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Billet Aluminum Slant 6 Head! Seriously!!
https://slantsix.org/forum/viewtopic.php?t=47607		 Page 3 of 18
Author:  DusterIdiot [ Wed Jan 18, 2012 6:23 pm ]
Post subject:  ARRRGHHH...I knew it!!!
Quote:
IIRC, the 114 MPH record passes were with 5.XX rear gears and they were turning 7300 or so in the traps on a 225...
Somewhere during my trip to the sandbox I had dialed in a 'Dream' build slant (with some outlandish valve choices/etc...)and determined that 5.xx-ish gears would have done the job on an slightly lightened late A-body (about 2900-3000 lbs)...

Maybe I should pull out my notes and revisit that idea again, now that I know someone put that idea into reality...7300rpm...I gotta see that.... :shock:

Thanks for sharing!

-D.Idiot
Author:  slantzilla [ Wed Jan 18, 2012 7:13 pm ]
Post subject: 
Quote:

He didn't mention being pestered too much about this, did he? He said I could post it, but I'd feel bad if he regretted letting me let the cat outta the bag. :oops:
I don't think he is being bothered yet. I called to buy some parts. :lol:
Author:  64drtGt [ Thu Jan 19, 2012 12:39 pm ]
Post subject: 
Quote:
From the initial text, the head will be used on a drag race engine so I doubt that water jackets are part of the design. Over in the (big) Ford inline camp, they have a VERY EXPENSIVE billet head that comes from Allen Johnson and it is solid billet with no jackets and exclusively for (comp class) drag racing.
Didn't know allen messed with fords lol I need to go over and have a talk with him about some /6 parts then seeing as we are related and his shop is a mile from my old house.
Author:  CNC-Dude [ Thu Jan 19, 2012 1:18 pm ]
Post subject: 
Just the bare billet Ford inline head is $8000 dollars,no,seats or guides. Make sure you are sitting down when he prices one to you, you wont have as far to fall. :shock:
Author:  slantzilla [ Thu Jan 19, 2012 2:50 pm ]
Post subject: 
I think he is referring to Alan Johnson, the top fuel guy. I know he has a cylinder head business, don't think Allen and Roy do. :D
Author:  64drtGt [ Thu Jan 19, 2012 3:04 pm ]
Post subject: 
Quote:
I think he is referring to Alan Johnson, the top fuel guy. I know he has a cylinder head business, don't think Allen and Roy do. :D
Thats what I was thinking after I posted that I would like to get some of Allen's old prostock stuff for my dart one of his old hemi's should wake it up nicely.
Author:  terrylittlejohn [ Thu Jan 19, 2012 5:10 pm ]
Post subject: 
the B1 engine would be nice to come accross too 8) 8) 8)
Author:  Exner Geek [ Fri Jan 20, 2012 6:54 am ]
Post subject: 
Sandy makes the Toyota swap sound easier than it really is. If you are on a budget you should consider the mid 60s overhead cam Jeep head.
All you have to do is offset the bore a tad on 2 and 4, if you show him the Jeep head gasket a good man with a boring bar can do this. 1 and 6 have to be moved a bit more but offset wet sleeves will do the job. As far as the cam drive goes the Sandy-Bee belt drive can be adapted, just send him you cam and he can make you a new top sprocket. If Sandy refuses to do this because of the pipeline deal you will have to find a 38 tooth sprocket from a Moto Guzzi trail rider and machine it out to press onto the slant 6 crank. If you put in a .146 wide spacer first it will line
right up.

Due to the six lobe cam you will have to use the same timing on your intake and exhaust but this is a small price to pay for those 1.89 and 1.62 valves. If you want an normally aspirated build you will have to find some pre-war unmachined forgings for a 220 Offy. With a little machine work you will find that the dome will produce up to 11:1 compression. Most guys just stay with a flat top piston and go the turbo route. You can invert the cast Jeep exhaust manifold and fabricate a pipe to the turbo on the drivers side. You will have to find a war surplus turbo from a P-38 for the left hand engine as it needs to spin backwards in this application. This turbo takes a while to spool up but can supply up to 70# boost on a slant. If you need more throttle response try a 120 nitrous shot that starts on tip in and cuts out at about 10# boost.
Author:  Dart270 [ Fri Jan 20, 2012 7:26 am ]
Post subject: 
So cool. I'm on it...

Lou
Author:  billdedman [ Fri Jan 20, 2012 9:19 am ]
Post subject: 
Just my opinion... but, when it's all said and done, it's the BLOCK (with its narrow bore-center spacing, and attendant small bores) that dictate valve sizes and make producing good specific output (horsepower-per-cubic-nch) a problem for the slant six. With bores of only 3.5", or so, to work with, as long as it's a 2-valve head, I don't think it matters much WHAT the head is made out of; it's not going to breathe (much) through those (relatively) small valves.

