HP is livable in a long distance car with nothing fancy in the bottom end but pistons and maybe rods. We will see.

CJ, I will be in Portland area in late June. We should get together. I'll see Dave too.

Lou

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Home of Slant6-powered fun machines since 1988

Thanks for weighing Lou
I got the rockers in the mail the other day.
Thanks

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Hyper_pak

Looks like Lou answered most of the questions. There are very few in the high HP range. Under boost or giggle gas, you can keep the revs in check. Naturally aspirated, those numbers make for trouble. I don't know that dave knows what he was putting down when he disassembled his main caps making a pass. I think that was his high compression Alcohol engine. 13.x:1? Maybe he has an answer. We'll see how O'ringed copper works in my Engine. I don't have high expectations for a long service life.
So north of 500 hp, Cameron Tilly comes to mind. But that's second hand info.
Will might be in that range. I don't think Mark's engine was up there, even on the hose.
I'm not going to blow my stuff up on a dyno to find out. Even so, I doubt it rolls 500. (If it holds together for more than one hit.)
I'll get the time slip and blow it up out on the track where it belongs. It has a diaper.
The Crank is a Crower. Slant flange.
CJ

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Part of Tyrde-Browne Racing

[quote=slantzilla post_id=525715 time=1738298527 user_id=8]
The main drawback to a Slant will forever be the tiny bore. You can make a head that flows great on a bench, but will be lackluster on a block. There's just not enough room for a big valve that won't be shrouded by the cylinder wall. Yes, you can notch the wall, but then you lose compression.............
[/quote]

It's a matter of will & $$$$$, ricers have no problem dropping ridiculous amounts on a civic engine, & look at the Darton sleeve system. IIRC, there's enough room for a solid 3.75" bore using that technique on a Slanty, which yields a 273c.i. 6cyl., and enough room for fully unshrouded 1.82"/1.50" inline valves. A 21% increase in displacement will make getting squeeze a non issue, or cast a race only siamese block, those ricer Civics came that way factory in Al-U-minimum. The only real difference being the little Honda head bolts are anchored near the bottom of the block, not the deck, so that would have to be accommodated/addressed going the Darton route.

OK, please tell us who can do reliable sleeves like that (that will live in a street/race motor) and I'll try it! 1.84 valves will fit in the head and I have one.

Lou

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Home of Slant6-powered fun machines since 1988

OK, please tell us who can do reliable sleeves like that (that will live in a street/race motor) and I'll try it! 1.84 valves will fit in the head and I have one.

As I get older, I am having less trouble spending money...

Lou

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Home of Slant6-powered fun machines since 1988

It's been tried. They couldn't get it to hold water long enough to start it.

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Official Cookie and Mater Tormentor.

Start casting the blocks next week. That is when we all start getting delivery of the new aluminum head, right! A big bore aluminum siamese block would seem to do a lot more for weight loss than a head. Plus it would allow the existing head to flow bettter with larger valves.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Darton's the only one I know of to do it successfully.

Who & when was this?