I am referring to a 225 motor. If it's using forced induction or is a 170, everything changes. A 4-valve head might also be a way around this breathing restriction caused by the (relatively) small valves. But, that is really getting complicated...

I used a 302 Chevy head ('68 Z-twenty-eight) to compare with the slant 6 over on another BB, and found that the 2.02" intake and 1.6" exhaust valve (stock) on 39-cubic inch cylinders, gave that engine breathing capacity far beyond the wildest dreams of modified /6 head users. The geniues that run that board couldn't stand to see that much good, analytical, information in general usage about the /6, so they deleted my posts that had those figures.

But, suffice it to say that a ported 302 Chevy V-8 head flows in excess of 300cfm on the same displacement cylinder as a 225 /6, and that's why they run as well as they do. The Boss 302 Ford head is even better, with even larger (canted) valves and bigger ports.

As long as the /6 has such small bores, dictating small (for the cylinder displacement) valves, getting 1.5 or 2 hp/cubic inch will, I think, remain the realistic goal of the 170 and turbo/supercharger advocates.

Just sayin'...
Author:  Matt Cramer [ Fri Jan 20, 2012 9:46 am ]
Post subject: 
Quote:
You can also drill long intersecting passages from outside, then put in expansion or NPT plugs to seal up the water jacket.

Skeptical and not at all excited yet...

Lou
While this turned out to lack water cooling, I heard Bruce Crower sometimes made billet cylinder heads in a 2-piece version with the two halves siliconed together, and the water jacket in between.
Author:  CNC-Dude [ Fri Jan 20, 2012 9:54 am ]
Post subject: 
Others have done that with Flathead style heads. Seem to work ok for Bonneville and Drag Racing.
Author:  CNC-Dude [ Fri Jan 20, 2012 10:26 am ]
Post subject: 
Quote:
Just my opinion... but, when it's all said and done, it's the BLOCK (with its narrow bore-center spacing, and attendant small bores) that dictate valve sizes and make producing good specific output (horsepower-per-cubic-nch) a problem for the slant six. With bores of only 3.5", or so, to work with, as long as it's a 2-valve head, I don't think it matters much WHAT the head is made out of; it's not going to breathe (much) through those (relatively) small valves.

I am referring to a 225 motor. If it's using forced induction or is a 170, everything changes. A 4-valve head might also be a way around this breathing restriction caused by the (relatively) small valves. But, that is really getting complicated...

I used a 302 Chevy head ('68 Z-twenty-eight) to compare with the slant 6 over on another BB, and found that the 2.02" intake and 1.6" exhaust valve (stock) on 39-cubic inch cylinders, gave that engine breathing capacity far beyond the wildest dreams of modified /6 head users. The geniues that run that board couldn't stand to see that much good, analytical, information in general usage about the /6, so they deleted my posts that had those figures.

But, suffice it to say that a ported 302 Chevy V-8 head flows in excess of 300cfm on the same displacement cylinder as a 225 /6, and that's why they run as well as they do. The Boss 302 Ford head is even better, with even larger (canted) valves and bigger ports.

As long as the /6 has such small bores, dictating small (for the cylinder displacement) valves, getting 1.5 or 2 hp/cubic inch will, I think, remain the realistic goal of the 170 and turbo/supercharger advocates.

Just sayin'...
Thats a good point, but advances can still be made in the cylinder head department on a Slant. The small bore, you are not going to be able to overcome that much, but making the bores as large as you can helps the valve shrouding problems when you install bigger ones. There is also a lot of crossover technology that can be used from other inlines like the Chevy and Fords, especially in the head porting area, that can benefit the Slant even more. I would bet that most of those things haven't even been done on a Slant yet! The Chevy's and Fords also have many of the same limitations as a Slant does in the cylinder head department, but there are too many 250 Chevy's to count that have exceeded 500 HP in N/A trim despite those limitations, and near that many Fords as well. The 225 can implement many of these same techniques and technologies and raise the bar also.
Author:  Dart270 [ Fri Jan 20, 2012 11:26 am ]
Post subject: 
There are a few 225s out there with 1.5 HP/cube or a bit more with a stock (ported) head with around 1.78/1.50 valves on race gas.

Some better port flow could be had by a new head, and would make pretty high HP engines easier to build.

Lou
Author:  slantzilla [ Fri Jan 20, 2012 4:45 pm ]
Post subject: 
Howard told me who did his port work. I think he'll be just fine. :lol:
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